Cochrane Collaboration researchers conducted a review of the effects of antibiotics for treating people with cholera. After searching for relevant trials, they included 39 randomized controlled trials enrolling 4623 people with cholera.
What is cholera and how might antibiotics work
Cholera is a form of severe watery diarrhoea, which spreads from person to person through food and water contaminated with the bacterium Vibrio cholerae. Cholera is common in places with poor water and sanitation, and sometimes causes large epidemics with thousands of people falling ill.
Cholera can cause severe dehydration and death, so the main treatment is to give fluids and salt either orally as oral rehydration salts, or by injection. By clearing the bacteria earlier than the patients own immune system, antibiotics could reduce the duration and severity of the illness, and reduce onward transmission to other people.
What the research says
Antibiotic treatment shortened the duration of diarrhoea by about one and a half days (the normal duration is between three and four days), and reduced the total amount of diarrhoea fluid by half. Consequently, the need for rehydration fluids was also reduced by almost half.
Antibiotic treatment also shortened the period of time where the patient remains contagious by reducing the duration of excretion of Vibrio cholerae in the diarrhoea.
The benefits of antibiotics were seen in trials recruiting only people with severe dehydration, and in those recruiting people with mixed levels of dehydration.
Tetracycline or azithromycin appear more effective than some of the other antibiotics tested, but the choice of which antibiotic to use will depend on local drug resistance.