The kissing bug disease in US may spread as health officials warn of the risk for a parasitic infection that can lead to serious problems and even sudden death.
The infection is transmitted by insects that feed on the faces of humans at night. Early studies thought that the disease was limited to Mexico, Central America and South America, according to the Daily Mail.
That’s no longer the case, the new research shows. Melissa Nolan Garcia, a research associate at Baylor College of Medicine in Houston and the lead author of two of the three studies, is concerned. She says that the number of infected people is growing and far exceeds the Centers for Disease Control and Prevention’s estimate of 300,000.
“We are finding new evidence that locally acquired human transmission is occurring in Texas.”
In one pilot study, her team looked at 17 blood donors in Texas who tested positive for the kissing bug disease in US.
“We were surprised to find that 36 percent had evidence of being a locally acquired case … Additionally, 41 percent of this presumably healthy blood donor population had heart abnormalities consistent with Chagas cardiac disease.”
The CDC, however, still believes most people with the disease in the United States were infected in Mexico, Central and South America, said Dr. Susan Montgomery, of the agency’s parasitic diseases branch, according to Philadelphia Daily News.
“There have been a few reports of people becoming infected with these bugs here in the United States … We don’t know how often that is happening because there may be cases that are undiagnosed, since many doctors would not think to test their patients for this disease. However, we believe the risk of infection is very low.”
Maybe so, but kissing bugs — blood-sucking insects called triatomine bugs — are found across the lower half of the United States, according to the CDC. The insects feed on animals and people at night.
The feces of infected bugs contains the parasite Trypanosoma cruzi, which can enter the body through breaks in the skin. Chagas disease can also be transmitted through blood.
The kissing bug disease in US is a silent killer, Garcia said. People don’t feel sick, so they don’t seek care, but it causes heart disease in about 30 percent of those who get infected, notes The Business Insider.
In another study, Garcia’s team collected 40 insects in 11 Texas counties. They found that 73 percent carried the parasite and half of those had bitten humans as well as other animals, such as dogs, rabbits and raccoons.
A third study found that most people infected with Chagas aren’t treated.
For that project, Dr. Jennifer Manne-Goehler, a clinical fellow at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, collected data on nearly 2,000 people whose blood tested positive for the kissing bug disease in US.
Her team found that only 422 doses of medication for the infection were given by the CDC from 2007 to 2013. “This highlights an enormous treatment gap,” Manne-Goehler said in a news release.
The findings of all three studies, published recently in the American Journal of Tropical Medicine and Hygiene, were to be presented Tuesday in New Orleans at the annual meeting of the American Society of Tropical Medicine and Hygiene.
“Physicians should consider Chagas when patients have swelling and enlargement of the heart not caused by high blood pressure, diabetes or other causes, even if they do not have a history of travel.”
However, the two treatments for this kissing bug disease in the US are “only available [in the United States] via an investigative drug protocol regulated by the CDC,” Garcia said. They are not yet approved by the Food and Drug Administration.
Efforts are under way to develop other treatments for Chagas disease, Montgomery said.
“Several groups have made some exciting progress in drug development,” she said, “but none have reached the point where they can be used to treat patients in regular clinical practice.”
The kissing bug disease in US, also known as Chagas or American trypanosomiasis, is a tropical parasitic disease and spreads mostly by insects known as Triatominae. The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild and may include: fever, swollen lymph nodes, headaches, or local swelling at the site of the bite.
After 8-12 weeks, individuals enter the chronic phase of disease and in 60-70% it never produces further symptoms. The other 30 to 40% of people develop further symptoms 10 to 30 years after the initial infection. This includes enlargement of the ventricles of the heart in 20 to 30% leading to heart failure. An enlarged esophagus or an enlarged colon may also occur in 10% of people.
A vaccine has not been developed as of 2013. Early infections are treatable with the medication benznidazole or nifurtimox. They nearly always result in a cure if given early however become less effective the longer a person has had the disease.
Prevention of the kissing bug disease in US mostly involves eliminating and avoiding their bites. Other preventative efforts include screening blood used for transfusions. The disease causes about 12,500 deaths a year.