“What can you tell me about diarrhea in your country?”
It should have been a simple question for an official at Mali’s Ministry of Health, but when researchers backed by the Bill & Melinda Gates Foundation first asked it of Dr. Samba Sow a few years ago, his immediate thought, he said, was, “Not much.”
International organizations like UNICEF and the World Health Organization estimate diarrhea is the second most common cause of death for children under 5 in Mali. But, on a local level, the only hard data Sow had to work with at the time was an annual report of the number of children who checked into hospitals showing symptoms of diarrhea.
“If I was just looking at the numbers and considering nothing else, I didn’t know enough to say for sure that we even had a problem,” he said by phone.
The Ministry of Health agreed to make Mali one of seven sites in the Global Enterics Multi-center Study (GEMS), the largest and most in-depth research project examining diarrheal disease in the developing world to date. Sow used the resulting statistics to secure funding for a vaccine against diarrheal disease — among other things. But the findings, recently published in The Lancet, aren’t just helpful to Mali. They’re illuminating for the global health community as a whole.
Diarrhea is a tough problem to solve because it is caused by more than 40 different viruses, bacteria and parasites. GEMS found, though, that just four pathogens are responsible for the majority of moderate-to-severe diarrhea cases. The virus that topped the list — rotavirus — has long been regarded as a formidable foe. But the second most common contributor to diarrheal disease was a parasite called cryptosporidium, which has, up to this point, been considered more of a nuisance than a lethal threat to all but the severely immune compromised. While there is a vaccine for rotavirus, a weapon against cryptosporidium isn’t even in the pipeline.