Do Houseflies Spread Diseases? What to Know

Flies land on waste and then on food, so they have a reputation for spreading illness. The risk is real but manageable.

The short answer

Houseflies can carry germs on their legs, bodies and mouthparts from waste, drains and rotting matter to food and surfaces, and are linked in general terms to stomach upsets and infections where hygiene is poor. Reduce risk by keeping food covered, discarding food flies have landed on if unsure, cleaning surfaces, managing waste and controlling breeding sources. This is general information, not medical advice.

How flies spread germs

• Landing on waste, then on food.
• Vomiting digestive fluid on food to feed.
• Leaving droppings on surfaces.

Reducing risk

1. Cover cooked and ready-to-eat food.
2. Wipe counters and tables.
3. Wash hands before eating and cooking.
4. Keep bins covered and drains clean.
5. Use screens and control breeding sources.

Vulnerable people

• Young children, older adults and people with weak immunity should be extra careful with food hygiene.

When to call a professional

Call a pest professional for persistent flies. See a doctor for illness symptoms.

Frequently asked questions

Are all flies dangerous?

Risk depends on hygiene and the fly's source.

Should I throw away food a fly landed on?

If it is uncooked or left out, be cautious.

Do fly sprays make food safe?

No. Cover food instead.

When to see a doctor?

If you have persistent stomach illness.

This guide is part of IPest's complete resource on fly control. For identification help, prevention and treatment options, see our full fly control guide for Bangalore.