Diphtheria is a serious bacterial infection that can affect the throat, nose and skin. It can spread from person to person and may cause severe illness. Vaccination is the best way to protect yourself, your family and your community.

This page provides information about diphtheria symptoms, treatment and prevention, vaccination recommendations, and resources for healthcare professionals.

An outbreak of diphtheria was reported from the Northern Territory and Western Australia at the end of 2025, with cases increasing significantly in early 2026. A small number of cases of diphtheria associated with this outbreak were notified in South Australia in April 2026. The outbreak is predominately impacting Aboriginal people.

Learn how to recognise the signs of diphtheria, reduce the risk of infection, and check whether your vaccinations are up to date.