An outbreak of diphtheria has been identified in regional Western Australia, starting in December 2025, and mainly affecting Aboriginal people in the Kimberley region. A small number of cases have also been reported in the Pilbara and Goldfields regions. The risk to the broader WA community is currently considered to be low.
Diphtheria is a serious infection of the throat or skin caused by Corynebacterium diphtheriae (or less commonly Corynebacterium ulcerans) bacteria. Some strains of the bacteria produce a toxin that can cause severe illness and may be life-threatening. Diphtheria was previously very rare in Australia due to high vaccination rates and improved living conditions – respiratory diphtheria had not been seen in WA for more than 50 years.
Diphtheria vaccines provide the best protection against severe disease.
