Fly Contamination of Food: Pathogen Transfer and Prevention

Flies (Musca domestica) are mechanical vectors. They feed on feces, garbage, decaying matter, then land on food, transferring pathogens via:

• Body surfaces: Setae, footpads, mouthparts.
• Regurgitation: Digestive enzymes liquefy solid food; vomit drop contains pathogens.
• Fecal deposition: Defecate while feeding.

Pathogens Transmitted

• Bacteria: Salmonella, E. coli O157:H7, Shigella, Campylobacter, Vibrio cholerae.
• Viruses: Hepatitis A, norovirus, rotavirus.
• Parasites: Giardia, Cryptosporidium, helminth eggs.

Eggs laid on food hatch into maggots, accelerating spoilage.

Prevention

• Cover food; refrigerate promptly.
• Screen windows/doors; use fly traps, UV lights.
• Sanitation: sealed trash, clean drains, remove breeding sites (manure, compost).
• Hand hygiene before eating.