CANADA - A controlled laboratory study that has challenged Atlantic and Sockeye salmon with a fish virus known to be endemic to western North America has found the virus is not linked to any disease or mortality.
The collaborative study was conducted at the Pacific Biological Station in Nanaimo, British Columbia, and the results were published in the Public Library of Science.
The study, titled 'Piscine orthoreovirus from western North America is transmissible to Atlantic salmon and Sockeye salmon but fails to cause Heart and Skeletal Muscle Inflammation (HSMI)', exposed salmon to Piscine orthoreovirus(PRV) either directly by injecting virus into fish or by cohabitating naïve fish with naturally infected fish.
The results concluded that although western North American PRV was easily transmitted by injection and cohabitation, its inability to induce disease in fish exhibiting high viral loads indicates factors other than PRV are required for disease causation.
Previous studies on PRV in Norway have suggested an association between PRV and a fish disease known as heart and skeletal muscle inflammation (HSMI), although no cases of HSMI have ever been confirmed in fish with western North American PRV.
Dr Diane Morrison (DVM), Marine Harvest’s Director of Fish Health and Food Safety, was one of the eight authors of the study.
“This important study provides definitive answers to many questions that have been asked since PRV was detected on our coast a few years ago,” said Dr Morrison.
“The body of research now tells us that PRV has been ubiquitous in the Pacific Northwest for many decades, and that it isn’t linked to any fish disease or mortality.”
Other authors of the study include Kyle A. Garver, Stewart C. Johnson, Mark P. Polinski, Julia C. Bradshaw, Jon Richard (Pacific Biological Station, Department of Fisheries and Oceans); Gary D. Marty, Heindrich N. Snyman (Animal Health Centre, Ministry of Agriculture).
TheFishSite News Desk