Schistosomiasis, also known as bilharzia, is the second most prevalent tropical disease after malaria and is a leading cause of morbidity in many parts of the world.
It is not uncommon in Australia because of the many travellers who visit endemic areas and swim or bathe in freshwater lakes and streams.
Places commonly implicated include Lake Kariba and Lake Malawi in Africa. Immigrants and refugees from bilharzia endemic countries are also likely to present with untreated infection. With increasing travel to and migration from Africa and the Americas knowledge of the dangers and means of avoiding schistosomiasis is essential.
Schistosomiasis is caused by trematodes of the genus Schistosoma. The principal schistosomes of medical importance, S japonicum, S mansoni, S mekongi (intestinal schistosomiasis) and S haematobium (urinary schistosomiasis), infect people who enter water in which infected snails (intermediate hosts) are living.
The larval cercariae shed by the snail actively penetrate unbroken skin and develop into schistosomulae that migrate through the ...