House flies (Musca domestica) are common insects found globally. They frequently encounter unsanitary materials like decaying organic matter and waste. While seemingly harmless, house flies can pose a risk to human health as carriers of various pathogens.
Health Risks from Fly Excrement
House flies can carry over 100 types of pathogens, including bacteria, viruses, fungi, and parasites. These microorganisms originate from unsanitary environments like feces, animal manure, and rotting materials. When flies feed or rest on contaminated sources, their bodies and digestive systems pick up disease-causing agents.
Flies transmit bacteria like Escherichia coli (E. coli), Salmonella, and Shigella, common causes of foodborne illnesses. They also carry agents for severe conditions such as cholera, dysentery, and typhoid fever. Parasitic organisms like Giardia and hookworms have also been associated with house flies.
How Contamination Spreads
Flies spread contamination through several mechanisms as they move between unsanitary sites and human spaces. Their bodies, covered with tiny hairs, and sticky footpads pick up pathogens from surfaces like garbage and animal waste. When a fly lands on food, kitchen counters, or utensils, these pathogens can be mechanically transferred.
Flies also spread contamination through their feeding habits. Lacking teeth, they regurgitate digestive fluids onto solid food to liquefy it before ingesting. This “vomiting” action deposits bacteria and other microbes from their digestive tract onto surfaces and food. Flies also frequently defecate, and their feces can contain pathogens, further contributing to contamination wherever they land.
Preventing and Cleaning Up
Preventing fly infestations involves maintaining a clean environment and limiting access points. Regularly dispose of garbage in tightly sealed bins and empty them frequently. Rinse recyclables and cover compost piles, as decaying organic matter attracts flies.
Sealing entry points into buildings also reduces fly presence. Use tight-fitting screens on windows and doors, ensuring no tears or gaps. Promptly cleaning food spills and crumbs prevents flies from finding food or breeding grounds indoors.
When cleaning areas with fly excrement, wear disposable gloves. For general cleaning, warm water and mild dish soap can break down spots. White vinegar and water is another option, as its acidic nature dissolves grime. After cleaning, dispose of contaminated materials properly and practice good hand hygiene to prevent the spread of any remaining pathogens.