Long Term School Based Deworming against Soil-Transmitted Helminths Also Benefits the Untreated Adult Population: Results from a Community-Wide Cross Sectional Survey

Abstract

Background. Soil-transmitted helminths (STH) are a public health problem in Kenya. The primary control strategy for these infections is preventive chemotherapy (PC) delivered through school based deworming (SBD) programs. The World Health Organization (WHO) recommends the inclusion of other at-risk groups in the PC. The untreated groups in endemic areas have been shown to act as reservoirs for STH transmission. Few field based studies have focused on the possible benefits of SBD to the untreated groups in the community. This study sought to determine the levels of STH among all age groups in a community where SBD has been going on for more than 10 years. Methods. This was a cross sectional study where 3,292 individuals, ranging from 2 to 98 years, were enrolled. Stool samples were analyzed using duplicate Kato Katz thick smear technique for presence of STH eggs. Statistical analysis was conducted using STATA software 14.0 (Stata corporation). Results. Out of the total 3,292 stool samples analyzed, only 13 were positive for any STH. Of these, 12 were infected with Trichuris trichiura and one case was of hookworm. There was no Ascaris lumbricoides infection detected. Of the 13 STH infections, seven of the infections were of school going age (6-18 years), 5 were of preschool age (<6 years), and one was of adult age group (18>). More male (61.5%) than female were infected with STH. Conclusion. This study shows very low prevalence of STH among all age groups in Mwea, suggesting that long term SBD may also be benefitting the untreated groups in the community and thus the potential to achieve STH elimination in such endemic areas.