English Inside
Stubborn Infection, Spread by Insects, Is Called ‘The New AIDS of the Americas’
Chagas disease, caused by parasites transmitted to humans by blood-sucking insects, has been named “the new AIDS of the Americas” in a lengthy editorial published in PLoS Neglected Tropical Diseases.
The authors, several of whom are tropical disease experts from Baylor College of Medicine in Houston, argue that
the dangerous spread of Chagas through this hemisphere somewhat resembles the early spread of H.I.V.
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, the authors say,
Chagas disease has a long incubation time and is hard or impossible to cure. Chagas infects up to eight million people in the 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 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.
“Both diseases are highly stigmatizing,” the editorial noted.
Immigrants may not get medical treatment, making Chagas more likely to spread.
www.nytimes.com/2012/05/29/science/spread-of-chagas-is-called-the-new-aids-of-the-ameri...
----------------------------------------
Chagas Disease: “The New HIV/AIDS of the Americas”
www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd...
----------------------------------------
Parasites - American Trypanosomiasis (also known as Chagas Disease)
www.cdc.gov/parasites/chagas/epi.html
-----------------------------------------
Chagas disease, or American trypanosomiasis, is set to be “the new HIV/AIDS of the Americas” according to a paper in the Public Library of Science (PLoS) journal “Neglected Tropical Diseases.” The New York Times cited the article Tuesday, saying that the social and economic impact of Chagas disease, which is a close relative of African trypanosomiasis, more commonly known as sleeping sickness, will be just as devastating in coming years as HIV/AIDS has been to Africa.
The paper’s authors, a group composed largely of faculty from Houston’s Baylor College of Medicine, argue that the spread of Chagas (which is named for the Brazilian physician who discovered it, Dr. Carlos Chagas) through Latin and Central America mirrors the early spread of HIV in several key ways. According to the study,
approximately 10 million of the poorest 100 million people in the Americas have some stage of the disease, which like AIDS is highly stigmatized and disproportionately affects the poor.
Chagas is neither a virus nor a bacteria, but an
incurable single-celled parasite like malaria and sleeping sickness. Rural areas and poverty stricken communities are most commonly hit with Chagas disease because, according to the Centers for Disease Control (CDC), the triatomine bug that carries the disease “thrives under poor housing conditions (for example, mud walls, thatched roofs), so in endemic countries, people living in rural areas are at greatest risk for acquiring infection.”
The bugs — also called “kissing” bugs — drink the victims’ blood, typically while they sleep, then leaves their droppings near the site of the resulting wound. The droppings carry larval trypanosomes called trypanomastigotes, which penetrate skin cells around the bite wound and move on the next phase of their life cycle, when they become amastigotes, which multiply and divide until they burst free of the skin cells and enter the bloodstream as tiny worms.
At this point, the victim enters the disease’s acute stage, which is marked by fatigue, fever, nausea, vomiting, diarrhea, rashes and headaches as the body’s immune system reacts to the onslaught of worms. It is also at this stage that the parasites get taken back up into the triatomine bug, where they mate and complete the other half of their life cycle.
During the acute phase, many patients develop the most distinctive sign of the disease, called Romaña’s sign, the swelling and irritation of the inner eyelids, which is caused by contact with the fecal matter of triatomine bugs.
The symptom occurs typically 1 to 2 weeks after exposure and is what earned the disease its previous name, “river blindess.”
Chagas disease, like AIDS, can have a
long, asymptomatic incubation period, and in its chronic manifestation, which follows the acute phase, it is similarly devastating to the long-term health and productivity of infected individuals. In addition to overall fatigue and malaise, according to the Times, “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.”
Once the disease reaches a certain point in its development, it becomes incurable. Drugs to treat it are cheaper than AIDS drugs, but are in short supply in poorer countries. The authors of the PLoS paper argue that because Chagas is a disease of the poor, it is not a priority of governments and public health departments.
The heaviest concentrations of the disease are in Mexico, Bolivia, Colombia and in Central America.
An estimated 300,000 people in the U.S. have Chagas, typically in Texas and the Gulf Coast region, most of whom are immigrants. The disease can also be transmitted from mother to child during gestation, through blood transfusions and, less commonly, in contaminated food or water.