Wed. Nov 30th, 2022
A typical bed bug aggregation with blood-fed and non-fed bed bugs and fecal patches containing histamine (photo credit: Matt Bertone)
enlarge / A typical bed bug aggregation with blood-fed and non-fed bed bugs and fecal patches containing histamine (photo credit: Matt Bertone)

It’s official: Pooping in bed isn’t the worst thing you can do. Letting bed bugs do it is worse.

While the creepy critters bite you while you slumber, they also squeeze feces that are full of histamine, a chemical that pushes our own bodies out during an inflammatory response to allergens. Histamine can cause itching, watery eyes, sneezing, difficulty breathing, headaches, and asthma attacks, among other things. Homes with bedbug infestations can become histamine Dutch ovens, according to a new study led by entomologists and health experts at North Carolina State University. The researchers found that histamine levels in infested homes were at least 20 times higher than levels in the home without bedbugs.

And that’s not all. Researchers enroll PLOS ONE also found that those histamine levels linger. In infested homes that received heat treatment — circulating hot air (~50̊C) inside a home to wipe out the insects — histamine levels remained high for months.

In fact, the effective treatment can make the blast worse. The researchers speculate that the flow of hot air could trigger poop storms that spread histamine from contaminated mattresses and couches to the rest of the house — a “poop hits the fan” scenario, if you will.

The authors, led by entomologist Zachary DeVries, conclude that the study’s findings are “significant because exogenous histamines can cause allergic reactions and asthma.” They are calling for more research into the butt asplosions and the bug fallout.

“The intimate association of bedbugs with humans and the spatial distribution and persistence of histamine in homes suggest that histamine may be an emerging indoor pollutant whose impact on human health needs to be explored,” they write.

Since the early 2000s, bed bugs have resurfaced and have become a worldwide scourge. The little critters gather in the folds of mattresses and seams of sofas (or any other good hiding place) and come out to feast on your blood while you snooze. Their size, hiding abilities and high resistance to some insecticides make them incredibly difficult to eradicate.

That said, while pests are annoying, the bugs are generally not thought to pose a significant health risk. Unlike other leeches, such as ticks and mosquitoes, they are not known to spread infectious diseases. Their bites simply cause skin irritation and can haunt your dreams forever – not causing serious illness or injury.

But the new study by DeVries and colleagues may challenge that idea.

A few years ago, Canadian researchers noticed that bedbugs secrete histamine among a potpourri of pheromones that lure their species into coveted crevices to lurk. DeVries and colleagues wondered if that could cause health problems. To answer the question, they set out to see if histamine levels are even a measurable problem in contaminated homes.

They analyzed poo dust samples from 14 bedbug-infested apartments and 10 unaffected apartments in the same building. Due to the risk that the uninfected apartments could be peripheral or previously infested apartments, they also looked at dust samples from five apartments in a bedbug-free building five miles away. They repeatedly took dust samples for weeks. The researchers sampled heat-treated apartments for 12 weeks after treatment.

Ultimately, they found that contaminated apartments contained an average of 54 micrograms of histamine per 100 milligrams of dust. Non-infected apartments in the same building averaged 2.5 g per 100 mg of dust, and the remote bedbug-free apartments averaged 0.3 g per 100 mg of dust. The researchers noted that the apartment categories did not have significantly different amounts of dust. They also noted that heat treatments did not significantly flush out histamine levels over the following 12 weeks.

The health effects of 54 g of histamine per 100 mg of substance are as yet unclear. Previous experiments in which people inhaled histamine found that as little as 24.5 µg can affect respiration. And the level in the bedbug-infested house dust is about 10 times higher than what the Food and Drug Administration allows in fish. (If fish spoil at high temperatures, bacteria can form histamine, which can lead to poisoning.) But that limit is based on ingesting histamine, not inhaling it.

The researchers say much more work needs to be done to confirm their findings and determine if there are other, more confusing sources of histamine. They also want to understand the health effects of those histamine levels and come up with effective ways to lower them.

PLOS ONE2018. DOI: 10.1371/pone.0192462 (About DOIs).

By akfire1

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