Diphtheria outbreak spreads across Western Australia, Queensland, and South Australia, raising health concerns

A disease most people thought was history is making a comeback in Australia, and health authorities are sounding the alarm. The National Notifiable Disease Surveillance System has recorded several cases of diphtheria to date in 2026, with the bulk of cases coming from the Northern Territory and Western Australia, ABC reported.


Most Australians grew up with diphtheria as something their grandparents worried about, not something real. Although it is now rare in Australia, diphtheria is common in many overseas countries and can be brought into Australia by returning travellers. Diphtheria can spread easily in communities with low vaccination coverage.


The bulk of infections are cutaneous, skin infections, with over 80% of cases being cutaneous infections. So you're looking at grey-white sores on the skin. But respiratory diphtheria exists too, and that's where things get dangerous fast. Respiratory diphtheria commonly presents with sore throat, low‑grade fever and cervical lymphadenopathy, followed by development of a white exudate and adherent grey pseudomembrane, which can lead to airway obstruction.

How it's spreading

The cases across different states are connected. An AusTrakka analysis of recent diphtheria cases indicates that the recent Western Australia cases in the Kimberley region are genomically linked to cases in the Northern Territory and Queensland. So this isn't three separate outbreaks popping up by coincidence. It's one cluster moving through the country.


Diphtheria is transmitted through respiratory droplets, direct contact with cutaneous lesions and less commonly via fomites. The incubation period is usually 2–5 days but may be longer (range 1-10 days). So you could be infected and not show symptoms for nearly two weeks. That makes it sneaky from a public health perspective.

Preventive measures

The biggest protection against diphtheria is still vaccination. A lot of people assume this disease disappeared years ago, but outbreaks keep showing up when vaccination rates drop or booster shots are missed. Children usually get vaccinated early, but adults often forget that immunity can fade over time. That’s why booster doses matter. If you can’t remember when you last got one, it’s worth checking with a doctor instead of assuming you’re covered.


And if there’s an outbreak in your area, don’t ignore symptoms that seem “minor.” Diphtheria can start like a regular sore throat or cold. Mild fever, swollen glands, tiredness, trouble swallowing — it doesn’t always look dramatic in the beginning. But the infection can become serious quickly because it affects breathing and can even damage the heart or nerves in some cases.

Simple habits still make a difference

Diphtheria spreads through respiratory droplets, which means coughing, sneezing, and close contact play a big role. So basic hygiene still matters more than people think. Washing hands properly, covering your mouth while coughing, and avoiding close contact with someone who’s sick can reduce risk. It sounds simple because it is simple, but these habits genuinely help during outbreaks.


Ventilation matters too. Crowded indoor spaces with poor airflow make it easier for infections to spread. And honestly, people often underestimate how fast illnesses move through schools, public transport, workplaces, or even family gatherings.


If someone around you has been diagnosed, don’t wait around hoping you’ll “probably be fine.” Doctors may recommend testing, antibiotics, or preventive treatment for close contacts.


This outbreak is a reminder that diseases we thought we'd beaten don't stay beaten. They wait for immunity to drop. They find communities where vaccination rates slip. And when they do come back, they come back serious.