Scientists have discovered that two types of flies that are very common in urban environments can carry more diseases than previously thought.
The housefly (Musca domestica) and the fly fly (Chrysomya megacephala) each carry more than 300 types of bacteria , according to a study by researchers at Penn State University in the United States.
Many of these bacteria are causing diseases that affect humans, including infections in the stomach, intoxications and even pneumonia .
Microbes focus on the legs and wings of insects and spread through the environment, for example, each time a fly lands on food. Each movement of insects can spread bacteria, experts say.
“People had some notion that flies carried pathogens, but they had no idea of the size of that fact and the scale at which these bacteria can be transported,” said Donald Bryant , professor of biochemistry and molecular biology at PennState University and one of authors of the study.
Outbreaks of diseases
The researchers analyzed 116 flies from various habitats on three continents and used DNA sequencing techniques to identify the bacteria that were on the body of the insects.
The housefly , found all over the planet, carries 351 types of bacteria. In turn, the fly , more common in hot climates, carries 316 types. Many of the microorganisms were found in both species.
Scientists, who published the study in the Scientific Reports, point out that flies may be underestimated by public health authorities as sources of outbreaks for a number of diseases.
“We believe this may demonstrate a mechanism of pathogenic transmission that has been neglected by public health authorities that flies can contribute to the transmission of pathogens in outbreak situations,” Bryant said.
Some researchers believe, however, that flies can be useful and act as warning systems for certain diseases or as “living drones” capable of entering into confined spaces to search for microbes.
“Flies could be intentionally launched as autonomous bionic drones into the smallest spaces and cracks and, after being recaptured, provide information on all the biological material they encountered,” says Stephan Schuster , research director at Nanyang University of Technology in Singapore.
Domestic flies are known for their poor hygiene habits, between going to landfills and feeding on all kinds of decaying food, dead animals and fecal matter. They are potential vectors of diseases for humans, animals and plants.
The vias are the most common flies seen on dead animals. They are usually in urban areas and are often found near meat processing plants, slaughterhouses and garbage dumps.