DAO prepress abstract   -  DOI: https://doi.org/10.3354/dao03732

ABSTRACT: Herein, we report the detection of an alphaherpesvirus infecting an adult female narwhal Monodon monoceros live captured during a tagging project in Tremblay Sound, Nunavut, Canada, in August 2018. The individual had 2 open wounds on the dorsum but appeared in good overall health. A blowhole swab was collected, and subsequent virus isolation was performed using a beluga whale primary cell line. Non-syncytial cytopathic effects were seen in contrast to syncytial cytopathic effects described for monodontid alphaherpesvirus 1 (MoAHV1) isolates previously recovered from beluga whales Delphinapterus leucas from Alaska, USA, and the Northwest Territories, Canada. Next-generation sequencing was performed on the viral isolate and the analysis of the assembled contigs permitted the recovery of 6 core genes, conserved in all members of the family Orthoherpesviridae, for downstream genetic and phylogenetic analyses. BLASTN analyses of the narwhal herpesvirus conserved genes showed the highest nucleotide identities to MoAHV1, ranging between 88.5 and 96.8%. A maximum likelihood phylogenetic analysis based on the concatenation of the 6 conserved herpesviruses amino acid alignments revealed the narwhal herpesvirus to be the closest relative to MoAHV1, forming a clade within the genus Varicellovirus, subfamily Alphaherpesvirinae. The narwhal herpesvirus is the first alphaherpesvirus characterized from a narwhal and represents a new viral species to be known as Varicellovirus monodontidalpha2. Further research is needed to determine the prevalence and potential clinical impacts of this alphaherpesvirus infection in narwhals.