Healthy Travel Diphtheria returns to the Northern Territory
The NT Centre for Disease Control is investigating a diphtheria outbreak in the Northern Territory. Four cases of respiratory diphtheria have been notified since 23 March 2026 – two in Darwin and two in Alice Springs – alongside 37 cases of cutaneous (skin) diphtheria notified since May 2025. A public health alert was issued on 31 March 2026.
This outbreak is quite unusual. Respiratory diphtheria has not been seen in the Territory for over 26 years. The skin form is more common, but the recent cluster of respiratory cases has prompted heightened vigilance from clinicians and public health authorities.
While a diphtheria outbreak might be very unusual in Australia, it isn’t unusual when considering infectious disease globally. Between 12,000 and 24,000 cases are reported to WHO on an annual basis.
In 2023/24, more than 28,000 cases and 828 deaths were reported across Nigeria, Guinea, Mauritania, and South Africa, with more than 80% of cases coming from Nigeria. According to the report on the outbreak, only 24% of cases were fully vaccinated, with 70% under the age of 15 years.