Not all kisses are sweet

Every summer, an insect with a sweet name poses a serious threat to the populations of the southern United States and Latin America. Known as the kissing bug, this insect carries a parasite that can cause the potentially fatal Chagas disease.

"Kissing bugs are not your typical insect. Feeding on blood—mostly at night—they’re stealthy, and their bites often go unnoticed, which makes them particularly dangerous," said Joshua Bast, an entomologist with the Defense Health Agency-Public Health in Aberdeen, Maryland. Bast warns that these bugs can carry a parasite called Trypanosoma cruzi that causes Chagas disease.

What is a kissing bug?

"Kissing bugs, also known as triatomines, cone-nose bugs, or chinches, are blood-sucking insects found in the U.S., especially during the warmer summer months," said Bast. 

These elusive insects find refuge in various outdoor locations, including beneath porches, between rocks, and in animal burrows. They’re often drawn to artificial lights that bring them into close proximity to humans and animals. In homes without good ways to keep the bugs out, they can hide in cracks or small holes.

There are 11 different kinds of kissing bugs in the U.S. that can carry the parasite, but not all kissing bugs are infected. Research by Texas A&M University has shown an average infection rate of 55 percent from over 7,000 kissing bugs tested from 27 different U.S. states. 

“This is an alarmingly high infection rate, but the parasite transmission to humans is quite inefficient,” said Bast. “This parasite is spread to people and animals by the feces of infected kissing bugs.” 

After taking a blood meal, a kissing bug may defecate, depositing the parasite on the skin, said Bast. The parasite then enters the host when the feces is rubbed into the wound or into mucous membranes, such as the eyes. Other ways the disease can spread are from mother to fetus, ingestion of infected kissing bugs, and through contaminated blood products.

“Dogs and other animals may also become infected by eating the kissing bug, which is certainly a concern for our military working dogs in kennels that are outdoors or near areas with kissing bugs,” Bast said.

What is Chagas disease?

Chagas disease has an acute phase and a chronic phase, said Bast. The acute phase occurs immediately after infection and can last 8–10 weeks. During this phase, parasites may be found in the blood, but symptoms are usually mild or absent. 

"Left untreated, the disease is for life and can be fatal. The parasites will hide in the heart and digestive muscle tissue," said Bast. “Diagnosing Chagas disease can be challenging, as symptoms may not appear for years or even decades, and treatment must occur before that happens.”

Chagas disease diagnosis

Bast advises that if you suspect you’ve encountered a kissing bug and may have Chagas disease, discuss your concerns with your medical provider. Chagas disease is diagnosed by blood tests. 

"During the acute phase, parasites may be found in blood smears under microscopic examination,” said Bast. “However, it is rare to be diagnosed during this phase. Diagnosis of chronic Chagas disease is made by serologic tests after the 8- to 10-week window of acute infection and is usually performed by a commercial laboratory." 

The Centers for Disease Control and Prevention recommends treatment only after a confirmed diagnosis.

Chagas disease treatment

The two FDA-approved treatments (https://www.cdc.gov/chagas/hcp/clinical-care/index.html) for Chagas disease are benznidazole and nifurtimox, both available by prescription.

"Treatment should be offered to all people diagnosed with acute infection, babies born from infected mothers, those with suppressed immune systems, and all children with chronic infection. Adults with chronic infection should be considered for treatment on a case-by-case basis," said Bast.

What to do if you find a kissing bug

If you find a kissing bug, Bast recommends having it tested by an expert. “First of all, don’t panic!” said Bast. “There are many look-alike bugs that aren’t actually kissing bugs.” Bast advises that if you capture a bug that you suspect has bitten you or someone in your home, get the bug tested for the parasite. "Many state health departments accept kissing bugs for testing if they were found inside the home or suspected of having bitten someone,” said Bast. “If the kissing bug tests positive, it will often also be tested to determine if it had a human blood meal. If that result is positive, speak with your doctor about getting tested.”

If the kissing bug was found outside the home and not suspected of biting a human, it may be sent to a Kissing Bug Citizen Science Program from universities such as Texas A&M University; the University of Nevada, Las Vegas; and the University of Delaware.

While Chagas disease poses a significant health threat, awareness and understanding can help prevent its spread. "Education is key," said Bast. "The more people know about Chagas disease and its transmission, the better equipped they are to protect themselves and their families." 

By staying informed and taking preventative measures, you can protect yourself and your loved ones from the dangers of kissing bugs and Chagas disease.

Resources

For more information about Chagas disease:
• DHA-Public Health Chagas website
• Kissing Bug and Chagas Disease Guide

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