Diphtheria

Diphtheria is a serious communicable bacterial disease that causes severe inflammation of the nose, throat and windpipe (trachea). It is caused by the bacterium Corynebacterium diphtheriae. The bacteria produce toxins that cause an abnormal membrane to grow in the throat, which can lead to suffocation.

Other dangerous complications include paralysis and heart failure if the toxins spread throughout the body. Around 10 per cent of people exposed to diphtheria die from the disease.

Diphtheria is extremely rare in most developed countries, including Australia, because of the widespread use of the diphtheria vaccine. However, it is important to continue vaccinating children against diphtheria because there is a risk that the infection can be brought in by people who have travelled to or come from developing nations.

Symptoms of diphtheria

Symptoms of diphtheria may include:

• runny nose
• severe sore throat
• fever
• generally feeling unwell (malaise)
• swollen lymph nodes in the throat
• a furry grey or black coating on the throat membranes, which is made up of bacteria and dead cells
• breathing problems
• swallowing problems.

Diphtheria and skin infection

Sometimes, diphtheria causes a skin infection. The wound is sore, inflamed and full of pus and may be surrounded by greyish skin patches. This condition is known as cutaneous diphtheria. It is quite rare in developed countries.

Complications of diphtheria

Without treatment, the extremely serious and potentially lethal complications of diphtheria can include:

• suffocation, as the abnormal throat membrane obstructs breathing
• heart damage, including inflammation (myocarditis) or congestive heart failure
• kidney damage
• nerve damage, with health problems depending on which nerves are affected.

How diphtheria is spread

Diphtheria is most commonly spread when someone ingests (swallows) or inhales the cough or sneeze droplets from an infected person. Symptoms occur between two and 10 days following infection.

Sometimes, a person has such a mild case of diphtheria that they don't realise they are sick. However, they are still contagious for about six weeks and may infect a lot of other people. An apparently healthy person who spreads an infectious disease is called a 'carrier'.

Diphtheria – high-risk groups

Diphtheria is very rare in Australia. People at increased risk of diphtheria include:

• unimmunised or incompletely immunised people exposed to a person infected with diphtheria
• people who have immune system problems
• people living in unhygienic and crowded conditions
• travellers to particular areas known to harbour diphtheria such as South-East Asia, Russia and surrounding countries, Baltic countries and Eastern European countries.

Diagnosis of diphtheria

Tests used to diagnose diphtheria may include:

• medical history including immunisation status
• travel history
• physical examination
• swabs of the throat (or wound) for laboratory testing.

Treatment for diphtheria

If diphtheria is suspected, treatment begins before the test results are back from the laboratory. Treatment may include:

• hospitalisation
• isolation to prevent the spread of infection
• antibiotics, such as penicillin, to destroy the bacteria
• diphtheria antitoxin given
• other medicines to reduce the risk of adverse reactions to the vaccine, for example corticosteroids, adrenaline or antihistamines
• surgery to remove the grey membrane in the throat, if necessary
• treatment of complications, for example medications to treat myocarditis
• bed rest for about six weeks or longer, depending on the severity of the illness.

Prevention of diphtheria

The best prevention against diphtheria is immunisation.

People who are caring for someone with diphtheria should practise strict hygiene – for example, wash hands frequently, particularly before handling, preparing or eating food – and get a booster vaccination. All contacts should also receive a course of antibiotics.

Immunisation against diphtheria

Vaccinations against diphtheria are part of childhood vaccination and are given in a combination vaccine known as ‘DTP’ vaccine, which contains vaccines against diphtheria, tetanus and pertussis (whooping cough).

Free diphtheria -containing vaccine is available through the National Immunisation Program for:

• Infants 2 (can be given from 6 weeks of age), 4 and 6 months of age
• Children at 18 months and 4 years of age
• Adolescents in Year 7 (or age equivalent)

Catch-up vaccinations are also available for people who did not receive vaccination against diphtheria as children:

• people up to 19 years of age
• refugees and humanitarian entrants aged 20 years and over

Adults

A course of diphtheria-containing vaccines are recommended for adults who have never been vaccinated against diphtheria. Adults who have been fully vaccinated in the past are recommended to receive a booster dose at the age of 50 years unless a booster dose has been documented in the previous 10 years. Adults should receive this dose as the combined diphtheria-tetanus-pertussis vaccine to also protect against pertussis (whooping cough).

Before diphtheria vaccination

Tell your immunisation provider if you or your child:

• are unwell (fever over 38.5°C)
• have allergies to any other medications or substances
• have had a serious reaction to any vaccine, or vaccine component
• are pregnant

Side effects of the diphtheria vaccine

Immunisations against diphtheria, tetanus and whooping cough are effective and safe.

Most side effects are mild and temporary, and do not require specific treatment:

• localised pain, redness and swelling at the injection site
• Small lump at the injection site (this may last several weeks)
• low-grade temperature (fever)
• children may be unsettled and fatigued

To manage side effects:

• Offer extra fluids to drink
• Don’t overdress if feverish
• Use paracetamol if needed (check the correct dose)
• Apply a cool wet cloth to manage injection site discomfort

Seek medical help if:

• Side effects are unexpected, persistent, or severe
• You’re worried about your or your child’s health

Concerns about immunisation side effects

If the side effect following immunisation is unexpected, persistent, or severe or if you are worried about youror your child’s condition after a vaccination, see your doctor or immunisation provider as soon as possible or go directly to a hospital. Immunisation side effects may be reported to SAEFVIC, the Victorian vaccine safety service.

Rare side effects of immunisation

There is a very small risk of a serious allergic reaction (anaphylaxis) to any vaccine. This is why you are advised to stay at the clinic or medical surgery for at least 15 minutes following immunisation in case further treatment is required.

Where to get help

• In an emergency, call triple zero (000)
• The emergency department of your nearest hospital
• Your doctor
• Your local council immunisation service
• Immunisation Program, Department of Health, Victorian Government Email: immunisation@health.vic.gov.au
• Nurse-on-Call Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
• Maternal and Child Health Line (24 hours, 7 days) Tel. 13 22 29
• Immunise Australia Information Line Tel. 1800 671 811
• SAEFVIC Tel. 1300 882 924 – see the SAEFVIC website for hours of operation