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What is diphtheria?

Page last updated 13 January 2022

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. Victorian Government. Better Health Channel. Diphtheria. Available at: (accessed 24 November 2021).

6. Centers for Disease Control. Diphtheria. Diagnosis and Treatment. Available at: (accessed 24 November 2021).

9. Australian Institute of Health and Welfare. Diphtheria in Australia. Available at: (accessed 24 November 2021).

MAT-AU-2102461   Date of preparation January 2022