Chagas Disease and HIV Are Killers With Very Different M.O.'s

Deadly Chagas affects millions and needs attention, but calling it new HIV is a publicity stunt.

A kissing bug

Earlier this week, the medical community was rocked with the release of an editorial that called Chagas disease "The New HIV/AIDS of the Americas." But is that true?

Chagas disease—considered a "neglected tropical disease"—is estimated to affect about 10 million people in Latin America—most of them living in poverty. After contracting the disease, victims experience mild fevers, fatigue, and swelling at the site of infection.

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The disease then goes dormant, sometimes forever, sometimes for many years. When it resurfaces, it causes heart, digestive, and nervous system problems, eventually killing many of those infected.

While Chagas is no small problem, it's no HIV, according to experts who study both diseases—and even the editorial's author says he wrote the essay to cause a stir.

"I wrote it purposefully to have a provocative title … there's no attention at all [on Chagas]. I didn't write this in any way to diminish the importance of HIV/AIDS," says Peter Hotez, who is currently working on a vaccine for Chagas.

He certainly got what he wanted—his editorial has been covered far and wide. "When you work on something called neglected tropical diseases, it's amazing to see this kind of press. It's more than I can ever remember," he says.

Hotez was well placed to write the editorial. He was (and still is) the founding editor of PLoS Neglected Tropical Diseases, the journal that published his piece.

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Comparing a disease to HIV has become a common tactic used to call attention to a disease. In the past couple years, scientists have called leishmaniasis the "parasitic version of HIV," while others have said hepatitis C and cancer are "the new AIDS."

"As an organization working to develop new and improved medicines for both diseases, we would not compare the two for various reasons, both scientific and otherwise," says Rachel Cohen, executive director of the North American branch of the Drugs for Neglected Diseases initiative.

Cohen says she's glad someone has pointed a spotlight on Chagas, "but [she's] not going to make a judgment about whether the ends justify the means."

"I think the only thing we have to be concerned about is this leading to misleading information. That's where you'd have concerns," she adds. "There's no question [Chagas] is a terribly neglected disease and we need a huge amount of increased attention on it, but I wouldn't make the comparison from any scientific standpoint."

Chagas and HIV do have similarities—they disproportionately affect poverty-stricken populations, can be passed from mothers to their offspring, and often have a long dormant period before causing severe complications—but there are many important differences, Cohen says.

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HIV eventually kills nearly everyone it affects; Chagas kills between 20 percent and 30 percent. If treated during its acute stage, Chagas is curable in one to three months, while managing an HIV infection requires a lifetime of antiviral drugs. And Chagas is almost always caused by a protozoan parasite passed through the feces of the kissing bug, native to Latin America, while HIV is a virus spread from person to person, most often through sexual activity or intravenous drug use.

In his editorial, Hotez writes that Chagas and other neglected diseases "cause a burden of disease in the Latin American and Caribbean region that closely approximates or even exceeds that resulting from HIV/AIDS," but then later writes that although Chagas affects more than five times as many Latin Americans as HIV, the number of "attributed deaths are about five times higher for HIV/AIDS."

No expert denies that Chagas is a growing problem in Latin America, and it is becoming increasingly prevalent in Texas and other parts of the United States.

Mario Grijalva, director of the Tropical Disease Institute at Ohio University who takes frequent trips to study Chagas in Ecuador, says "the problem of Chagas is directly related to socioeconomic conditions." Poorer houses in Latin America are often easily penetrable by the bugs, where they live on boxes, the floors, and walls. Kissing bugs feed on human flesh for up to 20 minutes at a time, then defecate.