Scolaris Content Display Scolaris Content Display

Antibiotska terapija za infektivne proljeve uzrokovane bakterijom Shigella

Contraer todo Desplegar todo

Abstract

disponible en

Background

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self‐limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

Objectives

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

Search methods

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

Selection criteria

Randomized controlled trials of antibiotics for Shigella dysentery.

Data collection and analysis

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random‐effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

Main results

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three‐armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow‐up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).

There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

Authors' conclusions

Antibiotics reduce the duration of Shigella dysentery.

Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

PICO

Population
Intervention
Comparison
Outcome

El uso y la enseñanza del modelo PICO están muy extendidos en el ámbito de la atención sanitaria basada en la evidencia para formular preguntas y estrategias de búsqueda y para caracterizar estudios o metanálisis clínicos. PICO son las siglas en inglés de cuatro posibles componentes de una pregunta de investigación: paciente, población o problema; intervención; comparación; desenlace (outcome).

Para saber más sobre el uso del modelo PICO, puede consultar el Manual Cochrane.

Laički sažetak

Antibiotska terapija za infektivne proljeve uzrokovane bakterijom Shigella

Šigeloza je bakterijska infekcija debelog crijeva koja može prouzročiti proljev, proljev s krvlju i / ili sluzi i može dovesti do smrti. To se događa uglavnom u zemljama s niskim i srednjim dohotkom, gdje postoji prenapučenost i loši sanitarni uvjeti, a može dovesti do oko 1,1 milijun smrti godišnje na globalnoj razini, uglavnom kod djece mlađe od pet godina.

Ciljano davanje antibiotika za šigelozu ubrzava oporavak bolesti, dovodi do manjih komplikacija bolesti i smanjuje trajanje infekcije pacijenata. Međutim, neki antibiotici mogu imati ozbiljne nuspojave, dok drugi nisu učinkoviti protiv bakterije Shigella.

Ovim pregledom istraživanja se uvidjela učinkovitost i sigurnost antibiotika u liječenju Shigella crijevne infekcije. Ispitivani antibiotici u istraživanjima su bili sigurni i djelotvorni, ali nije bilo dovoljno dokaza koji bi ukazivali na to da su neki antibiotici bili bolji. Potrebno je napraviti više ciljanih dobro osmišljenih istraživanja koji će pomoći u donošenju odluka.

Authors' conclusions

Implications for practice

We recommend the use of antibiotics for moderate to severe Shigella dysentery. The choice of antibiotic to use as first line against Shigella dysentery should be governed by periodically updated local antibiotic sensitivity patterns of Shigella isolates. Other supportive and preventive measures recommended by the WHO (WHO 2005a; WHO 2005b) should also be instituted along with antibiotics (eg health education and handwashing).

Implications for research

Randomized controlled trials which adhere to the CONSORT guidelines (CONSORT 2008) are required to address many of the issues such as the need for antibiotics in mild Shigella dysentery, the class or classes of antibiotics best suited against Shigella in populations at risk of high case‐fatality such as malnourished children, older adults, patients presenting with serious complications due to shigellosis, and HIV infected individuals.

Trials should stratify participants according to severity of clinical presentation and report the effects of antibiotics separately for each group. Trials must report outcomes for all randomized participants including those with confirmed Shigella and those with negative culture. Antibiotic sensitivity patterns should also be studied and reported. Data regarding outcomes presented in graphs and pictures also need to be expressed in numbers. See Table 5 for the suggested features of a future trial.

Open in table viewer
Table 5. Suggestions for a trial of antibiotic for Shigella dysentery

Methods

Participants

Interventions

Outcomes

Notes

Allocation:
Centralized sequence generation with table of random numbers or computer generated lists

Stratified by severity of illness

Sequence concealed until interventions are assigned

Blinding:
Those recruiting and assigning participants, those administering the intervention, and those assessing the outcomes, must all be blind to the allocated group; the administered drugs have to be identical or a double dummy technique has to be used. Liquid medications have to be in similar looking bottles, identical in shape and weight; the medications must themselves be similar in colour and flavour.

Duration:
Minimum of 4 weeks after completion of therapy to assess relapse

Entry criteria can be clinical dysentery, i.e. acute onset frequent loose stools with blood or mucus or both lasting for less than 72 hours and at least 3 stools per day. Other features, such as fever and tenesmus at presentation, have to be recorded but need not be necessary for inclusion into study.

If it is possible to presumptively or decisively detect Shigella in stool before inclusion into study, it should be done. Real‐time PCR is a rapid but expensive method to diagnose Shigella early (Legros 2004).

Sample size:
(See Table 6). Age group: trials should be separately done for adults and children (less than 15 years of age) or at least presented separately if they are in the same trial. In children, infants must be a separate group.

Setting: in‐ or out‐patients. The number of participants, if hospitalized for standardization of administration of the interventions, have to be reported separately from those hospitalized due to complications.

Sex: men and women.

Special groups (those who have higher risk of complications:

  • Malnourished children

  • HIV positive individuals

  • Adults more than 50 years of age

  • Infants

Exclusion criteria:
Allergy to the drug studied; history of antibiotic use for this episode of illness in the previous 48 hours; pregnant and lactating women; clinical presence of another infection needing antimicrobials

  1. Any antibiotic studied for efficacy and safety

  2. Any other antibiotic that is the standard for the treatment of Shigella dysentery at that period of time in that country

Others: placebos or probiotics to be studied only on those with no risk of complications and those who have mild illness

Primary outcomes:

  1. Number of patients with diarrhoea on follow up.

  2. Clinical relapse

  3. Adverse effects of antibiotics

    1. Life threatening adverse effects of the drug

    2. Those that require discontinuation of the drug

    3. MIld adverse events that need extra therapy but not discontinuation of the drug

  4. Duration of fever

  5. Duration of blood in stools

Secondary outcomes:

  1. Removed from study due to clinical worsening

  2. Fever on follow up

  3. Abdominal pain on follow up

  4. Bacteriological cure

  5. Bacteriological relapse

  6. Duration of diarrhoea

  7. Duration of abdominal pain

  8. Number of days of hospitalisation

Once patients are randomized into the treatment groups, they should not be removed until final analysis. The trial author(s) must publish the outcome findings of the whole group first and then present data for those positive for Shigella by stool or rectal swab culture or PCR and those negative for Shigella. The data have to be presented according to the severity of illness the patients presented with.

Antibiotic sensitivity patterns have to be reported for all antibiotics studied and in all groups

Response to treatment stratified by in vitro antibiotic sensitivity also needs to be reported

Drop‐outs:
The patients who drop out after randomization due to loss of follow up, withdrawal from protocol or consent withdrawal etc have to be reported and accounted in the final analysis (intention‐to‐treat analysis).

Open in table viewer
Table 6. Sample size suggestions for trial of antibiotics in Shigella dysentery

SAMPLE SIZES

Antibiotic versus no drug or placebo (placebo response at 45%)

or

Antibiotic versus another antibiotic

1 sided α

10% difference: 310

20% difference: 75

25% difference: 50

30% difference: 30

40% difference: 15

2 sided α

10% difference: 390

20% difference: 95

25% difference: 60

30% difference: 40

40% difference: 20

1. The sample size required to detect the assumed difference in improvement or worsening with 80% power and 5% significance level using the outcome of 'diarrhoea at follow up' from this review using StatCalc 2006.
2. The sample size mentioned is for each arm of the study.

Summary of findings

Open in table viewer
Summary of findings for the main comparison. Antibiotic versus no drug or placebo for Shigella dysentery

Antibiotic versus no drug or placebo for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Mexico and Bangladesh
Intervention: Antibiotic versus no drug or placebo

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Antibiotic versus no drug or placebo

Diarrhoea on follow up ‐ Furazolidone versus no drug
clinical criteria
Follow‐up: 6 days

58 per 100

12 per 100
(5 to 28)

RR 0.21
(0.09 to 0.48)

73
(1 study)

⊕⊝⊝⊝
very low1,2,3

Antibiotic sensitivity of Shigella isolates not reported; Trial done in 1989

Diarrhoea on follow up ‐ Cotrimoxazole versus no drug
clinical criteria
Follow‐up: 6 days

58 per 100

17 per 100
(9 to 34)

RR 0.3
(0.15 to 0.59)

76
(1 study)

⊕⊝⊝⊝
very low1,2,4

Same trial as above; had three arms

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The two trials for this comparison were too short in follow up duration (6‐7 days) to estimate relapses and none were reported.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

None of the two trials for this comparison reported serious adverse events

Other adverse events
clinical criteria
Follow‐up: 7 days

0 per 100

0 per 100
(0 to 0)

RR 1.43
(0.06 to 34.13)

94
(1 study)

⊕⊝⊝⊝
very low5,6,7

Data from a three armed trial; only one non‐serious adverse event in the antibiotic arms and none in placebo arm

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: The method of randomization was not described and there were baseline imbalances in duration of diarrhoea. Allocation concealment and blinding were not reported and this increases the risk of bias in the detection and reporting of some adverse events, though not for other primary outcomes that were objectively ascertained.
2 Serious indirectness: The single trial included only children and hence the evidence for effectiveness of antibiotics over no antibiotics in adults is uncertain. Though the trial did not exclude participants who were malnourished, it is unclear if any participant was malnourished.
3 No imprecision: Both limits of the point estimate of the trial indicated benefit with furazolidine over not receiving an antibiotic
4 No imprecision: Both limits of the point estimate showed appreciable benefit with cotrimoxazole over not receiving an antibiotic
5 Very serious limitations: Allocation was not concealed and there were baseline imbalances in antibiotic sensitivity to those allocated to ceftriaxone (100%) and ampicillin (80%)
6 Serious indirectness: The trial randomized only adults. The antibiotics assessed were ceftriaxone and ampicillin.
7 Very serious imprecision: The 95% CI of the point estimate of the trial includes appreciable risk of adverse events for antibiotics over placebo with no significant differences between interventions.

Open in table viewer
Summary of findings 2. Fluoroquinolones versus beta‐lactams for Shigella dysentery

Fluoroquinolones versus beta‐lactams for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh (4 trials), Israel (1 trial), USA (1 trial)
Intervention: Fluoroquinolones versus beta‐lactams

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Fluoroquinolones versus beta‐lactams

Diarrhoea on follow up ‐ All trials
clinical criteria
Follow‐up: 5 to 180 days

251 per 1000

259 per 1000
(113 to 595)

RR 1.03
(0.45 to 2.37)

686
(6 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial from 1973; four trials in the 1990s; only one trial after 2000. The fluoroquinolones evaluated were nalidixic acid, and ciprofloxacin and the beta‐lactams evaluated were ampicillin, (intra‐muscular) ceftriaxone and pivmecillinam.

Relapse ‐ All trials
clinical criteria
Follow‐up: 5 to 180 days

70 per 1000

64 per 1000
(8 to 529)

RR 0.91
(0.11 to 7.55)

357
(3 studies)

⊕⊝⊝⊝
very low5,6,7,8

One trial from 1973, one from 1990 and one from 2000. Only two reported relapse.

Serious adverse events
clinical criteria
Follow‐up: 16 to 21 days

0 per 100

0 per 100
(0 to 0)

RR 10.9
(0.61 to 194.82)

221
(1 study)

⊕⊝⊝⊝
very low9,10,11

Only seen in 4.5% of those allocated to fluoroquinolones and not in those given beta‐lactams

Adverse events leading to discontinuation of treatment

62 per 1000

64 per 1000
(17 to 245)

RR 1.02
(0.27 to 3.89)

127
(1 study)

⊕⊝⊝⊝
very low12,13,14

Other adverse events
clinical criteria
Follow‐up: 5 to 180 days

177 per 1000

182 per 1000
(136 to 246)

RR 1.03
(0.77 to 1.39)

570
(4 studies)

⊕⊝⊝⊝
very low15,16,17,18

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 No serious limitations: Four of the six trials in this comparison had limitations in reporting outcomes for some participants but a sensitivity analysis did not appreciably alter the results
2 Serious inconsistency: I squared for the pooled data from six trials was 83% but could be partially explained by subgroup analyses of adults and children and by culture‐confirmed versus unconfirmed diagnosis of Shigella dysentery and resultant sensitivity patterns. The one trial in adults showed that a fluoroquinolone (ciprofloxacin) was superior (no imprecision) to a beta‐lactam (ampicillin) when sensitivity of the Shigella isolates was 100% for the former and 43% for the latter . Homogenous data (I squared 0%) from two trials in children showed that beta‐lactams (ampicillin and intra‐muscular ceftriaxone) were superior to fluoroquinolones (nalidixic acid and ciprofloxacin) when >90% of participants had culture‐confirmed Shigella dysentery with 100% sensitivity to the antibiotic used (no imprecision).
3 No serious indirectness: The six trials included children and adults and only two excluded severely malnourished children. The fluoroquinolones used included nalidixic acid and ciprofloxacin and the macrolides used included ampicillin, ceftriaxone and pivmecillinam.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with both interventions.
5 No serious limitations: One of the three trials for this comparison had limitations in reporting the method of randomization and allocation concealment but exclusion of this trial in sensitivity analysis did not alter results.
6 Serious inconsistency: The I squared for the pooled data was 63% and could not explained by subgroup analyses.
7 Serious indirectness: The trials that reported this outcome only included children; hence the effects of antibiotics in preventing relapses in adults is unclear.
8 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with both interventions
9 No serious limitations: There were imbalances in those excluded from analysis in the single trial but randomization, allocation concealment and blinding were free of the risk of bias and follow up included 91% of participants
10 Serious indirectness: The trial included only infants and children and the applicability of the results for this outcome in adults is uncertain.
11 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ceftriaxone and ciprofloxacin.
12 Serious limitations: This outcome was reported only for 75% of randomized participants with culture‐confirmed Shigella dysentery.
13 Serious indirectness: The trial that reported this outcome included only adults
14 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ampicillin and ciprofloxacin in this single trial.
15 Serious limitations: Three of the four trials that reported this outcome reported on less than 85% of those randomised.
16 No inconsistency: I squared was 0%
17 No serious indirectness: The four trials included adults and children and two did not specifically exclude malnourished children.
18 Very serious imprecision: The 95% CI of the pooled estimate indicated appreciable harm and non‐appreciable benefit with beta‐lactams (ampicillin, ceftriaxone and pivmecillinam) over fluoroquinolones (ciprofloxacin and nalidixic acid)

Open in table viewer
Summary of findings 3. Fluoroquinolones versus macrolides for Shigella dysentery

Fluoroquinolones versus macrolides for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh and Kenya
Intervention: Fluoroquinolones versus macrolides

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Fluoroquinolones versus macrolides

Diarrhoea on follow up
clinical criteria
Follow‐up: 6 to 10 days

105 per 1000

63 per 1000
(25 to 156)

RR 0.6
(0.24 to 1.49)

189
(2 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial reported that none of the participants had diarrhoea on day 10 and in the other 16/76 had diarrhoea on the sixth day

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Duration of follow up in both trials were too short (6 to 10 days) to assess relapse and none were reported.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

None of the two trials reported that any participant developed serious adverse events

Other adverse events
clinical criteria
Follow‐up: 6 days

Study population

RR 1.33
(0.32 to 5.56)

76
(1 study)

⊕⊝⊝⊝
very low5,6,7

79 per 1000

105 per 1000
(25 to 439)

Medium risk population

79 per 1000

105 per 1000
(25 to 439)

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Serious limitations: One of the two included trials had limitations in allocation concealment and both reported outcomes for less than 90% of those randomized (82% and 87%)
2 No serious inconsistency: One of the trials had no participants with this outcome and hence risk ratios were estimated for only one trial.
3 Serious indirectness: Both trials randomized only adults. Effects of fluoroquinolones over macrolides in children, especially those who are malnourished are unclear. Antibiotics used were azithromycin and ciprofloxacin in both trials.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ciprofloxacin and azithromycin.
5 Very serious limitation: The trial reported this outcome only for 82% of randomized participants.
6 Serious indirectness: The trial included only adults. The antibiotics studied were ciprofloxacin and azithromycin.
7 Very serious imprecision:The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ciprofloxacin and azithromycin.

Open in table viewer
Summary of findings 4. Cotrimoxazole versus beta‐lactams for Shigella dysentery

Cotrimoxazole versus beta‐lactams for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Guatemala and USA
Intervention: Cotrimoxazole versus beta‐lactams

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus beta‐lactams

Diarrhoea on follow up
clinical criteria
Follow‐up: 11 to 21 days

227 per 1000

134 per 1000
(52 to 338)

RR 0.59
(0.23 to 1.49)

89
(2 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial was reported in 1976 and the other in 1993. The antibiotics compared with cotrimoxazole were ampicillin and pivmecillinam respectively.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The two trials followed participants for 11 to 21 days but did not report any relapses in this time.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No serious adverse events leading to death or hospitalization were reported in either trial.

Other adverse events
clinical criteria
Follow‐up: 11 to 21 days

136 per 1000

110 per 1000
(37 to 333)

RR 0.81
(0.27 to 2.45)

89
(2 studies)

⊕⊝⊝⊝
very low1,2,3,5

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Serious limitations: Inadequate allocation concealment in one trial and inadequate outcome data reporting (for 39% of randomized participants whose cultures were negative for Shigella) in the other
2 No inconsistency: I squared was 0% and the direction of effect favoured cotrimoxazole in both trials.
3 Serious indirectness: Both trials included only infants and children. The antibiotics compared were cotrimoxazole versus ampicillin and pivmecillinam.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole and ampicillin and pivmecillinam.
5 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with beta‐lactams and cotrimoxazole.

Open in table viewer
Summary of findings 5. Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery

Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Peru
Intervention: Cotrimoxazole versus fluoroquinolones (norfloxacin)

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus fluoroquinolones (norfloxacin)

Diarrhoea on follow up ‐ not reported

See comment

See comment

Not estimable

See comment

Outcome assessed as number of days to last unformed stool. Data not available for proportions with diarrhoea on follow up.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The trial followed up participants for 14 days. Relapses were not reported in this time.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events leading to death or hospitalisation.

Other adverse events
clinical criteria
Follow‐up: 2 weeks

0 per 1000

0 per 1000
(0 to 0)

RR 2.82
(0.12 to 66.62)

62
(1 study)

⊕⊝⊝⊝
very low1,2,3

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Inadequate allocation concealment and blinding and very inadequate outcome data reporting (for only 32% of 174 randomized). Baseline imbalance in antibiotic sensitivity (100% sensitivity in norfloxacin arm and 84% in the cotrimoxazole arm).
2 Serious indirectness: The trial included only adults.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole and norfloxacin.

Open in table viewer
Summary of findings 6. Cotrimoxazole versus furazolidone for Shigella dysentery

Cotrimoxazole versus furazolidone for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Mexico
Intervention: Cotrimoxazole versus furazolidone

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus furazolidone

Diarrhoea on follow up
clinical criteria
Follow‐up: 6 days

173 per 1000

123 per 1000
(47 to 318)

RR 0.71
(0.27 to 1.84)

101
(1 study)

⊕⊝⊝⊝
very low1,2,3

Trial reported in 1989; antimicrobial sensitivity to Shigella isolates not reported

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Follow up duration too short (6 days) in the sole trial for this comparison

Serious adverse events

Medium risk population

RR 0
(0 to 0)

0
(0)

See comment

No participant is reported to have developed serious adverse events leading to death or hospitalization.

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No adverse effects reported; unclear if formally evaluated

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Risk of bias likely due to inadequate allocation concealment and blinding. Baseline imbalances in participant characteristics (significantly fewer days of diarrhoea in those allocated to furazolidone‐ P =0.02).
2 Serious indirectness: The single trial included only infants and children.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole over furazolidone.

Open in table viewer
Summary of findings 7. Oral gentamicin versus nalidixic acid for Shigella dysentery

Oral gentamicin versus nalidixic acid for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh
Intervention: Oral gentamicin versus nalidixic acid

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Oral gentamicin versus nalidixic acid

Diarrhoea at follow up
clinical criteria
Follow‐up: 5 days

308 per 1000

527 per 1000
(302 to 915)

RR 1.71
(0.98 to 2.97)

79
(1 study)

⊕⊝⊝⊝
very low1,2,3

Data from a single trial reported in 1994. Antimicrobial sensitivity for Shigella isolates was 100% in those allocated to oral gentamicin and 70% to those allocated to nalidixic acid.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Follow up duration too short (5 days) to assess.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No adverse effects reported; unclear if systematically assessed.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Though randomization, allocation and blinding were adequate, data were reported only for 87% randomized and there were baseline imbalances in antibiotic sensitivity (100% sensitive in gentamicin arm and 70% in nalidixic acid arm).
2 Serious indirectness: The trial randomized only infants and children and specifically excluded those severely malnourished.
3 Serious imprecision: The 95% CI for the point estimate from the trial includes appreciable and non‐appreciable benefit for nalidixic acid over oral gentamicin.

Open in table viewer
Summary of findings 8. Sulphonamides versus tetracycline for Shigella dysentery

Sulphonamides versus tetracycline for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Sri Lanka
Intervention: Sulphonamides versus tetracycline

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Sulphonamides versus tetracycline

Diarrhoea at follow up
clinical criteria
Follow‐up: 8 days

0 per 1000

0 per 1000
(0 to 0)

RR 7.68
(0.46 to 128.12)

60
(1 study)

⊕⊝⊝⊝
very low1,2,3

Trial reported in 1961. Antimicrobial sensitivity not reported

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Duration of follow up too short (8 days) to assess relapse

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events.

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

Not reported or pre‐stated as an outcome; unclear if assessed.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Risk of bias likely due to inadequate allocation concealment and blinding and unclear reporting of numbers randomized and numbers analysed.
2 Unclear indirectness: Unclear from report if trial included adults and children; malnourished participants were not specifically excluded.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with tetracycline and sulphonamides.

Background

Description of the condition

Shigellosis is a bacterial infection of the colon that causes diarrhoea and can lead to death. Dysentery (frequent mucoid or bloody stools) when caused by Shigella is called Shigella dysentery. Of the estimated 164.7 million Shigella diarrhoeal episodes occurring globally every year, most occur in developing countries (99%) and mainly in children (69%) (WHO 2006). Of the 1.1 million deaths due to Shigella, 69% are in children aged less than five years (Kotloff 1999; WHO 2006).

Microbiology and mode of spread

Shigella dysenteriae, S. flexneri, S. sonnei, and S. boydii are the four species of small, Gram‐negative, non‐motile bacilli that cause shigellosis, and all but S. sonnei have more than one genetically distinct subtype (serotype) (von Seidlein 2006). The species distribution varies globally; for example, S. flexneri was reported to be most prevalent in India (58%, Dutta 2002) and Rwanda (68%, Bogaerts 1983), while S. sonnei was the most frequently detected species in Thailand (85%, von Seidlein 2006), Israel (48.8%, Mates 2000), and the USA (75%, Gupta 2004; Shiferaw 2004).

Shigellae are transmitted by the faeco‐oral route, via direct person‐to‐person contact, and via food, water, and inanimate objects. Only a small number of ingested bacteria are required to produce illness. The disease is communicable as long as an infected person excretes the organism in the stool, which can extend up to four weeks from the onset of illness. Secondary attack rates, the number of exposed persons developing the disease within one to four days following exposure to the primary case (Park 2005), can be as high as 40% among household contacts (Sur 2004).

Shigellosis occurs predominantly in developing countries and is most common where overcrowding and poor sanitation exist. It occurs in densely populated areas and institutions where populations are in close contact with each other, such as day‐care centres, cruise ships, institutions for people with mental or psychological problems, and military barracks (Shane 2003; Gupta 2004).

Clinical features

The clinical manifestation of shigellosis ranges from an asymptomatic illness to bacteraemia and sepsis. Symptoms include fever, diarrhoea and/or dysentery with abdominal cramps and ineffectual and painful straining at stool or in urinating (Niyogi 2005). Shigellosis may be associated with mild to life‐threatening complications, such as rectal prolapse, arthralgia (painful joints), arthritis, intestinal perforation, and toxic mega colon (extreme inflammation and distension of the colon), central nervous disorders, convulsions, enteropathy (protein‐losing disease of the intestines), electrolyte imbalance of salts, and sepsis (Sur 2004; WHO 2005b). About 3% of those infected with S. flexneri and who are genetically predisposed can develop Reiter's syndrome (pains in their joints, irritation of the eyes, and painful urination) that can lead to a difficult to treat chronic arthritis (CDC 2005). Haemolytic uraemic syndrome (a complication resulting in kidney failure, bleeding, and anaemia) and leukemoid reaction (blood findings resembling leukaemia) complicate infection due to S. dysenteriae type 1 and may be fatal (Sinha 1987). S. dysenteriae type 1 is the only Shigella species with chromosomal genes encoding the protein known as Shiga toxin (Thorpe 2001).

Diagnosis

The clinical features of fever with blood and/or mucous diarrhoea associated with abdominal pain suggest that the aetiology of diarrhoea is Shigella. Routine microscopy of fresh stool is a simple screening test that is cheap, rapid, and easy to perform; and visualization of numerous poly‐morphonucleocytes suggests a bacterial aetiology. Definite diagnosis of shigellosis can only be made by stool culture (WHO 2005a). However, Shigella species die rapidly in unfavourable environments and stool culture should ideally be supplemented by attempts to identify Shigella DNA using polymerase chain reaction (PCR) (von Seidlein 2006).

Relapse

Clinical relapse can occur. This manifests as an initial clinical improvement or apparent cure with the treatment, followed by the recurrence of diarrhoea after the course of drug treatment is completed. In some instances people have sought the continued presence of Shigella in cultures of stool after the treatment, irrespective of apparent clinical recovery and have documented these as bacteriological failures (Martin 2000), indicative of the potential for relapse. Relapse is an important indicator of treatment failure, though it is clinically difficult to differentiate a relapse of infection with the same species or serotype of Shigella without additional testing for Shigella DNA using PCR analysis (von Seidlein 2006).

Mortality

The case‐fatality rate is estimated to be less than 1% among those with mild illness (WHO 2005a), which is usually self‐limiting (CDC 2005), and those affected are usually treated as out‐patients. However, case fatality is as high as 15% among patients with S. dysenteriae type 1 who require hospitalization; this rate is increased by delayed arrival and treatment with ineffective antibiotics. Infants, non‐breast fed children, children recovering from measles, malnourished children, and adults older than 50 years have a more severe illness and a greater risk of death (WHO 2005a).

Shigella and HIV infection

Human immunodeficiency virus (HIV) infection may be an important risk factor for Shigella infection. Particularly in HIV‐positive people, shigellosis is associated with extensive illness, including Shigella septicaemia, and increased health‐care expenditures. The diagnosis of shigellosis in an otherwise healthy adult without obvious exposure risk for Shigella should prompt consideration of the possibility of HIV infection (Huebner 1993; Baer 1999).

Description of the intervention

The World Health Organization (WHO) recommends that all suspected cases of shigellosis based on clinical features be treated with effective antimicrobials (antibiotics). The choice of antimicrobial drug has changed over the years as resistance to antibiotics has occurred, with different patterns of resistance being reported around the world. The following antibiotics were used to treat Shigella dysentery:

  • class: beta‐lactams: ampicillin, amoxicillin, first and second generation cephalosporins (cefixime, ceftriaxone) and pivmecillinam;

  • class: quinolones: nalidixic acid, ciprofloxacin, norfloxacin, ofloxacin;

  • class: macrolides: azithromycin; others: sulphonamides, tetracycline, cotrimoxazole, and furazolidone.

The WHO now recommends that clinically diagnosed cases of Shigella dysentery be treated with ciprofloxacin as first line treatment, and pivmecillinam, ceftriaxone, or azithromycin as second line treatment and lists the others as ineffective (WHO 2005a). However, resistance to quinolones has also been observed since the late 1990s, and some authors have questioned the effectiveness of this class for Shigella (Datta 2003; Sarkar 2003; Sur 2003; Pazhani 2004; Talukder 2004).

Why it is important to do this review

When an effective antibiotic is given, clinical improvement is anticipated within 48 hours (WHO 2005a). This lessens the risk of serious complications and death, shortens the duration of symptoms, and hastens the elimination of Shigella and the subsequent spread of infection (WHO 2005a). Since the antibiotics used for treating shigellosis can have adverse effects (Table 1; BNF 2007), some life‐threatening, the clinician is faced with a dilemma in choosing an appropriate drug to treat shigellosis. This drug must be effective, locally available at affordable costs, be associated with minimum adverse effects and be sensitive to local Shigella species and strains. We undertook this review in the hope of identifying such a drug or group of drugs.

Open in table viewer
Table 1. Known adverse effects of antibiotics used to treat Shigella dysentery^

Antibiotic

Life threatening

Discontinuation^^

Other

Tetracycline

Anaphylaxis

Oesophageal irritation, antibiotic‐associated colitis, headache and visual disturbances

In children under 12 years of age causes dental hypoplasia and staining, benign intracranial hypertension

Chloramphenicol

Blood disorders, peripheral and optic neuritis, erythema multiforme

Dyspepsia

Ampicillin

Hypersensitivity reactions

Diarrhoea

Co‐trimoxazole or trimethoprim ‐ sulphamethoxazole

Stevens‐Johnson syndrome

Diarrhoea, rash

Fluoroquinolones

Hypersensitivity

Dyspepsia, headache, hypotension

Pruritis, tachycardia

Norfloxacin

Dyspepsia, headache, hypotension

Euphoria, tinnitus, polyneuropathy

Ciprofloxacin

Dyspepsia, headache, hypotension

Hot flushes, sweating, tenosynovitis

Ofloxacin

Dyspepsia, headache, hypotension

Anxiety, unsteady gait

Azithromycin

Hypersensitivity

Dyspepsia, flatulence, headache

Ceftriaxone

Hypersensitivity reactions

Diarrhoea, headache, abdominal discomfort

Nalidixic acid

Same as in fluoroquinolones

Toxic psychosis, increased intracranial tension, cranial nerve palsy

Rifaximin

Allergic reactions

Allergic reactions

Cefixime

Hypersensitivity reactions

Flatulence, headache, abdominal pain, defecation urgency, nausea, constipation, pyrexia, vomiting

Pivmecillinam

Same as ampicillin, dyspepsia

^Source: BNF 2007.
^^Can result in discontinuation of treatment.

Objectives

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

Methods

Criteria for considering studies for this review

Types of studies

Randomized controlled trials (RCTs).

Types of participants

Adults and children with clinical symptoms suggestive of Shigella dysentery. Both hospitalized and non‐hospitalized participants were included.

Types of interventions

Intervention

Antibiotics, irrespective of the dose or route of administration.

Control

Other antibiotic of a different class (irrespective of the dose or route of administration), placebo, or no drug.

We included trials that used additional interventions if the interventions were used in all treatment arms.

Types of outcome measures

Primary outcomes

  • Diarrhoea at follow up.

  • Relapse, defined as the reappearance of diarrhoea associated with Shigella in the stool or dysentery during follow up.

Secondary outcomes

  • Fever at follow up: defined as body temperature above 37.0 ºC or 98.6 ºF.

  • Time to cessation of fever.

  • Time to cessation of diarrhoea.

  • Time to cessation of blood in stools.

  • Total number of stools per day.

  • Bacteriological cure: defined as a negative stool culture at the end of a specified time period after treatment.

  • Duration of hospital stay.

  • Development of severe complications.

  • Death.

  • Serious adverse events (i.e. those that are life‐threatening or require hospitalization); those that lead to discontinuation of treatment; other types of adverse events.

Search methods for identification of studies

We identified all relevant trials regardless of language or publication status (published, unpublished, in press, and in progress).

Electronic searches

We searched the following databases using the strategies and search terms set out in Table 2: the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4); MEDLINE (1966 to June 2009); EMBASE (1974 to June 2009); and LILACS (1982 to June 2009). We also searched the metaRegister of Controlled Trials (mRCT) using 'shigell*' as the search term (June 2009).

Open in table viewer
Table 2. Detailed search strategies

Search set

CIDG SR^

CENTRAL

MEDLINE^^

EMBASE^^

LILACS^^

1

Shigell*

Shigell*

Shigell*

Shigell$

Shigell*

2

Dysentery

DYSENTERY, BACILLARY

DYSENTERY, BACILLARY

SHIGELLOSIS

Dysentery

3

1 or 2

1 or 2

1 or 2

DYSENTERY

1 or 2

4

antibiotic*

ANTI‐BACTERIAL AGENTS/THERAPEUTIC USE

ANTI‐BACTERIAL AGENTS/THERAPEUTIC USE

1 or 2 or 3

antibiotic*

5

tetracycline*

ANTI‐INFECTIVE AGENTS/THERAPEUTIC USE

ANTI‐INFECTIVE AGENTS/THERAPEUTIC USE

tetracycline$

tetracycline*

6

chloramphenicol

antibiotic*

antibiotic*

chloramphenicol

chloramphenicol

7

ampicillin*

tetracycline*

tetracycline*

ampicillin

ampicillin

8

co‐trimoxazole

chloramphenicol

chloramphenicol

co‐trimoxazole

co‐trimoxazole

9

fluoroquinolone*

ampicillin

ampicillin

fluoroquinolone$

fluoroquinolone*

10

quinolone*

co‐trimoxazole

co‐trimoxazole

quinolone$

quinolone*

11

norfloxacin

fluoroquinolone*

fluoroquinolone*

norfloxacin

norfloxacin

12

ciprofloxacin

quinolone*

quinolone*

ciprofloxacin

ciprofloxacin

13

ofloxacin

norfloxacin

norfloxacin

ofloxacin

ofloxacin

14

azithromycin

ciprofloxacin

ciprofloxacin

azithromycin

azithromycin

15

ceftriaxone

ofloxacin

ofloxacin

ceftriaxone

ceftriaxone

16

nalidixic acid

azithromycin

azithromycin

nalidixic acid

nalidixic acid

17

pivmecillinam

ceftriaxone

ceftriaxone

rifaximin

rifaximin

18

4‐17/or

nalidixic acid

nalidixic acid

cefixime

cefixime

19

3 and 18

rifaximin

rifaximin

trimethoprim‐sulfamethoxazole

trimethoprim‐sulfamethoxazole

20

cefixime

cefixime

antibiotic$

pivmecillinam

21

trimethoprim‐sulfamethoxazole

trimethoprim‐sulfamethoxazole

pivmecillinam

4‐20/or

22

pivmecillinam

pivmecillinam

5‐21/or

3 and 21

23

4‐22/or

4‐22/or

Limit 22 to human

24

3 and 23

3 and 23

25

Limit 24 to human

^Cochrane Infectious Diseases Group Specialized Register.
^^Search terms used in combination with the search strategy for retrieving trials developed by The Cochrane Collaboration (Higgins 2006); upper case: MeSH or EMTREE heading; lower case: free text term.

Searching other resources

In Table 3 we list the conference proceedings searched for relevant abstracts, individual researchers working in this field contacted, organizations and pharmaceutical companies contacted to identify unpublished and ongoing trials, along with the dates when this was done. We also checked the reference lists of all studies identified by the above methods.

Open in table viewer
Table 3. Search strategy: proceedings, organizations, and pharmaceutical companies

Type

Detail

Conference proceeding

‐ Commonwealth Congress on Diarrhoea and Malnutrition: 8th, Dhaka, Bangladesh, 6 to 8 February 2006 (searched on 12 April 2007)
‐ Asian Conference on Diarrhoeal Diseases and Nutrition: 10th, Dhaka, Bangladesh, 7 to 9 December 2003 (searched on 13 April 2007)
‐ Annual Scientific Conference: 10th Dhaka, Bangladesh, 11 to 13 June 2002 (searched on 13 April 2007)
‐ Annual Meeting of Infectious Disease Society of America: 44th, Toronto, Ontario, Canada, 12 to 15 October 2006; 43rd, San Francisco, California, 6 to 9 October 2005; 42nd, Boston, Massachusetts, USA, 30 September to 3 October 2004 (searched on 18 March 2008)
‐ Interscience Conference on Antimicrobial Agents and Chemotherapy: 46th, San Francisco, California, 27 to 30 September 2006; 45th, Washington DC, USA, 16 to 19 December 2005; 44th, Washington DC, USA, 30 October to 2 November, 2004 (searched on 18 March 2008)
‐ European Congress of Clinical Microbiology and Infectious Diseases: 16th, Nice, France, 1 to 4 April 2006; 15th, 2 to 5 April 2005 (searched on 18 March 2008)
‐ International Congress on Infectious Diseases: 12th, Lisbon, Portugal, 15 to 18 June 2006; 11th, Cancun, Mexico, 4 to 7 March 2004 (searched on 18 March 2008)
‐ Annual Meeting of The European Society for Paediatric Infectious Disease: 24th, Basel, Switzerland, 3 to 5 May 2006 (searched on 18 March 2008)
‐ Western Pacific Congress of Chemotherapy and Infectious Diseases: 10th, Fukuoka, Japan, 3 to 6 December 2006 (searched on 18 March 2008)
‐ European Congress of Chemotherapy and Infection: 8th, Budapest, Hungary, 25 to 28 October 2006 (searched on 18 March 2008)

Organizations

‐ Liverpool School of Tropical Medicine (contacted on 11 April 2007)
‐ World Health Organization (contacted on 17 March 2008)
‐ American Society of Tropical Medicine and Hygiene (contacted on 15 April 2007)
‐ International Society of Tropical Pediatrics (contacted on 15 April 2007)
‐ South East Asian Ministers Education Organization (SEAMEO) TROPMED Network (contacted on 17 March 2008)
‐ International Center for Diarrhoeal Disease Research in Bangladesh (contacted on 21 April 2007)

Pharmaceutical companies

‐ Goldshield Pharmaceuticals Ltd (tetracycline, Deteclo; chloramphenicol, Chloromycetin) ‐ contacted on 17 March 2008
‐ Chemidex (ampicillin, Penbritin) ‐ contacted on 17 March 2008
‐ GlaxoSmithKline (co‐trimoxazole, Septrin) ‐ contacted on 17 March 2008
‐ Merck Sharp & Dohme Ltd (norfloxacin, Utinor) ‐ contacted on 17 March 2008
‐ Bayer (ciprofloxacin, Ciproxin) ‐ contacted on 20 April 2007
‐ Aventis Pharma (ofloxacin, Tarivid) ‐ contacted on 15 April 2007
‐ Pfizer (azithromycin, Zithromax) ‐ contacted on 17 March 2008
‐ Roche (ceftriaxone, Rocephin) ‐ contacted on 20 April 2007
‐ Rosemont Pharmaceuticals Ltd (nalidixic acid, Uriben) ‐ contacted on 13 April 2007
‐ Salix Pharmaceuticals (rifaximin, Xifaxan) ‐ contacted on 17 March 2008
‐ Rhone‐Poulenc Rorer (cefixime, Suprax) ‐ contacted on 17 March 2008
‐ LEO pharma (pivmecillinam, Selexid) ‐ contacted on 17 March 2008

Data collection and analysis

Selection of studies

Two pairs of authors (PC and KVD, and SMJ and VS ) independently assessed the results of the literature search to determine whether the title or abstract of each trial cited was an RCT . We retrieved the full reports of all trials considered by one or both pairs of authors as potentially relevant as well as those that were unclear from scrutinizing the abstracts. Each pair used a standard eligibility form based on the inclusion and exclusion criteria to assess the trials. We resolved disagreements through discussion. If eligibility was uncertain due to unclear or inadequate information, we attempted to contact the trial authors for clarification. The reasons for excluding studies were noted in the 'Characteristics of excluded studies' table. Each trial report was scrutinized to ensure that multiple publications from the same trial are included only once, and all reports were linked to the original trial report in the reference list of included studies.

Data extraction and management

The pairs of authors independently extracted data from the trials using pre‐tested data extraction forms. We extracted data on the inclusion and exclusion criteria for the participants, treatment/intervention given, total number randomized, number of participants in each group for all outcomes, drop‐outs, and withdrawals and numbers experiencing each outcome. For every outcome, we extracted the number analysed and the number randomized in each treatment group to allow for the assessment of losses to follow up. Any disagreements about data extracted were resolved by referring to the trial report and by discussion. Where data were insufficient or missing, attempts were made to contact the trial authors.

For continuous outcomes, we extracted the arithmetic mean values, standard deviations, and the number of participants in whom the outcome was assessed in each of the two groups. We noted whether the numbers assessed in the trial were the number of participants that completed the trial or the number randomized. If medians were reported we extracted ranges, or interquartile ranges.

Assessment of risk of bias in included studies

The pairs of authors independently assessed the risk of bias in each included trial for the following six components: sequence generation, allocation concealment, blinding or masking, incomplete outcome data, selective outcome reporting, and other sources of bias. For each of these components, we assigned a judgment regarding the risk of bias as 'yes', 'no', or 'unclear' (Higgins 2008). We recorded follow up to be adequate if more than 90% of the randomized participants were included in the final analysis, inadequate if less than or equal to 90%, or unclear if this information was not available from the report or trial authors. We recorded these assessments in the standard table in RevMan 5 (Review Manager 2008), and summarized them in 'Risk of bias' tables and a graph (Figure 1; Figure 2). We used these assessments to perform a sensitivity analysis based on methodological quality when appropriate. We attempted to contact the trial authors for clarification when methodological details were unclear. We resolved differences by discussion and by contacting an Editor with the Cochrane Infectious Diseases Review Group.


Methodological quality summary: review authors' judgments about each methodological quality item for each included study.

Methodological quality summary: review authors' judgments about each methodological quality item for each included study.


Methodological quality graph: review authors' judgments about each methodological quality item presented as percentages across all included studies.

Methodological quality graph: review authors' judgments about each methodological quality item presented as percentages across all included studies.

Measures of treatment effect

The measures of treatment effect used were risk ratio (RR) for dichotomous outcomes and mean difference for continuous outcomes with their 95% confidence intervals (CIs).

Dealing with missing data

Where possible, we extracted data to allow an intention‐to‐treat analysis in which all randomized participants were analysed in the groups to which they were originally assigned. If there was discrepancy in the number randomized and the numbers analysed in each treatment group, we calculated the percentage loss to follow up in each group and reported this information. For dichotomous outcomes, we recorded the number of participants experiencing the event and the number analysed in each treatment group. We assigned those lost to follow up the worse outcome, except for the outcome of death, since it would be unreasonable to assume that all those who were lost to follow up died.

Assessment of heterogeneity

We determined the presence of statistical heterogeneity among the same interventions by examining the forest plot and by performing the Chi2 test for heterogeneity using a P value of 0.10 to determine statistical significance. The I2 statistic was used to quantify inconsistency across trials and a value greater than 50% was considered as substantial heterogeneity (Deeks 2005).

Assessment of reporting biases

All studies were assessed for adequacy of reporting of data for pre‐stated outcomes and for selective reporting of outcomes. We noted judgements based on the risk of selective reporting in the 'Risk of bias' table for each study in the 'Characteristics of included studies' table.

Had there been sufficient trials we would have evaluated asymmetry in the funnel plot as an indication of publication bias.

Data synthesis

The first two authors entered data into Review Manager 2008 using double‐data entry. PC synthesized the data, which the co‐authors checked. All results are presented with 95% CIs. The main comparisons were between any antibiotic drug and placebo, and any antibiotic drug and another antibiotic drug of a different class.

We synthesized dichotomous data using pooled and weighted RRs. Continuous data summarized by arithmetic means and standard deviations were combined using the weighted mean differences.

We used the fixed‐effect model to synthesize data if heterogeneity was not substantial. When there was substantial heterogeneity and this could not be explained by subgroup analysis, we synthesized data using the random‐effects model and recommended a cautious interpretation of the pooled result.

Subgroup analysis and investigation of heterogeneity

When there was significant statistical heterogeneity, we explored the possible sources using the following subgroup analyses: participant age (adults versus children) and percentage of participants with confirmed Shigella infection.

Sensitivity analysis

We performed sensitivity analyses for primary outcomes to assess the robustness of the meta‐analysis among the same interventions by calculating the results using all trials and then excluding trials of a lower methodological quality (i.e. trials with inadequate generation of allocation sequence and allocation concealment, trials that were not double blind, and trials where less than or equal to 90% of randomized participants were analysed).

Results

Description of studies

Results of the search

Out of 265 studies retrieved by the search, we obtained full texts of 123 studies. The rest were excluded as they were neither RCTs nor studies of antibiotic therapy for Shigella. Of the 123 studies, 16 parallel group, individually randomized trials met inclusion criteria (see 'Characteristics of included studies') and are summarized below. The reasons for excluding the other 106 trials are recorded in the 'Characteristics of excluded studies' table. One study awaits assessment (Carbo 1981).

Included studies

Location, setting and length of follow up

Seven trials were conducted in Bangladesh, all at the International Centre for Diarrhoeal Disease Research (ICDDR,B). Two trials were from the United States of America (Haltalin 1973; Nelson 1976a) and one each from the following countries: India (Dutta 1995), Sri Lanka (Bibile 1961), Peru (Gotuzzo 1989), Israel (Leibovitz 2000), Guatemala (Prado 1993), Mexico (Rodriguez 1989), and Kenya (Shanks 1999). Twelve trials were carried out in hospitalized patients, three in out‐patients and one did not mention the setting. The trials used different lengths of follow up: eight trials were for six days, three trials for five days, two trials for 14 days and one trial each for seven days, 10 days, and six months.

Participants

The trials included a total of 1748 participants. All trials but one (Haltalin 1973) were randomized based on clinical symptoms of dysentery and prior to bacteriological confirmation. People with neither blood nor mucus in stools were excluded. Haltalin 1973 randomized participants after a presumptive confirmation of Shigella by immunofluorescence study of rectal swabs. Dutta 1995 did not seek microbiological confirmation for Shigella by culture of stool samples or rectal swabs. In the remaining trials, only the data from participants with microbiologically confirmed Shigella were reported and thus only those data were included in the analyses. Ten trials were carried out only in children, five in adults, and one included both. Among the 10 trials in children, only one (Dutta 1995) included malnourished children (11 of 72) but did not provide data on them separately. Two trials excluded children with malnutrition and the remaining seven trials did not provide such information. None of the trials reported the HIV status of participants. The other inclusion criteria were fairly similar across all trials.

Interventions

Two trials (Kabir 1986; Rodriguez 1989) compared antibiotics and placebo or no drug. Both were three‐armed trials. Rodriguez 1989 compared furazolidone, cotrimoxazole, and no drug. Kabir 1986 compared ceftriaxone, ampicillin, and a placebo. Six trials compared flouroquinolones and beta‐lactams (Alam 1994, pivmecillinam and nalidixic acid; Bennish 1990, ciprofloxacin and ampicillin; Haltalin 1973, nalidixic acid and ampicillin; Leibovitz 2000, ciprofloxacin and ceftriaxone; Salam 1988, nalidixic acid and ampicillin; Salam 1998, ciprofloxacin and pivmecillinam). Two trials compared flouroquinolones and macrolides (Khan 1997a; Shanks 1999), both compared azithromycin and ciprofloxacin). Two trials compared cotrimoxazole and beta‐lactams (Prado 1993, pivmecillinam and cotrimoxazole; Nelson 1976a, cotrimoxazole and ampicillin). Gotuzzo 1989 compared cotrimoxazole and flouroquinolones (norfloxacin). Dutta 1995 compared furazolidone and nalidixic acid. Islam 1994 compared oral gentamicin and nalidixic acid. Bibile 1961 was a four‐armed trial: the first three had different types of sulphonamides: sulphamidine, sulphamethoxypyridazine, 'Streptotriad' and the fourth arm was tetracycline. Each tablet of Streptotriad contained streptomycin sulphate, sulphamerazine, sulphadiazine and sulphathiazole. This arm was not included in analysis (sulphonamide versus tetracycline) since it contained a non‐sulphonamide drug, streptomycin.

Outcomes

This review had two primary efficacy outcomes. The first primary outcome, diarrhoea on follow up, was reported by all but three trials (Kabir 1986; Gotuzzo 1989; Islam 1994); the duration of follow up was five days in 10/13 trials. The second primary outcome, relapse, was reported by four trials (Haltalin 1973; Salam 1998; Shanks 1999; Leibovitz 2000); the duration of follow up for this outcome ranged from 10 to 20 days. Among the secondary outcomes, fever at follow up was reported by four trials, time to cessation of fever was reported by five trials, time to cessation of diarrhoea was reported by six trials, time to cessation of blood in stools was reported by three trials, bacteriological cure or failure was reported by 11 trials, and development of severe complications was reported by only one trial. Duration of hospital stay was not an outcome measured by any of the trials. One trial (Kabir 1986) reported the mean number of stools per day in a graph that did not permit extraction of data for analysis. Adverse events were reported by all but four trials (Haltalin 1973; Alam 1994; Islam 1994; Dutta 1995). Only Leibovitz 2000 reported serious adverse events related to antibiotic therapy leading to hospitalization. None of the trials reported any deaths.

Excluded studies

We excluded 107 studies for the following reasons. Twenty‐nine studies were not RCTs. In 59 studies the inclusion criteria for the participants was not dysentery. Eighteen studies compared antibiotics of the same class, which we decided should be the subject of a separate review. One trial was excluded as the interventions were not antibiotics (Raqib 2008). Carbo 1981 awaits assessment as it provided no data on the numbers allotted to interventions and we are awaiting a reply from the authors.

Risk of bias in included studies

See Figure 1 for a summary of the 'risk of bias' in each included study and Figure 2 for a summary graph of methodological quality expressed as percentages across included trials. The risk of bias for each study is summarized additionally in 'Characteristics of included studies'.

Allocation

Among the included studies, 81% (13/16) had low risk of bias in the generation of the allocation sequence. Of these, four trials (Bibile 1961; Prado 1993; Salam 1998; Leibovitz 2000) used random number lists. The remaining trials (Nelson 1976a; Kabir 1986; Salam 1988; Gotuzzo 1989; Bennish 1990; Alam 1994; Islam 1994; Dutta 1995; Khan 1997a) used block randomization techniques. However, only 9/16 (56%) of the studies clearly reported adequate concealment of allocation (Salam 1988; Bennish 1990; Prado 1993; Alam 1994; Islam 1994; Dutta 1995; Khan 1997a; Salam 1998; Leibovitz 2000).

Blinding

Eleven trials (69%) had low risk of bias for the component of blinding. Salam 1988, Khan 1997a, Salam 1998, Shanks 1999 and Leibovitz 2000 had blinded the participant, the provider, and the outcome assessor. Kabir 1986, Bennish 1990, Prado 1993, Alam 1994 and Islam 1994 had blinded the participant and the provider. Dutta 1995 had only the outcome assessor blinded. Bibile 1961, Haltalin 1973, Nelson 1976a, Gotuzzo 1989 and Rodriguez 1989 were open trials.

Incomplete outcome data

Only 25% (4/16) trials (Bibile 1961; Haltalin 1973; Nelson 1976a; Kabir 1986) were judged to have adequately addressed incomplete outcome data. The remaining 12 trials did not adequately address incomplete outcome data because they excluded participants from data analysis after randomization as their stool cultures were later negative for Shigella. This is a serious methodological flaw (see 'Potential biases in the review process').

Selective reporting

All the studies were free of selective reporting.

Other potential sources of bias

More than 90% (15/16) of the studies had no other potential sources of bias. One study (Rodriguez 1989) had a significant baseline imbalance as the participants in one of the study arms had fewer days of diarrhoea than the other arms.

Effects of interventions

See: Summary of findings for the main comparison Antibiotic versus no drug or placebo for Shigella dysentery; Summary of findings 2 Fluoroquinolones versus beta‐lactams for Shigella dysentery; Summary of findings 3 Fluoroquinolones versus macrolides for Shigella dysentery; Summary of findings 4 Cotrimoxazole versus beta‐lactams for Shigella dysentery; Summary of findings 5 Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery; Summary of findings 6 Cotrimoxazole versus furazolidone for Shigella dysentery; Summary of findings 7 Oral gentamicin versus nalidixic acid for Shigella dysentery; Summary of findings 8 Sulphonamides versus tetracycline for Shigella dysentery

We intended to prepare separate meta‐analyses for trials of: (1) an antibiotic drug versus another antibiotic drug belonging to the same or different drug class; (2) antibiotic drugs grouped by drug class versus other antibiotic drugs belonging to a different drug class; and (3) monotherapy with any antibiotic drug versus combination drug therapy with two or more different drugs given together or sequentially. However, we were only able to synthesize data from trials comparing single antibiotics of different classes and of antibiotics grouped by class. Comparisons of antibiotics within the same class were deferred to a subsequent review and thus 17 potential trials of this comparison were excluded from this review and are listed as such in the 'Characteristics of excluded studies'. We did not identify trials of an antibiotic drug versus combination drug therapy with two or more different drugs given together or sequentially.

We present trial results grouped as eight sets of comparisons.

1. Versus no drug or placebo (two trials)

Diarrhoea on follow up (primary outcome):

Rodriguez 1989 compared both oral furazolidone and cotrimoxazole with no treatment. Fewer patients in the antibiotic group had diarrhoea at follow up (for furazolidone, RR 0.21, 95% CI 0.09 to 0.48, 73 participants; and for cotrimoxazole versus no treatment, RR 0.30, 95% CI 0.15 to 0.59; 76 participants, Analysis 1.1).

Kabir 1986 compared intravenous ceftriaxone (n=64) and intravenous ampicillin (n=60) with placebo (n=30). There was no difference detected in time to diarrhoea resolution (Analysis 1.3), fever resolution (Analysis 1.2), and time to resolution of blood in the stools (Analysis 1.4), or adverse events (Analysis 1.5).

(See 'summary of findings Table for the main comparison')

2. Fluoroquinolones versus beta‐lactams (six trials)

Diarrhoea on follow up (primary outcome):

Six trials measured this, and the comparative effects varied considerably between the trials, with no obvious trend (686 participants, six trials, Analysis 2.1; Haltalin 1973; Salam 1988; Bennish 1990; Alam 1994; Salam 1998; Leibovitz 2000). This variability was still present after exclusion of trials with a higher risk of bias (Haltalin 1973; Bennish 1990; Alam 1994; Salam 1988). Most of the trials were in children; one trial was in adults (Bennish 1990).

In trials where 90% or more of included patients were confirmed with Shigella, beta‐lactams were more effective than fluoroquinolones (RR 4.68, 95% CI 1.74 to 12.59; 257 children, two trials, (Analysis 2.1). (Haltalin 1973; Leibovitz 2000); in the four trials with less than 90% confirmed Shigella positive patients the results showed no obvious pattern (Analysis 2.1). (Salam 1988; Bennish 1990; Alam 1994; Salam 1998).

Relapse:

No obvious pattern was apparent in the three trials examining this outcome ( Analysis 2.1; Haltalin 1973; Salam 1998; Leibovitz 2000) and subgroup analysis did not provide any further insights.

Fever at follow up:

Heterogenous data from two trials (Alam 1994; Salam 1998) showed no difference between the groups (191 participants, Analysis 2.2). Subgroup analysis was not done as both trials were done in children and had less than 90% of participants with Shigella in stool culture.

Bacteriological failure:

Pooled heterogenous data from five trials (Haltalin 1973; Salam 1988; Bennish 1990; Alam 1994; Salam 1998) showed no difference between the two groups for this outcome (450 participants, Analysis 2.4). However on subgroup analysis based on participant's age, the single study done on adults (Bennish 1990) showed that fluoroquinolones were better than beta‐lactams in producing bacteriological cures (RR 0.28; 95% CI 0.08 to 0.95; 127 participants, Analysis 2.4). Even though the data from the children's subgroup (Haltalin 1973; Salam 1988; Alam 1994; Salam 1998) were homogenous, there was no difference between the two groups (223 participants, Analysis 2.4). The heterogeneity persisted on subgroup analysis based on number of participants with proven Shigella included in analysis.

Development of severe complications:

Data from two trials (Haltalin 1973; Salam 1988) showed no difference between two groups for this outcome (90 participants, Analysis 2.5). Though formal tests did not reveal significant heterogeneity, the differences in size and direction of treatment effect for the two trials is important to consider in interpreting this result.

Adverse events:

For serious adverse events,Leibovitz 2000 showed no difference between the two groups (Analysis 2.6, n=221); Bennish 1990 did not detect a difference in adverse events leading to discontinuation of treatment (127 participants, Analysis 2.7); for other adverse events, no difference was detected in four trials reporting this (Analysis 2.8). ( Salam 1988; Bennish 1990; Salam 1998; Leibovitz 2000).

(See 'summary of findings Table 2').

3. Fluoroquinolones versus macrolides (two trials)

Diarrhoea on follow up (primary outcomes):

Data from two trials (Khan 1997a; Shanks 1999) showed no difference between the two groups (189 participants, Analysis 3.1). Heterogeneity could not be assessed since the results from Shanks 1999 were not estimable (no patients had diarrhoea on follow up in both arms) and hence neither subgroup analysis nor sensitivity analysis was done.

Relapse:

Shanks 1999 reported on relapse but the results were not estimable as no patients had experienced relapse.

Fever at follow up:

Homogenous data from two trials (Khan 1997a; Shanks 1999) showed no difference between the two groups (189 participants, Analysis 3.2).

Time to cessation of blood in stool:

One trial (Shanks 1999) that reported this outcome showed no difference between the two groups (113 participants, Analysis 3.3).

Bacteriological failure:

One trial (Khan 1997a) showed no difference between the two groups (76 participants, Analysis 3.4).

Adverse events:

Khan 1997a did not show any difference between the two groups (76 participants, Analysis 3.5).

(See 'summary of findings Table 3').

4. Cotrimoxazole versus beta‐lactams (two trials)

Diarrhoea on follow up (primary outcome):

Homogenous data from two trials (Nelson 1976a; Prado 1993) did not show any difference between the two groups (89 participants, Analysis 4.1). Exclusion of the poorer quality trial (Nelson 1976a) did not affect the results in sensitivity analysis.

Bacteriological failure:

One trial (Nelson 1976a) which compared this outcome did not show any difference between two groups (28 participants, Analysis 4.2).

Time to cessation of diarrhoea:

One trial (Prado 1993) that compared this outcome did not show any significant difference between the two groups (61 participants, Analysis 4.3).

Time to cessation of fever:

One trial (Prado 1993) reported this outcome and there was no difference between the two groups (61 participants, Analysis 4.4).

Time to cessation of blood in stools:

One trial (Prado 1993) that compared this outcome did not show any difference between the two groups (61 participants, Analysis 4.5).

Adverse events:

Homogenous data from two trials (Nelson 1976a; Prado 1993) showed no difference between the two groups for adverse events (89 participants, Analysis 4.6).

(See 'Summary of findings table 4').

5. Cotrimoxazole versus fluoroquinolones (one trial)

Bacteriological failure:

One trial (Gotuzzo 1989) that compared this outcome did not show any difference between the groups (62 participants, Analysis 5.1).

Adverse events:

Gotuzzo 1989, the only trial for this comparison, did not show any difference between the groups (62 participants, Analysis 5.2).

(See 'summary of findings Table 5').

6. Cotrimoxazole versus furazolidone (one trial)

Diarrhoea on follow up (primary outcome):

One three‐armed trial (Rodriguez 1989, furazolidone, cotrimoxazole, and no drug) reported this outcome and there was no significant difference between the groups (101 participants, Analysis 6.1).

(See 'summary of findings Table 6').

7. Oral gentamicin versus nalidixic acid (one trial)

Diarrhoea on follow up (primary outcome):

One trial (Islam 1994) that reported this outcome showed no difference between the two groups (79 participants, Analysis 7.1).

Fever at follow up:

Islam 1994 reported this outcome and found nalidixic acid more effective than oral gentamicin in reducing the number patients with fever on follow up (RR 2.37, 95% CI 1.11 to 5.07; 79 participants, Analysis 7.2). While both the antibiotics were effective against Shigella in vitro, nalidixic acid was more effective in vivo due to better absorption when taken orally.

Bacteriological failure:

Islam 1994 reported that nalidixic acid was more effective than oral gentamicin in achieving bacteriological cures (RR 2.10, 95% CI 1.29 to 3.42; 79 participants, Analysis 7.4).

(See 'Summary of findings table 7')

8. Sulphonamides versus tetracyclines (one trial)

Diarrhoea on follow up (primary outcome):

One trial (Bibile 1961) that compared this outcome showed no difference between the two groups (60 participants, Analysis 8.1).

Bacteriological failure:

Bibile 1961 reported no difference between the groups (60 participants, Analysis 8.2).

(See 'summary of findings Table 8').

Discussion

Summary of main results

This review identified 16 trials conducted over a span of four decades that randomized 1748 participants to evaluate the safety and efficacy of antibiotics in the treatment of Shigella dysentery. Most trials were at risk of bias due to limitations in reporting details of randomization or allocation concealment or blinding, but the most common source of bias occurred due to failure to report outcome details for participants who were randomized but in whom Shigella could not be isolated from stool culture.

In this review we focused on trials done with antibiotics belonging to different classes compared against placebo or no treatment or to each other. We found limited evidence to support the use of antibiotics in children and adults with Shigella dysentery compared to no treatment or placebo. One trial reported that antibiotics are effective in reducing the proportion of those with diarrhoea but it did not report on relapse. Another trial suggested that antibiotics were effective in reducing the duration of fever though they did not reduce the time to cessation of diarrhoea or bloody stool.

We did not find robust evidence to suggest that antibiotics of a particular class were better than those belonging to a different class. However, there were limited data from a subgroup of studies to suggest that a fluoroquinolone (ciprofloxacin) was more effective than a beta‐lactam (ampicillin) in reducing diarrhoea among adults and that beta‐lactams were more effective than fluoroquinolones in reducing diarrhoea among children with proven Shigella dysentery. Oral gentamicin was also reported to be inferior to nalidixic acid in achieving bacteriological cure and reducing fever in one small trial. The trials in this review report that at various periods of time different antibiotics have been effective against isolates of Shigella dysentery (Table 4) in different parts of the world. They are: ampicillin, cotrimoxazole, nalidixic acid, fluoroquinolones like ciprofloxacin, pivmecillinam, ceftriaxone, and azithromycin. However oral gentamicin was relatively ineffective, due to poor absorption when given orally, compared to nalidixic acid and therefore is not recommended. There was insufficient evidence to comment on the use of tetracyclines, sulphonamides, and chloramphenicol.

Open in table viewer
Table 4. Sensitivity patterns of the Shigella isolates reported in included trials

Study ID

Group 1

Group 2

Group 3

Alam 1994

Pivmecillinam group:

All were sensitive to pivmecillinam

Nalidixic acid sensitivity not reported

Nalidixic acid group:

All were sensitive to pivmecillinam

26/37, 45%, were sensitive to nalidixic acid

Nil

Bennish 1990

Ciprofloxacin group:

All were sensitive to ciprofloxacin; 34/60, 56.6%, were sensitive to ampicillin

Ampicillin group:

All were sensitive to ciprofloxacin; 26/61, 42.6%, were sensitive to ampicillin.

Nil

Bibile 1961

This is a 4‐armed trial with sulphadimidine, sulpha methoxy pyridazine, Strepto triad, and tetracycline in each group respectively

Sensitivity patterns not reported for any group

Dutta 1995

Furazolidone and nalidixic acid

Sensitivity patterns not reported for any group

Gotuzzo 1989

Cotrimoxazole group:

27/32, 84%, were sensitive to cotrimoxazole; all were sensitive to norfloxacin

Norfloxacin group:

26/30, 86%, were sensitive to cotrimoxazole; all were sensitive to norfloxacin

Nil

Haltalin 1973

Nalidixic acid group:

All were sensitive to nalidixic acid; ampicillin sensitivity not reported.

Ampicillin group:

All were sensitive to ampicillin; nalidixic acid sensitivity not reported

Nil

Islam 1994

Nalidixic acid group:

26/37, 70%, were sensitive to nalidixic acid; all were sensitive to gentamicin

Oral gentamicin:

Nalidixic acid sensitivity not reported; all were sensitive to gentamicin

Nil

Kabir 1986

Ceftriaxone group:

All were sensitive to ceftriaxone; all were sensitive to ampicillin

Ampicillin group:

All were sensitive to ceftriaxone; 24/30, 80%, were sensitive to ampicillin

Placebo:

All were sensitive to ceftriaxone; 28/30, 93%, were sensitive to ampicillin

Khan 1997a

Azithromycin group:

All were sensitive to both antibiotics

Ciprofloxacin group:

All were sensitive to both antibiotics

Nil

Leibovitz 2000

Ciprofloxacin group:

All were sensitive to both antibiotics

Ceftriaxone group:

All were sensitive to both antibiotics

Nil

Nelson 1976a

Cotrimoxazole group:

All were sensitive to cotrimoxazole; 9/14, 64%, were sensitive to ampicillin

Ampicillin group:

All were sensitive to cotrimoxazole 10/14, 71%, were sensitive to ampicillin

Nil

Prado 1993

Cotrimoxazole group;

24/30, 80%, were sensitive to cotrimoxazole; 25/30, 83.3%, were sensitive to pivmecillinam

Pivmecillinam group:

23/29, 79.3%, were sensitive to cotrimoxazole; 26/29, 89.7%, were sensitive to pivmecillinam

Nil

Rodriguez 1989

3‐armed trial with furazolidone, cotrimoxazole and a control (no antimicrobials) respectively

Sensitivity patterns not reported for any group

Nil

Salam 1988

Nalidixic acid group:

All were sensitive to nalidixic acid; ampicillin sensitivity not reported

Ampicillin group:

All were sensitive to nalidixic acid; 25/40, 62.5%, were sensitive to ampicillin

Nil

Salam 1998

Ciprofloxacin group:

All were sensitive to ciprofloxacin; 58/60, 96.7%, were sensitive to pivmecillinam

Pivmecillinam group:

All were sensitive to ciprofloxacin; 57/60, 95%, were sensitive to pivmecillinam

Nil

Shanks 1999

Azithromycin and ciprofloxacin

Sensitivity patterns not reported for any group

Nil

Sensitivity patterns not reported by 4 trials (Bibile 1961; Rodriguez 1989; Dutta 1995; Shanks 1999).

There is also insufficient evidence to indicate that any antibiotic class prevents relapse of Shigella dysentery.

None of the antibiotics studied in the trials were associated with major adverse events that were drug related.

Overall completeness and applicability of evidence

With respect to the review's objectives, this review found limited evidence that antibiotics reduce diarrhoea and the duration of fever compared to no antibiotic. However, we are unable to recommend an antibiotic or an antibiotic class for the treatment of Shigella dysentery. The studies identified could not sufficiently address relapse. All the antibiotics studied in this review were safe.

The studies addressed both adults and children. However, populations at risk for complicated Shigella dysentery, such as HIV infected populations and malnourished children, were not included (or adequately represented) in the trials we identified.

In current practice, antibiotics are recommended and used in the treatment of Shigella dysentery. The conclusions of this review confirm these recommendations and current practice. However this review is unable to recommend a specific antibiotic or antibiotic group as universally effective for the treatment of Shigella dysentery.

Even though mild forms of Shigella dysentery are said to be self‐limiting, this review is unable to comment on the need for antibiotics in this group since the included trials did not grade patients with respect to the severity of illness.

This review did not include studies using drugs belonging to similar antibiotic classes. Another review is needed to study differences between antibiotics belonging to the same class and also between different antibiotic dosing schedules, and short‐course versus longer‐course therapy of the same antibiotic.

Quality of the evidence

The body of evidence identified does not allow a robust conclusion regarding the objectives of the review or strong recommendations regarding the choice of preferred antibiotics. Of the 16 trials (1748 participants) included in the review, most had methodological limitations including inadequate reporting of the generation of allocation sequence, inadequate allocation concealment, and lack of blinding. Many trials removed participants after randomization since they did not grow Shigella in their stool culture and had not reported their outcome. This is a serious methodological error. Most trials were thus graded of low or very low quality and further research may change the estimates of efficacy and our confidence in these estimates.

Potential biases in the review process

We selected trials that compared the efficacy and safety of antibiotics of different classes only and deferred inclusion of trials evaluating antibiotics of the same drug class to an update or a separate review. Seventeen trials were excluded on the basis of this. This might have biased the results and conclusions of this review. We also did not include comparisons of different doses, routes of administration, or duration of treatment of the same antibiotic in Shigella dysentery.

We selected trials which included participants with clinical evidence of dysentery. However, Shigella infection can also present as diarrhoea in up to three‐quarters of infections, particularly in Asian countries (von Seidlein 2006). Excluding such patients in trials of antibiotics in Shigella and excluding trials using a broader definition than that used in this review could have biased the evidence presented. Many trials in this review also excluded participants randomized to receive antibiotics if their stool did not grow Shigella isolates. However, Shigella species and strains are highly sensitive to inhospitable environments and failure to grow Shigella in culture does not rule out Shigella infection (von Seidlein 2006). None of the included trials utilized alternative or additional, sensitive, diagnostic techniques such as identification of Shigella DNA using real‐time PCR. Exclusion of data from such participants in these trials, and exclusion of more stringent inclusion criteria for the diagnosis of Shigella dysentery in this review is likely to have introduced reporting and selection biases, respectively.

Agreements and disagreements with other studies or reviews

The overall results of this review suggest that most of the antibiotics used were effective. However, only 10 of the 16 included trials reported the proportion of participants that were sensitive to the antibiotics used. The outcomes in these trials correlated with the sensitivity patterns of the antibiotics used.

The WHO recommended nalidixic acid as the first line treatment for Shigella dysentery until 2004 when complete resistance to nalidixic acid in large parts of China and Bangladesh led to recommendations by the WHO to avoid using nalidixic acid altogether in Shigella dysentery (Legros 2004; WHO 2005a). However, nalidixic acid continues to be a potential option in parts of the world where resistance to this drug is not, as yet, a widespread problem, such as the Dakar region of the Senegal, where resistance to ampicillin, chloramphenicol, tetracycline, and cotrimoxazole are common (Sire 2008). However, widespread use of nalidixic acid may increase resistance to ciprofloxacin due to cross‐resistance of some strains of Shigella and thus has limited utility (WHO 2005a). The WHO recommends the use of ciprofloxacin as the first line antibiotic in suspected Shigella dysentery but also suggests that this choice should be based on sensitivity patterns of Shigella strains recently isolated in the area (WHO 2005a). Temporal and geographical shifts in Shigella strains are reported in parts of the world (von Seidlein 2006) and regular surveillance and ascertainment of antimicrobial sensitivity to local and regional strains is necessary to determine the choice of antibiotic to be used as first line in Shigella dysentery. Emerging drug resistance to ciprofloxacin and second line drugs such as pivmecillinam, ceftriaxone, and azithromycin is increasingly being reported in many parts of the world, as is multiple‐drug resistance (Kosek 2008; Kuo 2008; Pazhani 2008). The results of this review provides systematically ascertained evidence that the most commonly used antibiotics are potentially effective against Shigella dysentery, provided the local species and strains of Shigella are susceptible. Regular, periodic antibiotic‐susceptibility testing of isolates is required to guide local empiric therapy for Shigella dysentery.

Methodological quality summary: review authors' judgments about each methodological quality item for each included study.
Figuras y tablas -
Figure 1

Methodological quality summary: review authors' judgments about each methodological quality item for each included study.

Methodological quality graph: review authors' judgments about each methodological quality item presented as percentages across all included studies.
Figuras y tablas -
Figure 2

Methodological quality graph: review authors' judgments about each methodological quality item presented as percentages across all included studies.

Comparison 1 Antibiotic versus no drug or placebo, Outcome 1 Diarrhoea on follow up.
Figuras y tablas -
Analysis 1.1

Comparison 1 Antibiotic versus no drug or placebo, Outcome 1 Diarrhoea on follow up.

Comparison 1 Antibiotic versus no drug or placebo, Outcome 2 Time to cessation of fever (in days).
Figuras y tablas -
Analysis 1.2

Comparison 1 Antibiotic versus no drug or placebo, Outcome 2 Time to cessation of fever (in days).

Comparison 1 Antibiotic versus no drug or placebo, Outcome 3 Time to cessation of diarrhoea (in days).
Figuras y tablas -
Analysis 1.3

Comparison 1 Antibiotic versus no drug or placebo, Outcome 3 Time to cessation of diarrhoea (in days).

Comparison 1 Antibiotic versus no drug or placebo, Outcome 4 Time to cessation of blood in stools (in days).
Figuras y tablas -
Analysis 1.4

Comparison 1 Antibiotic versus no drug or placebo, Outcome 4 Time to cessation of blood in stools (in days).

Comparison 1 Antibiotic versus no drug or placebo, Outcome 5 Other adverse events.
Figuras y tablas -
Analysis 1.5

Comparison 1 Antibiotic versus no drug or placebo, Outcome 5 Other adverse events.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 1 Diarrhoea on follow up.
Figuras y tablas -
Analysis 2.1

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 1 Diarrhoea on follow up.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 2 Fever at follow up.
Figuras y tablas -
Analysis 2.2

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 2 Fever at follow up.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 3 Relapse.
Figuras y tablas -
Analysis 2.3

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 3 Relapse.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 4 Bacteriological failure.
Figuras y tablas -
Analysis 2.4

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 4 Bacteriological failure.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 5 Development of severe complications.
Figuras y tablas -
Analysis 2.5

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 5 Development of severe complications.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 6 Serious adverse events.
Figuras y tablas -
Analysis 2.6

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 6 Serious adverse events.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 7 Adverse events leading to discontinuation of treatment.
Figuras y tablas -
Analysis 2.7

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 7 Adverse events leading to discontinuation of treatment.

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 8 Other adverse events.
Figuras y tablas -
Analysis 2.8

Comparison 2 Fluoroquinolones versus beta‐lactams, Outcome 8 Other adverse events.

Comparison 3 Fluoroquinolones versus macrolides, Outcome 1 Diarrhoea on follow up.
Figuras y tablas -
Analysis 3.1

Comparison 3 Fluoroquinolones versus macrolides, Outcome 1 Diarrhoea on follow up.

Comparison 3 Fluoroquinolones versus macrolides, Outcome 2 Fever at follow up.
Figuras y tablas -
Analysis 3.2

Comparison 3 Fluoroquinolones versus macrolides, Outcome 2 Fever at follow up.

Comparison 3 Fluoroquinolones versus macrolides, Outcome 3 Time to cessation of blood in stools.
Figuras y tablas -
Analysis 3.3

Comparison 3 Fluoroquinolones versus macrolides, Outcome 3 Time to cessation of blood in stools.

Comparison 3 Fluoroquinolones versus macrolides, Outcome 4 Bacteriological failure.
Figuras y tablas -
Analysis 3.4

Comparison 3 Fluoroquinolones versus macrolides, Outcome 4 Bacteriological failure.

Comparison 3 Fluoroquinolones versus macrolides, Outcome 5 Other adverse events.
Figuras y tablas -
Analysis 3.5

Comparison 3 Fluoroquinolones versus macrolides, Outcome 5 Other adverse events.

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 1 Diarrhoea on follow up.
Figuras y tablas -
Analysis 4.1

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 1 Diarrhoea on follow up.

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 2 Bacteriological failure.
Figuras y tablas -
Analysis 4.2

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 2 Bacteriological failure.

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 3 Time to cessation of diarrhoea (hours).
Figuras y tablas -
Analysis 4.3

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 3 Time to cessation of diarrhoea (hours).

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 4 Time to cessation of fever (hours).
Figuras y tablas -
Analysis 4.4

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 4 Time to cessation of fever (hours).

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 5 Time to cessation of visible blood in stools.
Figuras y tablas -
Analysis 4.5

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 5 Time to cessation of visible blood in stools.

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 6 Other adverse events.
Figuras y tablas -
Analysis 4.6

Comparison 4 Cotrimoxazole versus beta‐lactams, Outcome 6 Other adverse events.

Comparison 5 Cotrimoxazole versus fluoroquinolones (norfloxacin), Outcome 1 Bacteriological failure.
Figuras y tablas -
Analysis 5.1

Comparison 5 Cotrimoxazole versus fluoroquinolones (norfloxacin), Outcome 1 Bacteriological failure.

Comparison 5 Cotrimoxazole versus fluoroquinolones (norfloxacin), Outcome 2 Other adverse events.
Figuras y tablas -
Analysis 5.2

Comparison 5 Cotrimoxazole versus fluoroquinolones (norfloxacin), Outcome 2 Other adverse events.

Comparison 6 Cotrimoxazole versus furazolidone, Outcome 1 Diarrhoea on follow up.
Figuras y tablas -
Analysis 6.1

Comparison 6 Cotrimoxazole versus furazolidone, Outcome 1 Diarrhoea on follow up.

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 1 Diarrhoea at follow up.
Figuras y tablas -
Analysis 7.1

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 1 Diarrhoea at follow up.

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 2 Fever at follow up.
Figuras y tablas -
Analysis 7.2

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 2 Fever at follow up.

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 3 Bacteriological relapse.
Figuras y tablas -
Analysis 7.3

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 3 Bacteriological relapse.

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 4 Bacteriological failure.
Figuras y tablas -
Analysis 7.4

Comparison 7 Oral gentamicin versus nalidixic acid, Outcome 4 Bacteriological failure.

Comparison 8 Sulphonamides versus tetracycline, Outcome 1 Diarrhoea at follow up.
Figuras y tablas -
Analysis 8.1

Comparison 8 Sulphonamides versus tetracycline, Outcome 1 Diarrhoea at follow up.

Comparison 8 Sulphonamides versus tetracycline, Outcome 2 Bacteriological failure.
Figuras y tablas -
Analysis 8.2

Comparison 8 Sulphonamides versus tetracycline, Outcome 2 Bacteriological failure.

Table 5. Suggestions for a trial of antibiotic for Shigella dysentery

Methods

Participants

Interventions

Outcomes

Notes

Allocation:
Centralized sequence generation with table of random numbers or computer generated lists

Stratified by severity of illness

Sequence concealed until interventions are assigned

Blinding:
Those recruiting and assigning participants, those administering the intervention, and those assessing the outcomes, must all be blind to the allocated group; the administered drugs have to be identical or a double dummy technique has to be used. Liquid medications have to be in similar looking bottles, identical in shape and weight; the medications must themselves be similar in colour and flavour.

Duration:
Minimum of 4 weeks after completion of therapy to assess relapse

Entry criteria can be clinical dysentery, i.e. acute onset frequent loose stools with blood or mucus or both lasting for less than 72 hours and at least 3 stools per day. Other features, such as fever and tenesmus at presentation, have to be recorded but need not be necessary for inclusion into study.

If it is possible to presumptively or decisively detect Shigella in stool before inclusion into study, it should be done. Real‐time PCR is a rapid but expensive method to diagnose Shigella early (Legros 2004).

Sample size:
(See Table 6). Age group: trials should be separately done for adults and children (less than 15 years of age) or at least presented separately if they are in the same trial. In children, infants must be a separate group.

Setting: in‐ or out‐patients. The number of participants, if hospitalized for standardization of administration of the interventions, have to be reported separately from those hospitalized due to complications.

Sex: men and women.

Special groups (those who have higher risk of complications:

  • Malnourished children

  • HIV positive individuals

  • Adults more than 50 years of age

  • Infants

Exclusion criteria:
Allergy to the drug studied; history of antibiotic use for this episode of illness in the previous 48 hours; pregnant and lactating women; clinical presence of another infection needing antimicrobials

  1. Any antibiotic studied for efficacy and safety

  2. Any other antibiotic that is the standard for the treatment of Shigella dysentery at that period of time in that country

Others: placebos or probiotics to be studied only on those with no risk of complications and those who have mild illness

Primary outcomes:

  1. Number of patients with diarrhoea on follow up.

  2. Clinical relapse

  3. Adverse effects of antibiotics

    1. Life threatening adverse effects of the drug

    2. Those that require discontinuation of the drug

    3. MIld adverse events that need extra therapy but not discontinuation of the drug

  4. Duration of fever

  5. Duration of blood in stools

Secondary outcomes:

  1. Removed from study due to clinical worsening

  2. Fever on follow up

  3. Abdominal pain on follow up

  4. Bacteriological cure

  5. Bacteriological relapse

  6. Duration of diarrhoea

  7. Duration of abdominal pain

  8. Number of days of hospitalisation

Once patients are randomized into the treatment groups, they should not be removed until final analysis. The trial author(s) must publish the outcome findings of the whole group first and then present data for those positive for Shigella by stool or rectal swab culture or PCR and those negative for Shigella. The data have to be presented according to the severity of illness the patients presented with.

Antibiotic sensitivity patterns have to be reported for all antibiotics studied and in all groups

Response to treatment stratified by in vitro antibiotic sensitivity also needs to be reported

Drop‐outs:
The patients who drop out after randomization due to loss of follow up, withdrawal from protocol or consent withdrawal etc have to be reported and accounted in the final analysis (intention‐to‐treat analysis).

Figuras y tablas -
Table 5. Suggestions for a trial of antibiotic for Shigella dysentery
Table 6. Sample size suggestions for trial of antibiotics in Shigella dysentery

SAMPLE SIZES

Antibiotic versus no drug or placebo (placebo response at 45%)

or

Antibiotic versus another antibiotic

1 sided α

10% difference: 310

20% difference: 75

25% difference: 50

30% difference: 30

40% difference: 15

2 sided α

10% difference: 390

20% difference: 95

25% difference: 60

30% difference: 40

40% difference: 20

1. The sample size required to detect the assumed difference in improvement or worsening with 80% power and 5% significance level using the outcome of 'diarrhoea at follow up' from this review using StatCalc 2006.
2. The sample size mentioned is for each arm of the study.

Figuras y tablas -
Table 6. Sample size suggestions for trial of antibiotics in Shigella dysentery
Summary of findings for the main comparison. Antibiotic versus no drug or placebo for Shigella dysentery

Antibiotic versus no drug or placebo for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Mexico and Bangladesh
Intervention: Antibiotic versus no drug or placebo

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Antibiotic versus no drug or placebo

Diarrhoea on follow up ‐ Furazolidone versus no drug
clinical criteria
Follow‐up: 6 days

58 per 100

12 per 100
(5 to 28)

RR 0.21
(0.09 to 0.48)

73
(1 study)

⊕⊝⊝⊝
very low1,2,3

Antibiotic sensitivity of Shigella isolates not reported; Trial done in 1989

Diarrhoea on follow up ‐ Cotrimoxazole versus no drug
clinical criteria
Follow‐up: 6 days

58 per 100

17 per 100
(9 to 34)

RR 0.3
(0.15 to 0.59)

76
(1 study)

⊕⊝⊝⊝
very low1,2,4

Same trial as above; had three arms

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The two trials for this comparison were too short in follow up duration (6‐7 days) to estimate relapses and none were reported.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

None of the two trials for this comparison reported serious adverse events

Other adverse events
clinical criteria
Follow‐up: 7 days

0 per 100

0 per 100
(0 to 0)

RR 1.43
(0.06 to 34.13)

94
(1 study)

⊕⊝⊝⊝
very low5,6,7

Data from a three armed trial; only one non‐serious adverse event in the antibiotic arms and none in placebo arm

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: The method of randomization was not described and there were baseline imbalances in duration of diarrhoea. Allocation concealment and blinding were not reported and this increases the risk of bias in the detection and reporting of some adverse events, though not for other primary outcomes that were objectively ascertained.
2 Serious indirectness: The single trial included only children and hence the evidence for effectiveness of antibiotics over no antibiotics in adults is uncertain. Though the trial did not exclude participants who were malnourished, it is unclear if any participant was malnourished.
3 No imprecision: Both limits of the point estimate of the trial indicated benefit with furazolidine over not receiving an antibiotic
4 No imprecision: Both limits of the point estimate showed appreciable benefit with cotrimoxazole over not receiving an antibiotic
5 Very serious limitations: Allocation was not concealed and there were baseline imbalances in antibiotic sensitivity to those allocated to ceftriaxone (100%) and ampicillin (80%)
6 Serious indirectness: The trial randomized only adults. The antibiotics assessed were ceftriaxone and ampicillin.
7 Very serious imprecision: The 95% CI of the point estimate of the trial includes appreciable risk of adverse events for antibiotics over placebo with no significant differences between interventions.

Figuras y tablas -
Summary of findings for the main comparison. Antibiotic versus no drug or placebo for Shigella dysentery
Summary of findings 2. Fluoroquinolones versus beta‐lactams for Shigella dysentery

Fluoroquinolones versus beta‐lactams for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh (4 trials), Israel (1 trial), USA (1 trial)
Intervention: Fluoroquinolones versus beta‐lactams

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Fluoroquinolones versus beta‐lactams

Diarrhoea on follow up ‐ All trials
clinical criteria
Follow‐up: 5 to 180 days

251 per 1000

259 per 1000
(113 to 595)

RR 1.03
(0.45 to 2.37)

686
(6 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial from 1973; four trials in the 1990s; only one trial after 2000. The fluoroquinolones evaluated were nalidixic acid, and ciprofloxacin and the beta‐lactams evaluated were ampicillin, (intra‐muscular) ceftriaxone and pivmecillinam.

Relapse ‐ All trials
clinical criteria
Follow‐up: 5 to 180 days

70 per 1000

64 per 1000
(8 to 529)

RR 0.91
(0.11 to 7.55)

357
(3 studies)

⊕⊝⊝⊝
very low5,6,7,8

One trial from 1973, one from 1990 and one from 2000. Only two reported relapse.

Serious adverse events
clinical criteria
Follow‐up: 16 to 21 days

0 per 100

0 per 100
(0 to 0)

RR 10.9
(0.61 to 194.82)

221
(1 study)

⊕⊝⊝⊝
very low9,10,11

Only seen in 4.5% of those allocated to fluoroquinolones and not in those given beta‐lactams

Adverse events leading to discontinuation of treatment

62 per 1000

64 per 1000
(17 to 245)

RR 1.02
(0.27 to 3.89)

127
(1 study)

⊕⊝⊝⊝
very low12,13,14

Other adverse events
clinical criteria
Follow‐up: 5 to 180 days

177 per 1000

182 per 1000
(136 to 246)

RR 1.03
(0.77 to 1.39)

570
(4 studies)

⊕⊝⊝⊝
very low15,16,17,18

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 No serious limitations: Four of the six trials in this comparison had limitations in reporting outcomes for some participants but a sensitivity analysis did not appreciably alter the results
2 Serious inconsistency: I squared for the pooled data from six trials was 83% but could be partially explained by subgroup analyses of adults and children and by culture‐confirmed versus unconfirmed diagnosis of Shigella dysentery and resultant sensitivity patterns. The one trial in adults showed that a fluoroquinolone (ciprofloxacin) was superior (no imprecision) to a beta‐lactam (ampicillin) when sensitivity of the Shigella isolates was 100% for the former and 43% for the latter . Homogenous data (I squared 0%) from two trials in children showed that beta‐lactams (ampicillin and intra‐muscular ceftriaxone) were superior to fluoroquinolones (nalidixic acid and ciprofloxacin) when >90% of participants had culture‐confirmed Shigella dysentery with 100% sensitivity to the antibiotic used (no imprecision).
3 No serious indirectness: The six trials included children and adults and only two excluded severely malnourished children. The fluoroquinolones used included nalidixic acid and ciprofloxacin and the macrolides used included ampicillin, ceftriaxone and pivmecillinam.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with both interventions.
5 No serious limitations: One of the three trials for this comparison had limitations in reporting the method of randomization and allocation concealment but exclusion of this trial in sensitivity analysis did not alter results.
6 Serious inconsistency: The I squared for the pooled data was 63% and could not explained by subgroup analyses.
7 Serious indirectness: The trials that reported this outcome only included children; hence the effects of antibiotics in preventing relapses in adults is unclear.
8 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with both interventions
9 No serious limitations: There were imbalances in those excluded from analysis in the single trial but randomization, allocation concealment and blinding were free of the risk of bias and follow up included 91% of participants
10 Serious indirectness: The trial included only infants and children and the applicability of the results for this outcome in adults is uncertain.
11 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ceftriaxone and ciprofloxacin.
12 Serious limitations: This outcome was reported only for 75% of randomized participants with culture‐confirmed Shigella dysentery.
13 Serious indirectness: The trial that reported this outcome included only adults
14 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ampicillin and ciprofloxacin in this single trial.
15 Serious limitations: Three of the four trials that reported this outcome reported on less than 85% of those randomised.
16 No inconsistency: I squared was 0%
17 No serious indirectness: The four trials included adults and children and two did not specifically exclude malnourished children.
18 Very serious imprecision: The 95% CI of the pooled estimate indicated appreciable harm and non‐appreciable benefit with beta‐lactams (ampicillin, ceftriaxone and pivmecillinam) over fluoroquinolones (ciprofloxacin and nalidixic acid)

Figuras y tablas -
Summary of findings 2. Fluoroquinolones versus beta‐lactams for Shigella dysentery
Summary of findings 3. Fluoroquinolones versus macrolides for Shigella dysentery

Fluoroquinolones versus macrolides for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh and Kenya
Intervention: Fluoroquinolones versus macrolides

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Fluoroquinolones versus macrolides

Diarrhoea on follow up
clinical criteria
Follow‐up: 6 to 10 days

105 per 1000

63 per 1000
(25 to 156)

RR 0.6
(0.24 to 1.49)

189
(2 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial reported that none of the participants had diarrhoea on day 10 and in the other 16/76 had diarrhoea on the sixth day

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Duration of follow up in both trials were too short (6 to 10 days) to assess relapse and none were reported.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

None of the two trials reported that any participant developed serious adverse events

Other adverse events
clinical criteria
Follow‐up: 6 days

Study population

RR 1.33
(0.32 to 5.56)

76
(1 study)

⊕⊝⊝⊝
very low5,6,7

79 per 1000

105 per 1000
(25 to 439)

Medium risk population

79 per 1000

105 per 1000
(25 to 439)

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Serious limitations: One of the two included trials had limitations in allocation concealment and both reported outcomes for less than 90% of those randomized (82% and 87%)
2 No serious inconsistency: One of the trials had no participants with this outcome and hence risk ratios were estimated for only one trial.
3 Serious indirectness: Both trials randomized only adults. Effects of fluoroquinolones over macrolides in children, especially those who are malnourished are unclear. Antibiotics used were azithromycin and ciprofloxacin in both trials.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ciprofloxacin and azithromycin.
5 Very serious limitation: The trial reported this outcome only for 82% of randomized participants.
6 Serious indirectness: The trial included only adults. The antibiotics studied were ciprofloxacin and azithromycin.
7 Very serious imprecision:The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with ciprofloxacin and azithromycin.

Figuras y tablas -
Summary of findings 3. Fluoroquinolones versus macrolides for Shigella dysentery
Summary of findings 4. Cotrimoxazole versus beta‐lactams for Shigella dysentery

Cotrimoxazole versus beta‐lactams for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Guatemala and USA
Intervention: Cotrimoxazole versus beta‐lactams

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus beta‐lactams

Diarrhoea on follow up
clinical criteria
Follow‐up: 11 to 21 days

227 per 1000

134 per 1000
(52 to 338)

RR 0.59
(0.23 to 1.49)

89
(2 studies)

⊕⊝⊝⊝
very low1,2,3,4

One trial was reported in 1976 and the other in 1993. The antibiotics compared with cotrimoxazole were ampicillin and pivmecillinam respectively.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The two trials followed participants for 11 to 21 days but did not report any relapses in this time.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No serious adverse events leading to death or hospitalization were reported in either trial.

Other adverse events
clinical criteria
Follow‐up: 11 to 21 days

136 per 1000

110 per 1000
(37 to 333)

RR 0.81
(0.27 to 2.45)

89
(2 studies)

⊕⊝⊝⊝
very low1,2,3,5

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Serious limitations: Inadequate allocation concealment in one trial and inadequate outcome data reporting (for 39% of randomized participants whose cultures were negative for Shigella) in the other
2 No inconsistency: I squared was 0% and the direction of effect favoured cotrimoxazole in both trials.
3 Serious indirectness: Both trials included only infants and children. The antibiotics compared were cotrimoxazole versus ampicillin and pivmecillinam.
4 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole and ampicillin and pivmecillinam.
5 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with beta‐lactams and cotrimoxazole.

Figuras y tablas -
Summary of findings 4. Cotrimoxazole versus beta‐lactams for Shigella dysentery
Summary of findings 5. Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery

Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Peru
Intervention: Cotrimoxazole versus fluoroquinolones (norfloxacin)

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus fluoroquinolones (norfloxacin)

Diarrhoea on follow up ‐ not reported

See comment

See comment

Not estimable

See comment

Outcome assessed as number of days to last unformed stool. Data not available for proportions with diarrhoea on follow up.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

The trial followed up participants for 14 days. Relapses were not reported in this time.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events leading to death or hospitalisation.

Other adverse events
clinical criteria
Follow‐up: 2 weeks

0 per 1000

0 per 1000
(0 to 0)

RR 2.82
(0.12 to 66.62)

62
(1 study)

⊕⊝⊝⊝
very low1,2,3

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Inadequate allocation concealment and blinding and very inadequate outcome data reporting (for only 32% of 174 randomized). Baseline imbalance in antibiotic sensitivity (100% sensitivity in norfloxacin arm and 84% in the cotrimoxazole arm).
2 Serious indirectness: The trial included only adults.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole and norfloxacin.

Figuras y tablas -
Summary of findings 5. Cotrimoxazole versus fluoroquinolones (norfloxacin) for Shigella dysentery
Summary of findings 6. Cotrimoxazole versus furazolidone for Shigella dysentery

Cotrimoxazole versus furazolidone for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Mexico
Intervention: Cotrimoxazole versus furazolidone

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Cotrimoxazole versus furazolidone

Diarrhoea on follow up
clinical criteria
Follow‐up: 6 days

173 per 1000

123 per 1000
(47 to 318)

RR 0.71
(0.27 to 1.84)

101
(1 study)

⊕⊝⊝⊝
very low1,2,3

Trial reported in 1989; antimicrobial sensitivity to Shigella isolates not reported

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Follow up duration too short (6 days) in the sole trial for this comparison

Serious adverse events

Medium risk population

RR 0
(0 to 0)

0
(0)

See comment

No participant is reported to have developed serious adverse events leading to death or hospitalization.

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No adverse effects reported; unclear if formally evaluated

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Risk of bias likely due to inadequate allocation concealment and blinding. Baseline imbalances in participant characteristics (significantly fewer days of diarrhoea in those allocated to furazolidone‐ P =0.02).
2 Serious indirectness: The single trial included only infants and children.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with cotrimoxazole over furazolidone.

Figuras y tablas -
Summary of findings 6. Cotrimoxazole versus furazolidone for Shigella dysentery
Summary of findings 7. Oral gentamicin versus nalidixic acid for Shigella dysentery

Oral gentamicin versus nalidixic acid for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Bangladesh
Intervention: Oral gentamicin versus nalidixic acid

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Oral gentamicin versus nalidixic acid

Diarrhoea at follow up
clinical criteria
Follow‐up: 5 days

308 per 1000

527 per 1000
(302 to 915)

RR 1.71
(0.98 to 2.97)

79
(1 study)

⊕⊝⊝⊝
very low1,2,3

Data from a single trial reported in 1994. Antimicrobial sensitivity for Shigella isolates was 100% in those allocated to oral gentamicin and 70% to those allocated to nalidixic acid.

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Follow up duration too short (5 days) to assess.

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No adverse effects reported; unclear if systematically assessed.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Though randomization, allocation and blinding were adequate, data were reported only for 87% randomized and there were baseline imbalances in antibiotic sensitivity (100% sensitive in gentamicin arm and 70% in nalidixic acid arm).
2 Serious indirectness: The trial randomized only infants and children and specifically excluded those severely malnourished.
3 Serious imprecision: The 95% CI for the point estimate from the trial includes appreciable and non‐appreciable benefit for nalidixic acid over oral gentamicin.

Figuras y tablas -
Summary of findings 7. Oral gentamicin versus nalidixic acid for Shigella dysentery
Summary of findings 8. Sulphonamides versus tetracycline for Shigella dysentery

Sulphonamides versus tetracycline for Shigella dysentery

Patient or population: patients with Shigella dysentery
Settings: Sri Lanka
Intervention: Sulphonamides versus tetracycline

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Control

Sulphonamides versus tetracycline

Diarrhoea at follow up
clinical criteria
Follow‐up: 8 days

0 per 1000

0 per 1000
(0 to 0)

RR 7.68
(0.46 to 128.12)

60
(1 study)

⊕⊝⊝⊝
very low1,2,3

Trial reported in 1961. Antimicrobial sensitivity not reported

Relapse ‐ not reported

See comment

See comment

Not estimable

See comment

Duration of follow up too short (8 days) to assess relapse

Serious adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

No participant is reported to have developed serious adverse events.

Other adverse events ‐ not reported

See comment

See comment

Not estimable

See comment

Not reported or pre‐stated as an outcome; unclear if assessed.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Very serious limitations: Risk of bias likely due to inadequate allocation concealment and blinding and unclear reporting of numbers randomized and numbers analysed.
2 Unclear indirectness: Unclear from report if trial included adults and children; malnourished participants were not specifically excluded.
3 Very serious imprecision: The 95% CI of the pooled estimate includes appreciable benefit and appreciable harm with tetracycline and sulphonamides.

Figuras y tablas -
Summary of findings 8. Sulphonamides versus tetracycline for Shigella dysentery
Table 1. Known adverse effects of antibiotics used to treat Shigella dysentery^

Antibiotic

Life threatening

Discontinuation^^

Other

Tetracycline

Anaphylaxis

Oesophageal irritation, antibiotic‐associated colitis, headache and visual disturbances

In children under 12 years of age causes dental hypoplasia and staining, benign intracranial hypertension

Chloramphenicol

Blood disorders, peripheral and optic neuritis, erythema multiforme

Dyspepsia

Ampicillin

Hypersensitivity reactions

Diarrhoea

Co‐trimoxazole or trimethoprim ‐ sulphamethoxazole

Stevens‐Johnson syndrome

Diarrhoea, rash

Fluoroquinolones

Hypersensitivity

Dyspepsia, headache, hypotension

Pruritis, tachycardia

Norfloxacin

Dyspepsia, headache, hypotension

Euphoria, tinnitus, polyneuropathy

Ciprofloxacin

Dyspepsia, headache, hypotension

Hot flushes, sweating, tenosynovitis

Ofloxacin

Dyspepsia, headache, hypotension

Anxiety, unsteady gait

Azithromycin

Hypersensitivity

Dyspepsia, flatulence, headache

Ceftriaxone

Hypersensitivity reactions

Diarrhoea, headache, abdominal discomfort

Nalidixic acid

Same as in fluoroquinolones

Toxic psychosis, increased intracranial tension, cranial nerve palsy

Rifaximin

Allergic reactions

Allergic reactions

Cefixime

Hypersensitivity reactions

Flatulence, headache, abdominal pain, defecation urgency, nausea, constipation, pyrexia, vomiting

Pivmecillinam

Same as ampicillin, dyspepsia

^Source: BNF 2007.
^^Can result in discontinuation of treatment.

Figuras y tablas -
Table 1. Known adverse effects of antibiotics used to treat Shigella dysentery^
Table 2. Detailed search strategies

Search set

CIDG SR^

CENTRAL

MEDLINE^^

EMBASE^^

LILACS^^

1

Shigell*

Shigell*

Shigell*

Shigell$

Shigell*

2

Dysentery

DYSENTERY, BACILLARY

DYSENTERY, BACILLARY

SHIGELLOSIS

Dysentery

3

1 or 2

1 or 2

1 or 2

DYSENTERY

1 or 2

4

antibiotic*

ANTI‐BACTERIAL AGENTS/THERAPEUTIC USE

ANTI‐BACTERIAL AGENTS/THERAPEUTIC USE

1 or 2 or 3

antibiotic*

5

tetracycline*

ANTI‐INFECTIVE AGENTS/THERAPEUTIC USE

ANTI‐INFECTIVE AGENTS/THERAPEUTIC USE

tetracycline$

tetracycline*

6

chloramphenicol

antibiotic*

antibiotic*

chloramphenicol

chloramphenicol

7

ampicillin*

tetracycline*

tetracycline*

ampicillin

ampicillin

8

co‐trimoxazole

chloramphenicol

chloramphenicol

co‐trimoxazole

co‐trimoxazole

9

fluoroquinolone*

ampicillin

ampicillin

fluoroquinolone$

fluoroquinolone*

10

quinolone*

co‐trimoxazole

co‐trimoxazole

quinolone$

quinolone*

11

norfloxacin

fluoroquinolone*

fluoroquinolone*

norfloxacin

norfloxacin

12

ciprofloxacin

quinolone*

quinolone*

ciprofloxacin

ciprofloxacin

13

ofloxacin

norfloxacin

norfloxacin

ofloxacin

ofloxacin

14

azithromycin

ciprofloxacin

ciprofloxacin

azithromycin

azithromycin

15

ceftriaxone

ofloxacin

ofloxacin

ceftriaxone

ceftriaxone

16

nalidixic acid

azithromycin

azithromycin

nalidixic acid

nalidixic acid

17

pivmecillinam

ceftriaxone

ceftriaxone

rifaximin

rifaximin

18

4‐17/or

nalidixic acid

nalidixic acid

cefixime

cefixime

19

3 and 18

rifaximin

rifaximin

trimethoprim‐sulfamethoxazole

trimethoprim‐sulfamethoxazole

20

cefixime

cefixime

antibiotic$

pivmecillinam

21

trimethoprim‐sulfamethoxazole

trimethoprim‐sulfamethoxazole

pivmecillinam

4‐20/or

22

pivmecillinam

pivmecillinam

5‐21/or

3 and 21

23

4‐22/or

4‐22/or

Limit 22 to human

24

3 and 23

3 and 23

25

Limit 24 to human

^Cochrane Infectious Diseases Group Specialized Register.
^^Search terms used in combination with the search strategy for retrieving trials developed by The Cochrane Collaboration (Higgins 2006); upper case: MeSH or EMTREE heading; lower case: free text term.

Figuras y tablas -
Table 2. Detailed search strategies
Table 3. Search strategy: proceedings, organizations, and pharmaceutical companies

Type

Detail

Conference proceeding

‐ Commonwealth Congress on Diarrhoea and Malnutrition: 8th, Dhaka, Bangladesh, 6 to 8 February 2006 (searched on 12 April 2007)
‐ Asian Conference on Diarrhoeal Diseases and Nutrition: 10th, Dhaka, Bangladesh, 7 to 9 December 2003 (searched on 13 April 2007)
‐ Annual Scientific Conference: 10th Dhaka, Bangladesh, 11 to 13 June 2002 (searched on 13 April 2007)
‐ Annual Meeting of Infectious Disease Society of America: 44th, Toronto, Ontario, Canada, 12 to 15 October 2006; 43rd, San Francisco, California, 6 to 9 October 2005; 42nd, Boston, Massachusetts, USA, 30 September to 3 October 2004 (searched on 18 March 2008)
‐ Interscience Conference on Antimicrobial Agents and Chemotherapy: 46th, San Francisco, California, 27 to 30 September 2006; 45th, Washington DC, USA, 16 to 19 December 2005; 44th, Washington DC, USA, 30 October to 2 November, 2004 (searched on 18 March 2008)
‐ European Congress of Clinical Microbiology and Infectious Diseases: 16th, Nice, France, 1 to 4 April 2006; 15th, 2 to 5 April 2005 (searched on 18 March 2008)
‐ International Congress on Infectious Diseases: 12th, Lisbon, Portugal, 15 to 18 June 2006; 11th, Cancun, Mexico, 4 to 7 March 2004 (searched on 18 March 2008)
‐ Annual Meeting of The European Society for Paediatric Infectious Disease: 24th, Basel, Switzerland, 3 to 5 May 2006 (searched on 18 March 2008)
‐ Western Pacific Congress of Chemotherapy and Infectious Diseases: 10th, Fukuoka, Japan, 3 to 6 December 2006 (searched on 18 March 2008)
‐ European Congress of Chemotherapy and Infection: 8th, Budapest, Hungary, 25 to 28 October 2006 (searched on 18 March 2008)

Organizations

‐ Liverpool School of Tropical Medicine (contacted on 11 April 2007)
‐ World Health Organization (contacted on 17 March 2008)
‐ American Society of Tropical Medicine and Hygiene (contacted on 15 April 2007)
‐ International Society of Tropical Pediatrics (contacted on 15 April 2007)
‐ South East Asian Ministers Education Organization (SEAMEO) TROPMED Network (contacted on 17 March 2008)
‐ International Center for Diarrhoeal Disease Research in Bangladesh (contacted on 21 April 2007)

Pharmaceutical companies

‐ Goldshield Pharmaceuticals Ltd (tetracycline, Deteclo; chloramphenicol, Chloromycetin) ‐ contacted on 17 March 2008
‐ Chemidex (ampicillin, Penbritin) ‐ contacted on 17 March 2008
‐ GlaxoSmithKline (co‐trimoxazole, Septrin) ‐ contacted on 17 March 2008
‐ Merck Sharp & Dohme Ltd (norfloxacin, Utinor) ‐ contacted on 17 March 2008
‐ Bayer (ciprofloxacin, Ciproxin) ‐ contacted on 20 April 2007
‐ Aventis Pharma (ofloxacin, Tarivid) ‐ contacted on 15 April 2007
‐ Pfizer (azithromycin, Zithromax) ‐ contacted on 17 March 2008
‐ Roche (ceftriaxone, Rocephin) ‐ contacted on 20 April 2007
‐ Rosemont Pharmaceuticals Ltd (nalidixic acid, Uriben) ‐ contacted on 13 April 2007
‐ Salix Pharmaceuticals (rifaximin, Xifaxan) ‐ contacted on 17 March 2008
‐ Rhone‐Poulenc Rorer (cefixime, Suprax) ‐ contacted on 17 March 2008
‐ LEO pharma (pivmecillinam, Selexid) ‐ contacted on 17 March 2008

Figuras y tablas -
Table 3. Search strategy: proceedings, organizations, and pharmaceutical companies
Table 4. Sensitivity patterns of the Shigella isolates reported in included trials

Study ID

Group 1

Group 2

Group 3

Alam 1994

Pivmecillinam group:

All were sensitive to pivmecillinam

Nalidixic acid sensitivity not reported

Nalidixic acid group:

All were sensitive to pivmecillinam

26/37, 45%, were sensitive to nalidixic acid

Nil

Bennish 1990

Ciprofloxacin group:

All were sensitive to ciprofloxacin; 34/60, 56.6%, were sensitive to ampicillin

Ampicillin group:

All were sensitive to ciprofloxacin; 26/61, 42.6%, were sensitive to ampicillin.

Nil

Bibile 1961

This is a 4‐armed trial with sulphadimidine, sulpha methoxy pyridazine, Strepto triad, and tetracycline in each group respectively

Sensitivity patterns not reported for any group

Dutta 1995

Furazolidone and nalidixic acid

Sensitivity patterns not reported for any group

Gotuzzo 1989

Cotrimoxazole group:

27/32, 84%, were sensitive to cotrimoxazole; all were sensitive to norfloxacin

Norfloxacin group:

26/30, 86%, were sensitive to cotrimoxazole; all were sensitive to norfloxacin

Nil

Haltalin 1973

Nalidixic acid group:

All were sensitive to nalidixic acid; ampicillin sensitivity not reported.

Ampicillin group:

All were sensitive to ampicillin; nalidixic acid sensitivity not reported

Nil

Islam 1994

Nalidixic acid group:

26/37, 70%, were sensitive to nalidixic acid; all were sensitive to gentamicin

Oral gentamicin:

Nalidixic acid sensitivity not reported; all were sensitive to gentamicin

Nil

Kabir 1986

Ceftriaxone group:

All were sensitive to ceftriaxone; all were sensitive to ampicillin

Ampicillin group:

All were sensitive to ceftriaxone; 24/30, 80%, were sensitive to ampicillin

Placebo:

All were sensitive to ceftriaxone; 28/30, 93%, were sensitive to ampicillin

Khan 1997a

Azithromycin group:

All were sensitive to both antibiotics

Ciprofloxacin group:

All were sensitive to both antibiotics

Nil

Leibovitz 2000

Ciprofloxacin group:

All were sensitive to both antibiotics

Ceftriaxone group:

All were sensitive to both antibiotics

Nil

Nelson 1976a

Cotrimoxazole group:

All were sensitive to cotrimoxazole; 9/14, 64%, were sensitive to ampicillin

Ampicillin group:

All were sensitive to cotrimoxazole 10/14, 71%, were sensitive to ampicillin

Nil

Prado 1993

Cotrimoxazole group;

24/30, 80%, were sensitive to cotrimoxazole; 25/30, 83.3%, were sensitive to pivmecillinam

Pivmecillinam group:

23/29, 79.3%, were sensitive to cotrimoxazole; 26/29, 89.7%, were sensitive to pivmecillinam

Nil

Rodriguez 1989

3‐armed trial with furazolidone, cotrimoxazole and a control (no antimicrobials) respectively

Sensitivity patterns not reported for any group

Nil

Salam 1988

Nalidixic acid group:

All were sensitive to nalidixic acid; ampicillin sensitivity not reported

Ampicillin group:

All were sensitive to nalidixic acid; 25/40, 62.5%, were sensitive to ampicillin

Nil

Salam 1998

Ciprofloxacin group:

All were sensitive to ciprofloxacin; 58/60, 96.7%, were sensitive to pivmecillinam

Pivmecillinam group:

All were sensitive to ciprofloxacin; 57/60, 95%, were sensitive to pivmecillinam

Nil

Shanks 1999

Azithromycin and ciprofloxacin

Sensitivity patterns not reported for any group

Nil

Sensitivity patterns not reported by 4 trials (Bibile 1961; Rodriguez 1989; Dutta 1995; Shanks 1999).

Figuras y tablas -
Table 4. Sensitivity patterns of the Shigella isolates reported in included trials
Comparison 1. Antibiotic versus no drug or placebo

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea on follow up Show forest plot

1

Risk Ratio (M‐H, Fixed, 95% CI)

Subtotals only

1.1 Furazolidone versus no drug

1

73

Risk Ratio (M‐H, Fixed, 95% CI)

0.21 [0.09, 0.48]

1.2 Cotrimoxazole versus no drug

1

76

Risk Ratio (M‐H, Fixed, 95% CI)

0.30 [0.15, 0.59]

2 Time to cessation of fever (in days) Show forest plot

1

Mean Difference (IV, Fixed, 95% CI)

Subtotals only

2.1 Ceftriaxone (IV) versus placebo

1

64

Mean Difference (IV, Fixed, 95% CI)

‐1.20 [‐2.20, ‐0.20]

2.2 Ampicillin (IV) versus placebo

1

60

Mean Difference (IV, Fixed, 95% CI)

‐1.50 [‐2.41, ‐0.59]

3 Time to cessation of diarrhoea (in days) Show forest plot

1

Mean Difference (IV, Fixed, 95% CI)

Subtotals only

3.1 Ceftriaxone (IV) versus placebo

1

64

Mean Difference (IV, Fixed, 95% CI)

‐0.30 [‐1.41, 0.81]

3.2 Ampicillin (IV) versus placebo

1

60

Mean Difference (IV, Fixed, 95% CI)

‐0.30 [‐1.37, 0.77]

4 Time to cessation of blood in stools (in days) Show forest plot

1

Mean Difference (IV, Fixed, 95% CI)

Subtotals only

4.1 Ceftriaxone (IV) versus placebo

1

64

Mean Difference (IV, Fixed, 95% CI)

‐0.30 [‐1.43, 0.83]

4.2 Ampicillin (IV) versus placebo

1

60

Mean Difference (IV, Fixed, 95% CI)

‐0.30 [‐1.41, 0.81]

5 Other adverse events Show forest plot

1

94

Risk Ratio (M‐H, Fixed, 95% CI)

1.43 [0.06, 34.13]

Figuras y tablas -
Comparison 1. Antibiotic versus no drug or placebo
Comparison 2. Fluoroquinolones versus beta‐lactams

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea on follow up Show forest plot

6

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 All trials

6

686

Risk Ratio (M‐H, Random, 95% CI)

1.03 [0.45, 2.37]

1.2 Adults (subgroup)

1

127

Risk Ratio (M‐H, Random, 95% CI)

0.14 [0.04, 0.44]

1.3 Children (subgroup)

5

559

Risk Ratio (M‐H, Random, 95% CI)

1.46 [0.64, 3.34]

1.4 Confirmed Shigella > 90% (subgroup)

2

257

Risk Ratio (M‐H, Random, 95% CI)

4.68 [1.74, 12.59]

1.5 Confirmed Shigella < 90% (subgroup)

4

429

Risk Ratio (M‐H, Random, 95% CI)

0.65 [0.29, 1.42]

2 Fever at follow up Show forest plot

2

191

Risk Ratio (M‐H, Random, 95% CI)

0.87 [0.25, 3.06]

3 Relapse Show forest plot

3

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 All trials

3

357

Risk Ratio (M‐H, Random, 95% CI)

0.91 [0.11, 7.55]

3.2 Confirmed Shigella > 90% (subgroup)

2

237

Risk Ratio (M‐H, Random, 95% CI)

0.91 [0.11, 7.55]

3.3 Confirmed Shigella < 90% (subgroup)

1

120

Risk Ratio (M‐H, Random, 95% CI)

0.0 [0.0, 0.0]

4 Bacteriological failure Show forest plot

5

1350

Risk Ratio (M‐H, Random, 95% CI)

0.74 [0.50, 1.11]

4.1 All trials

5

450

Risk Ratio (M‐H, Random, 95% CI)

0.73 [0.33, 1.62]

4.2 Adults (subgroup)

1

127

Risk Ratio (M‐H, Random, 95% CI)

0.28 [0.08, 0.95]

4.3 Children (subgroup)

4

323

Risk Ratio (M‐H, Random, 95% CI)

0.95 [0.43, 2.09]

4.4 Confirmed Shigella > 90% (subgroup)

1

36

Risk Ratio (M‐H, Random, 95% CI)

5.56 [0.29, 108.16]

4.5 Confirmed Shigella < 90% (subgroup)

4

414

Risk Ratio (M‐H, Random, 95% CI)

0.65 [0.29, 1.43]

5 Development of severe complications Show forest plot

2

90

Risk Ratio (M‐H, Fixed, 95% CI)

0.89 [0.28, 2.85]

6 Serious adverse events Show forest plot

1

221

Risk Ratio (M‐H, Fixed, 95% CI)

10.90 [0.61, 194.82]

7 Adverse events leading to discontinuation of treatment Show forest plot

1

127

Risk Ratio (M‐H, Fixed, 95% CI)

1.02 [0.27, 3.89]

8 Other adverse events Show forest plot

4

570

Risk Ratio (M‐H, Fixed, 95% CI)

1.03 [0.77, 1.39]

Figuras y tablas -
Comparison 2. Fluoroquinolones versus beta‐lactams
Comparison 3. Fluoroquinolones versus macrolides

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea on follow up Show forest plot

2

189

Risk Ratio (M‐H, Fixed, 95% CI)

0.6 [0.24, 1.49]

2 Fever at follow up Show forest plot

2

189

Risk Ratio (M‐H, Fixed, 95% CI)

0.33 [0.08, 1.35]

3 Time to cessation of blood in stools Show forest plot

1

113

Mean Difference (IV, Fixed, 95% CI)

‐0.20 [‐0.68, 0.28]

4 Bacteriological failure Show forest plot

1

76

Risk Ratio (M‐H, Fixed, 95% CI)

0.33 [0.07, 1.55]

5 Other adverse events Show forest plot

1

76

Risk Ratio (M‐H, Fixed, 95% CI)

1.33 [0.32, 5.56]

Figuras y tablas -
Comparison 3. Fluoroquinolones versus macrolides
Comparison 4. Cotrimoxazole versus beta‐lactams

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea on follow up Show forest plot

2

89

Risk Ratio (M‐H, Fixed, 95% CI)

0.59 [0.23, 1.49]

2 Bacteriological failure Show forest plot

1

28

Risk Ratio (M‐H, Fixed, 95% CI)

0.75 [0.20, 2.75]

3 Time to cessation of diarrhoea (hours) Show forest plot

1

61

Mean Difference (IV, Fixed, 95% CI)

‐0.20 [‐15.10, 14.70]

4 Time to cessation of fever (hours) Show forest plot

1

61

Mean Difference (IV, Fixed, 95% CI)

5.90 [‐5.30, 17.10]

5 Time to cessation of visible blood in stools Show forest plot

1

61

Mean Difference (IV, Fixed, 95% CI)

2.80 [‐12.71, 18.31]

6 Other adverse events Show forest plot

2

89

Risk Ratio (M‐H, Fixed, 95% CI)

0.81 [0.27, 2.45]

Figuras y tablas -
Comparison 4. Cotrimoxazole versus beta‐lactams
Comparison 5. Cotrimoxazole versus fluoroquinolones (norfloxacin)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Bacteriological failure Show forest plot

1

62

Risk Ratio (M‐H, Fixed, 95% CI)

1.69 [0.64, 4.47]

2 Other adverse events Show forest plot

1

62

Risk Ratio (M‐H, Fixed, 95% CI)

2.82 [0.12, 66.62]

Figuras y tablas -
Comparison 5. Cotrimoxazole versus fluoroquinolones (norfloxacin)
Comparison 6. Cotrimoxazole versus furazolidone

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea on follow up Show forest plot

1

101

Risk Ratio (M‐H, Fixed, 95% CI)

0.71 [0.27, 1.84]

Figuras y tablas -
Comparison 6. Cotrimoxazole versus furazolidone
Comparison 7. Oral gentamicin versus nalidixic acid

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea at follow up Show forest plot

1

79

Risk Ratio (M‐H, Fixed, 95% CI)

1.71 [0.98, 2.97]

2 Fever at follow up Show forest plot

1

79

Risk Ratio (M‐H, Fixed, 95% CI)

2.37 [1.11, 5.07]

3 Bacteriological relapse Show forest plot

1

79

Risk Ratio (M‐H, Fixed, 95% CI)

1.95 [0.64, 5.95]

4 Bacteriological failure Show forest plot

1

79

Risk Ratio (M‐H, Fixed, 95% CI)

2.1 [1.29, 3.42]

Figuras y tablas -
Comparison 7. Oral gentamicin versus nalidixic acid
Comparison 8. Sulphonamides versus tetracycline

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Diarrhoea at follow up Show forest plot

1

60

Risk Ratio (M‐H, Fixed, 95% CI)

7.68 [0.46, 128.12]

2 Bacteriological failure Show forest plot

1

60

Risk Ratio (M‐H, Fixed, 95% CI)

11.78 [0.73, 190.30]

Figuras y tablas -
Comparison 8. Sulphonamides versus tetracycline