Bug Week

You Are Viewing

A Blog Post

Chagas disease — get the facts

If you’re a dog owner — and particularly if you have any reason to take your furry friend(s) to visit Texas in the near future — you may have been disturbed by recent news coverage about a malady called Chagas disease.

Dogs in South Texas have been dying suddenly and unexpectedly, and postmortem testing has indicated that Chagas disease is to blame.

Here is one news story, from the Houston Chronicle.

Named for the Brazilian physician Carlos Chagas, who first described it in 1909, Chagas disease is nothing new. But anecdotal evidence suggests that there’s been an uptick in cases affecting Texas dogs for the past couple of years.

The disease is caused by a microscopic parasite, a protozoan called Trypanosoma cruzi. The reason we’re covering the story in the BugWeek website is, Chagas is spread by insects in one of the Hemiptera order’s subfamilies, Triatominae. They’re commonly called assassin bugs, bloodsucking conenose or kissing bugs.

There are roughly 140 species of Triatominae, and virtually all of them feed on vertebrate blood. These insects locate prey in part by following the odor of exhaled carbon dioxide. Consequently, Triatominae often bite their hosts near the mouth — the apparent origin of the “kissing bug” nickname.

When an infected specimen bites a host and inadvertently releases the parasite, the parasite travels through the bloodstream until it reaches an area where smooth muscle tissue is present. This tissue is a component of some internal organs, notably the heart.

That’s where the trouble really begins. If the parasite settles in heart muscle tissue it causes damage, which can ultimately lead to the host suffering a fatal heart attack.

Chagas disease isn’t limited to dogs, either. It’s a serious threat to human health and infects millions in Mexico, Central and South America. Thousands of people die from Chagas each year in some countries.

One piece of good news — there are tests for Chagas disease, and if detected early there’s a good chance of successful treatment. Of course, this requires a doctor or veterinarian who’s familiar with the symptoms.

Another piece of good news is, relatively few Triatominae species routinely attack people, notably Triatoma infestans, which is not native to the United States.

Unfortunately, that’s no help to our canine companions.

The U.S. Centers for Disease Control and Prevention has posted detailed information about Chagas disease online, which you can find here.

Also, the UF entomology department recently posted a “Featured Creatures” document on one Triatominae species found in Florida, which you can read here.