What do schistosomiasis, cysticercosis, and lymphatic filariasis have in common?
Besides verging on the unpronounceable, they are all classified as neglected tropical diseases (NTDs). NTDs are a set of diseases – seventeen, by the World Health Organization’s count – that collectively affect over a billion people, but have historically received little attention. The most common NTDs, including those listed above, are caused by parasitic worms or protozoa. Others, such as leprosy and trachoma, are the result of bacterial or viral infections.
Though caused by a range of pathogens, NTDs share some important characteristics. First, many are diseases of rural poverty. Most neglected diseases affect the poor in the developing world, particularly in Africa and Asia, but some have also been found in “pockets of poverty” in the United States. For instance, hundreds of thousands of Americans, most of whom are Hispanic immigrants, suffer from Chagas disease. Second, most NTDs cause bodily impairment and disability (i.e., they have high morbidity) but are not very lethal (i.e., they have low mortality).