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  1. CFSAN Constituent Updates

FDA Sampling Frozen Berries for Harmful Viruses

What's New

September 26, 2019

As of June 30, 2019, the FDA has tested 253 domestic samples and 320 import samples of frozen berries. Of the frozen berries sampled, the FDA found genetic material from hepatitis A virus in three samples and genetic material from norovirus in seven samples, using multiple-laboratory validated RT-qPCR methods for the detection of hepatitis A and norovirus viral sequences in soft fruit. These 10 samples were then further tested by another method called Sanger sequencing to see if the viral material could be further characterized by examining a separate, distinct section of the virus genomes.  Six of the ten samples could be further characterized using this technique. As the assignment is still underway, no conclusions can be drawn at this time.

The FDA began the frozen berries assignment in November 2018 and plans to test a total of 2,000 frozen berry samples under this assignment.  The FDA initially collected some samples at retail locations but, beginning in July 2019, removed retail collection from the sampling assignment to minimize the amount of product in commerce in the event of a positive sample. 

From the beginning of the assignment, the FDA used RT-qPCR methods that have undergone multi-laboratory validation by the FDA for the detection of genetic materials from hepatitis A virus and norovirus viral sequences in soft fruit.  While these methods remain the primary tests for this assignment, starting in July 2019, we also initiated Sanger sequencing as a routine component of the assignment to further characterize viral sequences detected in any samples by RT-qPCR.

If the FDA detects genetic material from hepatitis A virus or norovirus in a sample, the agency will notify the firm of the finding(s) and work with the firm to take appropriate action to protect the public health.  This may include action to correct and prevent violations and to remove violative food from the market, as appropriate.  With the addition of Sanger sequencing in July, the FDA began awaiting the sequencing results before asking the affected firm to conduct an immediate voluntary recall of the product.

View the Microbiological Surveillance Sampling: FY 19-20 Frozen Berries (Strawberries, Raspberries and Blackberries) Results as of 7/1/2019.

Original Constituent Update

May 9, 2019

The U.S. Food and Drug Administration is sampling frozen berries for hepatitis A virus and norovirus as part of the agency’s efforts to protect consumers and ensure food safety. The sampling assignment began in November 2018 and is estimated to last approximately 18 months. The agency is collecting domestic samples of frozen berries in retail packaging from processors, distribution centers, warehouses, and retail locations. The agency is also collecting import samples from ports of entry, importer warehouses and other storage facilities where foreign goods are cleared for entry into the country. The FDA plans to collect and test 2,000 samples in all.

Frozen berries are used as ingredients in many foods and like other produce can be an important part of a healthy eating pattern. While frozen berries are used in pies and other baked goods, they are also used raw in fruit salads or smoothies and have been associated with outbreaks of foodborne illness. The FDA reported three hepatitis A virus outbreaks and one norovirus outbreak linked to frozen berries in the United States from 1997 to 2016.

Strawberries, raspberries and blackberries are delicate and may become contaminated with bacteria or viruses if handled by an infected worker who does not use appropriate hand hygiene, or if exposed to contaminated agricultural water or a contaminated surface, like a harvesting tote. Freezing preserves berries but generally does not kill viruses, which can survive at low temperatures.

If the FDA detects hepatitis A virus or norovirus in a sample, the agency will notify the firm of the finding(s) and work with the firm to take appropriate action to protect the public health. Upon detecting a positive test result, the FDA may also take actions such as placing a firm on an import alert, overseeing a recall, or issuing public warnings.

The FDA will post the sampling results on its FY 19-20 Frozen Berries Assignment page on a quarterly basis and will publish an analytical report once the assignment is complete.

Additional Information

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