Australia has recorded its first diphtheria death in almost a decade as the country grapples with the worst outbreak of the vaccine-preventable disease in decades, BBC reported. 

In March, the Northern Territory (NT) declared an outbreak of diphtheria with cases also in Western Australia, South Australia and Queensland. Cases started rising in late-2025 with a sharp increase in February.

This year, there have been 245 cases, marking the largest outbreak in Australia since 1991, mainly in remote Indigenous communities.

On Tuesday, NT's health minister said autopsy results from an overseas lab found diphtheria was the cause of a man's death in April at Royal Darwin Hospital, the first such case since 2018, according to BBC.