Detection of IHHN virus in a Specific Pathogen Free bonafide Penaeus vannamei (Boone, 1931) broodstock consignment imported to India

Abstract

The World Organization for Animal Health (formerly Office International des Epizooties OIE) listed pathogenic shrimp virus, infectious hypodermal haematopoetic necrosis virus (IHHNV), has been detected in a specific pathogen free (SPF) declared consignment imported from an approved SPF vannamei broodstock supplier to India. The Aquatic Quarantine Facility (AQF), Chennai the only Government-approved quarantine premise for ensuring the SPF status of imported Penaeus vannamei broodstock detected this pathogen during its routine screening process. The AQF, which has so far screened about 1068 SPF batches of vannamei consignment, recorded that one particular batch imported to India was not SPF, though the exporting country declared the stock as SPF. The presence of the viral pathogen was confirmed by both nested PCR and quantitative PCR (qPCR). Sequencing data of the target viral genome revealed 100% similarity with the already published decapod penstyldensovirus-1 isolate IHHNV partial genome (GenBank accession no. KJ862253). The test results declared by AQF were further validated by the Central Institute of Brackishwater Aquaculture, Chennai, which is the referral laboratory of AQF. As the import of non-SPF stock into the country is a source of biosecurity threat, the entire batch was incinerated according to the standard operating procedure of AQF. Thus the stringent biosecurity measures and disease diagnostic strategies followed at AQF served to safeguard the industry from this virus, which would have otherwise gained entry into the country through the falsely claimed SPF stock. This communication highlights the importance of SPF stock and detection of IHHNV.