Salmonella

Salmonellosis is an infection of the bowel caused by the Salmonella bacteria.

How it spreads

Salmonellosis is usually spread by eating:

• undercooked food from infected animals such as:
  • chicken
  • eggs
  • other meats
• ready-to-eat foods such as fruits or vegetables that have been contaminated with faeces from an infected animal.
• food or drinking water that has been contaminated by small amounts of faeces from infected people.

Salmonellosis can also be acquired through contact with objects or an environment contaminated by the faeces of infected animals.

Common animals that can carry Salmonella include chickens and other birds, reptiles (including geckoes, lizards and snakes), frogs, kangaroos, livestock, cats and dogs.

Who is at risk

The most severe illness is seen in children, the elderly and those with impaired immune systems.

Children who attend childcare facilities are at greater risk of infections due to spread through faecal contamination.

Spread occurs when children share toys or food that have become contaminated and place it in their mouths. Particular care has to be taken wherever there are children in nappies.

Travellers to developing countries where sanitation and hygiene standards are poor are also at higher risk.

Symptoms

The symptoms usually develop between 6 to 72 hours after infection, but most commonly between 12 to 36 hours.

Symptoms of salmonellosis include:

• watery diarrhoea (sometimes with blood or mucus)
• fever
• headache
• abdominal pain
• nausea
• vomiting
• loss of appetite.

In healthy people, the diarrhoea usually improves within several days to a week but persists for longer in some people. It may be several months before bowel habits are entirely normal.

Rarely, the infection spreads beyond the bowel to the blood and other parts of the body. This can be very serious and require hospital treatment.

Infectious period

While the Salmonella bacteria remains in their faeces, infected people can pass the infection on to others.

This can be from several days to several weeks. Some people carry the bacteria in their bowel for months after the illness. They appear well but can still spread the infection.

Children who are not toilet trained and carry the bacteria are a source of infection to parents and within child care settings.

Treatment

Antibiotics are generally not recommended for salmonellosis as the infection usually resolves on its own within days.

Treatment mainly focuses on preventing and treating dehydration caused by vomiting or diarrhoea.

To avoid dehydration, anyone with vomiting or diarrhoea should drink extra fluids.

Rehydration therapy with oral glucose / electrolyte solution is particularly effective.

If children refuse this solution, diluted fruit juice may be given (1 part juice to 4 parts water).

Babies should continue to be offered their normal feeds plus extra fluids in between feeds.

Medicines to prevent vomiting or diarrhoea should not be given, especially to children, except when prescribed by a doctor.

When to see a doctor

Children who refuse extra fluids should see a doctor.

Additionally, anyone with the following should also see a doctor:

• prolonged (>3 days) or severe diarrhoea
• blood in their stools
• people concerned about their symptoms.

Control measures

People with vomiting or diarrhoea should not:

• prepare or handle food that will be eaten by others
• go back to work, school or childcare until 48 hours after diarrhoea and vomiting have ceased
• swim, wade or paddle in public pools.

Doctors and public health workers are interested in preventing outbreaks of diarrhoea.

If there are 2 or more cases in a group, these should be reported to the local Centre for Disease Control.

Prevention

Good hygiene is the best way to prevent salmonellosis.

Hands should be washed thoroughly with warm soapy water:

• after going to the toilet
• before preparing, handling or eating food
• after handling raw poultry and meats
• after every nappy change
• after changing soiled linen
• after touching animals, reptiles, birds or other pets.

In the kitchen:

• cook all meat and eggs thoroughly before eating
• avoid using dirty or cracked eggs
• to minimize risk, cook eggs until the white is completely firm and the yolk begins to thicken
• do not consume unpasteurised milk or other dairy products made from unpasteurised dairy products
• wash hands, kitchen work surfaces, and utensils with warm soapy water immediately after they have been in contact with raw meat or poultry
• separate the preparation of raw meat from that of ready-to-eat foods (e.g. salad) by using separate utensils and chopping boards.

Other measures include:

• never change nappies on tables or counters where food is prepared or eaten
• clean change areas with warm soapy water and disinfectant after every nappy change
• clean books, toys, equipment, furnishings, floors and toilets regularly (including toilet door handles).

Information for health professionals

To find out more, go to the NT Health website.

Contact

Contact your nearest Centre for Disease Control on the NT Health website.