What causes a middle ear infection?

Most middle ear infections are caused by a virus (most often the viruses that cause colds). Bacteria can also cause middle ear infections.

Children or adults who have a cold can get an ear infection caused by the same virus. The ear infection often follows after the cold.

The middle ear infection happens when the viruses causing your cold spread from your nose and throat through your Eustachian tube, the tube that connects the throat and the middle ear.

Who is at risk of a middle ear infection?

Adults and children with a respiratory tract infection such as a cold are also at risk of a middle ear infection.

Children are at particular risk of middle ear infections. This is because their ear Eustachian tubes are shorter, more horizontal and less developed, so it is easier for viruses to spread into the middle ear. Children are more susceptible to infections such as colds than adults are. This is because their immune systems are still developing, and they haven’t been exposed to as many infections as an adult has.

Children who are most at risk of a middle ear infection include:

  • those born with a cleft palate
  • those with a weakened immune system due to another illness or medicines they may be taking
  • Aboriginal children living in over-crowded conditions.

Find out more about the symptoms, diagnosis and treatments for a middle ear infection.