Research News

The big four diarrhoeal pathogens

BMJ 2013; 346 doi: (Published 15 May 2013) Cite this as: BMJ 2013;346:f3110

Researchers have identified the four pathogens responsible for a large proportion of childhood diarrhoea in sub-Saharan Africa and south Asia. Rotavirus, Cryptosporidium, one pathotype of enterotoxigenic Escherichia coli, and Shigella were implicated in more than a half of all cases of moderate or severe diarrhoea in some countries, particularly in young infants and toddlers.

The researchers analysed stool samples from 9439 children with diarrhoea and more than 13 000 matched controls from the same communities in the Gambia, Mozambique, Mali, Kenya, India, Bangladesh, and Pakistan. In most sites, fewer than half the children had easy access to clean water. The odds of death within 60 days were eight times higher for children with diarrhoea than for controls (2% v 0.28%, odds ratio 8.5, 95% CI 5.8 to 12.5). Children with diarrhoea had significantly worse short term growth.

Rotavirus was the dominant pathogen in children under 2 years across all sites in the study. These communities urgently need rotavirus vaccines, says a linked comment (doi:10.1016/S0140-6736(13)60941-1). Licensed vaccines may not be fully effective in poor areas, but even limited protection could have a big impact on public health. Cryptosporidium was more of a surprise. We tend to associate this pathogen with immune compromise, but it seems to be an important cause of diarrhoea in general among children under 2 years, says the comment. We need to find out why, while we continue and expand large scale microbial surveillance.


Cite this as: BMJ 2013;346:f3110