Triatomine bugs, or triatomines, are native to Mexico, Central America, South America, and parts of the United States. They’re nicknamed “kissing bugs” for a rather unpleasant reason — they tend to bite people on the face and near the mouth. They can bite people on other parts of the body, too.
Kissing bugs carry a parasite called Trypanosoma cruzi. They pick up this parasite by feeding on a person or an animal with a T. cruzi infection. The parasite then lives in the kissing bug’s intestines and feces.
If feces containing the T. cruzi parasite get inside your body, you’ll develop an infection known as Chagas disease.
Kissing bugs are nocturnal, which means they come out at night to feed. Kissing bugs usually bite people when they’re sleeping. The bites don’t hurt, and you may not even know you’ve been bitten.
Kissing bugs bite by injecting saliva that has an anesthetic property into the skin. It typically takes between 20 and 30 minutes for the bugs to feed.
Kissing bugs resemble other bugs naturally present in the United States, such as the Western corsair, leaf-footed bug, and wheel bug.
- a cone-shaped head
- a length of .5 to 1 inch
- a long, oval-shaped body with antennae
- a light brown to black body
- yellow, red, or tan markings on the body, in some cases
- six legs
Most people don’t have a skin reaction when a kissing bug bites them. The bite isn’t distinctive, either. It looks like any other bug bite, except there’s usually a cluster of bites together in one spot.
People who are sensitive to the kissing bug’s saliva may experience a reaction to the bite. This is usually only mild itching, redness, and swelling. Occasionally, a kissing bug bite causes a severe localized allergic reaction.
If you have a T. cruzi infection, a small hard area may form at the bite site 1 or 2 weeks after you’re bitten. This is called a chagoma. Chagomas look red and swollen.
If the T. cruzi parasite enters your body through the conjunctiva, it may cause swelling of the upper and lower eyelid. This response is known as Romaña’s sign.
In rare cases, a person who’s allergic to the kissing bug’s saliva can have a severe allergic reaction after being bitten. This reaction is known as anaphylaxis.
Anaphylaxis is a life threatening allergic reaction that comes on suddenly. Anaphylaxis can lower your blood pressure to dangerous levels and make it hard to breathe.
Anaphylaxis is a medical emergency and requires immediate treatment.
Chagas disease is another rare complication of a kissing bug bite. Not all people bitten by kissing bugs get Chagas disease. You only get the disease if infected feces from the parasite get into your body.
After a kissing bug bites you and feeds on your blood, the bug defecates. An infection can occur if the feces enter the body through your mouth, your nose, your eyes, or an opening in your skin. The feces can also enter your skin if you scratch or touch the bite and accidentally transfer the feces.
The first few weeks of the infection are what’s known as the acute phase. Most people have no symptoms or only very mild flu-like symptoms. These can include fever, body aches, a rash, and swollen glands. The symptoms are a reaction to the high number of parasites circulating in the blood.
Symptoms improve — even without treatment — as the number of parasites in the bloodstream decreases. This is the chronic phase. T. cruzi is still in the body, but most people don’t have symptoms.
However, according to the Centers for Disease Control and Prevention (CDC), an
- irregular heart rhythms that can lead to sudden death
- cardiomyopathy, or a weakening of the heart muscle
- cardiomegaly, or an enlarged heart
- dilation of the esophagus (megaesophagus) and colon (megacolon)
- difficulties eating or having a bowel movement
If Chagas disease is treated early, the chronic phase can be avoided. Seek treatment early if you think a kissing bug has bitten you, because there’s no cure for Chagas disease once it becomes chronic.
Where it’s found
Chagas disease is endemic to Mexico, Central America, and South America.
According to a 2020 study, around 8 to 11 million people worldwide have the infection. Researchers also estimate that between 326,000 and 347,000 Latin American immigrants to the United States have the infection.
Most people in the United States who have Chagas disease are immigrants from the endemic areas and acquired it before arriving in the United States.
There are kissing bugs in the lower half of the United States, but some experts believe that these particular species rarely transmit the parasite.
However, some research suggests that more people may acquire the infection in the United States than previously thought.
Since kissing bug bites don’t cause any pain, most people won’t need treatment.
If you experience a mild skin reaction, an anti-itch cream, such as calamine lotion, can help.
A severe localized allergic reaction should be evaluated by a healthcare provider, who may treat it with antihistamines and corticosteroids.
If you go into anaphylaxis and have already been prescribed epinephrine, use your autoinjector to administer it (or have someone else administer it) until medical help is available.
Treatment for Chagas disease
In the United States, awareness of Chagas disease is low. People are rarely diagnosed with or treated for the condition.
If a doctor diagnoses you with Chagas disease, they can prescribe antiparasitic medications such as benznidazole and nifurtimox (Lampit). Neither are readily available.
- Benznidazole. The Food and Drug Administration (FDA) has approved this medication for children 2 to 12 years old. It’s not available in U.S. pharmacies, but doctors can obtain it from the manufacturer’s website.
- Nifurtimox (Lampit). The FDA has approved this medication for children who are under 18 years old and weigh over 5.5 pounds.
Adults may be prescribed these medications as off-label treatments.
Off-label drug use
Off-label drug use means a drug that’s approved by the Food and Drug Administration (FDA) for one purpose is used for a different purpose that hasn’t yet been approved.
However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs but not how doctors use drugs to treat their patients. So your doctor can prescribe a drug however they think is best for your care.
Chagas disease needs to be treated early. Once the disease reaches the chronic phase, medications won’t cure it.
Antiparasitic medication helps kill the parasites and stop the disease from becoming chronic. It’s given to anyone in the acute phase. It’s also sometimes given to people in the chronic phase.
Medications can’t cure the disease after it becomes chronic, but they may slow the progression of the disease and help you avoid life threatening complications. People with chronic disease who should be treated are:
- anyone under 18 years old
- anyone under 50 years old who doesn’t have advanced cardiomyopathy
Benznidazole and nifurtimox can cause side effects in people who are pregnant or breastfeeding (as well as fetal harm). If you’re pregnant and have acute Chagas disease, ask your doctor whether the benefits of treatment will outweigh the risks. If you don’t have acute Chagas disease, avoid these medications during your pregnancy.
Also avoid nifurtimox if you have:
See a doctor if you:
- live in Mexico, Central America, South America, or the lower half of the United States, and have clustered insect bites on your body, especially your face
- have seen kissing bugs in your home
- are experiencing symptoms that could be caused by Chagas disease
During the day, kissing bugs usually live in mud, straw, and adobe. These materials are often used to build homes in the endemic areas of Mexico, Central America, and South America.
If you visit these areas, try to avoid sleeping in structures made of these materials. If you do sleep in them, take the following precautions:
- surround your bed with insecticide-coated netting
- spray insecticides to kill the bugs in the area
- apply bug spray to your skin regularly
If you live in a structure made of mud, straw, or adobe, you should also take the precautions above. In addition, get tested to see if you’ve already contracted the T. cruzi infection.
If you live in the lower half of the United States and see kissing bugs:
- seal cracks and crevices in your home with silicone-based caulk
- repair holes or damages in window screens
- remove debris or leaves within 20 feet of the home
- clean surfaces with a bleach or insecticidal solution
A professional exterminator can kill kissing bugs in your home.
If you think you see a kissing bug, try to capture it with a container or while wearing gloves. Don’t touch the bug directly.
Kissing bugs don’t always cause Chagas disease, but if you think you’ve been bitten, see a doctor. Early treatment is critical to preventing Chagas disease from reaching the chronic stage.
Keeping your home bug-free and notifying a doctor if you have bites or symptoms of Chagas disease can help you stay healthy.