What is diphtheria?

Diphtheria is an infectious disease. It's usually caused by the bacteria (germ) called Corynebacterium diphtheriae. It most often affects your upper respiratory tract — your nose, throat and tonsils.

When you catch diphtheria, the bacteria releases a toxin (poison) into your body. This toxin can affect your airways and cause a membrane to grow across your windpipe. This makes breathing difficult. If the membrane blocks your windpipe, it can lead to suffocation and death.

Although diphtheria is rare in Australia, outbreaks can still happen. This is because diphtheria is common overseas and travellers can bring it back to Australia.

What are the symptoms of diphtheria?

The symptoms of diphtheria depend on where the infection (germ) is in your body.

Diphtheria can give you:

• a sore throat
• loss of appetite
• mild fever

Within 2 to 3 days, a membrane can form over your throat. This can cause:

• swallowing problems
• breathing problems

It often causes the glands in your neck to swell. This is sometimes called 'bull neck'.

A less serious form of diphtheria causes skin sores to form. These form large ulcers that are slow to heal. This form of the disease is more common in tropical areas.

Diphtheria symptoms usually appear 2 to 5 days after coming into contact with the bacteria.

Some people won't get any symptoms. They can still pass the bacteria to others without realising it and make those people sick.

What causes diphtheria?

Diphtheria is usually caused by a bacteria called Corynebacterium diphtheriae. It can also be caused by other strains of corynebacterium, including Corynebacterium ulcerans.

How is diphtheria spread?

Diphtheria spreads from person to person, mostly through coughing and sneezing. You can catch it if you have close contact with someone who is infected — even if they don't have any symptoms.

You can also get diphtheria by touching:

• objects or surfaces that an infected person has coughed or sneezed on
• the skin sores of someone with diphtheria
• items contaminated by an infected person, such as used tissues or clothing

Practising good hygiene can help to stop diphtheria from spreading, such as:

• washing your hands to remove germs that can make you or others sick
• covering your mouth and nose with a tissue or your sleeve, when you sneeze or cough

Diphtheria can spread easily in communities where not many people have been vaccinated with the diphtheria vaccine.

When should I see my doctor?

You should see your doctor if you have diphtheria symptoms or have been close to someone who has diphtheria.

If a doctor isn’t available to you or you are concerned about diphtheria, call healthdirect on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

How is diphtheria diagnosed?

Your doctor will ask you about your symptoms and look in your mouth. They will look for a greyish white membrane in your throat. They may ask if you've been close to someone who has diphtheria.

If they suspect that you have diphtheria, they will organise for a throat swab to be taken. Or if you have a suspected skin infection, a skin swab will be taken.

Diphtheria is a notifiable disease. This means that the doctor who diagnoses diphtheria needs to report the case to the local health authorities. They will take steps to prevent or control an outbreak.

Because diphtheria spreads easily, contact tracing may be used to find people who have been in close contact with you. Contact tracers will ask about anyone you have recently been around, so they can be told and encouraged to seek medical advice if needed.

How is diphtheria treated?

Diphtheria is treated with antibiotics. Special treatment with diphtheria anti-toxin may also be needed. This helps to kill the bacteria and stop toxin production.

You may need treatment in hospital.

If you have diphtheria, you will need to isolate until you are no longer infectious. This helps to stop the disease spreading.

Can diphtheria be prevented?

Vaccination is the most effective way to prevent diphtheria.

The diphtheria, tetanus and whooping cough (pertussis) vaccines are given together. This vaccine is called 'DTP'.

About the DTP vaccine

To find out more about diphtheria vaccination, talk to your doctor, nurse or other health worker. Vaccinations are available at:

• your doctor
• immunisation clinics
• local councils
• community child health nurses
• Aboriginal and/or Torres Strait Islander community health services
• pharmacies
• schools (for teenagers)

Learn more about immunisation and vaccinations for your child with information from Pregnancy, Birth and Baby.

What are the complications of diphtheria?

Diphtheria can cause long-term:

• inflammation of the heart muscle — which can lead to heart failure
• neurological (brain and nerve) problems — which can cause paralysis
• kidney problems

You may need medicines to treat complications of diphtheria.

Even with treatment, people sometimes die from diphtheria.

Resources and support

Find out more about the National Immunisation Program from the Department of Health, Disability and Ageing.

Find an Aboriginal and Torres Strait Islander health service near you by using this map from the National Aboriginal Community Controlled Health Organisation.

If you are concerned about diphtheria you can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.