Diphtheria is caused by the spread of a bacterium, Corynebacterium diphtheria. When a person catches diphtheria, the bacteria release a toxin, or poison, into the person's body. The toxin infects the upper airways, and sometimes the skin, causing a membrane to grow across the windpipe. This makes it hard to breathe and if the membrane completely blocks the windpipe can lead to suffocation and death. The heart and nervous system can also be damaged.
Vaccination is the best protection against diphtheria. In Australia, diphtheria vaccines are combined with vaccines which include tetanus and pertussis, listed on the National Immunisation Program Schedule.
Since the vaccine was made available, diphtheria has almost disappeared. Vaccinating is still important because people can bring diphtheria into Australia from overseas.
Find out more about getting vaccinated against diphtheria.
Symptoms, diagnosis and treatment
For information about symptoms, diagnosis and treatment, see healthdirect's diphtheria page.
Surveillance and reporting
Diphtheria is a nationally notifiable disease.
We monitor cases through the National Notifiable Diseases Surveillance System.
For more on diphtheria in Australia, you can search Communicable Diseases Intelligence.