A kiss you don't want on Valentine's Day

There is one kiss Yuma County residents definitely won't want this Valentine's Day.

A new report from the University of Arizona focuses on the "kissing bug" — a bug that can bite humans on the lips or near the mouth and may make people sick.

In the report, Carolina E. Reisenman, Ph.D., and professor of entomology and neuroscience at U of A, said 41.5 percent of the bugs collected were infected with Trypanosoma cruzi, a protozoan parasite that transmits the Chagas disease.

Though three different species that carry the parasite live in southern Arizona, Craig Levy, program manager of the vector-borne disease program at the Arizona Department of Health Services, said there have only been nine cases statewide in the last three years. And, he said, those nine people were exposed to the disease outside of Arizona in places such as South America, Central America and Southern Mexico.

"The risk for people getting Chagas disease in Arizona is still very low," he said. "It's not zero, but it's very, very low."

According to the report, the kissing bugs live with animals such as packrats, mice, armadillos, raccoons, dogs and opossums. The bugs, Reisenman says, colonize with the packrats in southern Arizona and eventually move into cities, especially in May and June. The bugs, which have wings in their adult life, leave their nests in the desert, she said. On their flight in search of new food sources, according to the U of A Kissing Bug Project Web site, the bugs are attracted to light.

"They will find a way inside your house," Reisenman said, adding the bugs can be very flat.

To prevent attracting the kissing bugs — and others — she said she recommends turning off your porch light and other lights in your home overnight.

Attracted by heat and light, the bugs find their way into homes and then smell humans.

"They accidentally find us because they are attracted to blood," Reisenman said. "They tend to nest close to where we sleep."

But you'll be able to tell if there is a kissing bug infestation in your home, Reisenman said.

The bugs will leave molted skins they shed, brown spots on the sheets, and streaks of both clear and brown on the wall.

Research data from the U of A report indicate the infection rate of T. cruzi in the bugs is higher than researchers previously thought, but Reisenman said that could be for several reasons.

She said people are bitten all the time. "That's very common," she said.

However, being bitten doesn't necessarily mean a person will get sick. T. cruzi lives in the infected bugs' digestive tract, according to the Kissing Bug Project Web site. After the bug bites, it has to defecate or urinate on the same place for the disease to be transmitted, which is relatively uncommon.

Also, an individual human's antibodies and reaction to the disease can vary, Reisenman noted.

In addition, she said doctors might not recognize the symptoms, which include fever and cardiac problems later.

"That may cause problems 20 years down the road," she said.

However, she said when it comes to other possible transmission, such as through human blood, health care professionals cannot be too careful. Levy said screening for the disease at blood banks started in early 2007 to protect the blood supply.

And out of tens of thousands of people, with only nine cases reported, Levy said people should watch out for the bugs but not be too worried.

"That tells us the likelihood of getting this disease here is extremely low," he said. "Otherwise there would be a lot of (cases)."

ON THE WEB
http://www.neurobio.arizona.edu/kissingbug-info/chagas.html

Stephanie A. Wilken can be reached at swilken@yumasun.com or 539-6857.