Human Bertiellosis in Sri Lanka's Dry Zone: A Rare Documented Case Report.

Bertiella studeri is a zoonotic cestode that infects humans through accidental ingestion of cysticercoid-infected oribatid mites, with non-human primates serving as definitive hosts. Human bertiellosis remains rare and underdiagnosed, particularly in regions where primates interact closely with human populations. We report a confirmed case of B. studeri infection in a 41-year-old woman from Anuradhapura District in Sri Lanka's dry zone. The patient presented with a six-week history of nonspecific abdominal symptoms, weight loss, and passage of whitish, mobile segments in her stool. Microscopic examination confirmed the presence of characteristic Bertiella eggs and proglottids; however, molecular confirmation was not performed due to the unavailability of appropriate testing facilities. She was successfully treated with praziquantel, resulting in complete symptom resolution and parasite clearance. This case expands the known geographic distribution of human bertiellosis in Sri Lanka beyond the previously reported wet zone and highlights diagnostic challenges in resource-limited settings. The case highlights One Health concerns regarding increasing human-primate contact, limited access to anti-cestodal medications, and the need for improved environmental hygiene in endemic areas.