Can Flies on Food Make You Ill?
WouterWhile fly contamination is possible, the risk to humans is relatively small. The immune system can repel most insects, making the presence of a single fly on food unlikely to make you sick. Furthermore, the level of contamination depends on where you live. For example, urban flies are less dangerous than those in rural areas, thanks to chemicals that control their numbers.
Because flies are incapable of teeth, they regurgitate their saliva onto food. This saliva contains pathogens from their previous meals. In addition, the longer a fly stays on food, the higher the chances that it will pass along its germs. Furthermore, flies lay their eggs on food, making it even more likely that they carry disease-causing bacteria and viruses. The risk increases if you eat the food the fly has touched.
Flies also carry pathogens and other microbes from the environment. In urban environments, flies may have visited dog poop or farm waste, while in rural areas, flies may have been exposed to animal carcasses. These microbes can then be transferred to the food by the fly’s legs or wings.
It is also possible for flies to transfer disease-causing bacteria to foods, which is a cause of food poisoning. The bacteria they carry can cause diarrhea, fever, and even gastrointestinal pain.
