Thread: Latin American parasite becomes a threat to U.S.

Latin American parasite becomes a threat to U.S.
The parasitic disease called Chagas is becoming a concern to healthcare professionals in this country, as it could pose threats to blood and organ supplies.
By Rong-gong Lin Ii, Los Angeles Times

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LOS ANGELES - A little-known and potentially deadly parasite from Latin America has become one of the latest threats to the blood and organ supplies in the United States, especially in Los Angeles, where many donors have traveled to affected countries, health officials say.
Last year, two heart transplant patients at different Los Angeles hospitals contracted the parasitic disease, called Chagas, causing health authorities to issue a national bulletin. Within months, both patients subsequently died, although not directly from Chagas, according to the U.S. Centers for Disease Control and Prevention.

The parasite, generally passed to humans from a blood-sucking insect that looks like a striped cockroach, can feed over years on tissues of the heart and gastro-intestinal tract. After decades, tissues can be eroded so much that the organs fail.

Insect transmission of the parasite in the United States is rare, but public health and blood bank officials have been concerned about its increasing prevalence in the blood supply.

Using an experimental test, the American Red Cross found that one in 9,850 blood donors in the L.A. area tested positive for the parasite, Trypanosoma cruzi, in 1996. Two years later, it was one in every 5,400. By 2006, according to a more refined test, it was one in 3,800. About 10 percent to 30 percent of infected people develop symptoms of chronic disease, experts say.

By contrast, HIV, which blood banks screen for, shows up in 1 of every 30,000 donors, said Susan Stramer, executive scientific officer for the American Red Cross.

If caught early, when the parasites are few, strong anti-protozoal drugs such as nifurtimox can bring the parasite to undetectable levels or, in some cases, eliminate it entirely. If the parasite is given the chance to multiply over years or decades, however, Chagas can be managed only with such things as a pacemaker, heart-regulating drugs or a heart transplant.

Blood banks have just begun systematically checking their supplies for the Chagas parasite. The U.S. Food and Drug Administration approved a test suitable for widespread screening in December.

By late January, the American Red Cross and Phoenix-based Blood Systems had started screening blood for T. cruzi, accounting for about 65 percent of the U.S. blood supply. But some other banks have no immediate plans for screening, but are keeping an eye on test results from banks that are using the test. In late February, the CDC said in its Morbidity and Mortality Weekly Report that the "FDA is expected to recommend implementation of the test by all blood-collection establishments."

No organ donors in the United States are now being screened for the parasite, although the organ procurement agency that covers much of Southern California plans to begin testing some donors in mid-April. At first, the screening will be focused on people who have lived in or traveled to rural parts of Latin America, said Thomas Mone, chief executive officer of the agency, OneLegacy.

In Latin America, about 10 to 12 million people are believed to be infected with the Chagas parasite. As many as 1 million of them are expected to die of the disease unless there are advances in treatment, according to Dr. James Maguire, a University of Maryland Chagas expert.

"Chagas is very, very prevalent in South and Central America," said Marek Nowicki, a University of Southern California blood disease expert who studied Chagas' impact on Southern California organ supply with the National Institute of Transplantation.

"The number of [immigrant] Latinos in Southern California, Texas and other parts of the United States are growing, but especially in L.A., a large proportion of organ donors are Latino," Nowicki said. "They're basically bringing with them the disease prevalence in the area they used to live."

Chagas is a clear reminder that "diseases don't have geographic borders anymore," said Dr. Suman Radhakrishna, an infectious diseases expert in Los Angeles. Doctors need to be "cognizant that diseases happening elsewhere in the world can happen in our backyard, too."

http://www.startribune.com/722/story/1076043.html

very popular disease in Latin America, due to poverty .