Houseflies buzzing around your home are loaded with bacteria and that’s likely no surprise. But a new study suggests that they’re even more capable of spreading illnesses than expected.
Research published in Science Reports last week shows that houseflies and blowflies carry several bacteria on their bodies that are harmful to humans. Much of it has to do with what the insects feast on — fecal matter.
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“Blowflies and houseflies are the first organisms to arrive on carcasses, decaying organic matter and feces on which they feed, breed, and lay eggs,” the study reads.
The study notes that this can be a cause for concern because these flies tend to linger around humans and on household surfaces.
Reseachers analyzed DNA from the creatures to find that houseflies carry 351 types of bacteria. Some of the bacteria were linked to human infections and illnesses, such as stomach bugs.
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“We believe that this may show a mechanism for pathogen transmission that has been overlooked by public health officials, and flies may contribute to the rapid transmission of pathogens in outbreak situations,” one of the study’s researcher’s Donald Bryant said in a release.
This is all, well, gross. But how concerned should humans really be?
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“Flies essentially are a sign of a lack of cleanliness, we’ve sort of known this for decades and decades,” Tetro said. “This study is just confirming on a material level that, yeah, there definitely is potential for problems.”
People most at risk of illness from flies
But Tetro explained that while houseflies leave bacteria on surfaces, it’s a minimal amount and not enough to make most people sick.
‘The only way that you could come into problems is if you actually ate them, and while that may be a nice school children joke, most people I know don’t eat flies,” Tetro explained.
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But there are exceptions.
“Now, in terms of hospital, this is actually a pretty important thing, because you have people who are prone to infection. They don’t have particularly strong immunity,” the expert said, adding the same goes for babies and elders within households.
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Eating food touched by houseflies
Tetro said food touched by a fly isn’t necessarily dangerous — unless there’s a swarm of insects on the food.
“If you are in a situation where there are quite a number of flies in that area, and they all seem to be latching on to your food, then there is a good likelihood that there are going to be bacteria being transferred to the food,” Tetro said.
While the risk of infection or sickness is low, precautions are always a good idea. Tetro explained that people can take simple steps such as putting away food and regularly taking out the garbage to minimize the number of bugs roaming inside homes.