Kissing bugs, also known as triatomine bugs, are nocturnal insects that can transmit a serious parasitic disease. Their presence indicates a potential for infection and the spread of an illness with long-lasting health consequences.
What Are Kissing Bugs?
Kissing bugs are blood-feeding insects, typically 0.5 to 1.75 inches long, with a dark brown or black body often marked with red, orange, or yellow. They have cone-shaped heads, thin antennae, and a slender, needle-like mouthpart tucked beneath their body.
These bugs are primarily active at night, emerging to feed on the blood of mammals, including humans. They are attracted to carbon dioxide exhaled by sleeping individuals, which often leads them to bite around the face or lips, hence their common name. While the bite itself is usually painless due to an anesthetic in their saliva, it serves as an entry point for infection.
The Link to Chagas Disease
The primary reason kissing bugs are dangerous is their capacity to transmit the parasite Trypanosoma cruzi, which causes Chagas disease. Not all kissing bugs carry this parasite; however, approximately 50% of kissing bugs in the U.S. are infected. Kissing bugs acquire T. cruzi by feeding on the blood of infected animals or people, with the parasite then residing in the bug’s gut and feces.
Transmission to humans typically occurs when an infected bug defecates near the bite wound during or after feeding. The parasite is not in the bug’s saliva or bite itself. If a person scratches or rubs the bug’s feces into the bite, mucous membranes like the eyes or nose, or any break in the skin, the parasites can enter the bloodstream and establish an infection. While vector-borne transmission is the most common route, the disease can also spread through other less frequent means, including congenital transmission from mother to baby, blood transfusions, organ transplantation, or consumption of contaminated food or beverages.
Stages of Chagas Disease
Chagas disease progresses through two main phases: an acute phase and a chronic phase. The acute phase begins shortly after infection and can last for several weeks or months. During this period, a high number of parasites may circulate in the blood, but symptoms are often absent or mild and non-specific.
Common symptoms, if they appear, can include fever, fatigue, body aches, headache, rash, or swelling at the infection site, known as a chagoma. If the parasite enters through the eye, a characteristic purplish swelling of one eyelid, called Romaña’s sign, may develop. Many individuals in the acute phase may not realize they are infected, as the infection often goes unnoticed.
The chronic phase can develop years or even decades after the initial infection, often silently. Approximately 20% to 30% of infected individuals may develop serious complications during this long-term stage. These complications primarily affect the heart, leading to conditions such as cardiomyopathy, heart failure, and irregular heartbeats. Digestive issues, including enlargement of the esophagus (megaesophagus) or colon (megacolon), can also occur. These chronic complications can be severe if left untreated.
Where Kissing Bugs Are Found
Kissing bugs are found throughout the Americas, with a significant presence in Latin America, but they are also documented in at least 29 states across the southern United States. States like Texas, New Mexico, and Arizona report a higher number of different kissing bug species and findings. These bugs are not new to the U.S., having been documented as early as the mid-1800s.
They typically inhabit environments that provide shelter and access to hosts. These include cracks and crevices in homes, especially those with traditional construction materials like mud, straw, or adobe. Outdoors, they can be found under porches, in animal burrows, woodpiles, and rock structures. Proximity to wildlife that can carry the T. cruzi parasite, such as woodrats, raccoons, coyotes, and opossums, increases the risk of human exposure.
Protecting Yourself and Seeking Care
Protecting yourself from kissing bugs involves several preventative measures, especially in areas where they are common. Sealing cracks and gaps in your home’s walls, windows, and doors can help prevent their entry. Using screens on windows and doors is also important. Keeping outdoor areas clear of debris like wood, brush, and rock piles can reduce potential hiding spots for bugs and discourage wildlife that might carry the parasite.
If you encounter a suspected kissing bug, handle it carefully without direct skin contact. Instead of squashing it, which could release infected feces, capture the bug safely in a container or plastic bag. You can then freeze the bug to preserve it for identification and potential testing by local public health authorities or university programs. Some states, like Texas, New Mexico, and Arizona, have programs where residents can submit bugs for identification.
If you suspect you have been bitten by a kissing bug or experience symptoms consistent with Chagas disease, seeking medical evaluation is advisable. Healthcare providers can diagnose Chagas disease through blood tests. Treatment involves antiparasitic medications, such as benznidazole and nifurtimox, which are most effective when administered during the acute phase of the infection. While these medications can be less effective in the chronic phase, they may help slow disease progression and manage complications.