Frozen berries, a staple in smoothies and desserts, have been linked to multiple hepatitis A outbreaks worldwide, raising concerns about food safety in the frozen food industry. Unlike fresh produce, frozen fruit is often considered low-risk due to its extended shelf life and convenience. However, contamination can occur before freezing, turning these convenient foods into unexpected carriers of viruses.
How Frozen Berries Transmit Hepatitis A
Hepatitis A, a highly contagious liver infection, spreads through the fecal-oral route. In the case of frozen berries, contamination typically happens at the farm level. Berries may be exposed to hepatitis A through:
- Contaminated irrigation water
- Poor hygiene among harvesters
- Contact with animal feces
Unlike bacteria, viruses like hepatitis A can survive freezing temperatures, remaining infectious for months. Since most frozen berries are consumed raw or blended without cooking, the virus bypasses the heat that would normally kill it.
Major Outbreaks Linked to Frozen Berries
Several significant outbreaks have highlighted this risk:
- 2013 U.S. Outbreak: A hepatitis A outbreak tied to frozen pomegranate seeds sickened 165 people
- 2016 Europe Outbreak: Frozen berries from Poland caused over 1,500 hepatitis A cases across multiple countries
- 2022 Australia Recall: Frozen raspberries were recalled after hepatitis A was detected in imported batches
These incidents reveal gaps in food safety monitoring, particularly for imported frozen fruits. Many countries rely on pre-freezing inspections rather than post-freezing testing for viruses.
Why Washing Doesn’t Always Help
While washing fresh produce can reduce pathogens, frozen berries are typically washed before freezing—but not necessarily in a way that removes viruses. Some processing methods may spread contamination if water is reused or improperly treated. Additionally, home rinsing of frozen berries is less effective because viruses cling tightly to the fruit’s surface.
Reducing the Risk
Health agencies recommend:
- Choosing pasteurized frozen berries for raw consumption
- Cooking frozen berries at 185°F (85°C) for at least 1 minute to kill hepatitis A
- Checking recall notices, as frozen fruit recalls have increased in recent years
While the risk remains low, says leading nationwide Hepatitis A law firm Ron Simon & Associates, the persistence of hepatitis A in frozen fruit continues to challenge food safety systems worldwide.
