Hookworm Infection and Baboon Zoonosis in Schoolchildren in Bunda District, Tanzania

Abstract

Hookworm infection poses a major public health issue in developing countries, and is one of the most important parasitic infections in Sub-Saharan Africa, plaguing high-risk groups such as schoolchildren and pregnant women. Empirical and probability modeling studies suggest a high prevalence of soil-transmitted helminthes (STH), such as hookworm, in Tanzania. Furthermore, the transmission of these helminthes to humans, from domestic as well as wild animals, has been implied and documented. This study was designed to measure the prevalence of hookworm infection among a group of schoolchildren living in the villages surrounding the Serengeti in Tanzania, in order to estimate infection/reinfection rates and investigate some of the factors that might contribute to continued levels of infection or reinfection with hookworm, namely the zoonotic significance of baboon troops. The prevalence of hookworm infection in schoolchildren was relatively low, whereas the prevalence of hookworm infection in baboons, living in close proximity, was moderately high. Despite these differences, a Pearson’s R-correlation test for the relationship between the prevalence of hookworm infection in schoolchildren and the prevalence of infection in baboons provided an r-value of 0.914 (95% CI = 0.396-0.991). Additionally, Pearson’s R-correlation tests for the relationship between the intensities of hookworm infection of schoolchildren and the intensities of infection in baboons, using both geometric and arithmetic mean eggs per gram (epg), provided r-values of 0.722 (95% CI =-0.216-0.967) and 0.793 (95%CI= -0.0516-0.976), respectively. Linear-regression fit models using these variables also showed positive trends. These strong, positive correlations suggest that baboons are of substantial zoonotic significance, and may indeed be transmitting hookworm infections to their human counterparts. In light of these findings, it is safe to propose that the treatment of non-human primates, such as baboons, should be included in anti-hookworm health initiatives along with extant disease control initiatives in Tanzania, and elsewhere.