Health warning: Frozen berries pose a risk of dangerous viruses!

Health warning: Frozen berries pose a risk of dangerous viruses!

Summertime is berry time! The frozen fruits are very popular, especially with the temperatures that attract us outdoors during these months. But there are potential dangers beneath the colorful shells, as the Federal Institute for Risk Assessment (BfR) reports. Particularly alarming are the possible contaminations with noroviruses and hepatitis A viruses, which can cause health problems if uncooked frozen berries are consumed.

The BfR's warning, which has existed since 2013, is more relevant than ever. Over 2,000 cases of hepatitis A were recorded in Europe between January and May 2025, including many in neighboring countries such as Austria, Hungary and Slovakia. According to Professor Dr. Jürgen Wenzel, around 30 percent of imported berries come from risk areas, which increases the risk of infection for consumers. A particularly serious outbreak of the disease occurred in 2012, when almost 11,000 children and young people in Germany became ill from contaminated frozen strawberries.

Identify and avoid risks

The dangerous viruses that can colonize frozen berries should not be underestimated. Noroviruses cause severe gastrointestinal infections with symptoms such as nausea, vomiting and diarrhea. While hepatitis A viruses can cause acute liver inflammation accompanied by fever, fatigue and even jaundice. Particular caution is therefore required, especially in community facilities such as schools and kindergartens. Experts recommend always heating frozen berries to over 90 degrees Celsius before consumption to ensure that no harmful pathogens survive.

In its 2023 investigations, the Lower Saxony State Office for Consumer Protection (LAVES) did not detect any viruses in 30 tested samples, but there were still cases of illness due to the raw consumption of frozen berries. In an earlier incident in 2016, 27 people became ill at a clinic after eating a frozen raspberry dessert in which norovirus was found.

What to do to enjoy safely?

Consumer advocates strongly warn against eating frozen berries raw. In order not to endanger public health, it is advisable to consume berries from abroad with caution. The pathogens often get onto the fruit through improper fertilization, irrigation or during processing. If you want to be on the safe side, you should instead resort to cooking or baking and bring the berries to the temperature mentioned.

The good news is that with a little caution and proper handling, many health risks can be avoided. Before eating frozen fruit, you should always make sure to heat it sufficiently to protect yourself and your family.

Further information on the risks and current recommendations can be found on the BfR website Merkur reported and on the LAVES website LAVES Lower Saxony and GEO GEO informed.