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Silently ravaging the heart
July 8, 2012 10:45 PM   Subscribe

Chagas' disease can cast a silent, lifelong shadow. 'Chagas is a potentially fatal parasitic disease most often found in Latin American immigrants. There had been little awareness of it in the U.S., but' it is slowly making its way into the United States. 'Chagas affects an estimated 300,000 people in this country and about 13 million worldwide, chiefly in Latin America, where it is a leading cause of heart failure.'

'Most carriers in the United States are immigrants who acquired the disease in impoverished areas of Bolivia, Mexico or Central America, where kissing bugs inhabit the cracks and crannies of homes. The bugs nip at faces and lips while people sleep, and drop feces laden with the parasite Trypanosoma cruzi. The parasite can enter the open wound and circulate in the blood, attacking the heart, colon or esophagus.'

'The disease can trigger strokes and heart failure in people as young as 30. "Your heart just turns into a big, ineffective bag," said cardiologist Sheba Meymandi, director of a Chagas treatment program at Olive View-UCLA Medical Center, the only one of its kind in the nation. About 1 in 100 Latin American immigrants whom the center tests has the disease.

Insects carrying the parasite live throughout the southern half of the U.S.,' but there has only been a handful of cases where the disease was contracted locally.

'Kissing bugs are suspected of having infected two Los Angeles high school students recently. Meymandi treated the 17-year-olds, who tested positive for Chagas after donating at school blood drives. Neither is of Latin American descent or has ever traveled to the region. But both spend time outdoors mountain biking or golfing, and Meymandi thinks they acquired the disease locally.'

'Experts agree that Chagas needs more attention, but a recent editorial in the Public Library of Science's journal Neglected Tropical Diseases sparked controversy by labeling Chagas "the new HIV/AIDS of the Americas." Peter Hotez, the paper's lead author and dean of the National School of Tropical Medicine in Houston, noted that both are chronic diseases spread by blood, require toxic medications and disproportionately affect the poor.

But Chagas is not a virus and cannot be sexually transmitted. And there is little patient advocacy to draw attention and funding to the illness. "This is a forgotten disease among forgotten people," Hotez said.

Caryn Bern, a visiting global health expert at UC San Francisco, said the comparison to HIV is overblown and sensational. And Meymandi worries that the association will create additional stigma for immigrants with Chagas.

In the southern U.S., kissing bugs carrying the parasite can infect raccoons, dogs and, on occasion, people. The blood-borne disease also passes from mother to child in utero 5% to 10% of the time.'
posted by VikingSword (30 comments total) 8 users marked this as a favorite

 
Previously,

This was the comparison made to HIV in that PLOS paper,
"Both diseases are health disparities, disproportionately affecting people living in poverty. Both are chronic conditions requiring prolonged treatment courses… As with patients in the first two decades of the HIV/AIDS epidemic, most patients with Chagas disease do not have access to health care facilities. Both diseases are also highly stigmatizing, a feature that for Chagas disease further complicates access to … essential medicines, as well as access to serodiagnosis and medical counseling."
Of course the Daily Fail got wind of it and went with,
The 'new AIDS of the Americas': Experts warn of deadly insect-borne disease that can cause victims' hearts to explode
Hotez PJ, Dumonteil E, Woc-Colburn L, et al. (2012) Chagas Disease: “The New HIV/AIDS of the Americas”. PLoS Negl Trop Dis 6(5): e1498. doi:10.1371/journal.pntd.0001498

Tanowitz HB, Weiss LM, Montgomery SP (2011) Chagas Disease Has Now Gone Global. PLoS Negl Trop Dis 5(4): e1136. doi:10.1371/journal.pntd.0001136

Sarkar S, Strutz SE, Frank DM, et al. (2010) Chagas Disease Risk in Texas. PLoS Negl Trop Dis 4(10): e836. doi:10.1371/journal.pntd.0000836
posted by Blasdelb at 11:07 PM on July 8, 2012 [4 favorites]


Also, PLoS is openly available so just clicking the links gets you the papers.
posted by Blasdelb at 11:08 PM on July 8, 2012


Because lyme and ticks is not enough. The Wikipedia description is horrifying
Most triatomines aggregate in refuges during day and search for blood during night when the host is asleep and the air is cooler. Odors as well as heat guide these insects to the host. Carbon dioxide emanating from breath, as well as ammonia, short chain amines and carboxylic acids from skin, hair, and exocrine glands from vertebrate animals, are among the volatiles that attract triatomines. Vision also serves triatomines for orientation. During night, adults of diverse species fly to houses attracted by light.
Sleep well.
posted by stbalbach at 11:28 PM on July 8, 2012 [1 favorite]


I wonder how often this kind of thing is properly diagnosed in American hospitals and ends up being chalked up as something else. From what I see in the articles, there's not even any reporting or screening.

For what it's worth, I saw one of these bugs firsthand about 15 years ago in a mid-price rental house in Oklahoma. The fucker would stand its ground and turn to face you as you moved through the room. Given the average person's ignorance of bug identification and the lack of reporting, I would bet they're a lot more prevalent than the literature says. It would be interesting to see how often they turn up in hotels in San Antonio.
posted by crapmatic at 11:31 PM on July 8, 2012 [2 favorites]


CDC's Chagas page.
CDC's Neglected Parasitic Infections page.
The 300,000 figure is estimated by applying the proportion of people infected in regions where the disease is endemic to the size of US immigrant populations from those areas, reflecting the history of the disease here. People generally pick this up in an endemic area and bring it to the US, so it's a disease of importation rather than a common vector-borne disease. Although the triatomine bug that carries the parasite is found in about half of US states, our bug populations aren't very commonly infected with the trypanosome parasites that cause the disease. As vector-borne parasites go, too, it's a relatively hard one to catch, even from an infected vector.
posted by gingerest at 12:57 AM on July 9, 2012 [1 favorite]


How hard (and expensive) is it to detect and treat?
posted by pracowity at 1:10 AM on July 9, 2012 [1 favorite]


A Peace Corps buddy of mine woke
up ten years ago with a kissing bug on his arm. He lived in a poor remote area of Guatemala. We (fellow returned Volunteers) send him links whenever Chagas is in the news, but basically, he is just waiting and seeing what happens. He doesn't know what else there is to do.
posted by oneironaut at 1:22 AM on July 9, 2012


cf Shagger's disease - Chagas is probably better known in the UK by virtue of its comedy name.
posted by rongorongo at 2:10 AM on July 9, 2012


The act of scratching the bite is what introduces the pathogen into the body. Not scratching bug bites, and gently washing the area should suffice as adequate protective measures.
posted by Renoroc at 3:16 AM on July 9, 2012 [1 favorite]


And like that, my not-entirely-irrational fear of contracting an obscure, yet horrifically painful/deadly sickness from an insect bite has now put the southwest off-limits to me. Thanks.
posted by Ghidorah at 4:19 AM on July 9, 2012 [4 favorites]


This was the comparison made to HIV in that PLOS paper,

Except, then they go on to point out:
Whereas HIV/AIDS is almost always a fatal condition in the absence of antiviral therapy, up to 70%–80% of people with Chagas disease do not progress to cardiomyopathy.
That seems pretty darn relevant both from the an individual perspective and a public health perspective. Even skimming that paper again now, I get the impression that the main reason for comparing Chagas disease to HIV/AIDS is that HIV is sexy and Chagas isn't and they want people to pay attention to the disease they study.
posted by hoyland at 4:36 AM on July 9, 2012 [1 favorite]


I've only been aware of it from having been asked for years when donating blood if I've had it (among several other obscure maladies and not-so-obscure ones such as AIDS and malaria). But until now I've never know exactly what it is. Yeesh.
posted by Gelatin at 5:48 AM on July 9, 2012


Chagas is on the (rather long) list of diseases that I figure I've been exposed to by living in places where they are endemic, but isn't something I'm going to lose sleep worrying about. The biggest issue -- and part of the reason they made the HIV comparison, I suspect -- is that doctors here maybe had one class in med school on these diseases, and don't tend to know symptoms or to test for them.
posted by Forktine at 6:01 AM on July 9, 2012


OMG! Killer bees!

Seriously, this seems scary, but the HIV comparison makes no sense. Well, other than if you're trying to get funding to develop drugs for it or something.
posted by mondo dentro at 7:35 AM on July 9, 2012 [1 favorite]


...and, in five days I'm off to Guatemala for a month. No thatched roofs for me, but thanks anyway for the terrors.

Here's an interesting NY Times article on attempts to use genetic engineering to attack the parasite.
posted by univac at 7:40 AM on July 9, 2012


There was a hypothesis advanced (first in 1959) that Charles Darwin's health troubles were due to contracting Chagas Disease in South America during the Beagle's voyage. There is however quite a lot of evidence against this hypothesis, according to Wikipedia.

One of course hopes more attention would be given to people living now who suffer from the disease instead of a famous dead scientist, who may have had it, but probably did not.
posted by tykky at 8:32 AM on July 9, 2012


I am literally staying in the home of a Mayan family in Guatemala right now. No one down here talks about chagas or knows what it is, at least the people I've asked about. Dengue fever and malaria and just generally getting sick from the local food and water are more pressing concerns from the locals. I've got some Californian pre med students who are running a clinic up in the mountains for the next few weeks staying at the house with me, and they had never heard of it, either.

Same with the brain worm thing from a few months ago. Something that's going to kill you a few years from now seems like small potatoes compared to all the things down here that can kill you next week. And that's not even getting into the horrific bus accidents and random murders.
posted by empath at 8:49 AM on July 9, 2012 [1 favorite]


Tiny Ghost ants (1.3-1.5 mm), which are endemic in Florida and moving into Texas as well as other southern states, might be able to help control Chagas:

In coastal Venezuela, the ghost ant was found to be the primary predator of the eggs of Rhodnius prolixus, the vector of Chagas' disease. This effective predaceous activity on R. prolixus populations by T. melanocephalum may account for the absence of R. prolixus associated diseases from this area of Venezuela (Gomez-Nunez 1971).

In Gainesville, the ant preyed upon small beetle larvae and lepidopterous larvae from the cultures of insects in quarantine. The ant is also reported as a significant predator of the twospotted mite, Tetranychus urticae Koch, in greenhouses (Osborne et al. 1995).
posted by jamjam at 8:59 AM on July 9, 2012


empath, if you were looking for good public health information about the United States would you rather ask a random American family, some random Belgian pre-med students who are there for a few weeks, or the CDC?
posted by Blasdelb at 9:05 AM on July 9, 2012 [1 favorite]


I'm not saying its not down here. I'm saying that it is not a pressing concern for people, and that they have other health priorities, like getting clean water.
posted by empath at 10:56 AM on July 9, 2012


I hope they find a solution that doesn't involve more ants. I am always anti-ant.
posted by maryr at 10:59 AM on July 9, 2012 [1 favorite]


I was under the impression that the vinchuca species present in the US is much less dangerous than the one you find in South America (executive summary, the southamerican ones take a dump immediately after biting, the other ones, 20-30 minutes later).

I used to have a little plastic box with pinned vinchucas in different stages of growth, that my great-aunt used to use in her biology classes. I wonder what happened to it.
posted by palbo at 11:36 AM on July 9, 2012


and lepidopterous larvae
I'd be interested to know how this ant migration impacts the indigenous moth and butterfly populations. Whether by natural growth or human introduction, whenever a new species enters a habitat that is able to fight a species we dislike, some other animal or insect or vegetable is bound to change.

"Congratulations, your kissing bug population is at a manageable level! Unfortunately, 56 sub-species of some of your most colorful moth families, which just so happen to lay eggs on plants that grow best in the habitats your ant saviors prefer, will likely be wiped out in the next 30 years."

Ecology is not so simple.
posted by DisreputableDog at 11:51 AM on July 9, 2012


I used to have a little plastic box with pinned vinchucas in different stages of growth, that my great-aunt used to use in her biology classes. I wonder what happened to it.

Came back to life, unpinned themselves, now merrily spreading Chagas disease throughout the west coast.
posted by infinitywaltz at 12:19 PM on July 9, 2012


"Congratulations, your kissing bug population is at a manageable level! Unfortunately, 56 sub-species of some of your most colorful moth families, which just so happen to lay eggs on plants that grow best in the habitats your ant saviors prefer, will likely be wiped out in the next 30 years."

Ecology is not so simple.


Very good point, DisreputableDog, I was concerned about that too.

I would choose my moths (and butterflies!) in the face of a fairly significant level of Chagas' disease-- but it looks as if these ants will establish themselves will we or nill we.

I was under the impression that the vinchuca species present in the US is much less dangerous than the one you find in South America (executive summary, the southamerican ones take a dump immediately after biting, the other ones, 20-30 minutes later).

That's fascinating, palbo.

It struck me as remarkably poor strategy for a biting insect to hang around long enough to defecate after biting a person, because that would so markedly increase the probability of being swatted, so I was wondering whether that immediate defecation was a manipulation of kissing bug behavior by the parasite somewhat the way those parasites that reproduce in ducks cause bugs that are their secondary hosts to swim up into the light at the surface where they are likely to be eaten by ducks, as they would otherwise never do, and your report tends to point in that direction.

Unfortunately, that might mean US bugs would defecate immediately too, if they were infected.
posted by jamjam at 1:54 PM on July 9, 2012


See what happens when you worry about the (vanishingly small) dangers of (somebody else's) occasional second-hand smoke? You get something real to worry about. Oh, and used to explain why (in a nation full of immigrant children) we need to keep the immigrants out.

We worry about far too much. And besides that, it's usually the wrong things. Ever heard of this before? Think it just show up out of nowhere? Now, worry about what counts, then go enjoy yourself.
posted by Twang at 2:28 PM on July 9, 2012


I'm not saying its not down here. I'm saying that it is not a pressing concern for people, and that they have other health priorities, like getting clean water.

One of the reasons that this is an imported rather than locally-acquired disease in the US is that most US houses are well-sealed, so that even though the vector is widespread, it can't get in for blood meals at night. Like clean water, structurally sound, safe, and sanitary housing is a basic infrastructural improvement that directly improves public health. (Also, gee whiz, it's alliterative.)

CDC says of the five diseases on its neglected parasitic disease list that "(t)hese infections are considered neglected because relatively little attention has been devoted to their surveillance, prevention, and/or treatment." It doesn't surprise me that in some of the poor countries where it's endemic, people haven't heard much about it.
posted by gingerest at 6:55 PM on July 9, 2012 [1 favorite]


It struck me as remarkably poor strategy for a biting insect to hang around long enough to defecate after biting a person, because that would so markedly increase the probability of being swatted, so I was wondering whether that immediate defecation was a manipulation of kissing bug behavior by the parasite somewhat the way those parasites that reproduce in ducks cause bugs that are their secondary hosts to swim up into the light at the surface where they are likely to be eaten by ducks, as they would otherwise never do, and your report tends to point in that direction.

The sporozoans that cause malaria do a beautiful job of this, blocking the host mosquito's gut so it is desperately hungry and keeps flying on, feeding and feeding but getting no benefit, at the point in the sporozoan's life cycle where it inhabits the mosquito's salivary gland, increasing both the likelihood of infection for a particular host and the number of hosts likely to be infected.
From what I've found on the subject, the trypanosomes don't affect the triatomine's defecatory behavior (source), which is consistent with the observed comparatively low transmission efficiency, but the parasites may affect how the bugs decide where to live (source).
posted by gingerest at 7:30 PM on July 9, 2012 [1 favorite]


One of the reasons that this is an imported rather than locally-acquired disease in the US is that most US houses are well-sealed, so that even though the vector is widespread, it can't get in for blood meals at night

Good luck getting people in the jungle with no air conditioning to close their windows at night. I don't think you guys get how many bugs are down here. There are literally spider webs covering every available surface, and if you clear them out, they'll be back in a day or two. Every light is surrounded by swarms of flies at night, so you have to turn off all of your lights in the house. Even if you have screens, the flies are small enough to get in.

Also, these people literally could not afford to build houses to us standards, I don't think. Most of them are getting by on dollars a day. Even fairly wealthy people in town by local standards don't exactly build to any kind of code that I'm aware of. There are tons of concrete and rebar buildings here where people are literally propping up floors with a bunch of logs with wood wedges under them to make it even or where they just stopped building and never put up a proper roof. Rusty nails sticking out everywhere, wild dogs and cats running through the streets. Hell, even the carnival rides at the fair down here terrify me. As if just walking around isn't dangerous enough, they turbocharge their ferris wheels, and let people flip the cars over while the ride is going.

I mean, I love it and it's beautiful down here, in it's way, don't get me wrong, but there are so many dangerous things down here that a campaign to make major housing changes to 'prevent chagas' strikes me as absurd. They need major housing changes to stop you from stepping on rusty nails or from floors collapsing, or from getting electrocuted while you take a shower (this last one happened to me the first day I was here). And holy shit the roads through the mountains and the chicken buses. There are towns near here with no regular access to health care of any kind.

This is the kind of thing that will fix itself when its no longer a 'developing nation' and until then, they are probably just going to live with it.

I really should start posting pictures of every dangerous thing I see here when I'm walking around that isn't kissing bugs.
posted by empath at 7:44 AM on July 10, 2012


Sorry. I guess I was unclear about what I meant. Sound housing is taken for granted in rich countries like the USA. Being able to live in spaces that aren't also heavily occupied by rodents, insects and other animals is a public health advantage enjoyed by those with some financial resources even in wealthy countries. Poor people are not to blame for the fact clean water and safe housing are central to good health but not universally available.
posted by gingerest at 4:53 PM on July 10, 2012


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