Background: Traveller's diarrhoea is a syndrome frequently encountered in persons crossing an international boundary. Diarrhoea can lead to significant discomfort and interference with travel plans. Bacterial pathogens are a frequent cause of this syndrome. Several antibiotics have been tested for efficacy in reducing the duration and severity of the illness.
Objectives: The aims of this review were to assess the effects of antibiotics on traveller's diarrhoea in relation to duration of illness, severity of illness, and adverse effects of medications.
Search strategy: The Cochrane Collaboration Trials Register, MEDLINE, and EMBASE were searched. Additional trials were identified by hand searching. Content experts were contacted.
Selection criteria: All trials in any language in which travellers older than 5 years were randomly allocated to treatment for acute non-bloody diarrhoea with antibiotics and where the causative organism is not known at allocation.
Data collection and analysis: Two reviewers assessed trial quality and extracted data.
Main results: Twenty published studies met inclusion and quality criteria for inclusion. Twelve studies were placebo-controlled. A meta-analysis for the primary outcome was not feasible. All of the 10 trials reported a significant reduction in duration of diarrhoea in participants treated with antibiotics compared with placebo. Data from two trials demonstrated a small reduction for antibiotic treated patients in the number of unformed stools passed per each 24 hour period from randomisation up to 72 hours. Data from six trials demonstrated a greater number of participants being cured of diarrhoea by 72 hours (odds ratio [OR] 5. 9, 95% confidence interval [CI] 4.06 to 8.57). Data regarding side effects were available from five trials. There was wide variation in the prevalence of side effects reported in different trials. Persons taking antibiotics experienced more side effects than those taking placebo (OR 2.37, 95% CI 1.5 to 3.75).
Reviewer's conclusions: Antibiotic treatment is associated with shorter duration of diarrhoea but higher incidence of side-effects. Trials generally do not report duration of post-treatment diarrhoea using time-to-event analyses, and should do.