Association of Animal Ownership and Short-Term Rainfall Events with under-5 Diarrhea Prevalence in sub-Saharan Africa

According to the 2021 Global Burden of Diseases Study, diarrhea contributed to an estimated 340,429 deaths among children younger than five years old and an estimated 245,966 deaths in sub-Saharan Africa specifically. Some efforts to reduce the burden of diarrhea in Africa have focused on animal fecal contamination, particularly during extreme precipitation events (EPEs). A focus has been the concentration-dilution hypothesis, which is centered on EPEs immediately following dry periods. The source population included 12,007,303 individuals from 172 surveys between 1990 and 2022. We conducted descriptive analyses and modeled associations between EPEs and diarrheal prevalence on a study population that included 413,576 children under five whose families owned livestock. EPEs that occurred 15-21 days and 22-28 days before the surveys were administered showed a statistically significant increase in diarrhea prevalence compared to EPEs not occurring during those time periods. We utilized a mixed-effects Poisson regression model with a log link to assess the association between individual animal species and the two-week prevalence of diarrhea among children under the age of 5. There was a decreased two-week prevalence of diarrhea among families that own horses or donkeys and were exposed to an EPE (PR: 0.87, 95% CI: 0.83-0.92, p-value: <0.001), but an increased two-week prevalence among families that own pigs and experienced an EPE (PR: 1.15, 95% CI: 1.03-1.29, p-value: 0.01) compared to families that did not own these animals and did not experience an EPE. The results from this study further illustrate the complex relationship between the occurrence of EPEs and the prevalence of diarrhea. Future studies can refine the use of EPEs in their analysis to look at the occurrence of EPEs immediately after local droughts. Animal husbandry practices are also vital to improve the understanding of their role in diarrheal outcomes for the family.