MPI said while there was not sufficient information for a product recall, the evidence from the cases and international experience points to Hepatitis A from imported frozen berries.
It added ‘sufficient information’ would be test results which link specific brands to the outbreak.
Affected frozen berries
The agency said strawberries, raspberries, blackberries, blueberries and boysenberries in frozen form may pose a risk.
All brands, batches and sizes are subject to this risk and associated advice, it added.
A MPI spokesman told us the four confirmed cases were from the North Island of New Zealand and became ill in October and November.
“We have had four cases, and collectively those cases have not provided enough information to link to specific products. It’s important to bear in mind that New Zealand imports frozen berries from 26 different countries, and they are available throughout the country.
“What we are saying is that we are aware of this increased risk and we want consumers to be aware of that risk.
“Each strain of Hepatitis A has its own unique DNA make-up called genotypes. We have tested the genotype of the Hepatitis A associated with this outbreak in New Zealand and it is not the same as the one that caused the outbreaks in Australia.
“Our priority is the safety of consumers. So, while we don’t have information about the specific cause, we are taking a precautionary approach and increasing surveillance focussing on imported frozen berries, and that will include a testing regime.”
The Ministry has started a surveillance programme, including additional testing, focussed on imported frozen berries. Investigations have not implicated fresh berries.
MPI will require mandatory testing of imported frozen berries in accredited laboratories offshore or at the New Zealand border. The requirement will expire in six months (due to it being an ‘emergency’ measure) but will be reassessed before that.
Peter Thomson, the Ministry’s director of Plants, Food and Environment, said investigations have not revealed a specific cause, but there is an association with consuming imported frozen berries.
“We are giving a very high priority to instigating a testing programme that will provide increased surveillance of imported frozen berries. This will include previously imported stocks held by food companies here.”
The virus is inactivated by temperatures above 85 degrees Celsius for one minute, while washing frozen berries will not inactivate it.
Earlier this year, Patties Foods was linked to an outbreak in Australia through fruit imported from China and Canada.
- This article was updated on 1-12-15 with response from MPI.