Last updated: April 20, 2023
Article
Chagas Disease
(This page is part of a series. For information on other illnesses that can affect NPS employees, volunteers, commercial use providers, and visitors, please see the NPS A–Z Health Topics index.)
THE BASICS:
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted by the triatomine bug, also known as the kissing bug. This insect is typically found in the southern United States and Latin America, and the geographic range may be expanding northward, perhaps as a consequence of climate change. It is estimated that over 300,000 people living in the U.S. are infected with T. cruzi. Most of these people likely acquired their infection in Latin America where the bug and parasite are endemic. Vectorborne transmission is not known to occur in the Caribbean. Rare locally-acquired cases of Chagas disease have been noted in the southern United States.
During the day, the bugs hide in crevices in the walls and roofs of houses. During the night, when people are sleeping, the bugs emerge to seek a host. When the infected bug bites a new host, it also defecates on them. The parasite, T. cruzi, is passed through their feces. A person may not realize that they’ve been bitten, and they may accidently rub the feces containing the parasite into broken skin or into their eyes, nose, or mouth. Less commonly, people can become infected through blood transfusions, organ transplants, transmission from mother to fetus, or consumption of uncooked food contaminated with the parasite. Chagas disease is not transmitted from person-to-person.
Infection with T. cruzi can result in a variety of symptoms based on if the infection was recent (acute) or long-term (chronic). During acute infections (weeks to months after exposure) people may experience fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. Romaña’s sign, the swelling of the eyelid, is a marker of acute Chagas disease. Chronic infection (months to years after exposure) can cause cardiac and gastrointestinal complications. Treatment for Chagas disease can include antiparasitic medications or treatment to manage symptoms.
PREVENTION:
There is no vaccine or medication to prevent Chagas disease infection, so reducing exposure to triatomine bugs is the best prevention method. To help prevent the bug and the T. cruzi parasite:
Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted by the triatomine bug, also known as the kissing bug. This insect is typically found in the southern United States and Latin America, and the geographic range may be expanding northward, perhaps as a consequence of climate change. It is estimated that over 300,000 people living in the U.S. are infected with T. cruzi. Most of these people likely acquired their infection in Latin America where the bug and parasite are endemic. Vectorborne transmission is not known to occur in the Caribbean. Rare locally-acquired cases of Chagas disease have been noted in the southern United States.
During the day, the bugs hide in crevices in the walls and roofs of houses. During the night, when people are sleeping, the bugs emerge to seek a host. When the infected bug bites a new host, it also defecates on them. The parasite, T. cruzi, is passed through their feces. A person may not realize that they’ve been bitten, and they may accidently rub the feces containing the parasite into broken skin or into their eyes, nose, or mouth. Less commonly, people can become infected through blood transfusions, organ transplants, transmission from mother to fetus, or consumption of uncooked food contaminated with the parasite. Chagas disease is not transmitted from person-to-person.
Infection with T. cruzi can result in a variety of symptoms based on if the infection was recent (acute) or long-term (chronic). During acute infections (weeks to months after exposure) people may experience fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting. Romaña’s sign, the swelling of the eyelid, is a marker of acute Chagas disease. Chronic infection (months to years after exposure) can cause cardiac and gastrointestinal complications. Treatment for Chagas disease can include antiparasitic medications or treatment to manage symptoms.
PREVENTION:
There is no vaccine or medication to prevent Chagas disease infection, so reducing exposure to triatomine bugs is the best prevention method. To help prevent the bug and the T. cruzi parasite:
- Use an Integrated Pest Management approach to ensure a safe living facility. Sleep indoors in well-constructed facilities. Ensure that gaps around doors and baseboards are patched or repaired to prevent bug entry. Use screens on windows and doors.
- Keep the area under and around your house neat. Remove wild animal nests, piles of branches and wood, and trash, so that wildlife stay away from your house. Animals can carry the parasite and also be blood sources for kissing bugs.
- Turn off outside lights at night. Lights can attract the bugs which will crawl toward and enter sleeping areas.
- Consider utilizing bed nets treated with insecticides, particularly if there is concern about the ability of your living facility to keep out insects.
- Wear long sleeves, long pants, and socks to cover exposed skin, especially when sleeping.
- If you think you have been bitten by a triatomine bug or if you develop symptoms after being bitten by a triatomine bug, you should seek medical attention. It’s important to communicate the bite exposure and timing of symptoms to your medical provider.
- You should also keep the triatomine bug, to allow for confirmation that it is a triatomine bug and potentially for testing. Do not touch or squash the bug. Place a container on top of the bug, slide the bug inside, and fill it with rubbing alcohol or, if not available, freeze the bug in the container. You should also take 2-3 photos, including a side view. Contact the NPS Office of Public Health, as they can assist in finding identification and testing options.
NPS RESOURCES:
- NPS Integrated Pest Management (external site)
- NPS Integrated Pest Management (restricted access)
- Alvarado A, Mader EM, Buttke D, Harrington LC. Southwestern national park service employee risk, knowledge, and concern for triatomine exposure: A qualitative analysis using a novel knowledge, attitudes, and practices survey. Dinglasan RR, ed. PLoS Negl Trop Dis. 2022;16(9):e0010744. doi:10.1371/journal.pntd.0010744
- Curtis-Robles R, Meyers AC, Auckland LD, Zecca IB, Skiles R, Hamer SA. Parasitic interactions among Trypanosoma cruzi, triatomine vectors, domestic animals, and wildlife in Big Bend National Park along the Texas-Mexico border. Acta Trop. 2018;188:225-233. doi:10.1016/j.actatropica.2018.09.002