Schistosomiasis

A parasitic tropical disease, caused by any of 3 species of flukes called schistosomes, and acquired from bathing in infested water. The larval form penetrates the bather’s skin and develops in the body into adult flukes, which settle in the veins of the bladder and intestines. Eggs laid by adults provoke inflammatory reactions; there may be bleeding and ulceration in the bladder and intestinal walls, and the liver may also be affected. The first symptom is usually tingling and an itchy rash where the flukes have penetrated the skin. An influenza-like illness may develop weeks later, when the adults produce eggs. Subsequent symptoms include blood in the urine or faeces, abdominal or lower back pain, and enlargement of the liver or spleen. Complications of long-term infestation include liver cirrhosis, bladder tumours, and kidney failure. Treatment is with the drug praziquantel.