Your employees may be aware of food safety concerns related to the presence of cockroaches in the kitchen, but then simply dismiss a housefly buzzing around them as a nuisance as they shoo it away. Little do they realize that houseflies and other large flies also pose a serious food safety risk. Large flies including houseflies, bottle/blow flies and flesh flies are also called “filth flies” because they breed in filth such as manure, human excreta, dumpsters, garbage, and decaying vegetation. Large flies have enormous potential to transmit bacteria and other potentially pathogenic organisms directly to human food or food-contact surfaces.

Besides being a nuisance, large flies can present a serious food safety concern. Research has shown that house flies can harbor more than 200 pathogens, including types of foodborne illness-causing bacteria, such as Salmonella, Shigella, Campylobacter, E. coli, and others. Their sticky feet and body hairs are ideal for collecting and holding bacteria. Because of this, even a single fly in your facility is a food safety risk. Large flies landing on solid food items will often regurgitate digestive enzymes onto the food surface to dissolve the food allowing the fly to suck it back up. Flies will also deposit fecal matter on resting surfaces, leaving risks of contamination wherever they go. Additionally, a fly that has been on filth such as garbage, decaying meat, feces, etc. — can pick up pathogens and carry them onto a clean surface or ready-to-eat food product. Large flies can jeopardize your brand and their presence could be an indicator of poor sanitation to an auditor or inspector. This can result in fines or even closure putting your brand at risk.