Advice to boil imported frozen berries

Imported Frozen Berries

Information about berries and advice to boil imported frozen berries.

• Why does the FSAI advise that imported frozen berries should be boiled for one minute?

  As a result of outbreaks of norovirus and hepatitis A virus in imported frozen berries across Europe in recent years, the FSAI recommends boiling imported frozen berries for one minute before consumption. This is particularly important when serving these foods to vulnerable people such as nursing home residents.

• Why did FSAI issue this advice and is it still relevant?

  The FSAI first issued this advice in 2013, during the investigation of an outbreak of hepatitis A virus in Ireland which was linked to imported frozen berries. The outbreak turned out to be part of a multi-state outbreak, with over 1,000 cases reported in 12 EU countries.

  You can read the investigation report at this link.

  Between 2014 and 2024 (to date, 28 February 2024), there have been 7 alerts issued across Europe for hepatitis A virus and 49 alerts for norovirus in imported frozen berries. 

• How do I know if frozen berries are imported?

  If the label does not state the country of origin, you should assume that the berries are imported. The shop where you purchased the berries may be able to provide this information.

• How do I know that the berries used by food businesses (e.g. smoothie bars, cake manufacturers, etc.) are safe to eat?

  Food businesses selling imported frozen berries need to ensure that the berries they use are sourced from reputable suppliers operating effective food safety management systems and comprehensive traceability systems. As the food chain can be quite complex, it is necessary for food businesses at each stage of the food chain to seek assurances regarding the effectiveness of the food safety management systems in place from their suppliers. If such assurances are not available, the FSAI recommends that the retailer displays a notice advising customers that the frozen berries should be boiled for one minute before consumption. 
  If you are concerned about where the berries have come from, ask the food business. For prepared food items such as smoothies and desserts, the food business should also be able to advise whether the berries were boiled.

• Should I discard frozen berries in my freezer/ stop buying frozen berries?

  No, there is no need to discard or stop buying frozen berries. You can ensure that the berries are safe to eat by boiling for one minute, which will destroy viruses, if present.

• Are fresh berries safe/OK to eat?

  There is no evidence to suggest that fresh Irish or fresh imported berries are a risk. Fresh berries should be washed before consumption which is in keeping with the advice for all fresh fruit and vegetables.

• Can I eat the berries I grow in my own garden?

  Yes, this issue only relates to frozen imported berries and so this advice does not apply to berries grown in your own garden and frozen after picking. 

• Why are imported frozen berries more of a risk than other types of berries?

  Across Europe, more outbreaks have been linked to imported frozen berries than to other types of berries. Freezing preserves viruses such as norovirus and hepatitis A virus. 

• Are tinned berries also a risk?

  No, tinned or canned berries have not been identified as a risk. 

• What if I have eaten frozen berries recently, without boiling them?

  The time from consumption of contaminated food to the onset of illness with hepatitis A, ranges from 15-50 days, with the average being 28 days. In the case of norovirus, symptoms usually appear around 12 to 48 hours after consuming contaminated food.
  If you think that you may be ill as a result of having consumed frozen berries, you should seek medical advice. This applies in all cases if you believe that any food you have eaten has made you ill.

• I have given my toddler/child purée made from frozen berries, should I be worried?

  If you are concerned about your toddler/child, you should seek medical advice, but you should not be concerned about giving them frozen berries that have been boiled. Boiling for one minute will destroy viruses, if present.

• What is hepatitis A and what are the symptoms?

  Hepatitis A infection is an acute disease of the liver caused by the hepatitis A virus. 
  Illness usually starts about 28 days after exposure to the virus, but it can start anytime between 15 and 50 days after infection. The most common symptoms are fever, loss of appetite, nausea, fatigue, and abdominal pain, followed within a few days by jaundice. Symptoms may last from one or two weeks to a number of months. 
  If you believe that you have Hepatitis A, you should seek medical advice. More information on hepatitis A can be found on the Health Protection Surveillance Centre (HPSC) website. 

• How is hepatitis A virus spread?

  Hepatitis A is a human virus that is primarily spread from person-to-person via the faecal-oral route. The virus is shed in the faeces of infected people. It may also be spread through food that has been contaminated by infected food handlers or by contaminated water. People who have the virus are most infectious in the week or two before onset of symptoms and may be infectious up to one week after onset. 

• What is norovirus and what are the symptoms?

  Norovirus is one of the most common causes of gastroenteritis. Symptoms include - nausea (often sudden onset), vomiting (often projectile) and watery diarrhoea. Symptoms begin around 12 to 48 hours after becoming infected. The illness is usually brief, with symptoms lasting only about 1 or 2 days. Most people make a full recovery within 1-2 days, however some people (usually the very young or elderly) may become very dehydrated and require hospital treatment.
  If you believe that you have norovirus, you should seek medical advice. More information on norovirus can be found on the Health Protection Surveillance Centre (HPSC) website.

• How is norovirus spread?

  Noroviruses are very contagious and can spread easily from person-to-person. Both the faeces and vomit of an infected person contain the virus and are infectious. People infected with norovirus are contagious from the moment they begin feeling ill to 2 to 3 days after recovery. Some people may be contagious for as long as 2 weeks after recovery.
  It is important for people to use good handwashing and other hygienic practices after they have recently recovered from norovirus illness. In addition, noroviruses are very resilient and can survive in the environment (e.g. on surfaces) for a number of weeks. 

• How might berries become contaminated with norovirus and hepatitis A virus?

  Contamination could occur on the farm, through use of sewage-contaminated agricultural water or through contamination by infected workers. Cross-contamination could occur post-harvest along the supply chain, through contact with contaminated surfaces of machines, equipment and facilities during freezing, mixing and packaging processes.