If backyard hens become infected with the bacteria they can pass it on via faecal contamination of eggs at the time eggs are laid. As cooking kills the bacteria, well-cooked eggs and food are safe to eat. The risk will be highest where sick birds are able to enter an aviary. In aviaries where there is no contact with wild birds the risk is likely to be very low. In humans, the symptoms include diarrhoea, headache, abdominal pain, nausea, fever and vomiting.
Symptoms usually develop within two days after exposure.
People experiencing prolonged symptoms should seek medical advice. In sparrows, cats and other animals the symptoms vary, but include diarrhoea. Two of the cases were in Wellington, one in Manawatu, one in the West Coast, five in Southland, three South Canterbury and 32 in Canterbury. Seven people have been hospitalised and one person died. Last year only three cases of this type of Salmonella were reported.