Salmonella

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

How it’s spread

Salmonellosis is usually spread by eating undercooked food from infected animals such as chicken, eggs or other meats or by eating ready-to-eat foods such as fruits or vegetables that have been contaminated with faeces from an infected animal. Spread can also occur when food or drinking water has been contaminated by very small amounts of faeces from infected people.

Salmonellosis can also be acquired through contact with objects or an environment contaminated by the faeces of animals carrying Salmonella. Common animals that can carry Salmonella include chickens and other birds, reptiles (including geckoes, lizards and snakes), frogs, kangaroos, livestock, cats and dogs.

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 and loss of appetite.

In healthy people the diarrhoea usually improves within several days to a week but persists for longer in a small number of 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 an important source of infection to parents and within child care settings.

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 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 at higher risk of contracting diarrhoeal illnesses.

Treatment

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

Anyone with diarrhoea should drink extra fluids to avoid dehydration. Children with diarrhoea, who vomit or who refuse extra fluids should see a doctor. Anyone with prolonged or severe diarrhoea, or who has symptoms causing concern should see a doctor.

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

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).

People with diarrhoea should not prepare or handle food that will be eaten by others.

How it can be controlled

Anyone with diarrhoea should not attend childcare/school until there has not been a loose bowel action for 24 hours.

Anyone with diarrhoea should not 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 of diarrhoea in a group, these should be reported to the local Centre for Disease Control.

Contact

For more information contact your Centre for Disease Control.

Last updated: 27 June 2017