Hidden Threat: The Kissing Bug and Chagas Disease

 

State health officials tell NBC 5 Investigates Kissing Bugs have infected at least a dozen Texans with a parasite that causes Chagas disease, a disease typically found in the tropics.

The large bugs are turning up all over the state and research is showing most of them carry a parasite, Trypanosoma cruzi, which doctors describe as a silent killer. A person could be infected for years and not know until more serious symptoms set in.

Many Texas researchers are concerned, but statements from the federal government seem to barely acknowledge people are being infected here.

For four months NBC 5 Senior Investigative Reporter Scott Friedman teamed up with The Dallas Morning News’ Dr. Seema Yasmin to investigate the risks and what’s being done to protect people in Texas.

“I’ve never left the United States. I’ve never even been on a cruise,” said Candace Stark, who said she has no doubt she was infected here in Texas.

Stark, who lives in LaGrange, about an hour from Austin, found out she had Chagas after donating blood in 2013.

A month later, the blood bank sent her a letter saying routine screening found her blood tested positive for Trypanosoma cruzi -- the parasite which causes Chagas disease. Chagas often starts with flu-like symptoms but in some patients can lead to life-threatening heart problems and even death.

A second blood test form the Centers for Disease Control and Prevention confirmed Stark had the parasite in her body.

“I was scared. I was really scared, because everything I read about it was about your heart and what it would do to you,” said Stark.

Her doctors barely even heard of Chagas. It’s common in South and Central America, including Mexico, but not here in Texas.

The parasite is spread by kissing bugs, insects that get their name because they typically bite at night, on the face and lips.

The details of how they infect people aren’t pretty. It happens when the bug leaves its feces near the bite, which may itch and gets scratched, driving the feces under the skin and into the bloodstream.

Prior to learning she had been infected, Stark said she had never heard of The Kissing Bug and that she didn’t remember being bitten.

Months after her diagnosis, she found a clue about where she may have been infected. At her parent’s ranch in LaGrange, where she had spent many nights, she found a bug in a closet.

She sent the bug to Texas A&M where researchers confirmed it was a kissing bug that contained the parasite.

That lab is now receiving kissing bugs from all over the state.

“During peak season, we get bugs sent to us every day, multiple packages and every package can have one to 10 bugs, or even more,“ said Texas A&M researcher, Sarah Hamer.

Hamer has a website that asks people to send in the bugs so her team can track where people are finding them in Texas.

Most of the kissing bugs A&M receives come from South Central Texas. But as word has spread, bugs have come in from places much farther north around Austin, the area around Waco and all the way up to the DFW area. Kissing bugs have been found in most counties in North Texas including Dallas, Tarrant, Collin and Denton counties.

“What we’re receiving here in my research lab is just the tip of the iceberg of the bugs that are out there active and established across the state,” said Hamer.

Ed Wozniak, a researcher with the Texas Department of State Health, launched his own search for kissing bugs.

He was surprised by the number he’s been able to find.

“I was shocked by it. I never anticipated being able to get anything close to that,” said Wozniak.

Over three years he expected to find about 50 or 100 bugs. Instead, he found about 500 in south Texas neighborhoods.

“Most of my collection was focused around houses, and that’s what’s alarming,” said Wozniak.

Near houses, the bugs are more likely to come into close contact with people.

Wozniak said kissing bugs have been here for decades, but believes people are seeing them more often because more Texas suburbs are being developed on what was once untamed, rural land where the bugs can thrive.

Adding to that concern, researchers at Baylor Medical Schools in Houston have found most of the kissing bugs found in Texas are infected with the Chagas parasite. More concerning, when they test the bugs in a lab most of them have human blood in their bellies showing they’ve already bitten people.

Kristy Murray, a researcher with Baylor Medical School, said the number of bugs that had already bitten people was as high as 66 percent.

“About 60-ish percent were actually positive for Chagas as well. So we find positive bugs feeding on people,” said Murray.

Murray believes the situation is serious enough that all Texans need to be aware of and know exactly what the bugs look like.

But when NBC 5 Investigates asked state and federal health officials if Chagas is a big concern in Texas they seem to provide different answers.

“We do know it’s an emerging threat. We do know it’s of concern,” said Tom Sidwa, State Public Health Veterinarian with the Texas Department of State Health Services.

But in a satellite interview, a top CDC official, Dr. Sue Montgomery, seemed to downplay the situation in Texas.

“There certainly is growing awareness, but it’s hard to say that it’s an emerging health risk,” said Montgomery.

In some of the CDC’s public education materials you get little sense that Chagas is a threat to anyone in Texas. One CDC Chagas “fact sheet” has a long list of countries where people are at a “greater risk,” but there’s no mention of cases here.

When asked if it would be worth mentioning that people in Texas had contracted the disease locally, Montgomery said that in their printed and online materials they do say there have been a few cases of Chagas acquired in the United States.

But it’s more than just a few cases, according to the Texas Department of State Health Services. Records show the state suspects there are at least 12 cases where people contracted the disease in Texas since the state starting tracking Chagas two years ago.

Sidwa said there is so much that remains unknown that it’s tough to say if Chagas can gain a foothold in Texas.

The CDC said it knows people have contracted Chagas in Texas, but wants to see more research in the state before publishing more specific risk information.

“I think it's a question that needs a lot more study and the group out of Baylor in Houston is looking at exactly that. What are the risks for acquiring Chagas disease in Texas,” said Montgomery.

That group at Baylor is led by Dr. Peter Hotez, one of the world’s leading experts on tropical diseases.

“I think we are just now beginning to comprehend the full magnitude of this Chagas disease problem,” said Hotez.

He feared the number of local Chagas cases could grow. In poor neighborhoods in cities like Dallas or Houston, homes often have no screens on windows which allow bugs to enter at night.

But that’s not the only place people are at risk.

“We're even seeing this among some of the hunters and campers in Texas as well. So it's not only a disease of poverty -- Chagas disease,” said Hotez.

Hotez said no one really knows how many people have been infected here, because most with Chagas live for years without knowing they have been infected.

Initial symptoms are like the flu. It’s not until decades later that about one-third of patients develop serious heart or stomach problems.

Candace Stark heart is not showing any life-threatening symptoms, so far. She’s already taken a course of medication to treat Chagas, but there’s no way to know for sure what will happen.

Stark said she lives with the worry about what may come from the disease as more time passes.

“I worry about that every day. I worry about when it does happen -- if it does happen,” Stark said.

She decided only recently to speak out because she wants Texans to know this bug is here.

“I would tell them this is not a disease that is just in other countries anymore. It's now in the United States,” said Stark.

Researchers told NBC 5 Investigates people who live near a wooded area may be at higher risk and that they should avoid stacking wood around the home as the bugs like to hide in wood piles. Also, make sure there’s nothing near the house where small animals, like rats, may nest since they, too, attract bugs.

Standard pest control treatments seem to have an effect on the bugs, but not always because the bugs can fly over insecticide ground-based barriers.

Anyone who believes they have found a kissing bug can send it to Texas A&M for testing using instructions on their website. The site also describes precautions for collecting the bugs safely:

If you find kissing bugs in your home or suspect you have been bitten health officials suggest you contact your doctor or the Texas Department of State Health Services to discuss testing for the parasite.

You can read more about this from Dr. Seema Yasmin in Tuesday’s edition of The Dallas Morning News -- and online at DallasNews.com.

[This article was originally published by NBCDFW.]