Daijiworld Media Network – Sydney

Sydney, Apr 24: A resurgence of diphtheria in parts of Australia has raised public health concerns, with officials linking the return of the once-controlled disease to vaccination gaps and waning immunity.

Health authorities have reported outbreaks in the Northern Territory and Western Australia, with 17 cases of respiratory diphtheria recorded in the Northern Territory since March 23 this year, alongside 60 cases of cutaneous diphtheria since May 2025. Cases have also been reported in Western Australia’s Kimberly region.

The development is notable as diphtheria had become rare in Australia since the 1950s following widespread immunisation campaigns.

Medical experts say the re-emergence highlights the continuing importance of vaccination and booster doses.

Diphtheria is a contagious bacterial infection caused by Corynebacterium diphtheriae, which primarily affects the throat and upper airways and can produce toxins capable of damaging the heart and nervous system.

The disease spreads through respiratory droplets, close physical contact and, in some cases, through contaminated objects or infected skin lesions.

Experts say early symptoms include sore throat, mild fever and fatigue, while severe cases may involve a thick grey membrane in the throat that can obstruct breathing, along with swollen neck glands — commonly described as “bull neck”.

In cutaneous diphtheria, infected individuals may develop non-healing skin ulcers with a grey membrane.

Doctors have stressed that early treatment with diphtheria antitoxin and antibiotics can be highly effective, though toxin-related damage may be irreversible if intervention is delayed.

The outbreak has also revived attention on immunisation coverage, particularly after a diphtheria outbreak in Rajasthan’s Deeg in 2024 claimed seven children’s lives.

India has recently stepped up adult immunisation efforts with the launch of an indigenously manufactured Tetanus and Adult Diphtheria (Td) vaccine aimed at strengthening protection against such infections.

Health experts say maintaining high vaccination coverage remains the most effective safeguard against future outbreaks.