Risk of Chagas Disease in Texas May Be Higher than Previously Thought

Most assassin bugs feed on other insects, but conenose bugs in the genus Triatoma are assassin bugs that feed on vertebrates, including rodents and sometimes humans. They usually bite people at night while they’re sleeping, and the bites often occur on the face because it is not protected by blankets, which is why these insects are also known as “kissing bugs.”

Kissing bugs are capable of transmitting a parasite called Trypanosoma cruzi, which causes Chagas disease. The disease has been known to occur mainly in Mexico and South America, but new research shows that the parasite is also widespread in Texas. The finding suggests that the risk of Texans contracting the disease may be higher than previously thought.

Unlike mosquitoes that transmit malaria through their bites, kissing bugs drop feces on the subject while filling up with blood. The feces, which are contaminated with the parasite, often lands in the bite wound. From there, it penetrates the bloodstream and affects the heart and gastrointestinal system.

Curious to know the prevalence of T. cruzi in west Texas insects, researchers at the University of Texas at El Paso set traps to collect the bugs at the University’s Indio Mountains Research Station. The station sits about 100 miles north of the U.S.-Mexico border in Hudspeth County, Texas.

In all, the researchers trapped 39 kissing bugs (Triatoma rubida) and tests revealed that 24 bugs — or 61 percent — were infected with T. cruzi. The findings were published in the journal Acta Tropica.

“It surprised me that so many of them were carrying the parasite,” said Rosa A. Maldonado, an associate professor of biological sciences who led the study. “I was expecting to have some, but this is quite high.”

Maldonado added that there’s a high rate of heart disease along the border and one of the causes could be Chagas disease.

Thirty percent of people infected with the parasite develop life-threatening symptoms like heart rhythm abnormalities and difficulties when eating or passing stool. The disease can also lead to an enlarged esophagus, colon, and heart, and even heart failure.

“Doctors usually don’t consider Chagas disease when they diagnose patients, so they need to be aware of its prevalence here,” Maldonado said. To prevent parasite transmission by the kissing bug, the biologist says it’s important to be aware of the presence of the bugs in the house and yard because pets, like dogs and cats, are also vulnerable.

But getting bitten by a kissing bug isn’t the only way to contract the disease. Once a human is infected, the parasite can be transmitted to others via organ transplants, blood transfusions, and from a mother to a fetus. In addition, the parasite can be spread through foods and juices tainted by the contaminated bug feces.

Maldonado hopes her work brings more awareness to the often overlooked disease, which she calls an emerging infectious disease in the U.S. She is currently investigating the prevalence of T. cruzi in kissing bugs, street dogs, and cats found in El Paso, Texas, an urban city on the U.S.-Mexico border with more than 675,000 residents.

Read more at:

Incidence of Trypanosoma cruzi infection in triatomines collected at Indio Mountains Research Station

Comments

  1. Matt Blaine says:

    Have there been any recent surveys of Chagas Bugs in Florida?

  2. Triatoma rubida commonly contains Trypanasoma cruzi in its gut, but it does not vector the disease often. Unlike the Central and South American Triatominae, which defecate while feeding on the host, Triatoma rubida and other North American Triatoma sp. rarely defecate during feeding. This behavior makes them very low risk vectors for Chaga’s disease.
    Chaga’s disease can however be contracted if the feces of the Triatominae are inhaled, or otherwise come into contact with the mucous membranes (Eyes, nose, mouth, etc.) So if Kissing bugs are known in a structure and work is being done on said structure it is wise to wear proper PPE to reduce exposure of these membranes to fecal particles infected with Trypanosoma cruzi.
    But the take home point here is that this disease is very difficult to contract. And while one should remain cognizant of its presence in the environment, Chaga’s disease really isn’t a threat unless Triatoma infestans or Rhodnius prolixus are introduced into the United States.

  3. Dr. Edward Wozniak says:

    The triatomine illustrated is a T. sanguisuga which looks very different from T. rubida. This could possibly mislead the general public in the El Paso area about what the local vector(s) look like.

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