Diphtheria

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

Diphtheria is passed from person to person through coughing, sneezing or direct contact with fluids from an infected person.

When you catch diphtheria, the bacteria releases a toxin (poison) into your body. This toxin can damage tissues in the body. It can create a thick grey coating at the back of the throat that makes breathing and swallowing difficult. In severe cases, the toxin can also affect the heart, nerves and other organs. 

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

Some people may have very mild symptoms or no symptoms at all, especially if you have been vaccinated. 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 3 days, a membrane can form over your throat. This can cause:

• swallowing problems
• breathing problems
• bleeding

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. 

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

People without any symptoms can still pass the bacteria to others without realising it and make those people sick.

Diphtheria is usually caused by a bacteria called Corynebacterium diphtheriae and the toxin it produces. It can also be caused by other strains of bacteria, 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. It’s important to:

• wash your hands to remove germs that can make you or others sick
• cover your mouth and nose with a tissue or your sleeve when you sneeze or cough
• check with your doctor if you have a wound that won’t heal

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

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

Your doctor will ask you about your symptoms and look in your mouth. They will look for a grey-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 you to have a throat swab. If you have a suspected skin infection, a skin swab will be taken.

Notification

Diphtheria is a notifiable disease. This means that the doctor who diagnoses diphtheria needs to report it 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 near, so they can be told to seek medical advice if needed.

Diphtheria is treated with antibiotics. This helps kill the bacteria and stop toxin production. A special treatment with diphtheria anti-toxin may be needed to prevent complications and death.

You may need treatment in hospital.

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

Diphtheria can cause:

• myocarditis (inflammation of the heart muscle)
• 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.

Vaccination is the most effective way to prevent severe diphtheria and its complications. It does not prevent you from becoming infected or spreading the disease.

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

About the diphtheria vaccine

Visit the Australian Centre for Disease Control (Opens in new tab) for more information about diphtheria. 

Find out more about the National Immunisation Program. (Opens in new tab)

Languages other than English

Find an Aboriginal and Torres Strait Islander health service near you by using this map from the National Aboriginal Community Controlled Health Organisation (Opens in new tab).

Information for Aboriginal and/or Torres Strait Islander peoples

Find more information about diphtheria from Queensland Aboriginal and Islander Health Council (Opens in new tab).