Experts are warning people not to panic about an outbreak of listeria that has been linked to three deaths.
Six people have been admitted to hospital in Hawke's Bay and the Bay of Plenty after contracting the bacteria, and three have died in the past six weeks.
Dr Tim Blackmore, from Capital and Coast DHB's infectious diseases department, says a few cases of listeria a year are not uncommon.
"You shouldn't panic about it too much, we get very few cases in New Zealand a year, less than 20-25 cases for the whole country.
"When you have an outbreak like this it's an area of concern but overall the average person shouldn't be getting themselves too concerned."
He said healthy people may not show signs of listeria.
Meanwhile, health bosses are warning that more people could have eaten pre-packaged meat supplied to the hospital kitchen which was found to contain the listeria bug.
Meat products being recalled are Mad Butcher 500 gram salami and pepperoni rolls best before August 17, Ratanui whole, half and champagne cooked on the bone ham best before September 12, and Ezy Carve boneless leg ham pieces best before September 9.
People are being urged to take no risks, and to see a doctor if they are feeling unwell.
Hawke's Bay Director of Public Health Caroline McElnay said yesterday that she did not want to speculate about how the patients contracted listeria.
"Certainly we're taking very seriously the fact we've got positive results from food samples in our kitchen," she said.
Bay of Plenty Medical Officer of Health Dr Phil Shoemack said investigations have been unable to identify any link between the two cases or with a deadly outbreak in Hawke's Bay.
Andrew Coleman from the Ministry of Primary Industries (MPI) said there was still some product around but he hoped the public would comply with the recall.
"We're hoping the recall takes effect immediately, that the public works with us on this and gets the product back in."
Bay Cuisine, which supplies Hawke's Bay Hospital with the ready-to-eat-meat, said in a statement it was working with the Ministry for Primary Industries and that it had initiated the voluntary product recall as a "precautionary measure".
Mad Butcher managing director Michael Morton said none of the products recalled had shown contamination and there was no need for concern among customers.
Investigations by the DHB and the Primary Industries Ministry had not confirmed a common food source.
The disease takes an average of 30 days to show symptoms and is generally only of high risk to those already immuno-compromised, the elderly and pregnant women.
The hospital said no pre-packaged meat was served to patients in the maternity ward.
Listeria at a glance
Listeriosis is a serious illness caused by the bacterium Listeria monocytogenes.
It can be very dangerous for pregnant women and their unborn children, newborn babies, frail elderly, and anyone whose immune system is already weakened.
It is often associated with ready-to-eat products such as deli
meats and salads, soft cheeses and foods with long refrigerated
The bacteria multiply quickly, even in refrigerators.