Have worms lost their luster?

Childhood infections with some helminths have been reported to reduce the risk of acquiring some immune-mediated diseases like sensitization to allergens, asthma and inflammatory bowel disease. Denmark keeps a medical registry that collects data on disease prevalence and medication use throughout the country. Mebendazole frequently is used to treat pinworm (Enterobius vermicularis) infection. In this population-based analysis of a cohort of 924,749 children, prescriptions for Mebendazole were used as a surrogate marker for pinworm infection. Children who received this medication were compared to children who did not, for the frequency of asthma, type I diabetes, juvenile arthritis, ulcerative colitis and Crohn’s disease. It was found that Mebendazole use, and by inference pinworm infection, did not appear to reduce the risk for acquiring any of these immune-mediated diseases.