The Global Enteric Multicenter Study, GEMS, an extensive, ground-breaking study in the developing world, has come up with the clearest picture yet of the most common causes and impact of diarrheal diseases — the second leading killer of young children globally after pneumonia.

The study reveals that while the germs, rotavirus, Shigella and E Coli are notorious for causing the majority of moderate-to-severe diarrhoea cases, Cryptosporidiumand Aeromonas are two pathogens that have been underestimated for their ability to cause the disease.

 “When it comes to childhood disease and deaths, diarrhoea remains a leading culprit,” said Dr Anita Zaidi, principal investigator at the Pakistan study site of GEMS and Chair, Department of Paediatrics, Aga Khan University.”

The three-year-long GEMS enrolled more than 20,000 children from seven sites across Asia and Africa; in Pakistan, the study was conducted in four peri-urban field sites in Bin Qasim Town in Karachi.

Dr Zaidi said when we collected a stool sample from a sick child, we also collected one from a well child for comparison. Each stool sample was tested for 40 different diarrhoea causing pathogens. Many of these bugs were being tested for the first time in Pakistan."

Similar to other sites in the study, AKU researchers found that rotavirus, Shigella, Cryptosporidium and Enterotoxigenic E. Coli (ETEC) were the leading causes of diarrheal disease; prior to GEMS, Cryptosporidium was not considered a major cause of the disease.