Food poisoning factsheets Salmonella infection

What is Salmonellosis and how common is it?

Salmonellosis is the term for an infection with a bacterium (germ) called Salmonella. It’s more common in the summer than in the winter and many mild cases are not diagnosed or reported.

How is Salmonellosis caught?

  • Salmonella lives in the guts of humans and other animals, including birds, and is usually transmitted to humans by eating contaminated food. The contaminated foods look and smell normal.
  • Salmonella is found in foods such as poultry, beef and eggs but all foods including vegetables can become contaminated. Raw foods pose a greater threat than cooked foods as thorough cooking kills Salmonella.
  • Food may become contaminated by infected food handlers who don’t wash their hands after going to the toilet.
  • Salmonella may also be found in the faeces of some pets, especially those with diarrhoea, and people can become infected if they do not wash their hands after contact with these faeces. 90% of reptiles, even if healthy, can have Salmonella.

What are the symptoms of Salmonella?

Children are the most likely to get Salmonellosis. Most people infected with Salmonella develop diarrhoea, fever and abdominal cramps 12 to 72 hours after infection. The illness usually lasts for 4 to 7 days and most people recover without treatment.

However, in some people the diarrhoea may be severe enough to require admission to hospital. Very severe infections can be fatal. The elderly, infants and those with impaired immune systems are more likely to have a severe illness.

Are there any longer term complications of Salmonellosis?

Most people recover quickly without treatment although it may be several months before bowel symptoms completely disappear.

Long term effects, which include a condition called Reiter’s syndrome, are rare.

Some people continue to carry the germ although they themselves are well. In general, these people pass out the germ in small numbers and do not pose a risk to others.

Many different kinds of illnesses can cause diarrhoea, fever, or abdominal cramps. Salmonellosis can therefore only be diagnosed by growing Salmonella from a stool sample in a laboratory.

Once the Salmonella has been grown, further testing can determine its specific type and which antibiotics should be used to treat it, if the severity of the illness warrants it.

How is Salmonellosis treated?

Most Salmonellosis cases clear up without treatment. Because over‐use of antibiotics breeds resistant germs, antibiotics are held back for severe cases. Antibiotic treatment doesn’t make a difference to whether the person develops longer term complications.

What can I do to prevent Salmonellosis and what can I do if I have it?

There is no vaccine to prevent Salmonellosis, nor do you become immune to it. It’s important to prevent it spreading and to avoid infection as far as possible.

  • Don’t eat raw or undercooked eggs, poultry or meat. You may not recognise that raw eggs could be present in home‐made sauces, dressings, ice‐creams, mousses and other desserts.
  • Poultry and meat, including beef burgers, should be well cooked, not pink in the middle.
  • If you are served undercooked poultry in a restaurant, do not eat it and complain to the manager and to your local Environmental Health Department.
  • Do not consume unpasteurised milk.
  • Wash produce thoroughly before consuming.
  • Wash your hands with soap and hot water before and after handling raw meats.
  • Avoid cross‐contamination of foods by keeping raw and cooked foods apart.
  • Carefully clean all cutting boards, work surfaces and utensils with detergent and hot water after preparing raw meats. Use separate chopping boards for raw and ready‐to‐eat foods wherever possible.
  • If you have the illness and work with children or the elderly, or work in a hospital or a food business, advise your supervisor. Your local Environmental Health Department, who can investigate to try and prevent further cases, may contact you.
  • Salmonella germs stay in your system for several days after symptoms stop, so it’s important to maintain a very high level of personal hygiene during this time.
  • People who have Salmonellosis should not prepare food for others until they have been free of diarrhoea for at least 48hrs.