Chagas disease, a parasitic illness transmitted by insects known as “kissing bugs,” has officially been declared endemic in parts of the United States. This major shift in classification signals that the disease is no longer viewed as a rare, imported condition but one with active transmission inside the country.
Chagas Disease in the U.S.
The Centers for Disease Control and Prevention (CDC) recently confirmed that Chagas disease now meets the criteria for endemic status. Kissing bugs carrying the parasite Trypanosoma cruzi have been documented across 32 states, particularly in the southern regions. Local transmission to humans has been confirmed in at least eight states, including Texas, Arizona, Louisiana, and California.
While Chagas disease was historically associated with Latin America, experts now recognize that the U.S. has established, low-level transmission cycles involving wildlife, domestic animals, and people. This acknowledgment marks a turning point in how the illness is monitored and addressed nationwide.
Rising Concern in Texas and California
Texas has recorded dozens of locally acquired human cases over the past decade, alongside widespread infections in dogs and wildlife such as raccoons and opossums. California health officials estimate that between 70,000 and 100,000 residents of Los Angeles County may already be living with Chagas disease, many unaware of their infection. Nationally, it is believed that more than 300,000 Americans could be affected.
How the Disease Spreads
Chagas disease is caused by the parasite Trypanosoma cruzi and spreads in several ways, with kissing bugs being the primary vector. The parasite’s transmission is more complex than just insect bites, involving multiple routes that affect both humans and animals.
1. Primary Vector Transmission
Kissing bugs become infected after feeding on animals or people carrying the parasite. When they bite, they often defecate near the wound. The parasite enters the body if the contaminated feces come into contact with the bite, broken skin, or mucous membranes such as the eyes and mouth. Scratching the bite site increases the chances of infection.
2. Oral Transmission Through Food and Drink
In some outbreaks, the parasite has been spread through contaminated food or beverages. This occurs when kissing bug feces or crushed insects mix with food or drinks. Oral transmission often results in more severe symptoms because the body may receive a higher parasite load at once.
3. Mother-to-Child Transmission
Chagas disease can pass from mother to child during pregnancy or childbirth. This congenital transmission makes the disease particularly concerning for women of childbearing age who live in areas where the parasite is present.
4. Blood and Organ Transmission
The parasite can also spread through blood transfusions or organ transplants from an infected donor. This risk is significantly reduced in places where screening for T. cruzi is mandatory, but cases can still occur if the infection goes undetected.
5. Laboratory and Accidental Exposure
Rarely, laboratory workers or people handling infected material can acquire the infection through accidental contact. This route is uncommon but highlights the need for careful handling of samples in medical and research environments.
6. Pets and Animal Reservoirs
Domestic animals, especially dogs, are vulnerable to infection and can serve as reservoirs for the parasite. Wildlife such as raccoons, opossums, and rodents also play a role in maintaining the cycle of transmission. Because pets often live close to humans, they create another pathway for the parasite to circulate near households.
7. Emerging Spread in the United States
While Chagas disease has long been associated with Latin America, recent findings show that it is also present in parts of the southern United States. Kissing bugs have been identified in over 30 states, and locally acquired cases have been documented. The presence of infected wildlife and dogs in these areas suggests that the disease is becoming established beyond its traditional range.
Symptoms and Health Risks
The disease often begins with mild or unnoticed symptoms. In its acute phase, people may experience:
- Fever and fatigue
- Body aches
- Swelling near the bite or around the eye (Romaña’s sign)
If left untreated, the infection progresses to the chronic phase, which can remain silent for years. Over time, up to 30% of infected individuals may develop serious complications, including:
- Enlarged heart or heart failure
- Irregular heartbeat
- Sudden cardiac arrest
- Enlarged esophagus or colon, causing severe digestive issues
Treatment Options
Currently, only two medications are approved in the United States to treat Chagas disease: Benznidazole and Nifurtimox. Both are most effective when administered early, particularly during the acute stage or shortly after infection. Treatment can slow or even stop progression, but it is less effective once severe organ damage has developed.
Because many patients are asymptomatic for years, increasing early testing is critical. Pregnant women from at-risk areas, blood donors, and organ donors are among the groups prioritized for screening.
Public Health Response
Health officials are expanding surveillance programs to track the spread of kissing bugs and identify new human cases. Veterinarians are also encouraged to test dogs in high-risk regions, since infections in pets often serve as early warning signs of local transmission.
Communities in southern states are being urged to take preventive steps, such as:
- Sealing homes to prevent insect entry
- Reducing outdoor lighting at night, which attracts bugs
- Keeping sleeping areas away from walls or open windows
- Using bed nets in areas where kissing bugs are common
- Protecting pets with regular veterinary checkups and housing that limits bug exposure
Why Awareness Matters Now
The recognition of Chagas disease as endemic underscores the importance of raising awareness among doctors and the general public. Misdiagnosis is common, since many patients are unaware of their risk and symptoms mimic other illnesses. By increasing education, more cases can be detected before they progress to severe, life-threatening complications.
Looking Ahead
Chagas disease is no longer a distant concern confined to other regions of the world. With proven local transmission in multiple states, it has become a permanent part of the U.S. public health landscape. Continued research, stronger surveillance, and wider access to testing and treatment are essential to limit its impact.
The conversation now shifts to communities: how to protect families, pets, and neighbors from this silent but serious disease.
What steps do you think should be prioritized in your area to raise awareness and improve prevention? Share your thoughts—I’d love to hear your perspective.