A prolonged bout of intestinal parasites seems to slow the decline of patients with multiple sclerosis, according to a study released today. The results suggest that immune-modulating molecules from parasites could be developed into drugs to ease autoimmune diseases, and that by conquering parasite infections, modern medicine may have inadvertently increased our vulnerability to these illnesses. Autoimmune diseases such as multiple sclerosis (MS) occur far more often in developed countries than in developing countries. And parasitic infections, which have been beaten down in the United States, are still common in South America and elsewhere in the developing world, says neuroimmunologist...