The FDA is working to improve the safety of fresh and frozen berries in the wake of hepatitis A and norovirus outbreaks linked to those items. An ongoing hepatitis A outbreak linked to fresh organic strawberries has sickened at least 18 people in three states, and a hepatitis A outbreak in 2020 linked to blackberries sickened 20 people in seven states.
In the United States, there have been three hepatitis A outbreaks and three norovirus outbreak linked to frozen berries from 1990 to 2016, and since 2011, there have been three hepatitis A outbreaks linked to fresh berries. Globally, from 1983 to 2018, there were 50 outbreaks associated with frozen berries, with 36 caused by norovirus and 14 by hepatitis.
While freezing preserves berries, it does not inactive viruses. The berries can be contaminated in the field by infected workers, through contaminated water, or through contaminated food surfaces. And since these berries are usually eaten raw, without a heat kill step, any contamination can cause illness.
The strategy the FDA is developing will depend on surveillance sample findings. In August, the FDA will resume an assignment to collect and test frozen berries that was paused when the COVID-19 pandemic began in 2020. The assignment will try to estimate the prevalence of hepatitis A and norovirus in frozen raspberries, strawberries, and blackberries, and will help the FDA identify sites where practices or conditions may exist that are safety risks.
So far, the FDA has collected and tested more than 1,100 samples and plans to collect and test about 427 more. Frozen strawberries will not be tested in this phase, since the collection target has been met for that fruit.
The FDA will work with industry, academia, and regulatory partners in the development of a food safety prevention strategy. They want to identify measures that can limit or prevent contamination throughout the supply chain, along with reinforcing control measures and identifying areas where more research is needed.
