Assessment of Schistosoma mansoni infection on Nkombo Island, Rwanda

In Rwanda, Neglected Tropical Disease (NTD) control program was established in 2007 and initial mapping was completed in 2008 before starting mass drug administration (MDA) against schistosomiasis (S. mansoni) and soil-transmitted helminths (STHs). This work presents data of S. mansoni in area which was initially omitted from MDA based on initial mapping. In 2011, children from Nkombo Island located in a district previously classified as low endemic for S. mansoni, were screened for S. mansoni (and STHs) using Kato-Katz method. Prevalence of S. mansoni (and STHs) was measured. In total 331 school children aged 10-19 years were involved. Prevalence of S. mansoni was found to be 62.1%, ranging from 28.6% to 77.9% across schools. Prevalence of S. mansoni in school children of Nkombo was found high. Regular MDA with praziquantel to all school-aged children and adults of the Island is warranted. For effective control, current school-based mapping strategy (WHO guidelines) is insufficient to identify all hot spots, should therefore be revised or supplemented with localized community-based surveys in areas where infection is likely to occur but available data do not indicate MDA.