"Kissing bugs," whose bite can infect humans with a deadly infection known as Chagas disease, have been detected in every southern U.S. state, impacting more than half the country, health officials say.
The insect known as a triatomine is known as the "kissing bug" for its habit of usually biting people around the mouth and eyes, often at night when it comes out to feed.
That bite can infect people with the Trypanosoma cruzi parasite, leading to Chagas disease, which can cause long-term heart damage, the Centers for Disease Control and Prevention says.
The disease, most common in rural South and Central America, is increasingly showing up in the U.S., the agency says.
Once introduced into the body, the parasite can remain dormant for years or even decades before eventually causing symptoms including fatigue, fever, rash and headaches.
In severe cases, it can lead to cardiac damage, including cardiomyopathy — stretching of the heart muscle — or an irregular heartbeat.
"Once the bug gets into you, it goes throughout the body and sets up quiet housekeeping ... in particular in the heart," says Dr. William Schaffner, an infectious disease expert at Vanderbilt University. "It smolders there for many years, anywhere from 20 to 30 years."
Although not common in the United States, infectious disease doctors and cardiologists are coming across the rare infection more and more, he notes.
While the CDC estimates 300,000 people with Chagas disease live in the United States, it says the vast majority will not show any symptoms.
Since it's very difficult to determine when a person became infected, most people in the U.S. with the disease were likely infected before arriving in the country, Schaffner suggests.
While an infection can be eradicated with drugs, if heart tissue is damaged, then only supportive therapies are available, he says.
If kissing bugs gain entry into a home, they usually hide in cracks or crevices in walls or floors or under beds and mattresses, similar to bedbugs.
Also like bedbugs, they generally come out at night.
Cases in Latin America and South America — as many as eight million infections — are often the result of the insects gaining entry into poorly-constructed rural homes there, the CDC says.
Not all kissing bugs carry the Chagas parasite, the agency points out, and even if an insect is infected, transmission of the parasite from insect to human is not easy.
There is concern that climate change and warmer temperatures could cause an increase in both the Trypanosoma cruzi parasite or the triatomine insect in the U.S., Schaffner says.
"That is a smoldering concern," he notes. "We're concerned that the ecology will change and as we get warmer climates ... we may see some more of certain kinds of infections and this might well be one of them."