The effectiveness of domestic cook on inactivation of murine norovirus in experimentally infected Manila clams (Ruditapes philippinarum)




The aim of this work was to evaluate the efficacy of domestic cooking in inactivating Manila clams experimentally infected with murine norovirus (MNV).

Methods and Results

A cooking pan was modified to enable electronic temperature probes to be positioned to record both flesh and environment temperature. Manila clams were infected with 104 TCID 50% ml−1 of MNV. The infected whole-in-shell clams, divided into three replicates, were cooked on an electric stove, and groups of nine clams were removed from the pan at fixed intervals. Pools of three digestive glands were examined by virus isolation to ascertain residual viral load.


Results showed that 10 min of cooking by a traditional domestic method at a temperature close to 100°C, for at least 2 min, can completely devitalize the MNV in infected clams. This is generally the time needed for the majority of valves to open up.

Significance and Impact of the Study

At present, it is highly recommended to label all lagoon products as ‘requiring cooking before consumption’, but no specifications are given on how long and at what temperature they should be cooked. Our results can provide the consumer with useful indications on how to cook clams to prevent any risk of foodborne illness.