Though little known to most Americans, lymphatic filariasis, trachoma, leishmaniasis, onchocerciasis, schistosomiasis and other so-called neglected tropical diseases are responsible for severe health burdens, especially among the world's poorest people.
Together, it is estimated that these illnesses, most of which are caused by worms or other parasites, rank sixth among all conditions worldwide in robbing people of quality of life and life itself through disability or premature death, respectively. The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has a long-standing, robust program of research and clinical trials devoted to better understanding and combating neglected tropical diseases, most notably those caused by parasites. In 2006, NIAID devoted $117 million to these projects, which are carried out both in the United States and in countries where the diseases are endemic.