Countdown has recalled a pre-packed salad product after listeria was discovered during routine testing, the Ministry for Primary Industries (MPI) says.
The supermarket fears the product - a Countdown-branded potato, egg and bacon prepack salad with a use by date of July 13 - may contain the bacteria.
It's told all its Countdown, Fresh Choice and Supervalue supermarkets nationwide that stock the salad to immediately remove it from shelves.
New Zealand Food Safety national manager for food compliance services, Melinda Sando, says people who purchased the product should throw it away or return it for a full refund.
Listeria infections are rare but can be life-threatening, MPI says.
"Healthy adults are likely to experience only mild infection, causing mild diarrhoea and flu-like symptoms," Sando explains.
"However, listeriosis infection can be serious among vulnerable groups such as pregnant women and their unborn babies, newborn babies, people with weakened immune systems, and the frail and elderly."
"For those in the high-risk groups, listeriosis typically has an incubation period of two to three weeks or longer before symptoms appear. If you have consumed any of these products and have any concerns about your health, seek medical advice."
Neither New Zealand Food Safety nor Countdown have yet received any reports of illness after consuming the product.
About 90 percent of listeria infections come from eating food or drink that have high levels of the bacteria.
Higher risk foods include ready-to-eat products, deli meats and salads, unpasteurised milk, smoked seafood, soft cheeses, refrigerated foods with a long shelf life, and some fruits and vegetables.
MPI says to lower the risk of infection, people should ensure they eat food that was well-washed and recently prepared, follow good food hygiene practices, cook food thoroughly and not keep leftovers for more than two days.
People at high risk are advised to contact a doctor straight away if they think they’re infected, however most people recover fully. Healthy adults will probably only get mild flu-like symptoms or gastroenteritis, MPI says.