16 August 2009

Chagas Revisited

Yesterday I walked out on my patio to greet the sun and thank God for giving me life and I glanced down at a yellow plastic bucket that I use to water my plants. At the bottom of the bucket I spotted a bug called the "Assassin Bug" (Triatoma infestans) which in Latin America is known as "Vinchuca" (veen-CHOO-kah). This bug is the carrier of a dreaded disease called "Trypanosoma cruzi" or "T. cruzi" for short that causes an illness known as "Chagas". I posted an item to this blog on May 30th of this year entitled "Chagas and Vinchuca". Every year 15,000 people die from Chagas, mostly in Latin America and currently it is estimated that fourteen million people are infected. About thirty percent of people infected will eventually die a slow agonizing death from it and there is no known effective cure for the full blown disease. This year, 2009, is the 100th anniversary of the disease's discovery by a Brazilian doctor and scientist named Carlos Chagas and yet it still has not been made a priority by the World Health Organization (WHO). It almost made it this year but it was bumped off by the H1N1 influenza pandemic. Perhaps it is because it is considered a poor people's disease that it receives little attention. Maybe so, but there is now evidence that Chagas disease has already entered the U.S. donor blood supply and with more and more Americans retiring in Mexico it is something that we should educate ourselves and our Mexican friends and neighbors about. There is a good article about Chagas disease at http://www.scidev.net/en/features/chagas-disease-the-lost-century.html.

The bug that I found in my bucket is no great cause for alarm but it is a reminder that we have to be vigilant and particularly at this time of the year. The Vinchuca is attracted to light on warm humid nights where it knows there are humans to feed on. It is a blood sucking insect and it gets into houses through cracks and holes in window screens and hides in wall crevices, behind picture frames, and in beds. At night it comes out and bites its victim and sucks up a blood meal. It does not spread the disease this way, however. While it is sucking blood it constantly defecates and the T.cruzi organism which causes Chagas is contained in the feces of the bug. This feces then infects the wound made by the bug when the victim scratches the itch made by the wound which is like a mosquito bite. Where there is no human blood available the Vinchuca feeds on the blood of small mammals like tuzos (gophers), ardillas (squirrels), ratas (rats), ratones (mice), mapaches (raccoons), and especially tlacuaches (opossums, also called zarigüeyas).

What should you do to avoid catching this Chagas disease? First of all, tighten up your house. Make sure that there are no places where the insect can enter your home at night especially areas where there are bright lights (external or internal) close to doors and windows. If you should happen to see one of these bugs in your house, especially the bedroom, make a thorough search of your mattresses and bedclothes and also cracks, crevices, or other potential hiding places near your bed. In general if you keep your house neat and tidy there should be no problem. The greatest problem is for people who live in adobe houses or poorly constructed shacks that have no window or door screens. If one of your eyes should swell up for no apparent reason see a doctor immediately and be tested for Chagas. If detected right away, the disease can be treated, but if left to spread throughout the body there is little that can be done at this time. Be careful. It's a jungle out there.


1st Mate said...

Hi, Bob - Thanks for bringing this up again, especially since this bug is going to be more evident now. I'm guessing from the lower photo that he's slightly bigger than a mosquito. Haven't seen anything like that here in the desert, but I will certainly be on the alert now. Rather elegant-looking bug, isn't he? Looks like he was carved or cast out of metal. Oh, no! It's a terrorist robot bug! (lame joke)

1st Mate said...

Bob - I posted the image of the Assassin Bug on my blog and I was asked how big it is. Since you're the one who's seen it, maybe you could clarify. Is it, for instance, bigger than a tick? Also, does it fly?

Babs said...

Geez Louise and I"ve been afraid of scorpions.....now there is something else to worry about. Oy vey!

Mrs Mac said...

Oooo I'm so glad the UK doesn't get these! Yeuck!

Alice said...

Hmm..somebody let that chaga sit on it's arm long enough to take a picture?

I haven't seen any chagas crawling about, but I think we have a few cucarachas breeding in a crack under our sink area.

Bob Mrotek said...


There is no problem with the bite of the Vinchucha. The problems is in the feces from the bug that you rub into the wound when you scratch the bite.

If you have a few cucarachas under the sink you have many unseen. Get some borax powder and sprinkle it under the sink. It won't hurt you but it will sure kill the cucarachas. Also, put some bleach in the water that you wash your floors with. That will kill the tiny creatures that the cucarachas feed on. Ask any Mexican cleaning lady.

YayaOrchid said...

That is some scary looking bug! Sounds like a good storyline for a blockbuster movie. (shudders)

Nancy said...

I saw something in the courtyard today and sprayed the heck out of it. I think it was one of these guys. We've been leaving the light on in the courtyard at night and I wonder if that attracted it.

Our house is almost wide open all day long, and at night several doors are just wrought iron gates. No screens since mosquitoes aren't much of a problem. So now I am all itchy and feel like I need to tear the bed apart (even though it's upstairs and not near a bright light)

It is time for pest control to come again, I will tell them I think I saw them. Thanks for the heads up.

bordersaside said...

As always thanks for the great info Bob. We just stripped everything down and bleached the house and sprayed it is deff the time of year for critters to be getting in.

Javier Nava said...

Thanks for the advice Bob. I think that i`ve seen that bug before but don`t remember where. It really is a very important information as you usually do. Congratulations Bob

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I was born and raised in Chicago, Illinois, U.S.A. I have been living in Mexico since January 6th, 1999. I am continually studying to improve my knowledge of the Spanish language and Mexican history and culture. I am also a student of Mandarin Chinese.