There is no question that bed bugs are a nuisance. They seem to come from nowhere, multiply in no time, and can wreak havoc on their host’s sleep and sanity. Thankfully, they aren’t known to spread disease when they bite people. At least not yet.
However, researchers at Penn Medicine are concerned that bed bugs may be bringing more than itches and sleepless nights with them. A recent study carried out at the Center for Clinical Epidemiology and Biostatistics suggests that bed bugs may be able to transmit the parasite that causes Chagas Disease, a tropical disease that kills thousands of people each year.
Chagas disease, named after the scientist who discovered it, is a parasitic disease spread mostly by insects related to bed bugs. The symptoms are often minor at first and can go unnoticed for months or years. It’s estimated that millions of people in Central and South America have been infected for several years without knowing. However, chagas disease can lead to permanent organ damage, and can be fatal if left untreated.
Chagas disease is relatively unknown in Europe and North America, but that’s starting to change as some small outbreaks have started occurring farther north than usual. At the moment, infections in the United States is likely the result of immigration or blood transfusions using contaminated blood. The US has begun actively screening donated blood to minimize the risk of transfusions causing the disease to spread further.
The Kissing Bug
Panstrongylus geniculatus, AKA the kissing bug (Photo credit: Fernando Otálora-Luna)
Chagas disease is most commonly spread by the subfamily of insects known as Triatominae, also known as kissing bugs or assassin bugs. A kissing bug is nowhere near as pleasant as its name implies — it got that name due to its tendency to bite human faces to feed on their blood. These little vampires share a lot of similarities with bed bugs, such as their feeding anatomy and their tendency to feed while their host is asleep.
Kissing bugs are predominantly found in South America, though they can sometimes appear as far north as the United States in states like Texas and Louisiana. The doctor who discovered Chagas disease also discovered that kissing bugs were the ones infecting his patients in Brazil.
What About Bed Bugs?
Now that you’re lightly familiar with kissing bugs and the disease they often bring with them, it’s time to get back to the matter at hand: can bed bugs transmit Chagas disease the same way their distant cousins do?
The answer to this isn’t a simple “yes” or “no” just yet, and that’s why research like the Penn Medicine study is being done. In that study, researchers experimented with exposing bed bugs to mice infected with Chagas. After a month of regular feeding, most of the bed bugs used acquired the T. cruzi parasite that carries the disease. A second study confirmed that the infected bed bugs were able to transmit the disease back to mice that didn’t have it after living with them for a month.
However, these experiments do not determine whether or not bed bugs can transmit the disease to humans. The study can’t even conclude that what happened to the mice in the lab is likely to occur out in the wild. It’s very common for lab results to not reflect real-world events due to the different environment that testing is done in. What the study was definitely able to confirm was that bed bugs are capable of carrying the disease by drinking infected blood. This is true of many diseases that humans are susceptible to — bed bugs are known to carry agents of HIV, hepatitis, and Q fever, though they are not known to pass those agents on to other humans.
The likelihood of bed bugs transmitting Chagas disease to humans is uncertain due to how Chagas is usually transmitted. Kissing bugs generally don’t transmit the disease simply by biting humans; the infection is observed when the bug defecates near the bite wound after it’s done feeding, and the feces contaminates the bite wound. Basically, kissing bugs bite your face and then poop on it. Talk about adding insult to injury.
Bed bugs, on the other hand, are not known to be habitual people-poopers. They prefer to do their business after they’ve run away and tucked themselves into a hiding place. This makes it unlikely that feces rich in T. cruzi will have the opportunity to infect a fresh bed bug bite.
If you’re still concerned about Chagas or other diseases that your friendly neighborhood bed bugs might be carrying, why take the risk? Read up on how to prevent bed bugs at home and on the go so they don’t have the opportunity to make an experiment out of you.