Diphtheria Outbreak Declared in Northern Territory
The Northern Territory Department of Health has officially declared an outbreak of diphtheria, confirming four cases of a particularly virulent strain of the disease. This development has prompted a public health alert from NT Health’s Centre for Disease Control (CDC), following the identification of three cases in Darwin and one in Alice Springs within the past week.
This marks an alarming resurgence of a disease that was once a significant public health concern, particularly for children. Chief Health Officer for NT Health, Paul Burgess, expressed surprise at the outbreak, noting, “This is unusual; we haven’t had an outbreak in my 26 years in the Northern Territory.” Despite the confirmation of cases, Dr. Burgess assured the public that control measures are being effectively implemented and the risk to the general population remains extremely low. Contact tracing efforts are currently underway for individuals who may have been exposed to confirmed cases of diphtheria.
Beyond the current outbreak of the more severe strain, the Northern Territory has also seen a notable number of cutaneous diphtheria notifications, with 33 cases reported since 2025. This highlights the ongoing presence of the bacterium within the community.
Understanding Diphtheria
Diphtheria is a serious and highly contagious bacterial infection that has historically caused widespread illness and death, especially among children, prior to the widespread availability of vaccines. The disease is caused by toxic strains of the bacterium Corynebacterium diphtheriae.
In the Northern Territory, two primary forms of diphtheria have been identified:
- Respiratory Diphtheria: This is the more severe and potentially life-threatening form if left untreated.
- Symptoms can begin with a sore throat and a mild fever.
- Loss of appetite is also a common early sign.
- In severe cases, individuals may experience significant difficulty breathing due to the formation of a thick coating in the throat, which can obstruct the airway.
- Cutaneous Diphtheria: This form of the infection primarily affects the skin.
- Symptoms typically manifest as sores or ulcers, often appearing on the legs.
- These lesions are characterised by slow healing and can be a persistent source of infection.
Both strains are preventable through vaccination, underscoring the importance of immunisation programs.
The Critical Role of Vaccination
Dr. Burgess has issued a strong appeal to all Territorians, urging them to verify their vaccination status and to ensure they and their children are up-to-date with their diphtheria immunisations. He emphasised the continued presence of these diseases, stating, “These diseases are still with us, even though we don’t get sick with them because most of us are vaccinated.”
He also cautioned against the spread of misinformation, advising, “Don’t listen to the vaccine sceptics and the misinformation spread on social media.”
In Australia, the diphtheria vaccine is administered as part of a combination vaccine. This means it provides protection against diphtheria, as well as pertussis (whooping cough) and tetanus.
The Australian Immunisation Handbook outlines the recommended vaccination schedule:
Children: Vaccines are provided free of charge at the following ages:
- Six weeks
- Two months
- Four months
- Six months
- 18 months
- Four years
- 12 years
Adults: It is recommended that adults receive a booster vaccination every 10 years to maintain immunity.
- Pregnant Women: Pregnant women are advised to get vaccinated between 20 and 32 weeks of their pregnancy. This not only protects the mother but also provides passive immunity to the newborn infant during the critical first few months of life.
The current outbreak serves as a stark reminder that vaccine-preventable diseases, even those largely eradicated in the past, can re-emerge if vaccination rates decline or if the bacteria circulate within the community. Public health authorities are working diligently to contain the current outbreak and to reinforce the importance of vaccination as the most effective defence against diphtheria and other serious infectious diseases.
