Local variation in childhood diarrheal morbidity and mortality in Africa, 2000-2015

BACKGROUND: Diarrheal diseases are the third leading cause of morbidity and mortality in children under 5 in Africa, responsible for an estimated 30,000,000 (95% Uncertainty Interval [UI], 27,000,000 - 33,000,000) severe cases and 330,000 (95% UI, 270,000 - 380,000) deaths in 2015. Developing targeted approaches to combat this burden is hampered by the lack of comprehensive, fine-scale diarrhea estimates between and within countries. METHODS: Annual estimates of diarrheal prevalence, incidence, and mortality were produced with high geographic detail (5-km2) across Africa from 2000 to 2015. Estimates were created using Bayesian geostatistical techniques, and were calibrated to the results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016. RESULTS: The results revealed geographic inequality in diarrhea risk in Africa. Of the estimated 330,000 childhood deaths attributable to diarrhea in 2015, over 50% occurred in only 55 (of the 782) first administrative subdivisions. In 2015, mortality rates between first administrative subdivisions in Nigeria exhibited six-fold differences. The case fatality ratio is highly variable at the national level across Africa, with the highest values observed in Lesotho, Mali, Benin, and Nigeria. CONCLUSIONS: Our findings show concentrated areas of morbidity and mortality associated with diarrhea across countries with consistently high burden as well as countries that experienced considerable national-level improvements. In the era of precision public health, the distribution of limited resources can be optimized with proven interventions, targeted at locations most likely to have a high impact, reducing the avertable burden of diarrheal diseases.