We investigated the ability of hepatitis A virus (HAV) to persist for up to 6 weeks in Eastern oysters (Crassostrea virginica). Viral RNA was detected by reverse transcription–polymerase chain reaction 6 weeks after 16 h of exposure to 90,000 PFU (180 PFU/ml of seawater) of HAV. Assaying for infectious virus in oysters that received a daily feeding of phytoplankton recovered 3,800, 650, and 500 PFU of HAV 1, 2, and 3 weeks after contamination with 90,000 PFU of HAV, respectively. However, no infectious HAV was isolated from oysters 4, 5, or 6 weeks after contamination. These results support the position that shellfish depuration is insufficient for the complete removal of infectious viruses. Extended relay times (in excess of 4 weeks) may be required to produce virologically safe shellfish.
Detection of replication-defective hepatitis A virus based on the correlation between real-time polymerase chain reaction and ELISA in situ results