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What is diphtheria?

Page last updated 09 April 2020

Diphtheria is a bacterial disease that causes severe inflammation of the nose, throat and windpipe. 

The bacteria produce a toxin (poison) that attacks the lining of the back of the throat. The throat becomes inflamed and rapidly forms an abnormal membrane (barrier) over the back of the throat, which can make swallowing and breathing difficult. This alone can lead to suffocation.

The toxin can also spread throughout the bloodstream and affect other organs, including the heart and kidneys, as well as the nervous system. These complications can be fatal.

Vaccination is an effective way to prevent diphtheria.The disease is extremely rare in Australia due to ongoing routine vaccination programs.

Sources & Citations

1. Australian Government. Department of Health. Australia’s notifiable disease status, 2014: Annual report of the National Notifiable Diseases Surveillance System (main page). Available at: (accessed 27 February 2020).

2. Victorian Government. Better Health Channel. Diphtheria. Available at: (accessed 27 February 2020).

7. Centers for Disease Control. Diphtheria. Symptoms. Available at: (accessed 27 February 2020).

SPANZ.SAPAS.18.04.0134(1)a - Date of preparation March 2020