Salmonella is caused by bacteria which live in the intestines of people, birds and animals. When a person, bird or animal is infected they pass the bacteria out in their faeces (poo).
You can get salmonella from swallowing contaminated food or water or by touching contaminated objects (i.e. toys).
Food an objects become contaminated when someone does not wash their hands after changing the nappy of an infected child or by not washing their own hands after using the toilet. You can also get salmonella poisoning from eating under cooked meat and chicken, handling raw meat and chicken that is infected with salmonella, eating raw or poorly cooked eggs, drinking unpasteurised (raw) milk, drinking water from rivers, streams and shallow waters and from not washing hands after touching animals and birds.
Symptoms include diarrhoea, stomach cramps and a fever. Nausea and vomiting may also occur. Proper hand hygiene is the main way to prevent becoming unwell with salmonella.