A second batch of listeria-contaminated meat was taken from at least one hospital and cafes around the North Island yesterday.
Leonards Superior Smallgoods said listeria contamination had been found in a batch of packaged, cold, corned silverside beef.
The company recalled packaged roast beef last week after contamination was found at Waikato Hospital, and was yesterday asking supermarkets not to sell its products until they had been proven safe.
The corned silverside went to 18 outlets between Whangarei and Palmerston North in the past fortnight.
One recipient was North Shore Hospital.
The Waitemata District Health Board said yesterday that it had removed all processed and cold meat products from cafeterias and patient menus at Waitakere and North Shore Hospitals.
Leonards' manager and co-owner, Richard Kornman, said the company had quarantined all stocks of cooked, ready-to-eat products after the positive listeria test results.
"We've been supplying this product to the hospitals indirectly in excess of 10 years ... and these are the first issues we've had in 10 years."
He said other companies, including northern North Island cafes, had received the meat, but he wouldn't name them.
"We have instigated a full recall on the product," Mr Kornman said.
The company spent $3000 to $4000 a month on product testing, he said.
It was now asking supermarkets to put ready-to-eat Leonards meat products on hold until they were shown to be "micro-biologically compliant".
Mark Russell of Spotless Services, which is the food contractor to the Waitemata health board, said yesterday that a kilogram of the contaminated meat had been sent to North Shore Hospital.
None had gone to Waitakere Hospital.
The medical officer of health for the Auckland Regional Public Health Service, Dr Greg Simmons, said the meat was tested by its distributor, Wilson-Hellaby, on February 19 and the results returned positive for listeria yesterday.
He said cafes and hotels were asked to put up signs warning people of the risks, although the chances of developing a listeria infection after eating the contaminated product were "very small".
But it took up to 70 days for the infection to develop, so it was important that the public be made aware of the health risk.
"If you have eaten cold, sliced roast beef or corned silverside from a cafe between the beginning of February and February 24 and develop flu-like symptoms or become concerned about your health in the next few weeks, especially if you are pregnant, we suggest you contact your doctor, highlighting the possibility of listeria."
WHAT IS LISTERIA?
* A common bug widely found in dust, soil, water, plants, sewage and animal droppings.
* It is dangerous only to pregnant women, their babies and people with lowered immune systems. If a pregnant woman develops an infection caused by listeria, it can cause miscarriage and stillbirth. Newborn babies with listeriosis can have difficulty breathing and can develop a chest infection and an inflammation of the coverings of the brain, which can sometimes cause death.
* Symptoms include a mild fever, headache, nausea, vomiting and aches and pains in joints and muscles or a mild cough or cold.
HOW ARE PREGNANT WOMEN INFECTED BY LISTERIA?
* Listeria can be transmitted to pregnant women by infected food. The bug has been found in a variety of foods at all stages of preparation, from raw to well cooked. Listeria will grow on food that is stored in a fridge.
KEEP FOOD SAFE BY
* Keeping cooked foods and ready-to-eat foods separate from raw and unprocessed foods.
* Washing hands, cooking tools and chopping boards before preparing a different food.
* Using cooked, prepared and canned food that has been stored in the fridge within two days.
* Being sure to eat food before the use-by date.
* Cleaning the fridge regularly and checking the temperature control.