A silent killer tested on an African American

26th March 2012   ·   0 Comments

By Zoe Sullivan
Contributing Writer

Scandals over the treatment of African Americans and other non-whites in medical research have emerged over the years. In the infamous Tuskegee experiment, 300 African Americans to study the reaction to syphilis when left untreated. A similar study was also conducted in the 1940s in Guate­mala, deliberately infecting people with syphilis.

So perhaps it’s no surprise that in a 1943 edition of the American Journal of Tropical Medicine, reported that “an adult, male negro” in Texas was infected with Chagas disease. Identified only as a 24-year-old who was in good health at the time of the infection, there is no way to identify who this person is or was. The study followed the patient for roughly two years, but reported that the disease was no longer present 21 months after the initial infection.

What is now known, however, is that Chagas is a “silent killer,” in the words of Dr. Patricia Dorn of Loyola University. The disease will manifest in swelling at the point of entry, low-grade fever and malaise during its initial phase, but then the parasite, Trypanosoma cruzi, embeds itself into muscle tissue, particularly the heart, disappearing from circulation in the blood. Here, it can lay dormant or work quietly for decades, debilitating the heart muscle and leading to unexplained heart issues and ultimately, death.

Louisianians know something about heart disease. Fried chicken, grilled sausage, and barbecued shrimp are not exactly the best foods—in terms of heart health. But are they aware of this health threat?

Scientists estimate that 8 to 10 million people in Latin America are infected with the disease, which is transmitted through bites from the “kissing bug.” And while so far there have only been seven confirmed cases in the United States, one of these was identified in New Orleans shortly after Katrina. According to Dr. Patricia Dorn, a biologist at Loyola Univ­ersity, the infected woman lived in a house infested with the kissing bugs, over half of which tested positive for the disease.

The bugs like to be in tight spaces, such as cracks in wooden boards. Dorn says that in addition to different construction standards in the U.S. that tend to keep homes better sealed, and consequently keep the bugs out, the insect species more prevalent in the U.S. also has different habits feeding and defecation habits, which also impact infection rates.

“Since it afflicts mostly the poor, it’s one of these neglected diseases that pharmaceutical companies don’t have a lot of incentive to put money into, because who are they going to sell it to?” Dorn explained to The Louisiana Weekly. Although there is currently no vaccine for the disease and little effective treatment for adults, there is a high rate of success in treating new-born infants who can receive the parasite from their mother’s bloodstream. This raises particular concerns for the children of new immigrants, an estimated 300,000 of whom are infected with Chagas.

It is possible, however, that the likelihood of infection in the U.S. will change as temperatures rise. A report that Dorn co-authored that appeared in the Center for Disease Control journal, Emerging Infections Diseases, notes that infection rates could go up as changes in climate alters the natural environment and, consequently, the habitat available for the bugs.

People aren’t the only victims of the disease however, Dorn says that “about 30 percent of opossums and armadillos are infected.” She also pointed out that “the whole bottom two-thirds of the U.S. has the kissing bugs.” A recent study that Dorn co-authored. As a result, it can also afflict domestic animals such as dogs.

Dr. Jack Malone, with LSU School of Veterinary Medicine, told The Louisiana Weekly that he considers the Chagas infection rate in Southern Louisiana to be “low-level endemic.” The disease, he says, is common in the Atchafalaya River basin, where there are large wildlife areas. In one study of kennels in the area, Dorn explained how an “immaculate” kennel registered high infection levels. “It was right next to a sugar cane field,” Dorn said. The close proximity to the dogs gave the kissing bugs an ideal habitat as well as an easy food source. Dorn and Malone co-authored a report on this study with other scientists, and found that 22.1 percent of the dogs tested returned positive results for the Chagas parasite.

“They still not aware enough,” Dr. Malone said of Louisiana vets. “I think they’re missing cases.” Malone said that one issue is that because Chagas attacks the heart, it can easily be confused with heart worms, and, what’s worse, “very often they may have both.” There is a new, quick test for Chagas that’s in an experimental stage, Malone, commented. The “dipstick” test, he said is also “ap­proved for human use.” But one of the big issues is that most vets and doctors are unaware of the disease, and so they don’t think to screen for it.

Over the last few years, while actively looking, Malone says his lab has seen 30 cases. “That’s why we need a quick test, a screen,” Malone told The Louisiana Weekly. “In my own opinion, we would be surprised by how much is actually out there,” he went on, adding that the disease doesn’t always cause serious problems.

This article was originally published in the March 26, 2012 print edition of The Louisiana Weekly newspaper