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Schistosomiasis: an infectious disease also known as Bilharzia, Katayama Fever, and Snail Fever

Medical InBrief

Schistosoma Adult Haematobium or Adult Mansoni

by Richard Strongwater, MD, and Harish Moorjani, MD

Schistosomiasis (bilharzia) is an infection caused by a parasitic flatworm that lives in fresh water of the subtropics and tropics; the worms do not live in salt water or chlorinated swimming pools. It most commonly is seen in Africa, but it also occurs in parts of South America, the Caribbean, the Middle East, and Asia. These tiny worms (cercaria) will penetrate the skin during swimming or bathing in contaminated water or even paddling on a river. Once in the body, the worms grow and can migrate to the liver, bladder, kidneys, and bowel. The worms eventually lay eggs that leave the body via the urine or feces. If the eggs pass out of the body into water, they release larvae that grow inside freshwater snails. After a few weeks, the larvae can infect another human, completing the life cycle. More than 200-million people are infected worldwide.

Schistosomiasis, swim at your own risk


Read more about the signs and symptoms of schistosomiasis, diagnostic evaluations and differential diagnosis, as well as treatment options and prevention. members can get access to the PDF, non-members can pay $1.00 for the PDF.

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