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Spread of ‘kissing bug’ disease not a concern for snowbirds

Tue, Nov 17: Simon Fraser University researchers are part of an international team looking for ways to fight a blood-sucking insect known as the kissing bug. Linda Aylesworth reports. 
Today's News Hour on Global BC Health Matters brought to you by Pharmasave.
Tue, Nov 17: Simon Fraser University researchers are part of an international team looking for ways to fight a blood-sucking insect known as the kissing bug. Linda Aylesworth reports. Today's News Hour on Global BC Health Matters brought to you by Pharmasave.

The kissing bug sounds like something cute, but it’s anything but. Instead, this triatomine insect gets its nickname from its habit of biting sleeping people around the lips or face.

While it has made its way into the United States, it shouldn’t be a concern to most Canadians hoping to head south during the winter.

“In the U.S. I wouldn’t worry at all,” Carl Lowenberger, a professor of biology at Simon Fraser University who has studied the bug, tells Yahoo Canada News. “Where they are found is not usually in people's houses or hotels.”

The triatomine bug is responsible for spreading Chagas disease — not through its bites but through the feces it leaves behind, often close to the bites themselves. If those feces are infected with a parasite called Trypanosoma cruzi or T. cruzi and the bug’s bite is then infected with fecal matter, Chagas disease can be the result. The triatomine bug is most active at night, when it comes out to feed on human blood.

The average person visiting the southern United States, or even a country in Latin America where Chagas is more established, is unlikely to encounter the bug let alone be bitten and then infected by one carrying the Chagas-causing parasite, Lowenberger says.

Chagas is a life-threatening vector-borne disease that was previously confined to Latin America but has spread into other parts of the world, including the United States. Vectors are small organisms like mosquitos, sandflies and ticks that can transmit serious diseases with a single bite. Vector-borne diseases kill a million people around the world every year, according to the World Health Organization (WHO).

But many vector-borne diseases like Chagas are much more likely to be contracted by those living in affected areas, particularly those living in poor conditions that make it much more likely for bugs to have places like mud floors and thatched roofs to hide in during the day, Lowenberger says.

“It's considered to be a disease of the impoverished,” he says.

That’s not entirely true, he says, but reflects the fact that those living in poor conditions are much more likely to encounter a Chagas-carrying bug than the average tourist.

Potentially life-threatening

Chagas disease manifests in two phases, acute and chronic, according to research from the Centers for Disease Control and Prevention (CDC) and Texas A&M. The acute phase can last for weeks or months and symptoms could include fever, body aches, fatigue, vomiting, diarrhea, rash, headaches and loss of appetite. However, a person can be infected but remain symptom free, sometimes for years. In about 50 per cent of those bitten by a triatomine bug, visible first signs like a skin lesion or the purplish swelling of one eye will appear, according to the WHO.

Approximately 30 per cent of those who are infected with T. cruzi will develop chronic Chagas disease, which can be fatal. Chronic Chagas can lead to cardiac complications like enlarged heart, altered heart rate, heart attack and heart failure. Intestinal symptoms like enlarged colon or esophagus are also possible and show up in about 10 per cent of those who develop chronic Chagas.

Chagas is often curable if treatment begins soon after infection at the start of the acute phase of the disease. Anti-parasitic treatment can halt or lessen the disease if given during the chronic phase. But many people don’t know they have been infected early enough to receive treatment to cure the disease outright.

An estimated six to seven million people around the world — though mostly in Latin America — are estimated to be infected, according to the WHO.

Canadian concerns

The kissing bug has been seen in 28 U.S. states so far, according to the CDC, and it’s expected that more than 300,000 people in that country have Chagas. An estimated 5,000 to 10,000 people in Canada are infected and most of them are from Mexico, Central America and South America, Global News reports.

That news can be worrying to Canadians planning to head south for the winter. But the government says that most people are at low risk for contracting Chagas even though the bug’s reach has spread. Your risk is higher if you are travelling to an area where Chagas occurs and you will be sleeping outdoors, visiting or living in rural areas, or sleeping in houses with poor construction features like cracks in the walls.

Along with being transmitted through feces from kissing bugs, humans can also contract the parasite that causes Chagas by eating food contaminated with the insect feces or receiving a blood or organ donation from an infected person. The parasite can also be transmitted from mother to baby in utero or during childbirth.

The best prevention for Chagas is vector control, which means keeping the bugs from biting you in the first place. The WHO recommends installing screens on windows, wearing bug repellent, practising good hygiene for food preparation and storage, and sleeping under an insecticide-treated bed net for general vector control. Blood screening helps prevent transmission through organ and blood donation.

If you happen to catch an insect that you think might be a kissing bug, you can have it tested to be sure, Lowenberger says. If you do present with a rash you think may be from a bug bite, a physician can test your blood for signs of parasites like T. cruzi. But the risk of a snowbird contracting Chagas remains unlikely, he says.

“The probability of being bitten by one of these bugs is pretty low,” Lowenberger says, “and the probability of that bug being infected with the parasite is much lower.”