Typhoid and paratyphoid fever

Typhoid fever is a disease caused by the bacteria Salmonella Typhi, while paratyphoid fever is caused by Salmonella Paratyphi. They are both known as ‘enteric fevers’ and are common in some developing countries.

Typhoid and paratyphoid fever do not normally occur in Australia but are infections usually acquired in countries where they are endemic.

Symptoms

The symptoms of typhoid and paratyphoid fever are similar although paratyphoid tends to be less severe than typhoid.

Those infected can experience fever, headache, lack of appetite and perhaps a dry cough. Some people may experience diarrhoea but on the other hand some may get constipation.

Some cases, particularly those with light skin, may develop pink spots on the trunk.

A few people who become infected may only have a short mild illness or no symptoms at all, but continue to harbour the bacteria for long periods of time. These ‘carriers’ can pass the typhoid bacteria on without knowing that they are infected.

A small number of people may develop severe complications such as intestinal perforation, pneumonia, meningitis or kidney failure.

Typhoid and paratyphoid fever are diagnosed from a blood or faeces (stool) specimen.

How it is spread

Spread of disease occurs when people consume food or water that has been contaminated by the faeces of other people carrying the disease.

Raw fruits and vegetables, milk and shellfish are the types of food most associated with the illness.

Infectious period

The time between infection and the appearance of symptoms can vary, but generally people show symptoms around 8 to 14 days after they were infected but it can be up to 2 months.

People with typhoid can shed the bacteria in their faeces for 2 to 6 weeks. Between 1 to 4% of people continue to shed the bacteria for months or years if not treated with antibiotics.

Who is at risk

Anyone can be infected with typhoid or paratyphoid, however people most at risk are travellers to countries where typhoid is common. Household contacts and co-travellers of cases are also at risk.

People with a lowered immune system may become infected with typhoid much more easily and can develop a more severe disease. Anti-ulcer and anti-reflux medications can increase the risk of typhoid fever by lowering the acid level in the stomach.

Treatment

Some people may require hospitalisation and treatment with antibiotics. Others who may not show symptoms of typhoid but are carriers of the disease will also require treatment with antibiotics.

Prevention

People travelling in developing countries where typhoid is common should be vaccinated prior to travel and:

• avoid uncooked foods, including fruit unless it is able to be peeled
• avoid untreated water, including ice
• drink beverages from sealed containers
• wash their hands after going to the toilet and before eating
• avoid eating from street stalls
• ensure hot food is thoroughly cooked and eaten while hot.

Typhoid vaccine is available from your local General Practitioner (GP) or travel clinic and is either a 1 dose injection or a course of 3 capsules.

Even if you have previously lived in an area where typhoid is common, you will need to be vaccinated if you travel back on holiday.

The vaccine only covers typhoid fever, but not paratyphoid fever, and is not 100% effective. It is therefore extremely important to follow the food and hygiene recommendations, even if you have had the vaccination.

The vaccine only gives protection for about 3 years so it is important to check that you are up to date with your vaccinations every time you travel abroad, as booster doses may be needed.

How it can be controlled

It is very unusual for typhoid and paratyphoid fever to spread in Australia.

People with typhoid or paratyphoid fever are followed up to ensure that they have cleared the disease. In addition, their travelling companions and, in certain circumstances, their household contacts are screened for the disease. Cases should not prepare food for others.

A number of stool tests will be required to assess when a person is cleared of infection with Salmonella Typhi; this is done in collaboration with the local Centre for Disease Control and the case’s doctor.

All doctors and laboratories in the Northern Territory must notify cases of typhoid fever to the local Centre for Disease Control. Laboratories are also required to notify cases of paratyphoid fever.

Information for health professionals

To find out more go to the NT Health website.

Contact

For more information contact the Centre for Disease Control.