Chagas disease in Florida: What to know

Chagas disease is a poorly understood illness that can lead to heart failure and other fatal complications if left untreated. Symptoms may take decades to appear, and most people with Chagas are unaware they have the disease. While Chagas predominantly affects people who have spent significant time in Latin America, researchers have discovered locally acquired cases in multiple U.S. states. Researchers estimate 6-7 million people globally have Chagas disease, including 300,000 people in the U.S. About 75 million people worldwide are at risk for Chagas.

Chagas Basics

Chagas is a neglected tropical disease caused by a protozoan parasite known as Trypanosoma cruzi. Fewer than 1% of people living with this parasite have been diagnosed. The parasite spreads primarily through the feces of infected triatomine bugs, more commonly called kissing bugs or conenose bugs in the U.S. These blood-sucking insects can enter homes and bite people and pets at night. Trypanosoma cruzi and kissing bugs are present in the U.S., including Florida.

Early detection of Chagas disease is vital. Without treatment, people with Chagas disease can remain infected for life. About one-third will develop chronic Chagas, which can permanently affect the heart, brain and gastrointestinal and peripheral systems, regardless of a patient’s age or other health factors. These conditions can be life-threatening.

While most Chagas cases occur in Latin America, some researchers estimate thousands of people have acquired the parasite in the U.S. from local kissing bugs.

Chagas in Florida

Chagas is a particularly important disease in Florida due to the presence of kissing bugs and T. cruzi, as well as a high number of residents with close ties to Latin America.

Florida is thought to have the third-highest number of people living with chronic Chagas in the U.S., with an estimated 18,000 cases or more. Chagas is not a reportable disease in Florida, meaning that the state does not actively track cases of the disease.

Kissing bugs have been found in 30 states, including Florida. The species Triatoma sanguisuga, a known vector of Chagas disease, has been reported in at least 22 Florida counties throughout the state. Researchers have documented this kissing bug species invading Florida homes and biting people and animals. They have also found the parasite that causes Chagas in nearly 30% of Florida kissing bugs tested.

Kissing bug bites can also trigger serious allergic reactions, including anaphylaxis.

In Florida, more than 50% of opossums and 40% of raccoons tested were infected with T. cruzi. The findings suggest these animals may play a role in the transmission of Chagas in the state.

While researchers suspect that the disease is being acquired in Florida, only congenital cases (mothers passing the parasite to their fetus during pregnancy) and infections in people who have lived in Latin America have been documented.

Chagas transmission

Vector-borne transmission

The parasite T. cruzi spreads primarily through the feces of kissing bugs. Feces can infect the site of a kissing bug bite, eyes, nose or mouth and/or contaminate surfaces within the home.

Foodborne transmission

Some people have also become infected with T. cruzi by ingesting contaminated food or beverages. Fruit juice is the most common source of oral transmission. Food and beverages can contain kissing bugs and/or their feces, or secretions from other animals that can host the parasite, such as opossums and raccoons. Eating the undercooked meat from an infected animal could also be a transmission route for Chagas.

Clinical evidence shows foodborne transmission of Chagas can result in more severe symptoms and/or a higher risk of death than vector-borne transmission.

Congenital transmission

Mothers infected with Chagas may pass the parasite to their fetus during pregnancy. Researchers estimate 22-108 infants are born in the U.S. with congenital Chagas each year.

Other transmission routes

Less common transmission routes include blood transfusions, organ and bone marrow transplants and laboratory accidents.

Reservoir hosts

At least 27 mammal species can also carry the parasite that causes Chagas disease but other species may exist and further research is needed to understand sylvatic cycles. Their role in potential disease transmission remains unclear.

Chagas symptoms

Most people infected with T. cruzi are unaware they have the parasite. Symptoms vary and can take decades to appear, at which point they are often irreversible. The heart is the organ most commonly affected once Chagas progresses to the chronic phase.

Symptoms of Chagas disease can include:

Acute phase – first weeks or months after infection

• A majority of people will not present symptoms
• Non-specific symptoms, such as fever, enlarged lymph nodes, fatigue, rash, loss of appetite, diarrhea and/or vomiting
• Skin inflammation at the site where the parasite entered can occur (Chagoma)
• Romaña’s sign: swelling or sore around the eye or side of the face where kissing bug bite occurred
• A serious acute infection may occur if the person has a weakened immune system and cause acute myocarditis, encephalitis or even shock.

Chronic phase

Indeterminate form

• A majority of people remain asymptomatic
• Serological evidence of T. cruzi infection (antibodies can be detected in the blood)
• No clinical evidence of disease or organ-specific involvement
• Parasite can reactivate if the person develops a condition that weakens immune system. causing serious disease, such as brain abscesses, encephalitis, myocarditis and skin nodules or rashes

Determinate forms

• Heart disease:
  • Abnormal heart rhythm
  • Sudden cardiac arrest
  • Dilated cardiomyopathy and congestive heart failure
• Gastrointestinal tract disease:
  • Abnormal enlargement of esophagus and/or colon
  • Trouble eating and drinking
  • Chronic constipation and abdominal pain
  • Distended abdomen
• Thromboembolic disease, which can lead to higher rates of pulmonary embolism and stroke

People most vulnerable to Chagas

People of any age can become infected with Chagas, but some individuals are particularly susceptible to exposure to kissing bugs and/or T. cruzi.

People who spent significant time in Latin America

The T. cruzi parasite is most prevalent in Latin America. While there is no evidence of Chagas transmission in the Caribbean, kissing bugs and T. cruzi are present on some islands, such as Trinidad and Tobago. People who were born or have lived in Latin America for more than six months, or whose mother was born or lived there, are most at risk for Chagas disease.

People who live in rural areas

Kissing bugs are present in the U.S., including the species that is known to vector Chagas disease. Some bugs have tested positive for the T. cruzi parasite. Kissing bugs are most common in rural areas. 

Chagas diagnosis and treatment

Early screening is essential to diagnose and treat Chagas before it becomes chronic. Screening people with the highest risk of infection for Chagas disease is especially important.

Research has shown that the use of two rapid blood tests simultaneously can diagnose the disease quickly, but studies of this method are still being conducted. Serologically-based assays are available at commercial laboratories, which can be ordered by a physician.

When detected early enough, Chagas disease can be treated with the antiparasitic medications benznidazole and nifurtimox.

A chest X-Ray, echocardiogram, electrocardiogram, cardiac magnetic resonance imaging and/or heart tissue PCR tests can help diagnose patients with heart disease caused by chronic Chagas.

Patients with chronic Chagas should be monitored by healthcare providers. Some patients may require pacemakers or defibrillators, ventricular-assist devices or heart transplantation.

Chagas heart disease is typically a slowly progressive, fatal condition in spite of management. Some research suggests that antiparasitic treatment with mild heart involvement can delay or halt progressive failure. Heart transplants can be managed despite likely reactivation of T. cruzi after immunosuppression.

Early recognition and treatment are key to preventing the development of determinant chronic forms of Chagas.

Chagas prevention

The best way of preventing Chagas disease is to limit exposure to kissing bugs. These insects are most active at night and from May through October when adults are dispersing. They are most common in rural areas.

Another important prevention method is avoiding foods or drinks that could be contaminated with the parasite. In highly endemic regions, foods should be cleaned or thoroughly cooked and certain raw fruit juices, such as guava, sugarcane and acai, avoided.

Travel considerations

If you are spending significant time in Latin America, particularly in rural areas, consider using bed nets, wearing long sleeves and pants and applying insect repellants to protect yourself from kissing bugs.

Protecting your home

Preventing kissing bugs from gaining entry to your home can protect you and your pets.

Researchers recommend taking these steps to protect your home and outdoor areas from kissing bugs and mammals that attract them:

• Inspect your home and outbuildings for potential entryways for kissing bugs. These can include cracks and crevices in windows and doors, broken or damaged screens, holes in floorboards and breaches in chimney flues. Seal these areas.
• Inspect bedding, pet bedding and dog houses and kennels for signs of kissing bugs.
• Remove clutter around the exterior of the home or relocate it at least 400-500 feet away from the main dwelling. Examples of clutter include wood and rock piles and unused building and landscaping materials.
• Kissing bugs are attracted to artificial light, especially fluorescent bulbs that emit white light, blue light and UV (black light). Use bulbs that emit yellowish or orange light. Keep external lights off at night from May to October.
• Block off crawl spaces using solid exteriors with latching doors. Install lattice or other barriers on homes that sit above the ground. This can prevent rodents or other mammals from crawling or nesting under the house.
• Prune trees and shrubs so that they do not touch the home.
• Have a wildlife- or pest control professional remove rodent nests, fox dens, armadillo burrows and opossum latrines near the home. These sites are particularly attractive to kissing bugs.
• Spot-treat cracks and crevices with residual insecticides.
• Remove insect pests with a high-efficiency particulate air filter (HEPA) vacuum.

Additional Resources