Three-year study to assess human enteric viruses in shellfish

The main pathogenic enteric viruses able to persist in the environment, suc h as hepatitis A virus (HAV), Norwalk-like virus (NLV), enterovirus (EV), r otavirus (RV), and astrovirus (AV), were detected by reverse transcription- PCR and hybridization in shellfish during a 3-year study. Oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminate d, showing positivity for AV (17%), NLV (23%), EV (19%), and RV (27%), wher eas mussel samples, collected in areas routinely impacted by human sewage, were more highly contaminated: AV (50%), HAV (13%), NLV (35%), EV (45%), an d RV (52%). Sequences obtained from HAV and NLV amplicons shelved a great v ariety of strains, especially for NLV (strains close to Mexico, Snow Mounta in Agent, or Norwalk virus), Viral contamination was mainly observed during winter months, although there were some seasonal differences among the vir uses. This first study of virus detection over a fairly long period of time suggests that routine analysis of shellfish by a molecular technique is fe asible.