Basic Sanitation and Schistosomiasis Incidence in Rural Municipalities of Ceará: A 10-Year Comparative Analysis

Schistosomiasis, caused by Schistosoma mansoni , is a parasitic disease linked to exposure to contaminated water and lack of basic sanitation. Despite a reduction in cases in recent decades, the disease remains endemic in rural and peripheral areas of Ceará. In this context, outlining the epidemiological profile of schistosomiasis between 2015 and 2025 is important to identify vulnerable areas, evaluate sanitation policies, and understand transmission dynamics over time. Comparative ecological study using secondary data from DATASUS, SNIS (sewage coverage), and IBGE population projections. Mean annual schistosomiasis incidence per municipality was calculated (cases per thousand inhabitants) and correlated with sanitation coverage indices. Between January 2015 and June 2025, 31 schistosomiasis cases were confirmed in Ceará. An inverse relationship was observed between basic sanitation coverage and disease incidence. Viçosa do Ceará (22% coverage), Guaiúba (30%), Quixeramobim (18%), Missão Velha (27%), and Icó (43%) recorded one to two cases each, with incidences of 0.01–0.04 cases/1,000 inhabitants. In contrast, Forquilha (76%), Jaguaribara (81%), and Penaforte (84%) reported no cases, highlighting the protective effect of better sanitation coverage. Fortaleza recorded five cases between 2015 and 2022, with coverage ranging from 54% to 71%, but with low incidence (0.0004 cases/1,000 inhabitants), reflecting sanitation expansion impact. Sobral, predominantly urban with coverage increasing from 53% (2015) to 82% (2025), reported only one case in 2015 (0.004 cases/1,000 inhabitants). Increased sewage coverage in Ceará likely contributed to the reduction of schistosomiasis cases during the analyzed period. Municipalities with greater sanitation access showed null or very low incidence, demonstrating the impact of this infrastructure on interrupting the disease cycle. Underreporting and lack of control for factors such as presence of snail vectors and contact with contaminated water may be study limitations. For sustainable schistosomiasis control, continued and expanded investment in basic sanitation is recommended, combined with active surveillance, environmental control, and educational actions, especially in rural and vulnerable areas with epidemiological challenges.