Comparison between quantitative real-time reverse transcription PCR results for norovirus in oysters and self-reported gastroenteric illness in restaurant customers.

Norovirus is the principal agent of bivalve shellfish-associated gastroenteric illness worldwide. Numerous studies using PCR have demonstrated norovirus contamination in a significant proportion of both oyster and other bivalve shellfish production areas and ready-to-eat products. By comparison, the number of epidemiologically confirmed shellfish-associated outbreaks is relatively low.