Surveys for Schistosomiasis and Soil Transmitted Helminths in Luangwa, Kalabo and Serenje Districts of Zambia

Abstract

Background: Earlier publications have indicated that human infections with schistosomes and soil transmitted helminths (STH) are widespread in Zambia. Despite being classified as a moderate endemic country for these infections, and a recent modelling study suggesting an average schistosomiasis prevalence of 26% among school aged children, there is a lack of published data on the present occurrence and distribution of these infections.
Design: Cross sectional surveys for schistosomiasis and STH were carried out among individuals aged 4-20 years at three sites in Luangwa, Kalabo and Serenje districts, as an added component to comprehensive studies on lymphatic filariasis. Urine samples were examined for hematuria and Schistosoma haematobium ova using the Nuclepore filtration technique. Stool samples were examined for S. mansoni and STH ova using the Kato- Katz technique.
Results: The prevalence of S. haematobium was generally low, with the Serenje site recording the highest of 3.0%. S. mansoni was only seen at the Kalabo site, which had a moderate prevalence of 37.5%. Hookworm infections were relatively common at all three sites, with prevalences ranging from 12.1 to 35.0%. Other more rare STH infections noted were Ascaris lumbricoides, Hymenolepis nana and Enterobius vermicularis.
Conclusions: The study confirmed that schistosomiasis and STH infections were endemic at the study sites, but also suggested that the prevalences had declined compared to earlier reports. There is need for more surveys to be carried out to assess the current distribution and prevalence of these infections to provide guidance for implementation of mass drug administration for their control.