Both the Northern Territory and Western Australia are experiencing outbreaks of diphtheria.
NT Health’s ongoing diphtheria health alert was most recently updated on 22 April. In the Northern Territory, there have been 17 cases of respiratory diphtheria notified since 23 March 2026. Healthcare workers are recommended to receive a booster if their last diphtheria-containing vaccine was more than 5 years ago.
The Kimberly region of Western Australia has also seen respiratory diphtheria cases.
Diphtheria is vaccine-preventable. It mostly commonly causes an acute respiratory illness characterised by a “pseudo membrane” which forms over the pharyngeal area (throat); it can be life-threatening.
Read more about the current outbreaks at The Conversation: Before vaccines, diphtheria used to kill hundreds each year. Now it’s back in Australia.
Read more about diphtheria disease, transmission and prevention at MVEC: Diphtheria.