Food Safety Authority Reiterates Need to Boil Imported Frozen Berries

Sunday, 8 September 2013

The Food Safety Authority of Ireland (FSAI) today reiterated its advice to consumers to boil all imported frozen berries for at least one minute prior to consumption as it continues its investigation into a food poisoning outbreak of hepatitis A virus. The outbreak is associated with the consumption of imported frozen berries and to-date, 15 primary cases in Ireland have been identified.

According to Prof. Alan Reilly, Chief Executive, FSAI, boiling imported frozen berries for at least one minute before eating them, is a precautionary measure as it will destroy the virus if it is present. 

“The first indications of this outbreak emerged when cases of hepatitis A were identified to have the same strain of the virus as that causing an outbreak in Italy. As the Italian authorities had detected the virus in samples of frozen mixed berry products imported from a number of different countries, the Irish investigation has focused on imported frozen berries. Since the outbreak was identified, a small number of new cases have been reported and it would be prudent for consumers to continue to boil these berries until further notice. Investigations suggest it is unlikely that fresh Irish or fresh imported berries are a cause of the outbreak. However, we suggest that - as with all other fruit and vegetables - fresh berries should be washed thoroughly if they are being eaten uncooked.”

The FSAI continues to work in close collaboration with the Health Protection Surveillance Centre, the Health Service Executive and the National Virus Reference Laboratory in relation to this incident.

“Frozen imported berries are widely used in the food industry and distributed into the food service sector for use in cooked and ready-to-eat dishes.  The food sector also needs to take particular care to boil imported frozen berries for at least one minute prior to serving food to customers.  Food businesses must always ensure they source their ingredients from reputable suppliers with efficient and comprehensive traceability and food safety management systems,” Prof. Reilly continues.

Hepatitis A is a disease that can be relatively mild, lasting 1-2 weeks, or more, severe lasting months.  Severity of symptoms tends to increase with age. The most common symptoms are fever, loss of appetite, nausea, fatigue and abdominal pain, followed within a few days by jaundice. The incubation period (time from exposure to onset of illness) ranges from 15 to 50 days, the average being 28 days. 

The investigation is focused on tracking and tracing the foods that those infected with the virus say they have eaten and cross referencing this information with similar investigations in Italy. However, because of the long incubation period of hepatitis A, where illness can arise up to 50 days after exposure to the virus, the food histories obtained for patients over that long period do not have sufficient detail to enable the authorities to identify specific batches of imported frozen berries and this coupled with the complexity of the global frozen fruit distribution chain has hindered identification of the source of the outbreak.

Prof. Reilly explained that “the authorities are working hard to identify the source of the outbreak but it is so difficult for people to remember exactly what they ate with any degree of accuracy over the 50 day period in which they might have been infected and this makes it hard to pinpoint a suspect food or batch of food”.

Samples of various frozen berries and food containing berries were tested. However, given the suspected low level of contamination and the fact that exact batches have not been identified, it is more likely that the traceability investigation rather than the microbiological analysis will provide evidence as to the likely source of this outbreak. To date, test results of thirteen products have been found to be negative for hepatitis A.