Schistosomiasis is most commonly found in tropical parts of Africa, parts of Latin America, China, Japan, Indonesia and some parts of the Middle East.
Common symptoms in the first few weeks or months of the disease include fever, diarrhoea and skin disorders including dermatitis. These symptoms may then be followed by inflammation of the bladder or bowels; diarrhoea with blood in the faeces or blood in the urine can continue to occur for several months, even years, after the initial infection. It is possible, however, to be infected without experiencing any of these symptoms.
The infection is transmitted to humans by the larvae of freshwater snails. These are mainly found along the banks of rivers, lakes and marshes. The parasitic larvae can penetrate the skin of people who swim or bathe in contaminated water. Once inside the human body the larvae then develop into worms that live in the blood vessels of the bowel or bladder.
When visiting the areas mentioned above you should not swim, wade, paddle or wash your hands in stagnant or slow-flowing water. If you think you have contracted schistosomiasis or may have been infected by the larvae you should see a doctor or medical practitioner as soon as possible. If you are no longer in the country where the disease is endemic you should tell the person you see which areas you have visited. Schistosomiasis can be treated by means of medication. In the Netherlands, Praziquantel is usually prescribed. If you have been swimming in waters which may have been contaminated the infection can easily be detected by means of a simple blood test, even if you are not yet exhibiting any symptoms.