Schistosomiasis is a severe infectious disease caused by parasitic worms.
Schistosomiasis is a severe infectious disease caused by parasitic worms. As an intermediate host, freshwater snails play a central role in the life cycle of the parasite. In a recent study published in the journal Scientific Reports, researchers from the Helmholtz Centre for Environmental Research (UFZ) in cooperation with the Kenya-based International Centre of Insect Physiology and Ecology (icipe) succeeded in proving that snail populations in waterbodies contaminated with pesticides were significantly larger than in uncontaminated waterbodies. The pesticides used in agriculture may well be an outright driver for the risk of infection with schistosomiasis, the researchers warn.
According to WHO estimates, there are around 200 to 300 million people infected with schistosomiasis (also known as bilharzia) worldwide; around 200,000 die each year of the consequences. The disease also has far-reaching socio-economic effects in the tropical regions concerned: infected individuals are often unable to work and children are too weak to be able to go to school. It is transmitted through the skin following exposure to infected water. The pathogen is a parasitic trematode worm of the genus Schistosoma - the "blood fluke". To date, five different kinds of Schistosoma that can infest humans have been identified. Around two centimetres in length, the worms become lodged in the intestinal wall, the bladder or the liver. The consequences include inflammation and severe organ damage that can lead to death. Schistosomiasis can be treated with an anti-worm medication. But treatment does not protect against reinfection. "Contaminated waterbodies are the problem," says Professor Matthias Liess, Head of the Department of System Ecotoxicology at the UFZ. "Before schistosomiasis can be contained, something has to be done to prevent the proliferation of the pathogens in bodies of water."
Read more at Helmholtz Centre for Environmental Research - UFZ
Image: Researchers examined 48 bodies of running water in Kenya for pesticide contamination, composition of the biological communities and occurrence of snails. (Credit: @UFZ)
