Case study of vertical transmission of Ostreid herpesvirus-1 in Pacific oysters and biosecurity management based on epidemiological data from French, New Zealand and Australian hatchery-propagated seed

[SHORT COMMUNICATION] Introduction: “In recent decades, mortality caused by ostreid herpesvirus (OsHV-1) and a variant (OsHV-1 μvar) has severely impacted the production of Pacific oyster, Crassostrea gigas, chronologically in France, New Zealand (NZ) and Australia (Jenkins et al., 2013; Keeling et al., 2014; Segarra et al., 2010). This study was conceived based on observations made in several commercial hatcheries and research institutes in these countries where vertical transmission of OsHV-1 μvar has been absent or extremely rare. We have collated data from the pro-duction of Pacific oysters across these countries to assess the risk associated with breeding oysters from broodstock grown in OsHV-1 μvar- infected waters. The aim is to provide a reference point for regulatory authorities to use when developing or updating biosecurity management policy associated with the hatchery production of Pacific oysters. […]”

Keywords: Biosecurity; Crassostrea gigas; Epidemiology; Ostreid herpesvirus (OsHV-1) μvar; Oyster farming; Vertical transmission