Diphtheria

Diphtheria is a rare but serious disease caused by bacteria that’s easily spread from person to person. The infection affects your tonsils, throat, nose and sometimes your skin.

Diphtheria is now uncommon in Aotearoa New Zealand because of routine vaccination against the disease. However, there's still a risk that diphtheria could enter Aotearoa New Zealand from overseas. The best way to protect against diphtheria is by being vaccinated against the disease.

Video: Diphtheria

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(The Immunisation Advisory Centre, NZ)

Diphtheria is caused by bacteria that produce harmful toxins (poisons) which can damage tissues in your body. If the toxins get into your blood, this can lead to breathing problems, heart problems, kidney failure, paralysis or even death.

Diphtheria is very contagious. It’s usually spread from person to person by breathing in droplets when an infected person coughs or sneezes. It can also spread by touching infected skin sores. More rarely it can be spread by touching items (eg, cups, cutlery, tissues, bedding or clothing) that have been contaminated by someone with the infection. 

Some people may carry the diphtheria bacteria and spread the infection even though they don’t develop symptoms themselves.

Symptoms usually develop 2 to 5 days after you get infected. The common symptoms of diphtheria include:

• a sore throat and difficulty swallowing
• a thick grey-white coating at the back of your throat, which can block breathing and cause death
• fever
• throat and neck swelling due to swollen glands
• breathing difficulties.

Other symptoms may include chills, tiredness, a hoarse voice, cough and headache. At first, diphtheria may be mistaken for a simple sore throat or throat infection, but the symptoms quickly get worse.   

Some people with the infection may have no symptoms.

Diphtheria can sometimes affect your skin rather than your throat. This is known as cutaneous diphtheria. The symptoms of cutaneous diphtheria can range from a scaly rash to ulcers and pus-filled blisters.

Diphtheria is rare in Aotearoa New Zealand. Healthcare providers may suspect it if you’ve recently travelled to places where diphtheria still happens, been near someone with it, or haven’t had all your vaccinations. They check for diphtheria by taking a swab from your throat, nose, or any skin sore and sending it to a lab. Because it’s uncommon here, they need to tell the lab to check for it. Finding it early helps stop it spreading to others.

Results of the swab may take some time so you might be started on treatment before the results come back.

Diphtheria must be treated quickly to prevent serious complications. You maybe given an injection of antitoxin medicine into a muscle or vein. This works by blocking the harmful effects of the diphtheria toxin that’s in your blood. Since diphtheria is caused by bacteria, you’ll also be given antibiotics to kill the bacteria.

If you have a wound infected with diphtheria bacteria, this will be thoroughly cleaned and covered to reduce the spread of any infection.

Depending on how severe your symptoms are, you may also need:

• bed rest
• heart monitoring
• hospitalisation
• IV fluids (fluids given through a vein)
• oxygen
• a breathing tube.

In some cases, surgery may be needed to manage the blocked airway.

Things you can do to look after yourself if you have diphtheria include:

• getting plenty of bed rest
• avoiding too much physical activity especially if your heart has been affected
• eating soft foods or drinking liquids while your throat is sore and if you have trouble swallowing.

If you are looking after someone else with diphtheria, make sure you wash your hands often, especially before preparing food or eating. You should get a booster vaccination if you haven’t had one recently and you should have a course of antibiotics.

Your healthcare provider must notify local public health officials when someone gets diphtheria.

If you have diphtheria, you’ll be advised to have little or no contact with other people until you’ve recovered so that you don’t spread the infection. Also, health authorities may get in touch with people you may have come into contact with as they’re likely to be at risk of infection.

If you or your child has diphtheria, you can reduce the spread of the disease by staying home from early childhood care, school or work and avoiding large gatherings until:

• you’ve completely recovered, and
• have had 2 throat swabs that are clear of the bacteria. 

If you’ve been in close contact with an infected person, you should be given preventive doses of antibiotics, and you may be offered a complete course of diphtheria vaccine or a booster dose.

The best way to avoid getting diphtheria is by having a complete course of 3 doses of a diphtheria vaccine, plus booster doses. You can’t get diphtheria from the vaccine.

• In Aotearoa New Zealand, the diphtheria vaccine is combined with other vaccines and is part of the National Immunisation Programme(external link).
• Babies receive their diphtheria vaccinations at the ages of 6 weeks, 3 months and 5 months. Your pēpi needs all 3 doses to be fully protected against diphtheria.
• Booster doses are given to children when they’re 4 and 11 years of age.
• To ensure protection continues, a diphtheria booster vaccination is offered at 45 and 65 years of age. 
• If you’re travelling to a country where diphtheria is still common (developing countries where immunisation rates are low), you should make sure you’ve had a diphtheria booster in the last 10 years. If more than 10 years have passed since your last dose, a booster of low dose diphtheria vaccine is recommended.
• Even if you've had diphtheria, you’ll still need to get vaccinated. Contracting diphtheria doesn’t provide lasting immunity against the infection.

Read more about diphtheria vaccines.

Early treatment of diphtheria is important to prevent serious complications. Complications of diphtheria include:

• blockage of your airways causing breathing difficulties
• damage to your heart muscle
• nerve damage and paralysis
• kidney failure.

Diphtheria can be fatal – even with treatment, about 1 in 10 patients die. Without treatment, up to half of people with diphtheria can die from the disease.

Vaccination is the best way to protect against it.