Schistosoma mansoni Infection and Hepatic Morbidity in Agricultural Communities of Plateau State: An Ultrasound-Based Study

Schistosoma mansoni causes progressive hepatic and splenic pathology that often develops silently over years of chronic exposure, and ultrasound-based morbidity assessment provides objective staging data beyond egg-count diagnostics. This analytical study assessed S. mansoni infection intensity and associated hepatic morbidity in agricultural communities of Plateau State, North Central Nigeria. A total of 320 adults from four farming communities with confirmed S. mansoni endemicity were enrolled. Stool samples were examined using the Kato-Katz method for egg counts. Abdominal ultrasound was performed on all participants by a trained sonographer using the WHO-standardised protocol for schistosomal morbidity assessment. Hepatic periportal fibrosis was graded from A (none) to F (severe) on the Niamey protocol scale. S. mansoni prevalence was 41.9 percent, with heavy intensity infection in 18.8 percent of positive cases. Periportal fibrosis of grade C or above was detected in 22.8 percent of infected adults, with a significant dose-response relationship with cumulative egg burden. Splenomegaly was documented in 14.1 percent of participants with heavy infection. Males aged 35 to 55 years with over 15 years of farming showed the most advanced hepatic staging. The study provides the first systematic ultrasound-based hepatic morbidity mapping for S. mansoni in Plateau State and supports integration of morbidity monitoring into state control programme activities. Keywords: Schistosoma mansoni, hepatic morbidity, periportal fibrosis, ultrasound, Plateau State.