Diphtheria, symptoms and treatment
Diphtheria outbreaks are occurring in the Northern Territory and elsewhere in Australia. In response, the Chief Medical Officer declared diphtheria a Communicable Disease Incident of National Significance on 22 May 2026.
Diphtheria is a serious bacterial infection that can affect your throat and skin.
Vaccination is the best way to protect yourself and your family from diphtheria.
How diphtheria spreads
Diphtheria can spread through:
- coughing and sneezing from a person with a diphtheria infection
- direct contact with sores or wounds infected with diphtheria bacteria
- touching objects or surfaces with diphtheria bacteria on them, then touching your mouth, nose or an open wound.
You can spread diphtheria to other people even before you know you are sick.
Who is at risk
The risk of severe illness is lower if you're up to date with your diphtheria vaccination.
Staying up to date with your vaccinations remains the best way to protect yourself and your family.
Symptoms
Symptoms usually appear 2 to 5 days after infection.
Respiratory diphtheria affects the throat and airways.
Symptoms can include:
- sore throat
- fever
- swollen glands in the neck
- difficulty swallowing
- difficulty breathing
- a thick grey or white coating in the throat or nose.
Skin diphtheria can cause:
- sores, ulcers or wounds that do not heal
- redness and swelling around the affected area.
Treatment
Diphtheria is treated with antibiotics.
People with respiratory diphtheria may require treatment in hospital.
Prevention
Vaccination is the best protection against diphtheria, read more about the free diphtheria vaccination.
You can also help prevent the spread of diphtheria by:
- covering your mouth and nose when coughing or sneezing
- washing your hands regularly
- cleaning sheets, towels, clothes or household items.
- avoiding close contact with people who are unwell
- keeping cuts and sores clean and covered.
People who have been in close contact with someone who has diphtheria may also need antibiotics or vaccination to prevent illness.
Information for health professionals
Get the latest diphtheria alerts, guidelines and public health advice from the Surveillance and Response Unit and Chief Health Officer on the NT Health website.
Contact
Contact your nearest Centre for Disease Control on the NT Health website.