Flies are a well-known risk for spreading diseases and spoilage organisms in the food, healthcare and pharmaceutical sectors. In these sectors, standard hygiene practices, physical barriers and electric fly killers are required components of a good hygiene regime. This ensures the prevention of contamination from flies that are attracted to food.

A team of researchers from the US, Singapore, Brazil and Germany have shown that houseflies and blowflies can carry a far wider range of bacteria. With one key discovery being that the major route of contamination is from walking on a surface.

The researchers collected houseflies and blowflies from three continents in a range of environments, including tropical rainforest in Brazil and urban areas. The researchers used new genetic analysis techniques to identify all the microorganisms carried by the flies and the parts of their bodies they were present on.

The legs and wings show the highest microbial diversity of parts of the fly body,  which shows that just by landing on food or surfaces, flies could spread many types of bacteria.