Schistosomiasis is a tropical disease found in Africa, Brazil, and parts of South East Asia. Schistosomiasis is caused by a parasitic blood worm that inhabits certain types of freshwater snails. The worm can penetrate a traveller’s skin and can cause damage to the intestine, liver and urinary tract.


Symptoms may occur weeks after infection and include skin irritation at the site of entry, fever, lethargy, weight loss, and blood in urine or bowel motions.


Avoid direct contact with fresh water in risk areas. Wear rubber boots if you expect to wade in fresh water. If direct contact occurs, towel dry your skin vigorously as soon as possible.

Travellers visiting endemic areas should assume all fresh water may be infected. Dams, slow-moving streams, rivers and lakes often pose a high risk, as does showering in water from rivers.

Water free of snails that has been left to stand for three days is safe to drink after it has been boiled, or another effective method of water treatment has been used.

There is no risk in salt water or chlorinated swimming pools.


There is no vaccine to prevent schistosomiasis, however medications are available to treat the disease. Consult your travel doctor for a blood test to confirm diagnosis on your return.