Schistosoma mansoni flatworm, male with female

Schistosoma mansoni are a species of parasitic flatworm (trematode) found in freshwater habitats in tropical and subtropical areas. They are responsible for causing schistosomiasis (bilharzia). Humans are infected when their skin comes into contact with S. mansoni larvae in contaminated water. The larvae develop into adult worms which live in the blood vessels. Female worms release eggs which can be passed out of the body in urine or faeces to continue transmission, or which can become trapped in body tissues causing further tissue damage. Schistosomiasis presents symptoms including diarrhoea and blood in the stool and urine, and can lead to infertility, liver enlargement and bladder cancer. It can also cause stunted growth and learning difficulties in children. Schistosomiasis is treatable with the anthelmintic drug praziquante, alongside preventative measures such as increased sanitation and access to clean water. The male S. mansoni is approximately 0.8cm long