Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed through faeces. Humans become infected most frequently through contaminated water or food.

Salmonellas are a group of common bacteria that cause food poisoning. They are usually spread by inadequate cooking and through cross-contamination. Salmonella bacteria are most often found in:

• raw meat
• undercooked poultry such as chicken or turkey
• eggs
• unpasteurised milk

Young children, the elderly and people whose immune systems are not working properly have a greater risk of becoming severely ill with food poisoning caused by salmonella. The NHS has more information about the symptoms of salmonella poisoning.

How salmonella bacteria are spread

Salmonella bacteria live in the gut of many farm animals. During rearing, slaughter and processing, the bacteria can be transferred into food products.

Other foods like green vegetables, fruit and shellfish can become contaminated through contact with animal and human faeces. For example, from manure used to improve soil fertility or sewage in water. Salmonella bacteria can be spread from pets such as cats and dogs to people. They can also be spread from person to person through poor hygiene.

Reducing the risk of salmonella poisoning at home

You can avoid most forms of food poisoning by following advice on the 4Cs of food hygiene:

• chilling
• cleaning
• cooking
• avoiding cross-contamination

It’s also important to remember never to drink untreated water from lakes, rivers or streams. Always wash your hands thoroughly with soap and warm water:

• before preparing or eating food
• after handling raw foods
• after going to the toilet
• after changing a baby's nappy
• after touching bins
• after contact with pets and other animals