Presence and genetic variability of Piscine orthoreovirus genotype 1 (PRV-1) in wild salmonids in Northern Europe and North Atlantic Ocean

• Published in: Journal of Fish Diseases
• Main Authors: Vendramin, Niccolò, Cuenca, Argelia, Sørensen, Juliane, Alencar, Anna Luiza Farias, Christiansen, Debes H, Jacobsen, Jan A, Axen, Charlotte, Lieffrig, François, Ruane, Neil M, Martin, Patrick, Sheehan, Timothy, Iburg, Tine M, Rimstad, Espen, Olesen, Niels Jørgen
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: PRV-1; Atlantic salmon; Epidemiology; Phylogeny; Sequencing; Faroe Islands; Greenland; North Atlantic; Salmo salar
• Online Access: https://orbit.dtu.dk/en/publications/11fb2aa7-3aac-4ad2-a7ee-3d7d43f9335f; https://doi.org/10.1111/jfd.13025

Piscine orthoreovirus genotype 1 (PRV-1) is widespread in farmed Atlantic salmon (Salmo salar L.) populations in northern Europe, Canada and Chile. PRV-1 occurs in wild fish in Norway and Canada; however, little information of its geographical distribution in wild populations is currently available, and the effect of PRV-1 infection in wild populations is currently unknown. In this study, we present the findings of a survey conducted on 1,130 wild salmonids sampled in Denmark, Sweden, Ireland, Faroe Islands, France, Belgium and Greenland between 2008 and 2017. PRV-1 is reported for the first time in wild salmonids in Denmark, Sweden, Faroe Island and Ireland. The annual PRV-1 prevalence ranged from 0% in France, Belgium and Greenland to 43% in Faroe Islands. In total, 66 samples tested positive for PRV-1, including Atlantic salmon broodfish returning to spawn and Atlantic salmon collected at the feeding ground north of Faroe Islands. The phylogenetic analysis of S1 sequences of the PRV-1 isolates obtained in this survey did not show systematic geographical distribution. This study sheds light on the spread and genetic diversity of the virus identified in populations of free-living fish and provides rationale for screening wild broodfish used in restocking programmes.