It only takes a single fly to alight on your picnic lunch to make you uneasy about what germs may have landed with it. But what harm can come from a fly landing on your food?
Manytypes of flypose a health risk but none hang about our homes more than the house fly. It’s a ubiquitous presence during the warmer monthscan be a substantial annoyance and also be a potential health risk.Musca domesticais one of the most widespread nuisance insects in the world.After laying eggs, maggots will hatch out and eat their way throughdecaying organic material before pupating and then emerging as an adult fly a few days later. The adult flies can live up to a month and may lay hundreds of eggs over that time.
When it comes to passing on pathogens, it’s not necessarily the fly itself but where it’s come from that matters. Flies don’t just visit freshly made sandwiches. They spend far more of their time in rotting animal and plant waste. As well as leaving behind pathogen-filled footprints, the flies leave their poop on our food. They vomit too.
In most instances, spotting a fly on your food doesn’t mean you need to throw it out. While there is little doubt that flies can carry nasties fromwaste to our food, a single touchdown is unlikely to leadto illness for the average healthy person.Flies thatwander about for a few minutes vomiting and pooping on your food or food preparation area are more of a concern. The more time passes, the greater the chance of pathogensgrowing and multiplying on our food.
Ensure your food is coveredand don’t leave “leftovers” sitting about outside.Screens will help block flies from coming inside, butminimising garbage around the house is critical. Insecticidal surface sprays around bin areas will help.An old-schoolfly swatworks a treat too.
Cameron Webb is a clinical lecturer and principal hospital scientist, University of Sydney.Read the full article on The Conversation.