DEEP FROZEN BERRIES ARE BETTER THOROUGHLY COOKED BEFORE CONSUMPTION - BFR 2013
Data published in recent years show clearly that norovirus occur on deep-frozen berries and that they can cause outbreaks of illness. Laboratory detection of norovirus in the batch of deep-frozen strawberries that caused the outbreak in autumn 2012 has now also confirmed this insight for Germany.
Berries can come into contact with norovirus at different points of their production, for example through improper irrigation or fertilisation. In addition, persons infected with norovirus can spread the virus to the berries during the harvest or packaging. In the case of deep-frozen berries, norovirus also comes into contact with the berries through contaminated water which is added as part of the freezing process.
Noroviruses cause acute diarrhoea with vomiting in humans of all age groups, with the illness leading to a considerable loss of fluids. For babies and young children as well as old and ill persons, the illness can be severe and end in death in some cases.
According to the current state of knowledge, it is to be assumed that a high risk of infection is posed not only by raw but also by briefly or unevenly heated dishes made from deep-frozen berries, if they are contaminated with norovirus. However, heating to a core temperature of over 90 °C seems sufficient to completely inactivate any viruses that may be present.