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Last reviewed:

25 October 2022 – Disease outbreaks related to frozen berries

New Zealand has reported a number of hepatitis A cases linked to consumption of frozen berries.

Hepatitis A and frozen berries – Ministry of Health

As a precaution, Foodstuffs Own Brands Ltd is recalling various Pams brand frozen berries because of a possible link to these recent cases.

New Zealand's food safety rules keep berries grown here safe to eat. But not all countries have the same rules. Berries grown and processed overseas can be unsafe to eat.

Packets of imported frozen berries can contain berries from various farms and countries. This can make it difficult to find the source if there is an associated outbreak. 

New Zealand Food Safety’s investigation into the outbreak continues. Until we find the source, our advice is to heat treat all frozen berries.

More information about the recall of Pams brand frozen berries

Frozen berries recalled while investigation into source of hepatitis A continues (4 October 2022)

Risk of hepatitis A from frozen berries (14 September 2022)

 

How berries become unsafe to eat

Some berries can carry harmful bugs, like:

  • hepatitis A virus
  • norovirus
  • Shiga toxin-producing E. coli (STEC)
  • Salmonella.

Harmful bugs can come from the farm where berries are grown. Sources can include:

  • unclean water or soil
  • infected workers and animals.

Food handlers, machines, and equipment can contaminate berries after they are harvested. The bugs can be spread during freezing, mixing, or packaging. This can make the berries unsafe to eat.

Making berries safe to eat 

You can make frozen berries safe to eat by either:

  • bringing them to the boil, or
  • cooking them at a temperature over 85°C for at least 1 minute.

Washing frozen berries will not remove the risk. 

Most viruses and bacteria found on frozen berries can survive freezing. They also can survive freeze-drying, and heat treatments of less than 85 degrees Celsius.

Frozen berries that have been heat-treated can be cooled rapidly and refrozen for subsequent use. 

Video: Heat-treating frozen berries at home (1.46)

[Onscreen text] How to make frozen berries safe to eat.

Wash your hands with soap and water before and after handling frozen berries.

Method 1: Boiling

Bring to the boil for at least one minute

Or if you have a thermometer heat to more than 85 degrees for one minute

Method 2: Microwave

Stir halfway through to make sure berries are heated through

Cook berries until they are bubbling

Either use berries immediately or freeze for later use

Cool berries for at least 30 minutes before freezing

Once cooled pop into freezer for easy use

[End of transcript]

Some people are more at risk

Preparing berries safely is important when you:

  • make uncooked foods that normally contain frozen berries, like smoothies and desserts
  • serve berries to people with health risks.

People with health risks include:

  • older people, especially those with underlying health conditions
  • young children
  • pregnant women
  • people with low immunity.

Find out about food for people with low immunity

Find out more

Hepatitis A virus fact sheet [PDF, 203 KB]

Hepatitis A disease – Ministry of Health

Norovirus – Ministry of Health

Who to contact

If you have concerns for your health, consult your medical professional or phone Healthline at 0800 61 11 16.

If you have questions about the risks of imported frozen berries, email info@mpi.govt.nz

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