Parasite genetics may hold key to schistosomiasis treatment
Researchers from AfricaMuseum, the Institute of Tropical Medicine (ITM), and KU Leuven have found that some of the parasites causing schistosomiasis produce more offspring than others. This discovery opens up possibilities for finding new drugs and vaccines against the tropical disease.
Schistosomiasis, or bilharzia, is a disease caused by a worm that infests our intestines and urinary tract. It affects over 200 million people, mostly children in sub-Saharan Africa, and causes over 1,000 deaths a year. The infection is spread through lakes and rivers containing freshwater snails that serve as vectors for the parasitic worm.
‘Much of the research on tropical diseases, and schistosomiasis in particular, has focused on humans,’ explained parasitologist Tine Huyse of AfricaMuseum in Tervuren. ‘New technologies developed in recent years now make it possible to study the parasites themselves in greater detail. We can analyse the DNA of parasitic worm larvae that are barely a tenth of a millimetre long.’
Up to now, it was thought that an infection’s severity depended on exposure to the parasite and the patient’s immune system. For the first time, scientists from AfricaMuseum, ITM, and KU Leuven have demonstrated the existence of another factor. ‘After analysing samples from more than 1,500 Senegalese patients, we found that parasites with a mutation in a specific gene produce more offspring,’ said Huyse. ‘This is an important discovery, as the severity of infection depends on the number of eggs produced by the worms.’
With this discovery, new research can be carried out to develop drugs and vaccines targeting this gene.
Evolutionary epidemiology of schistosomiasis: linking parasite genetics with disease phenotype in humans (International Journal for Parasitology)