Peter Hotez of the George Washington University in Washington and the Sabin Vaccine Institute said there is evidence the parasitic diseases toxocariasis, cysticercosis and toxoplasmosis, as well as other neglected infections, are very common in the United States, especially among poor and minority populations in inner cities and rural areas.

The study, published in the PLoS Neglected Tropical Diseases, reported that as much as 23 percent of Americans living in poverty are exposed to the roundworm Toxocara canis oxocariasis.

The study also said cysticercosis, caused by the tapeworm Taenia solium, is emerging as the leading cause of epilepsy among Hispanic populations in the United States. Toxoplasmosis is an important cause of congenital birth defects among Mexican-Americans and African-Americans, the study determined.

In addition, a significant number of American schoolchildren living in poor areas also may be infected with other parasites, including Ascaris roundworms in the South, Strongyloides threadworms in Appalachia, Leishmania protozoan parasites in Texas and the bacteria that cause leptospirosis.