Kissing Bugs and Chagas Disease

Kissing bugs are blood-sucking insects that feed on rodents or other wild animals. They will also bite humans, and some people can develop allergies to their bites. Kissing bugs can spread the parasite (called Trypanosoma cruzi) that causes Chagas disease to many types of animals, but it is very rare for these bugs to infect people in California. Human cases of Chagas disease are more common in Mexico and Central and South America.

The scientific name for the most common type of kissing bug found in California is Triatoma protracta. But kissing bugs are known by many other names:

Triatomine bugs
Conenose bugs
Vinchucas
Chinchés
Barbeiros

Are kissing bugs new to California?

Kissing bugs are native to California, which means they are naturally found in the state and have been here for a long time. Kissing bugs are also native throughout the Americas, including the southern U.S., Mexico, and Central and South America.

Kissing bugs are common in undeveloped, natural areas throughout much of California, especially in foothill and mountainous regions. They have a long, cone-shaped head and a dark brown or black body and are mostly active at night. Adult kissing bugs can fly and are attracted to lights on warm nights. They may enter homes in gaps under doors or through open windows.

Is Chagas disease increasing and spreading in California?

The parasite that causes Chagas disease has been found in wildlife and kissing bugs in California since the early 1900s. But even so, it is very rare for people to become infected and develop Chagas disease in California. Most cases diagnosed in California are in people who lived in Mexico, Central America, or South America at some point in their lives and were infected there before coming to California. Very few people have gotten Chagas disease from kissing bugs in California, and there is no evidence that the risk of Chagas disease is increasing in California. One reason for this is because kissing bugs found in California are not very good at spreading the parasite to people.

Do I need to be worried about Chagas disease in California?

People who live near undeveloped, natural areas may occasionally encounter kissing bugs in or around their homes at night. These insects are not known to infest homes and not every kissing bug is infected with Chagas parasites. You cannot get Chagas disease just from the bite of a kissing bug. The parasite that causes Chagas disease is found in the droppings (poop) of infected kissing bugs. If a person scratches or rubs fresh kissing bug droppings into the bite area, or into their eyes, nose, or mouth, they can become infected with Chagas parasites. Luckily, kissing bugs in California usually do not defecate (poop) while biting and often do so much later and away from the bite area. This may be one reason why people rarely get Chagas disease from kissing bugs in California.

If you see a kissing bug in your home or find one crawling on you, do not smash or squish it. Doing this can increase your chances of coming in contact with contaminated material (droppings, blood, etc.) from an infected bug. If a bug is smashed:

Clean any hard surfaces with a household disinfectant
Wash contaminated clothes or bed sheets with normal laundry detergent
Wash your hands and any affected skin with soap and water

People who have lived in Mexico, Central America, or South America should be aware of Chagas disease and know the signs and symptoms. If you are concerned about Chagas disease, talk to a healthcare provider and remember to tell them if you have recently traveled to an area outside of the U.S. where Chagas disease is more common. Only a healthcare provider can diagnose Chagas disease, and treatment works best when started early.

Important:

Allergic reactions to kissing bug bites are a greater concern in California than getting Chagas disease. Kissing bug bites are usually painless, but some people may develop a reaction that can range from mild to severe. Mild reactions are most common and may include redness and irritation of the skin, itching, and swelling around the bite area within 24-48 hours. A smaller percentage of people may experience more severe reactions after a bite, including anaphylaxis, which can be very serious and cause difficulty breathing. People who have severe allergies and live in areas where kissing bugs are common, or who have experienced severe reactions to kissing bug bites in the past, should talk to a healthcare provider about the need to carry or use an injectable epinephrine device (like an "EpiPen") for use in emergencies.

How can I protect myself from kissing bug bites?

Kissing bugs and other insects are usually attracted to lights on warm nights, so the best way to protect yourself is to keep kissing bugs out of your home or living space:

Keep kissing bugs out

Seal windows and doors with weather stripping, sealant, and/or caulk to close all cracks.
Install tight-fitting door sweeps underneath doors to the outside.
Make sure window screens, door screens, and pet doors fit tightly – fix any holes in these screens where bugs might be able to crawl through.
Avoid hitchhiking kissing bugs: check firewood and other outdoor items before carrying them into the house.

Make your home less attractive to kissing bugs

Reduce the brightness of outdoor lighting and consider replacing outdoor lights with yellow bulbs that are less attractive to night-flying insects.
Clean up clutter around and under your home that could attract rodents (which kissing bugs like to feed on).
Store piles of firewood away from the house.