Diphtheria Outbreak in 20206: What Surry Hills Residents Need to Know
Diphtheria is a serious and potentially life-threatening bacterial infection that many Australians assume belongs to the past. Thanks to widespread vaccination, diphtheria became rare in Australia for decades. However, recent outbreaks across Australia have reminded health professionals that this dangerous disease remains a real public health concern. Australia is currently experiencing its largest recorded diphtheria outbreak in modern surveillance history, with cases reported across multiple states and territories.
At Crown St Medical Centre – Surry Hills’ local Medical Practice, we are committed to helping patients understand emerging health risks and ensuring vaccinations remain up to date. Whether you live in Surry Hills, Darlinghurst, Paddington, Redfern, Waterloo, Green Square, Woollahra or elsewhere in Sydney’s Eastern Suburbs, understanding diphtheria is an important part of protecting yourself, your family and your community.
This guide explains:
- What diphtheria is
- Current outbreaks in Australia
- Symptoms and health risks
- How diphtheria spreads
- Vaccination recommendations
- Who is at greatest risk
- Prevention strategies for Sydney residents
- When to see your GP
What Is Diphtheria?
Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae. Certain strains produce a powerful toxin that can damage tissues throughout the body.
The infection commonly affects the:
- Nose
- Throat
- Tonsils
- Airways
It can also affect the skin, causing chronic ulcers and wounds. The greatest danger comes from the toxin produced by the bacteria. This toxin can enter the bloodstream and cause severe complications affecting the heart, nerves and other organs. Before widespread vaccination programs, diphtheria was one of the leading causes of childhood death worldwide.
Why Is Diphtheria Making Headlines Again?
Australia is currently experiencing the largest diphtheria outbreak since national records began. Notifications have increased significantly since late 2025, particularly in the Northern Territory, Western Australia and South Australia. Cases have also been identified in Queensland.
Recent public health data shows:
- More than 200 cases have been reported nationally during the current outbreak.
- The Northern Territory has experienced the highest number of cases.
- Western Australia has seen rapidly increasing case numbers.
- Queensland and South Australia have also reported cases.
- Both skin (cutaneous) and respiratory forms have been identified.
- Hospitalisations and severe complications have occurred.
Although most cases remain outside New South Wales, infectious diseases do not respect state borders. Increased domestic travel, international travel and population movement mean Sydney residents should ensure their vaccinations are current.
Why Should Surry Hills Residents Be Concerned?
Many residents of Surry Hills and surrounding suburbs travel frequently for work, study and leisure.
Furthermore, areas such as:
- Darlinghurst
- Paddington
- Redfern
- Waterloo
- Green Square
- Woollahra
- Bondi
- Sydney CBD
are highly connected communities with significant interstate and international travel.
While there is currently no widespread outbreak in Sydney, maintaining high vaccination coverage is critical to preventing future cases. Public health experts have linked recent outbreaks to gaps in vaccination coverage and missed booster doses.
How Does Diphtheria Spread?
Diphtheria spreads through:
Respiratory Droplets
When an infected person:
- Coughs
- Sneezes
- Talks
small droplets containing bacteria can be inhaled by others.
Direct Contact
Contact with:
- Saliva
- Nasal secretions
- Skin lesions
can transmit infection.
Contaminated Surfaces
Although less common, bacteria may survive briefly on contaminated objects.
People can spread diphtheria even before severe symptoms develop.
What Are the Symptoms of Diphtheria?
Symptoms usually develop within 2 to 5 days after exposure.
Early Symptoms
Patients may initially experience:
- Sore throat
- Fever
- Fatigue
- Hoarse voice
- Difficulty swallowing
- Swollen neck glands
These symptoms may resemble a common respiratory infection.
Advanced Symptoms
As the disease progresses, patients can develop:
Thick Grey Membrane
A characteristic grey or white membrane may form in the throat.
This membrane can:
- Cover the tonsils
- Obstruct the airway
- Cause breathing difficulties
The membrane can become life-threatening if it blocks airflow.
“Bull Neck” Appearance
Severe swelling of the neck can occur due to enlarged lymph nodes and soft tissue inflammation.
Severe Respiratory Distress
Patients may experience:
- Noisy breathing
- Stridor
- Airway obstruction
- Respiratory failure
Can Diphtheria Affect the Heart?
Yes. One of the most dangerous complications is diphtheria myocarditis, where the toxin damages the heart muscle.
This may cause:
- Abnormal heart rhythms
- Heart failure
- Sudden cardiac death
Cardiac complications can develop days or weeks after the initial infection.
Can Diphtheria Cause Paralysis?
Unfortunately, yes.
The toxin can damage nerves and result in:
- Difficulty swallowing
- Vision problems
- Limb weakness
- Respiratory muscle paralysis
Neurological complications may persist long after the infection has resolved.
What Is Cutaneous Diphtheria?
Cutaneous diphtheria affects the skin rather than the respiratory tract.
Symptoms include:
- Persistent ulcers
- Slow-healing wounds
- Grey or bluish membranes over skin lesions
- Secondary bacterial infection
Although generally less dangerous than respiratory diphtheria, skin infections can spread bacteria to others and contribute to outbreaks.
Who Is Most at Risk?
Individuals at greatest risk include:
Unvaccinated Children
Children who have not completed routine vaccinations remain highly vulnerable.
Adults With Waning Immunity
Many adults mistakenly believe childhood vaccinations provide lifelong protection.
Immunity gradually declines over time.
People Who Have Missed Booster Doses
Overdue boosters increase susceptibility.
Travellers
Travel to regions where diphtheria remains endemic can increase exposure risk.
Healthcare Workers
Healthcare professionals may encounter infected individuals.
Immunocompromised Individuals
People with weakened immune systems may be at higher risk of complications.
Diphtheria Vaccination in Australia
Vaccination remains the most effective protection against diphtheria.
Australia’s National Immunisation Program includes diphtheria-containing vaccines throughout childhood.
Childhood Schedule
Diphtheria vaccination is routinely provided at:
- 2 months
- 4 months
- 6 months
- 18 months
- 4 years
- 11–13 years (school-based booster)
Adult Booster Recommendations
The Australian Immunisation Handbook recommends booster vaccination for:
Adults Aged 50+
A booster dose is recommended if it has been more than 10 years since the last vaccination.
Adults Aged 65+
Additional boosters may be recommended depending on vaccination history.
Travellers
More frequent boosters may be advised when travelling to high-risk regions.
Pregnant Women
Diphtheria-containing vaccines are commonly administered during pregnancy as part of the recommended dTpa vaccination program.
How Effective Is the Vaccine?
Diphtheria vaccines are highly effective.
Vaccination:
- Significantly reduces infection risk
- Prevents severe disease
- Reduces transmission
- Protects vulnerable community members
The dramatic reduction in Australian cases over previous decades has been attributed primarily to vaccination programs.
Preventing Diphtheria in Surry Hills and Sydney
1. Check Your Vaccination Status
Many adults cannot recall their last booster. A review with your Surry Hills doctors team can determine whether you are due.
2. Ensure Children Are Fully Vaccinated
Following the National Immunisation Program schedule remains essential.
3. Seek Medical Advice Before Overseas Travel
Travel vaccinations should be reviewed several weeks before departure.
4. Practise Good Hygiene
Simple measures help reduce spread:
- Frequent hand washing
- Covering coughs and sneezes
- Staying home when unwell
- Avoiding close contact with sick individuals
5. See a Doctor Early
Anyone experiencing:
- Severe sore throat
- Difficulty breathing
- Difficulty swallowing
- Neck swelling
should seek urgent medical attention.
When Should You See a GP?
Book an appointment if:
- You are unsure about your vaccination history.
- You are planning overseas travel.
- Your child has missed scheduled vaccinations.
- You require a catch-up vaccination program.
- You develop symptoms suggestive of diphtheria.
- You have been exposed to a confirmed case.
Early diagnosis and treatment can prevent serious complications.
Diphtheria Vaccination
Maintaining vaccination coverage across Sydney remains vital to protecting vulnerable groups including:
- Infants
- Elderly adults
- Pregnant women
- Immunocompromised individuals
At Crown St Medical Centre, our GPs regularly review vaccination status and provide evidence-based preventative healthcare to patients across Sydney’s Eastern Suburbs and Inner City.
Frequently Asked Questions About Diphtheria
Is diphtheria contagious?
Yes. Diphtheria spreads through respiratory droplets, close contact and contact with infected skin lesions.
Can adults get diphtheria?
Yes. Adults can become infected, particularly if their immunity has waned or they have missed booster vaccinations.
Is diphtheria still present in Australia?
Yes. Australia is currently experiencing its largest recorded outbreak in modern surveillance history.
What are the first symptoms of diphtheria?
Early symptoms include sore throat, fever, fatigue, hoarseness and difficulty swallowing.
Can diphtheria be fatal?
Yes. Severe cases may cause airway obstruction, heart failure, paralysis and death.
Is there a vaccine?
Yes. Safe and effective vaccines are available and form part of Australia’s National Immunisation Program.
How often do adults need boosters?
Many adults require booster doses every 10 years depending on age, travel plans and vaccination history.
Can vaccinated people still get diphtheria?
Vaccination greatly reduces the risk of infection and severe disease but no vaccine offers 100% protection.
Should travellers be vaccinated?
Yes. Travellers to countries where diphtheria remains more common should ensure vaccinations are current.
Can diphtheria be treated?
Yes. Early treatment with antibiotics and diphtheria antitoxin can reduce complications and improve outcomes.
Book Your Diphtheria Vaccination Review Today
With Australia’s largest diphtheria outbreak in decades now underway, there has never been a better time to check your vaccination status and ensure your family remains protected.
The experienced GPs at Crown St Medical Centre, Surry Hills can review your immunisation history, provide catch-up vaccinations where appropriate, discuss travel health requirements and help keep your family protected.
Book an Appointment Online today for a vaccination review, travel health consultation or general health check. Our team proudly cares for patients from Surry Hills, Darlinghurst, Paddington, Redfern, Waterloo, Green Square, Woollahra, Bondi and throughout Sydney.
