Meat containing listeria at three processing plants in Wellington and Porirua in New Zealand has been reported to health officials.
Listeria monocytogenes can cause serious illness. People most at risk include pregnant women, unborn or newborn babies, the elderly and people with weakened immune systems.
Regional Public Health and the Ministry of Primary Industries are investigating the plants after meat samples at two of the plants tested positive for listeria during routine checks.
The third plant discovered listeria via its own testing and reported the results to health officials.
Medical Officer of Health Margot Mclean told stuff.co.nz that only one case of a person contracting listeria had been reported in the past six months and said the case was not linked to any of the plants under investigation.
"It's a reasonably rare infection. The cases that we are notified about are at the severe end of the spectrum," she said.
Dr Duncan Craig, FZANZ’s principal microbiologist, said questions needed to be asked around what can be defined as a ready-to-eat product and what conditions supported the growth of listeria.
“The higher risk products for Listeria are ready to eat products We are particularly concerned about products that have a long shelf life and which are kept refrigerated for a long time,” Duncan told Food Magazine.
“We are also interested in asking questions around the need to have regulatory limits for listeria.”
The FSANZ website advises the best way to avoid the bug is to ‘eat freshly cooked or freshly prepared food’ and avoid cold meats, chilled seafood and unpasturied dairy products. They also advise to cook food thoroughly and use leftovers within 24 hours.