A parasitic disease, also called bilharzia, that spreads in contaminated water containing certain species of snails.

Fluke infection causes schistosomiasis, which can be mild or serious. The parasites pass from human stool or urine into warm waterways containing certain types of freshwater snails. After infecting the snails, the parasites return to the water. There, they can spread to people who swim, bathe or wash in the water.

Symptoms depend on which species of parasite causes the infection. Fluke species live in different places around the world. Some infections may cause a rash or itchy skin. Other infections cause illness that ranges from liver problems to bladder cancer. Long-term or repeat infection in children may lead to malnutrition or learning delays.

Medicines to kill the parasite treat schistosomiasis.