Third World diseases making their way into U.S. population

Preventable diseases commonly seen among impoverished people in Africa, Asia and Latin America are infecting millions of U.S. residents, mostly poor women and children, researchers found.

Chronic infections such as Chagas' disease and dengue fever are a major cause of disability, impaired child development and pregnancy complications in the U.S., said Peter Hotez, author of the study released by the Public Library of Science's journal Neglected Tropical Diseases.

Parasitic conditions including roundworm and toxoplasmosis, along with tropical bacteria, are widespread in many inner cities, the Mississippi Delta, Appalachia and the Mexican borderlands, the study said. Improved recognition, screening and treatment of the diseases are needed to reduce the impact on patients, who are often poor and less educated, Hotez said.

"If these diseases were hitting wealthy people in the suburbs, we would never tolerate it," said Hotez, chairman of microbiology at the George Washington University in Washington. "We need to make the names of these diseases household words."

Even before Hurricane Katrina drove thousands from their homes in Louisiana in 2005, poverty and lack of access to health care contributed to high rates of roundworm and other parasites, the study said. Prolonged flooding has paved the way for increased rates of Chagas, a parasite that can cause lethal heart and intestinal complications, according to the researchers.

An American Red Cross researcher has called for screening of all donated blood for signs of the parasite that causes Chagas' disease, which may be found in as many as one in 25,000 blood donors in the U.S., and kills as many as one third of patients. The disease can lurk undetected for as long as 20 years.

Hotez's study is a wake-up call to state, local and U.S. health officials that more needs to be done about tropical diseases in the U.S., said Mary Wilson, a Harvard School of Public Health associate professor.

"Most people are completely unaware that many of these diseases still exist in the U.S.," she said in a telephone interview.

The U.S. is spending billions to find treatments for anthrax, avian flu and smallpox, diseases that affect few or no one, Hotez said. More resources should be spent on finding new treatments for tropical diseases that sicken millions annually, he said.