Integration of Strongyloides Stercoralis Public Health Control Into the Soil-transmitted Helminths Control Programme in Rwanda - The SCAN Study

The World Health Organization (WHO) recently issued guideline for the public health control of Strongyloides stercoralis in endemic areas. We aimed to evaluate the feasibility of implementing the WHO recommendations in Rwanda, specifically to intergrate the activities for the public health control of strongyloidiasis in the ongoing national programme for the control of the other soil-transmitted helminths and schistosomiasis, that has been in place for several years. As additional objective, we aimed to estimate the prevalence of S. stercoralis in two districts of Rwanda (Gisagara and Rubavu). To evaluate the feasibility, we asked lab technicians to evaluate challenges emerged during the implementation of the laboratory procedures with a structured questionnaire. Also, we evaluated the costs needed to perform these tests. We estimated the prevalence of S. stercoralis by calculating the number of positive cases out of all people tested. The lab technicians participated to a training session, where they were taught the S. stercoralis-specific lab techniques, and to a two-day pilot study where they could practice. The tests used were parasitological techniques (agar stool culture, (APC) and Baermann method) and an antibody rapid diagnostic test (RDT). Duration of training, with a specific focus on larvae differentiation, was identified as pivotal for a successful implementation of the parasitological techniques. The use of the RDT was instead considered easy to apply at all evaluation time points. Raw cost (i.e. not including staff salaries and transport costs) of materials and equipment was below 2 euros/test for each assay. In both districts, Strongyloides prevalence was below the threshold recommended by the WHO for the implementation of mass treatment, hence this aspect was not evaluated.