Status: Active
Last updated: 3 July 2026
Issued by: Director of Communicable Disease Control Directorate, Dr Paul Armstrong
Issued to: Health professionals and the WA community
For numbers of diphtheria cases reported in Western Australia (WA), see the Notifiable infectious disease dashboard. Dashboard figures represent all notified diphtheria cases in WA and may not directly reflect outbreak-specific counts or time periods.
Key points
- There is a current outbreak of diphtheria in regional WA, mainly affecting Aboriginal people in the Kimberley, Pilbara and Goldfields regions.
- The risk to the broader WA community is currently considered to be low.
- Vaccination is the most effective protection against severe illness due to diphtheria.
- Ensure all individuals are up to date with diphtheria vaccination, including recommended booster doses.
- Diphtheria booster vaccine doses are available for people who have not had one in the past five years and who are Aboriginal, reside in the Kimberley, Pilbara, Goldfields or Midwest regions, or have regular face-to-face contact with Aboriginal communities in these regions.
- Health professionals should consider and test for diphtheria in patients from outbreak-affected regions who present with clinically suspicious skin lesions/wounds, or pharyngitis/tonsillitis, particularly those with epidemiological risk factors (e.g. contact with a case) or clinical features raising greater suspicion (e.g. pharyngeal/tonsillar exudate).
Signs and symptoms
Diphtheria is a serious bacterial infection of the throat or skin caused by Corynebacterium diphtheriae. Some strains of the bacteria produce a toxin (poison) that can cause severe illness and complications. Symptoms usually appear 2 to 5 days after exposure (range 1-10 days).
Respiratory (throat) diphtheria
- Often starts like a cold with sore throat, fever and chills
- Can cause a thick greyish-white coating in the back of the nose or throat
- May cause swollen, painful glands in the neck
- Can worsen, making it difficult to breathe or swallow
- Can become life-threatening.
Cutaneous (skin) diphtheria
- Can start from a cut or wound that becomes infected
- Usually appears as sores or ulcers that may be slow to heal, often on the legs
- May be covered with a grey, moist scab
- Is usually less severe but can still spread to others.
Diphtheria infection is treated with antibiotics. Some people may need care in a hospital, and severe cases may need antitoxin to stop the toxin from causing further damage.
Complications
Complications are uncommon; they mainly occur in severe respiratory (throat) diphtheria and are caused by the toxin produced by the bacteria. They can include heart inflammation, nerve damage causing weakness or paralysis, or kidney damage.
How diphtheria is spread
Diphtheria spreads through close contact with an infected person:
- breathing in droplets from coughing or sneezing
- direct contact with saliva, respiratory secretions, or infected skin sores
- contact with contaminated items such as bandages, towels or utensils.
People with diphtheria can spread the infection from shortly before symptoms start until they have been treated with antibiotics.
Who is at risk
Most cases in the current outbreak have been reported in children and young adults, with smaller numbers of cases spread across older age groups.
People at higher risk of diphtheria in the current outbreak include:
- people who are not vaccinated or not fully vaccinated
- close contacts of someone with diphtheria
- people living in crowded settings where infections can spread more easily
- Aboriginal people, particularly those in remote communities in outbreak-affected regions
- young children and people with weakened immune systems (higher risk of severe illness if infected).
What to do if you develop symptoms
If you live in, or have recently travelled to, an outbreak-affected region, or have had contact with a case of diphtheria:
- see a doctor as soon as possible if you have a sore throat, or skin sores that are not healing
- seek urgent medical care if you have a sore throat with difficulty breathing or swallowing
- call ahead before going to a clinic or hospital so they can take appropriate precautions, wear a mask if you have throat symptoms, and cover any skin sores.
Diphtheria is confirmed by testing a swab from the throat or skin sore in a laboratory.
For advice, call Healthdirect Australia on 1800 022 222.
How to prevent diphtheria
Vaccination is the most effective protection against severe illness due to diphtheria. Ensuring you and your family are up to date with vaccinations, including booster doses for teenagers and adults, is key to preventing severe illness.
You can also reduce the risk of infection and help prevent spread to others by:
- covering your mouth and nose when coughing or sneezing
- throwing away used tissues in the bin
- washing hands regularly with soap and water, especially before preparing food, after coughing or sneezing, and before and after touching skin sores or dressings
- keeping sores and wounds clean and covered
- getting skin conditions like ringworm (tinea), eczema and scabies treated early – healthy skin helps prevent infection
- avoiding close contact with people who are unwell
- staying home if unwell and limiting contact with others.
Diphtheria vaccination
Combined diphtheria, tetanus and pertussis vaccines are already free of charge across WA under the National Immunisation Program for the following groups:
- infancy and early childhood: at 6 weeks, 4, 6 and 18 months, and 4 years
- adolescence: in year 7 of school, typically between 12 and 13 years of age (up to 20 years)
- pregnancy: ideally between 20- and 32-weeks’ gestation in each pregnancy
- refugees and humanitarian entrants: who have not previously received diphtheria-containing vaccines.
In response to the diphtheria outbreak in regional WA, the following groups are eligible for a diphtheria vaccine booster if they have not received a diphtheria-containing vaccine in the past 5 years and they are not currently due a dose under the National Immunisation Program:
- Aboriginal people residing in Western Australia
- non-Aboriginal people residing in the Kimberley, Pilbara, Goldfields or Midwest regions
- people with regular face-to-face contact with Aboriginal communities in the Kimberley, Pilbara, Goldfields or Midwest (e.g. patient-facing healthcare workers, or frontline workers who work, but may not reside, in these regions).
Kimberley, Pilbara, Goldfields or Midwest regions: Diphtheria vaccines are available through GPs, Aboriginal Medical Services, community pharmacies and community health and remote area clinics. A consultation or administration fee may apply.
Other regions: Diphtheria vaccines are available through Aboriginal Medical Services, community health clinics, and selected GPs.
Advice for travellers
Advice for travellers to outbreak-affected regions varies depending on the nature and purpose of the travel. The highest risk of exposure to diphtheria is among people who reside in outbreak-affected regions or who have regular face-to-face contact with Aboriginal communities in these regions.
For other short-term visitors, including holidaymakers and school groups, the risk is considered low. However, travellers should ensure their vaccinations are up to date in line with routine recommendations, remain aware of symptoms, and seek medical advice if unwell.
The Australian Centre for Disease Control advises travellers to diphtheria outbreak-affected areas in WA, the Northern Territory or South Australia to:
- check their diphtheria vaccination status
- talk to a healthcare professional if they are unsure when they last had a diphtheria vaccine or to discuss their specific travel plans
- consider vaccinating if they have not had a diphtheria vaccine in the past five years.
People who are not eligible for a free vaccine can speak with their usual healthcare provider about accessing diphtheria vaccination via private prescription. Out-of-pocket costs for the vaccine and consultation may apply.
Information for health professionals
Health professionals should consider and test for diphtheria in patients from outbreak-affected regions who present with clinically suspicious skin lesions/wounds, or pharyngitis/tonsillitis, particularly those with epidemiological risk factors (e.g. contact with a case) or clinical features raising greater suspicion (e.g. pharyngeal/tonsillar exudate).
Key actions for suspected cases
- Infection prevention and control: Isolate suspected or confirmed cases and use appropriate infection prevention and control measures (standard, contact and droplet precautions) including when performing swabs.
- Test: Collect appropriate specimens (throat and/or skin lesion/wound swabs) using semi-solid (Amies) transport medium swab with or without charcoal for culture, and a paired dry swab for diphtheria toxin PCR, and clearly mark “culture and PCR for diphtheria” on the request form.
- Notification: Notify public health of suspected cases.
- Treat: Consider differentials; if cutaneous or respiratory diphtheria is confirmed or strongly suspected, commence appropriate antibiotics as per the interim guidance or Diphtheria – Therapeutic Guidelines.
- Advise: Provide the patient with the diphtheria flyer or diphtheria factsheet. Exclude from work, school or childcare settings and provide additional advice as per the interim guidance.
Further information on case and contact management, infection prevention and control, and vaccination recommendations, can be found in the latest clinician alert and interim guidance.
Vaccination
Health professionals should also support diphtheria vaccination by:
- ensuring children and adolescents are up to date with scheduled diphtheria vaccines under the National Immunisation Program, including school-based programs
- offering vaccination to Aboriginal people, and patient-facing healthcare workers in the Kimberley, Pilbara, Goldfields and Midwest, who have not received a diphtheria vaccination in the past five years
- supporting access to vaccination for other eligible individuals who have not received a diphtheria vaccination in the past five years, who may request vaccination at healthcare encounters.
Prevention and general skin health
- Optimise management of common skin conditions such as tinea (ringworm), eczema and scabies, as healthy skin is less likely to become infected with diphtheria and other infections.
- Reinforce hand hygiene, respiratory hygiene and wound care practices with patients and carers.
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