The FDA is sampling frozen berries for both hepatitis A and norovirus, in the wake of three hepatitis A outbreaks and one norovirus outbreak linked to those products from 1997 to 2016. Two of those hepatitis A outbreaks, one in 2013 and the other in 2016, sickened more than 300 people in this country.

The 2013 outbreak was linked to Townsend Farms Organic Antioxidant Blend, a mix of frozen berries, and sickened at least 162 people in 10 states with hepatitis A infections. The source of the virus was eventually determined to be pomegranate seeds that were imported from Goknur Foodstuffs import Export Trading in Turkey.

The 2016 outbreak, which sickened at least 143 people in 9 states, was linked to frozen strawberries made into smoothies at Tropical Smoothie Cafe restaurants in the Eastern United States. Those strawberries were imported from Egypt. The FDA found the virus in samples of ICAPP frozen strawberries; those berries were recalled on October 30, 2016.

The FDA’s sampling program began in November 2018 and will last about 18 months; they plan to collect and test 2,000 samples. Officials are collecting domestic samples of frozen berries in retail packaging from warehouses, retail stores, distribution centers, and processors. They are also collecting import samples from ports of entry and warehouses.

The issue with frozen berries is that they are most often used without being cooked first. Strawberries, raspberries, and blackberries can easily be contaminated if an infected worker handles them without good hygiene. The berries can also be contaminated with poor quality agricultural water or contaminated harvest totes. Freezing does not kill these viruses.

Symptoms of hepatitis A include fatigue, abdominal pain, jaundice, dark urine, clay-colored stools, and a fever. The virus can be spread because an infected person is contagious for weeks before they even know they are sick.

The FDA will post sampling results on its Frozen Berries Assignment page quarterly. A full analytical report will be published when the study is complete.