Schistosomiasis, also referred to as ‘bilharzia’ and ‘snail fever’, affects more than 200 million people, the majority of whom live in sub-Saharan Africa (Lai et al. 2015). Infection in humans is caused by contact with water that is infested with trematode flukes carried by freshwater snails. The larvae penetrate the skin of people who come into contact with infested water. The larvae then develop into adult worms in the body, colonizing the blood vessels, where they effectively invade the immune system. They can release hundreds of thousands of eggs a day, some of which are excreted in faeces or urine, while others are trapped in nearby tissues (Colley et al. 2014). The trapped eggs produce an immune response, causing chronic diseases such as anemia, stunted growth, impaired cognition and heart, liver, urinary and gastrointestinal complications.
From collection: Sanitation and Wastewater Atlas of Africa - Human Health