Water and sanitation factors associated with schistosomiasis and soil transmitted helminthiasis persistence in Rwanda

Schistosomiasis and soil transmitted helminthiases (STH) are still prevalent in Rwanda. We aimed to identify factors associated with the persistence of infection in selected sentinel sites that will be used to monitor the progress towards elimination. Infection prevalence and intensity were assessed using the Kato Katz (KK) and the Circulating Cathodic Antigen (CCA for schistosomiasis). Scooping and shedding were used to determine snail distribution and infectivity. Risk factors were collected through a structured questionnaire. Overall, the prevalence of STH and schistosomiasis on KK were 12.6% and 2.4% (higher on CCA) respectively. School aged children had significantly higher prevalence of infection except for Hookworm which was significantly higher among adults. Infection was significantly linked to the use of human excreta as fertilizers, the lack of clean water and poor quality toilets. Schistosomiasis distribution, higher in male participants compared to females, coincided with the geographical distribution of S. mansoni cercaria shedding. The findings highlight a significant contribution of agricultural practices and poor water/sanitation infrastructure on infection transmission, and call for a One Health (multi-sectoral collaboration) approach to enhance schistosomiasis and STH elimination in Rwanda. In addition, the correlation between infection and cercaria shedding emphasizes the potential benefits of snail surveillance in schistosomiasis hotspots.