Present in Raw meat, poultry, untreated milk, made-up foods such as sausage meat, mince, mayonnaise and egg mixes.
Transferred from food to hands, utensils or work surfaces which in their turn can contaminate other surfaces or cooked foods such as ham, corned beef and other cold meats to be eaten without further cooking. Also direct contamination from raw to cooked food.
Symptoms Nausea, vomiting, abdominal pain and diarrhoea, possibly accompanied by headache and fever - from 6-72 hours after eating (usually 12-36 hours). Speed of onset depends on dose. Elderly and AIDS patients susceptible to septicaemia.
Prevention Hand washing after handling raw food. Thoroughly clean utensils and work surfaces before re-use. Separate storage and preparation areas for raw and cooked food.