Chief Medical Officer’s statement declaring diphtheria a Communicable Disease Incident of National Significance
A statement from Chief Medical Officer, Professor Michael Kidd AO, on declaring diphtheria a Communicable Disease Incident of National Significance.
22 May 2026
Today I have declared diphtheria a Communicable Disease Incident of National Significance (CDINS). This means Australia is stepping up a nationally coordinated response to a growing outbreak. It allows governments and health services to work together more quickly to get vaccines, medicines, staff and support to the communities that need them most.
Diphtheria is a serious bacterial infection. It can affect the throat, breathing passages or skin. It spreads through droplets from coughing or sneezing, or by direct contact with infected skin sores. It can be treated, and vaccination is the best protection against serious illness.
Cases of diphtheria in Australia have been rising since late 2025, with a sharp increase since February this year. As of 22 May 2026, around 230 cases have been reported nationally. This is the largest outbreak since national records began in 1991.
The outbreak is affecting some communities more than others, especially Aboriginal and Torres Strait Islander communities. That is why this response is being delivered in close partnership with Aboriginal Community Controlled Health Organisations and local services, so support is practical, culturally safe and community-led.
The Australian Government is already working closely with states, territories, and local health services. On 21 May 2026, Minister Butler announced a $7.2m Commonwealth-funded diphtheria response package, including $5.2m to support activities delivered by the National Critical Care and Trauma Response Centre (NCCTRC) in collaboration with the Northern Territory Government and the Aboriginal Community Controlled health sector. This new support package will help increase vaccination, strengthen the health workforce, improve access to antibiotics and other treatment, and support local outreach in affected areas.
If you are unsure whether your vaccinations are up to date, please check with your GP, Aboriginal Medical Service, pharmacy or local health clinic. Vaccination is the strongest protection against diphtheria, especially for children, older adults needing boosters, and people living in or travelling to higher-risk areas.
I want to reassure Australians that health authorities are acting quickly and that most reported cases in this outbreak have been mild. But this is still a serious disease, and we must not be complacent. By staying up to date with vaccination and following public health advice, we can protect ourselves, our families and our communities.