Temperature-Dependent Persistence of Human Norovirus Within Oysters (Crassostrea virginica).

Food and environmental virology

PubMedID: 26983441

Choi C, Kingsley DH. Temperature-Dependent Persistence of Human Norovirus Within Oysters (Crassostrea virginica). Food Environ Virol. 2016;.
This study characterizes the persistence of human norovirus in Eastern oysters (Crassostrea virginica) held at different seawater temperatures. Oysters were contaminated with human norovirus GI. 1 (Norwalk strain 8FIIa) by exposing them to virus-contaminated water at 15 °C, and subsequently holding them at 7, 15, and 25 °C for up to 6 weeks. Viral RNA was extracted from oyster tissue and hemocytes and quantitated by RT-qPCR. Norovirus was detected in hemocytes and oysters held at 7 and 15 °C for 6 weeks and in hemocytes and oysters held at 25 °C for up to 2 and 4 weeks, respectively. RESULTS
confirm that NoV is quite persistent within oysters and demonstrate that cooler water temperatures extend norovirus clearance times.This study suggests a need for substantial relay times to remove norovirus from contaminated shellfish and suggests that regulatory authorities should consider the effects of water temperature after a suspected episodic norovirus-contamination event.