Schistosomiasis or snail fever

Schistosomiasis also known as bilharzias (sis), is a helminthic disease of human beings and both domestic and wild animals in many tropical and subtropical countries. It is a chronic disease caused by parasites of the genus Schistosoma.

The infection is sometimes called snail fever, because certain aquatic freshwater snails serve as intermediate hosts in the parasite’s life cycle. There is evidence that about 10% of the world’s population has been infected with Schistosoma parasites.

Schistosoma haematobium

The three species of schistosoma called S. haematobium, mansoni, and japonicum are highly infective in man. Schistosoma organisms are flukes which live in the blood vessels of man. They live in separate sexual forms, have non-operculated eggs and develop without an encysted metacercarial stage.

Symptomatology is variable and ranges from subclinical infection urinary tract infection, renal failure and bladder cancer.

Hygiene and play habits make children especially susceptible to infection, so in endemic areas initial infection occurs most often during childhood. Schistosomiasis usually peaks in the teen year and most of the morbidity occurs in adults.
Schistosomiasis or snail fever