Interventions for the control of diarrhoeal diseases among young children: chemoprophylaxis.

A number of situations place young children at increased risk of diarrhoea. Among these, the best documented in developing countries is contact with a diarrhoea case in a family or household. The most common application of chemoprophylaxis in developing countries is to prevent cholera or shigellosis among household contacts of known cases. There is little evidence that chemoprophylaxis is effective in reducing diarrhoea morbidity and mortality, except perhaps in travellers. Theoretical calculations in this paper (based on optimistic assumptions) suggest that chemoprophylaxis of household contacts of known cholera cases in Bangladesh might reduce overall diarrhoea incidence rates in children under 5 years of age by 0.02-0.06% and diarrhoea mortality rates by 0.4-1.2%. Chemoprophylaxis of household contacts of known shigellosis cases might reduce overall diarrhoea incidence rates by 0.15-0.35% and diarrhoea mortality rates by 0.3-0.7% in the same age group. The correct identification of index cases of cholera and shigellosis, followed by the rapid distribution of drugs to their household contacts, requires skills and resources that are scarce in the developing countries. Chemoprophylaxis can contribute to the widespread emergence and dissemination of antimicrobial resistance. The available evidence suggests that chemoprophylaxis is not feasible in many settings and that, even if successfully implemented, it is not a cost-effective intervention for national diarrhoeal diseases control programmes.