title: Horizontal transmission of nervous necrosis virus between turbot Scophthalmus maximus and Atlantic cod Gadus morhua using cohabitation challenge.
abstract: Experimental horizontal transmission of nervous necrosis virus (NNV) originating from halibut Hippoglossus hippoglossus was studied through cohabitation of intraperitoneally (i.p.) injected fish with uninfected fish for 125 d. The experimental groups consisted of i.p. injected turbot Scophthalmus maximus or i.p. injected Atlantic salmon Salmo salar with turbot, salmon or Atlantic cod Gadus morhua cohabitants. The initial weights were cod 10 g, salmon 40 g and turbot 3 g. NNV was detected in brain, eye and spleen by real-time reverse transcriptase PCR (qRT-PCR) in cod cohabitated with i.p. injected turbot after 90 and 125 d, suggesting NNV infection was transmitted horizontally from the turbot to cod. NNV was not detected in salmon that were cohabitated with i.p. challenged turbot or salmon. This study shows that NNV strains belonging to the Barfin Flounder Nervous Necrosis Virus (BFNNV) clade may be transmitted from halibut to cod via water. Hence there is a potential risk of horizontal transmission of the virus from farmed halibut to farmed and wild cod. The lack of detection of NNV in cohabitant salmon suggests that this fish species is less susceptible than cod, or not susceptible, to horizontal NNV transmission. This result might be influenced by the size of salmon, viral load in i.p. injected cohabitants or insufficient duration of the experiment.
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway. kjetil.korsnes@uin.no
authors.forename: Kjetil
authors.initials: K
authors.lastname: Korsnes
authors.forename: Egil
authors.initials: E
authors.lastname: Karlsbakk
authors.forename: Are
authors.initials: A
authors.lastname: Nylund
authors.forename: Audun Helge
authors.initials: AH
authors.lastname: Nerland
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000635:transmission / Q000821:virology*; D005412:Flatfishes; D048389:Gadus morhua; D007150:Immunohistochemistry / Q000662:veterinary; D030381:Nodaviridae / Q000502:physiology*; D012327:RNA Virus Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D012367:RNA, Viral / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary
chemical_list: D012367:RNA, Viral