July 2015 – Bo Peterson
The triatomine bug, popularly known as the kissing bug, can carry a serious disease. CDC
The kissing bug is no beauty. A half-inch long, it looks like a cross between a roach and a paper wasp, with wings folded back like a bat.
Don’t pucker up to it in the Lowcountry. It could be carrying Chagas, a disease that researchers are calling the new AIDS in the Americas.
And if that doesn’t cause you to cringe, the leprosy-prone armadillo might.
Health officials are becoming more concerned about the spread of once-obscure diseases like Chagas and leprosy, partly because of the apparent expanding range of both in the Southeast.
Chagas had been a disease found largely in Latin America and the arid Southwest. It is a disease caused by a parasite. At first the symptoms are fever, headache and nausea symptoms, a lot like a flu. But over time it can lead to complications, such as sudden-onset heart attacks and intestinal problems. A National Institutes of Health study suggested that it could kill as many as a third of the people infected with it in Latin America.
The parasite is known to be spread by the triatomine bug, popularly called the kissing bug because of a tendency to bite humans on or near the mouth. More than 130 species of the bug are bloodsuckers, literally, and at least a few carry a parasite that causes the disease.
South Carolina has at least three of the species, including a new one identified last year.
Now bed bugs have been shown to be able to carry it, too. So have coyotes.
The disease hasn’t shown up in the state so far except in dogs, as near as anyone can tell. Incidents aren’t required to be reported in South Carolina. But researchers recently found an outbreak in northern Virginia, brought in by people from other countries. Tennessee is among the states that do test for it, after it turned up there.
At least 300,000 people are thought to carry the disease in the United States, according to the Centers for Disease Control and Prevention. Most of them are thought to have acquired it in Latin America, said Sue Montgomery of the CDC. Only 28 cases are confirmed to have been acquired here.
“Because it’s not notifiable in key states where the bug lives and many infections have not been identified, the burden (incidence) among non-Latin Americans is not known,” Montgomery said.
Only five states now require reporting of the disease. Few doctors are experienced with it. Blood supplies are not screened for it.
Meanwhile, nine cases of leprosy have been diagnosed in Florida so far this year, according to CNN, in a state that usually sees two to a dozen per year. Leprosy is the skin disease usually thought of as a biblical scourge that is all but wiped out in the developed world.
But one carrier is the armadillo, the armor-shelled beast now burrowing under a fence near your yard. Once confined to the arid Southwest, the creatures have swarmed the Southeast lowlands and into the foothills. First spotted in South Carolina in the Lowcountry in the 1990s, they’re now common in subdivision neighborhoods.
The Florida leprosy reports are alarming because previously only one or two cases were known of humans getting the disease from a wild armadillo; in those cases the persons ate raw or undercooked meat, according to University of Georgia’s Center for Urban Agriculture.
Investigators for the Florida Department of Health haven’t determined yet just how the nine people became infected. But the department is recommending that people avoid contact with wild animals such as armadillos, and take precautions by using gloves and washing hands.
Chagas is a bigger puzzle because less is known about it in this country. The bright spot about the disease is that, like leprosy, it appears to be very hard to get. The bug is nocturnal, and doesn’t tend to be found indoors unless it is in cracks or holes in the walls.
If it has the parasite, it has to defecate — repeatedly, some health professionals think — on a person to transmit it.
Once the parasite is in the blood of humans, though, it can be transmitted with the exchange of blood. Chagas, in fact, has been called “the new AIDS in the Americas,” according to the Harvard University School of Health, because of its rapid spread through the hemisphere and because it infects the blood.
The disease certainly could turn up in South Carolina, said Brian Scholtens, College of Charleston entomologist.
“We have the bugs in the state and plenty of potential vectors. Up to this point, the only thing we have lacked is the actual disease organism,” he said. But that can change very quickly with movement of either infected dogs or humans, he said.
“Most humans are unlikely to get bitten (by the bug),” Scholtens said. “It is more likely that the other hosts would be involved in the overall increase in transmission rates, and humans may be more at risk from infected blood supplies if we don’t start routinely screening for the parasite.”
Chagas’ disease is most severe in children younger than five, who are more likely to have central nervous system involvement in their T. cruzi infections. Older children and adults generally show the subacute or chronic form of Chagas’ after an acute stage. The following list from the Center for Disease Control and Prevention (CDC) Chagas’ Disease Fact Sheet outlines the symptoms associated with each stage of Chagas’ disease. To see the list in its original context, click on the link above, or follow the link on the references page.
1] Acute stage: Acute infection is only symptomatic in about 1% of cases, lasts about 4-8 weeks, and may include any of the following:
- Romaña’s sign – unilateral edema affecting upper and lower eyelid (often occurs with conjunctivitis) occurring at bite site or were feces accidentally entered eye
- Hepatosplenomegaly (swollen spleen and liver)
- Lymphadenopathy (swollen lymph glands)
- Rash (at bite site)
- Appetite loss
- Brain damage sometimes progressing to death (generally in infants and children under 5)
- Romaña’s sign in young child with acute Chagas’ disease. Photo courtesy of The Journal of Young Investigators. http://www.jyi.org/features/ft.php?id=185
2] Indeterminate stage: Occurs about 10 weeks post-infection (PI) and is asymptomatic. May last for several years.
3] Chronic stage: Occurs around 10-40 years post-infection, affects about 20-30% of infected individuals. The most serious symptoms include:
- cardiac problems
- enlarged heart
- heart failure
- cardiac arrest
- GI problems
|Megacolon in chronic Chagas’ disease. Animated picture (top) courtesy of eMedicine. http://www.emedicine.com/MED/topic327.htm. Photo (bottom) courtesy of Images in Paediatric Cardiology. http://www.health.gov.mt/impaedcard/issue/issue5/2839/2839.htm.|
[The majority of the following information can be found in Chapter 5 of Markell and Voge’s Medical Parasitology, 9th ed.]
The rash which occurs at the site of entry of T. cruzi (called a chagoma) is the result of an acute local inflammatory reaction. Metacylcic trypomastigotes travel through the lymphatics to lymph nodes and are ingested by histiocytes and other cells or actively penetrate macrophages and other cells, within which they transform into amastigotes. Amastigotes multiply within the cell and may remain amastigotes or take on the trypomastigote form and leave the cell to travel through the blood and invade other areas. Trypaonsomes eventually infect organs and tissues throughout the body, with a particular affinity for Kupffer liver cells, spleen macrophages, and cardiac myocytes. In the cardiac muscles, amastigotes form pseudocysts, which results in the loss of muscle composition, diffuse inflammatory exudate, and proliferation of interstitial connective tissue. Cardiomegaly may develop with diffuse inflammation and fibrosis and infiltration of lymphocytes, macrophages, and plasma cells. Central nervous system invasion by T. cruzi is characterized by meningitis and cortical inflammation. GI organomegalies – including megacolon, and megaesophagus – can be attributed to muscle hypertrophy in response to the killing of cells by amastigotes.
A possible mechanism for chagasic cardiomyopathy involves secretion of cytokines by macrophages infected with T. cruzi, resulting in proliferation of lymphocytes producing antibodies against parasite and, possibly, host antigens, which may explain the severe autoimmune pathology associated with Chagas’ disease. One theory suggests that the parasites mimick host antigens as a means of evading the immune system.
Antibody-mediated immunity primarily involves IgG immunoglobulins. Cell-mediated immunity involves killing trypomastigotes by activated macrophages and by neutrophils and eosinophils.
Intracellular iron may also play a key role in host resistance to T. cruzi, as amastigotses require iron for growth and pathogenicity. Therefore, it is theorized that amastigote replication may be controlled by reducing intracellular iron levels.
Though symptoms of the acute stage may appear within a 3-21 days after infection with T. cruzi, most people remain asymptomatic until the chronic stage, which occurs 10-40 years after infection.
CBS News by Geoff Leo
Sean Pender says he couldn’t believe his eyes when he started working at Pedigree Poultry a couple of weeks ago.
“When I get there they tell us there’s going to be wood ticks. Those are not wood ticks, those are bedbugs,” Pender said.
Pender was part of a group of workers sent to the Regina Beach chicken farm by Labour Ready, an employment agency.
“You’d pull it out and let it drop and bang,” Pender said. “Just a seething mass of them all over the ground. It was just disgusting.”
“I ended up with [bedbugs] around the tops of my socks, just drinking blood like a whole line of them right around the top of my socks as far as they would go because I’m wearing shorts all the time.”
Pender said the bugs were crawling all over the other workers as well. He said they were concerned they might unwittingly be spreading them around Regina.
“If you don’t suit up properly you’re going drag these things home with you,” Pender said. “You’re going to infest your home with this stuff.”
Workers walked off the job
He said by noon he and the other workers had enough and decided to leave.
A spokesperson for Labour Ready, based in Tacoma, Washington, Stacey Burke, confirmed that.
She said the conditions the workers described is cause for concern.
“We did not know the condition of the farm. We did not know that there were some health and safety concerns,” Burke said. “I’m sure it wasn’t disclosed.”
She said Labour Ready should have been told and the workers should have been properly equipped.
Pedigree Poultry responds
The owner of Pedigree Poultry, James Glen, admitted there’s a problem which he said caught him by surprise too.
“The reason that they [the workers] weren’t notified of any issue was because we were unaware of it,” Glen said.
He pointed out the chickens had been laying eggs undisturbed in the barn for a year, and were just recently removed and sent for slaughter.
“The reason that they [the workers] weren’t notified of any issue was because we were unaware of it” – James Glen, Owner of Pedigree Poultry
He said that allowed the bedbugs “to increase without anybody’s knowledge.”
Glen said no one noticed because his workers are only in the barns during the day and bedbugs only come out at night.
While Glen agrees there’s an infestation in his barn he disputes Pender’s suggestion that there was a “seething mass” of bedbugs.
“I don’t think it’s true that there was gobs and gobs of bedbugs,” Glen said.
He said as soon as he became aware of the problem he started searching the internet for solutions, and he contacted veterinarians and pest control companies.
So far Glen has tried spraying a bleach solution and spreading diatomaceous earth, which he said works as a natural insecticide.
Glen said it seems to be working, though the bugs haven’t yet been completely eliminated.
This isn’t the first time Pedigree Poultry has run into bad luck with its flock.
Back in 2007 the Canadian Food Inspection agency confirmed it had been hit with avian flu. All 50,000 birds on the farm were destroyed.
Scientist called to investigate
A U of S poultry veterinarian, whose position is funded by Saskatchewan’s chicken industry, is familiar with the issue, which she said is becoming more common.
Dr. Jenny Fricke said bedbug infestations of poultry barns have “been reported to be increasing over recent years.”
She said chicken farms provide a perfect environment for bedbugs.
“They will feed on anything with blood. So if they’re introduced into a poultry barn environment there is a wealth of different hosts for them to feed upon.”
She said the iTeam’s call to Saskatchewan’s chicken industry association prompted officials to send a letter warning of a potential bug problem to the approximately 70 chicken farms in the province.
Fricke said a handful of those producers replied, including Pedigree Poultry, which invited Fricke to investigate.
She’s not able to discuss what she found because of confidentiality protocols.
She said a bedbug infestation is bad for the health of the flock, potentially limiting production.
“Anything that’s causing irritation and distress in a flock is also an animal welfare concern,” Fricke added.
However she said she has no reason to believe that bedbugs could affect the quality of the meat.
Occupational health and safety to investigate
In a written statement Occupational Health and Safety (OHS) told CBC’s iTeam it would be investigating this situation.
It said employers have an obligation to inform, train and equip their workers.
“In a situation where workers may be exposed to offensive substances they would have to be advised of that and provided with appropriate clothing to wear at work, as well as a suitable separate area to store their street clothing.”
Glen said he’s spoken with OHS officials and has agreed to take all of the steps they recommended.
Chagas disease, endemic to Mexico, Central America and South America, affects approximately 8 million people south of the American border. Due to increased immigration, Chagas has taken hold in the United States, too, where more than 300,000 people are estimated to be affected with the Trypanosoma cruzi infection, transmitted mainly by blood-sucking “kissing bugs.” But that’s not all.
According to a CDC report published on the Internet and last updated July 13, 2013, most people in the U.S. with Chagas disease “acquired their infections in endemic countries.”
Why be concerned? First, Chagas may go undiagnosed while continuing to do damage, because its symptoms mimic America’s number-one killer: heart disease. But if the parasitic infection goes untreated, Chagas continues to erode the heart organ. Second, evidence now indicates that bed bugs may spread the parasites linked to Chagas disease, as well. Scientific American divulged that a study released in November 2014 “raised the specter of Chagas from another more familiar insect pest: bed bugs,” which are found all over the country. Biting bed bugs have been found to transmit the [Chagas carrying] parasite between mice. There is conjecture in scientific circles that it may be just a matter of time before bed bugs begin spreading Chagas to humans, as well.
According to a report in Scientific American (December 10, 2014), “Every year, the hearts of millions of Central and South Americans are quietly damaged by parasites. During the night, insects called kissing bugs emerge by the hundreds from hiding places in people’s mud-and-stick homes to bite their sleeping victims. The bugs defecate near the punctured skin and wriggling wormlike parasites in the bug poop may enter the wound and head for their victims’ hearts. There, in about a third of victims, they damage the organs for decades before causing potentially lethal heart disease. Around 12,000 people worldwide die each year from the ailment, called Chagas disease.
CDC estimates that more than 300,000 persons with Chagas disease live in the United States. Most people with Chagas disease in the United States acquired their infections in endemic countries. Although there are triatomine bugs in the U.S., only rare vectorborne cases of Chagas disease have been documented, according to the CDC report. However, the “kissing bug” responsible for most Chagas transmission is a blood eater with similar traits to the bed bug.
The bed bug effect has not been demonstrated yet among people but these studies have made some physicians and scientists wonder if they have underestimated the chance of acquiring Chagas in this country. “We are very likely missing [Chagas] cases,” said a May 2014 editorial in The American Journal of Medicine. “A systemic survey of the high-risk population in the U.S. is urgently needed.”
What does it all mean? We need to remain vigilant in combatting both bedbugs and the encroachment of kissing bugs in this country. And we must adapt lifestyle to create an effective, lasting barrier between bed bugs and us.