Dr. Patricia Dorn's research group, including undergraduate biology researchers, have uncovered important aspects of a major parasitic disease of the Americas. Over the past year, her research group has published 6 papers in international journals and edited volumes.
Recent research conducted by Loyola University New Orleans biology professor Patricia Dorn, Ph.D., shows that 38% of the triatomine bugs, or kissing bugs as they are more commonly known, found in Arizona and California had fed on humans, and more than 50% are infected with the Chagas parasite. This indicates much more human-kissing bug contact in the U.S. than was previously known.
Chagas disease can lead to heart disease, and it is a leading cause of heart disease in Central and South America. Dorn’s research will be published in an upcoming edition of the journal Emerging Infectious Diseases. Chagas disease is contracted when infected kissing bugs bite humans or animals, opening a wound and producing parasite-contaminated waste that enters the wound or mucous membranes and ultimately the bloodstream. Dorn says reactions to the bite itself can range from slight to extremely severe allergic reactions called anaphylaxis. “Reaction to the initial bite is similar to a bee sting,” Dorn said. “For some people it’s just a little annoying, for others it’s potentially fatal. Allergic reactions to bites from kissing bugs are the leading cause of insect bite induced anaphylactic shock in the United States.” Once it enters the bloodstream, the Chagas parasite attacks muscle tissue, especially the heart, and may not be detected for 10 to 20 years. By that time, Dorn says the damage is done and the treatment options are limited. While Chagas disease is rare in the U.S., one of the seven insect-borne cases of Chagas was uncovered in a rural area in New Orleans in 2006. But Dorn says the potential for identifying new cases is a real possibility, especially as physicians become aware of the disease and the Latino population from endemic countries continues to increase in the U.S. “In Latin America, Chagas is prevalent. Eight to nine million people in Mexico, Central and South America are already infected with the parasite.” Dorn said. “Research indicates that an estimated 300,000 immigrants who came to the United States from that region are already infected with parasite.” In addition to the kissing bug feces, Chagas can also be transmitted by blood, and starting in 2007, the U.S. started screening its blood supply for the disease.
To date, more than 1,600 cases of Chagas-tainted blood have been uncovered. Dorn’s research of the Chagas-infected kissing bug led her to study rural communities in Guatemala over the last 17 years, where they had seen a high concentration of bug infestation. Dorn says that recent changes in human behavior have made a positive impact on reducing where the bugs make their home. “There were people living in the most basic of housing, which made it very easy for the kissing bug to invade the home. So, they made some changes, such as applying a layer of plaster on the inside of the house that plugged the holes and cracks that the bugs used to live in. They also replaced dirt floors with concrete and most importantly kept the pigs and chickens outside. The bugs are looking for a blood meal, which is most commonly farm animals and humans,” Dorn said. “We could tell right away whether or not we were going to find the kissing bugs by simply checking the condition of the house.”