Schistosomiasis (Bilharzia)

Schistosomiasis, also known as bilharzia, is a major water-borne trematode (fluke) infection caused by Schistosoma species, with S. haematobium and S. mansoni being endemic in Zambia. This is a pivotal topic in the parasitology syllabus for tertiary health science students in Zambia, given the disease's local prevalence. The module explores the unique life cycle involving freshwater snail intermediate hosts, cercarial skin penetration, and the adult worms' residence in the venous plexuses of the bladder or intestines. Students will learn about the pathogenesis, which is primarily immune-mediated granuloma formation around eggs, leading to urinary tract pathology (hematuria, fibrosis) or hepatic/intestinal disease. Diagnostic methods include urine filtration for S. haematobium eggs and stool examination for S. mansoni, along with serological assays. The topic also covers treatment with praziquantel, control strategies focusing on snail control and improved sanitation, and their implementation within the Zambian context. Mastery of schistosomiasis is crucial for exams and for future healthcare professionals aiming to manage and prevent one of Zambia's most significant neglected tropical diseases.