Chagas disease, caused by parasites transmitted to humans by blood-sucking insects, has been named “the new AIDS of the Americas”

The dangerous spread of Chagas somewhat resembles the early spread of HIV/AIDS. Chagas is also known as American trypanosomiasis, because the bugs carry single-celled parasites called trypanosomes. (Their best-known relative, spread by tsetse flies in Africa, causes sleeping sickness.) Like AIDS, Chagas disease has a long incubation time and is hard or impossible to cure. Chagas infects up to eight million people in the western hemisphere, mostly in Bolivia, Mexico, Colombia and Central America. But more than 300,000 of the infected live in the United States, many of them Hispanic immigrants. The disease can be transmitted from mother to child or by blood transfusion. About a quarter of its victims eventually will develop enlarged hearts or intestines, which can fail or burst, causing sudden death. Treatment involves harsh drugs taken for up to three months and works only if the disease is caught early. The drugs are not as expensive as AIDS drugs, but there are shortages in poor countries. Because it is a disease of the poor, little money is spent on finding new treatments. Immigrants may not get medical treatment, making Chagas more likely to spread. Of course, one way to limit the spread of the disease would be to stop immigration from high risk areas as Bolivia, Mexico, Colombia and Central America.