NT Health is awaiting results from an autopsy report about a possible diphtheria-related death in the Northern Territory.
If the death is found to have been caused by diphtheria, it would be the first fatal case of the infectious disease in Australia since 2018.
According to the Australian Centre for Disease Control, which is aware of the investigations into the death in the NT, diphtheria notifications have been increasing in Australia since October 2025.
Dr John Boffa from the Central Australian Aboriginal Congress, a primary health care service based in Alice Springs told NITV news, the death of an Aboriginal person, a few weeks ago was believed to be from diphtheria.
There have been 145 cases of diphtheria reported in the Northern Territory since the start of the year and another 75 cases in Western Australia, with most of those recorded in the Kimberley and in Aboriginal people.
There have also been some cases recorded in South Australia and Queensland.
Dr Boffa said about 95-97 per cent of cases in the NT were amongst Aboriginal people.
NT Health issued a public health alert in April reminding health professionals of the importance of vaccinations.
Diphtheria is a vaccine preventable disease, with the vaccine part of the standard childhood vaccination schedule.
The bacterial disease causes severe inflammation of the nose, throat and windpipe.
It is spread by direct skin contact with people who have infected sores or by coughing and sneezing from people with respiratory diphtheria.
Both respiratory and cutaneous diphtheria have been recorded within the current outbreak.
Since vaccination programs began in Australia in the 1940s, the incidence of diphtheria declined.
A spokesperson for NT Health said vaccination remained the most important measure for preventing, protecting and reducing transmission of the disease.
"NT Health is working with community organisations to undertake a Territory-wide vaccination program to address the outbreak starting with a staged approach focusing on vulnerable people and at-risk areas," they said.
NT Health urged parents to check their child’s vaccination status with their health care provider to make sure they are up to date with their immunisations and for adults to have a booster shot every 10 years.
The Australian Centre for Disease Control has told NITV it was aware of the investigation into the death and would await the outcome of the NT government's investigation.
