Dynamics of soil-transmitted helminths under mass drug administration among school children in Kumi Municipality, Eastern Uganda

Abstract

Soil-transmitted helminthiases (STH) are neglected tropical diseases of public health significance globally, WHO recommended periodic mass drug administration (MDA) in endemic areas. In 2003, Uganda initiated MDA but constant exposure post-treatment negates STH effective control and elimination. This study investigated STH dynamics post-treatment and associated risk factors. A cross-sectional study was conducted using questionnaires and interview guides to get data on risk factors and the Kato-Katz technique for STH diagnosis. A total of 403 children were grouped into two deworming regimens; 200 and 203 pupils were treated using Mebendazole every 3 and 6 months, respectively. Eggs for only hookworms were identified throughout the study, reflecting low STH species richness. All the hookworm infestations pre-and post-treatment were of low-intensity category. The overall pre-treatment hookworm prevalence was 9.9% (CI: 6.1–13.7). Across treatment groups, prevalence generally decreased at final treatment. There was a significant overall infestation-reduction rate of 74.5% (T-test, p = 0.046) among the 3-monthly group compared to 31.9% for the 6-monthly group. At 6 months post-treatment, both cure rate (69.2%) and infestation-reduction rate (74.5%) among the 3-monthly group were more than twice for the 6-monthly group (34.6% and 31.9% respectively). Risk factors associated with STH reinfestation among school-age children included low STH awareness, absence of a household latrine, and poor school hygiene conditions. In conclusion, deworming 3-monthly was more effective than biannually despite rapid reinfestation being a serious challenge. Sanitation and health education interventions should be emphasised to sustain the gains of school-based deworming.