Researchers have discovered a class of previously unknown genes that allows snails to resist infection by schistosomes, the flatworm parasites that cause schistosomiasis (Tennessen JA et al. PLoS Genet. 2015;11:e1005067). The condition—which can cause lifelong disability—affects more than 200 million people around the globe, and it is most common in areas with poor sanitation. Schistosomiasis is the second most common parasitic disease, behind malaria. The anthelmintic praziquantel is the only currently available treatment, and schistosomes can evolve to develop resistance to the drug in laboratory experiments.
Hampton T. Snail Genetic Variation Associated With Resistance to Schistosomiasis. JAMA. 2015;313(17):1703. doi:10.1001/jama.2015.3711