A KITCHEN knife was the culprit behind listeria bacteria found in sandwiches at a Middlemore Hospital café last week.
Investigations by the Auckland Regional Public Health Service (ARPHS) have revealed that bacteria found in 20 sandwiches from the hospital’s Aviary Café came from a contaminated knife used in the food supplier’s processing plant.
The infected product was Naturezone Thai Chicken sandwiches which were sold at the café on Monday last week.
Dr Greg Simmons of the ARPHS says the chiller containing the sandwiches at the café was closed after the incident and swabs were taken from the processing plant to identify the source of the contamination.
“Our officers went in there and took swabs and cells to prevent a reoccurrence,” says Dr Simmons. “The [food supply] company took all their produce off the market and started from scratch.” He says the plant has since had a “complete clean-down” and two sets of swabs have come back clear.
There are five types of listeria, two of which can cause illness in people with poor immune systems. The bacteria are typically found in processed meats and seafood.
Dr Simmons says Listeria thrives in “virtually all wet situations”, including in household fridges.
“Basically they need water and they need a medium to grow on. That’s why it’s important to follow the best used-by dates.” He says inspection officers were satisfied with the standard of hygiene in the plant.
“The plant was actually very tidy and clean. I don’t think we have concerns about the way they were running the plant. Listeria is a difficult organism.”
Where large doses of bacteria are consumed, listeria causes diarrhoea, vomiting and fever. Pregnant women, the elderly and people with weakened immune systems are most at risk.
“We call them Yopis – young, old, pregnant, immune compromised,” says Dr Simmons. “These people are people with very poor immune systems.”
A Middlemore Hospital spokesperson told the Times the hospital had not been notified of any Listeria cases resulting from the contaminated sandwiches.
Ten cases of the illness were reported in Auckland last year, three of which were in pregnant women.
Listeria is serious for women in their third trimester of pregnancy, as it can bring on early labour, says Dr Simmons. The infection can also lead to meningitis and blood poisoning.
The last confirmed case of Listeria in Auckland was in a cancer patient and was reported at the end of January.
Dr Simmons says anyone who ate sandwiches at the Aviary Café on March 3 and is concerned about symptoms in the coming weeks should contact their GP, highlighting the possibility of listeria infection.
• For more information on Listeria, see www.nzfsa.govt.nz.
