It was previously thought that Chagas disease, which kills an estimated 50,000 people per year, was exclusively carried by an insect called the kissing bug. But, according to a Newsweek article, new research shows that bedbugs can also spread the disease, at least among mice.

University of Pennsylvania epidemiologist Michael Levy says he’s worried that bedbugs could distribute the parasitic disease among people, although there is no proof yet that this is happening. 

Chagas disease is caused by a parasitic protozoan called Trypanosoma cruzi that slowly attacks internal organs like the heart. At first, it has very few outward signs. Then, about 20 years after infection, some 20 percent of infected people develop very serious problems, including arrhythmias and even sudden death from cardiac arrest, Levy tells Newsweek.

According to the article, the parasite is spread by kissing (or “assassin”) bugs, which generally feed at night and go for uncovered areas like the face, often around the eyes or lips. These insects don’t directly spread the disease through their bite, but rather through feces; the protozoan can be transmitted when their waste is spread into wounds via scratching, or by entering the body through the eyes or mouth.

Luckily, kissing bugs cannot generally get to humans if they live in well-made buildings, but with the increase of bedbugs, scientists are concerned.

In a study published this week in the American Journal of Tropical Medicine and Hygiene, researchers showed that bedbugs can become infected after feeding on diseased mice. They also found in another experiment that protozoa-carrying bedbugs can pass on the parasite to mice.

Scientists agree that many bedbugs do defecate shortly after feeding, increasing the chances that this insect could transmit the disease to humans via open wounds or another route. And bedbugs have an even closer relationship with humans than kissing bugs.

Read this full article here.