Updated: June 7, 2023

Flies are one of the most common insects found around the world. They are known for their buzzing sound and annoying behavior. Flies are often considered a nuisance, but are they also harmful to humans? In this article, we will explore the various ways in which flies can be harmful to human health.

Disease Transmission

One of the primary ways in which flies can be harmful to humans is through disease transmission. Flies are known to carry a variety of diseases, including typhoid, cholera, dysentery, and salmonella. These diseases can be transmitted to humans through contact with fly feces or through contaminated food and water.

Flies feed on a variety of substances, including garbage and excrement, which can contain harmful bacteria. When flies land on food or other surfaces, they can transfer these bacteria onto those surfaces. If a person then comes into contact with those surfaces or eats contaminated food, they can become infected with the bacteria.


In addition to transmitting diseases, flies can also cause allergic reactions in some people. Fly saliva and feces can contain allergens that can trigger an allergic reaction in sensitive individuals. These reactions can range from mild symptoms like itching and redness to more severe reactions like anaphylaxis.


Flies can also be carriers of parasites, such as tapeworms and roundworms. These parasites can live inside the fly’s body and be transmitted to humans through contact with the fly or ingestion of contaminated food. Once inside the human body, these parasites can cause a range of symptoms, including abdominal pain, diarrhea, and weight loss.

Wound Infections

Flies are attracted to wounds and sores on the human body. When they land on these wounds, they can transfer bacteria from their legs or mouthparts into the wound site. This can lead to infections, which can be difficult to treat and may require medical intervention.


Preventing flies from entering your home or workplace is the best way to reduce the risk of disease transmission and other health issues. Here are some tips for preventing flies:

  • Keep your home or workplace clean and free of clutter.
  • Dispose of garbage and food waste properly.
  • Use screens on doors and windows to keep flies out.
  • Seal cracks and crevices around doors and windows to prevent flies from entering.
  • Keep food covered or in sealed containers.


In conclusion, flies can be harmful to human health in a variety of ways. They can transmit diseases, cause allergic reactions, carry parasites, and cause wound infections. However, by taking steps to prevent flies from entering your home or workplace, you can reduce the risk of these health issues. If you do experience symptoms of a fly-borne illness or infection, it is important to seek medical attention right away.