EN
Noroviruses are the most frequent etiological factor of non-bacterial human gastroenteritis. Contaminated bivalve molluscs, especially oysters and mussels, are the most frequent source of infections. Shellfish are filter feeders. As they filter and clean the water, they simultaneously concentrate and accumulate viruses. Human (HuNoVs: genogrup I - GI and genogrup II - GII), porcine (PoNoV - GII.11, GII.18, GII.19) and bovine noroviruses (BoNoV - GIII) have been detected in bivalve molluscs. The stability of NoVs in the environment is high. Adequate heat treatment inactivates these viruses, but inactivation crucially depends on the time and temperature of such a treatment. Gastroenteritis outbreaks caused by viruses follow a pattern of winter seasonality between January and April. An increased number of foodborne viral outbreaks following the consumption of contaminated bivalve molluscs has been noted in recent years.