Spring viremia of carp virus: A RT-qPCR assay and surveillance in Ontario from 2008 to 2012 Ehab Misk a, ⁎, Lincoln Tubbs a,1 , Kyle Garver b , Shelby Isaac a , Elizabeth Wright c , Lowia Al-Hussinee a , John S. Lumsden a,d a Fish Pathology Laboratory, Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1,, Canada b Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo, BC V9T 6N7, Canada c Ontario Ministry of Natural Resources and Forestry, Peterborough, ON, Canada d Department of Pathobiology, St. George's University, True Blue, Grenada abstract article info Article history: Received 31 August 2016 Accepted 23 February 2017 Available online 5 April 2017 Spring viremia of carp (SVC) is a reportable contagious disease of fish that produces high economic losses in sev- eral species of fish, primarily in members of the family Cyprinidae. It is caused by a single-stranded negative- sense RNA virus. In 2006, SVC was first reported in Canada at Hamilton Harbour, Ontario; this remains the only report of SVC virus (SVCV) in Canada. A one-step reverse transcription quantitative PCR (RT-qPCR) was val- idated and used to test samples collected for surveillance between years 2008 and 2012. The assay was demon- strated to be specific and had a sensitivity of 50 copies of RNA or 1 × 10 exp 3 PFU/ml from spiked tissue samples. A total of 1432 fish, representing 31 different species, from 35 locations around Ontario were examined using the RT-qPCR assay. SVCV was not detected using RT-qPCR in any wild-caught fish examined. © 2017 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. Keywords: Surveillance RT-qPCR SVCV Cyprinus carpio Ontario Introduction Spring viremia of carp is a contagious widespread viral disease of fish. The virus, spring viremia of carp (SVCV), mainly affects fish from family Cyprinidae including common carp Cyprinus carpio Linnaeus (Fijan et al., 1971), koi Cyprinus carpio koi, Linnaeus (Goodwin, 2002) and goldfish Carassius auratus Linnaeus (Ahne, 1973). Most outbreaks occur during spring when temperatures range between 10 and 17 °C (Fijan, 1976). The disease is one of nine reportable fish diseases to the World Animal Health Organization (OIE) and accordingly its isolation or clinical impacts affect the international trade of live fish (OIE, 2010). In most of Europe and Asia, the disease is endemic, but it was not reported until 2002 in North America, first from a North Carolina koi farm that experienced a mortality event (Goodwin, 2002) and later that year from a common carp outbreak in Cedar Lake, Wisconsin (Dikkeboom et al., 2004). Since then SVCV has been reported in many areas across the USA including Illinois, Washington, Missouri and Ohio (Warg et al., 2007); and Minnesota (Phelps et al., 2012). The first and only observation of SVCV in Canada was at Hamilton Harbor, Ontario from asymptomatic common carp (Garver et al., 2007). Phylogenetic studies have indicated that all SVCV isolates from North America group with isolates from China, Italy, and the UK into two subgroups (Iai and Iaii) within genogroup Ia (Stone et al., 2003). Subgroup Iai con- tains isolates from Ontario, Canada, Illinois, USA and the first wild com- mon carp outbreak from Cedar Lake, Wisconsin, USA in 2002 while Iaii contains isolates in USA from Washington, Missouri and the original iso- late from North Carolina (Miller et al., 2007). The use of real-time PCR to screen fish for viral agents is gaining widespread use because of its high specificity and reduced time for diag- nosis compared to conventional isolation on cell culture (Garver et al., 2011; Purcell et al., 2011). Current reverse transcription real-time PCR assays have also demonstrated higher sensitivity over conventional virus isolation in cell lines for other fish rhabdoviruses such as viral hemorrhagic septicemia virus (VHSV) (Hope et al., 2010) and infectious hematopoietic necrosis virus (IHNV) (Knusel et al., 2007). Since the only detection of SVCV in Canada to date was from asymp- tomatic common carp in Hamilton Harbour Ontario (Garver et al., 2007) the goal of the present study was to determine if the virus might be present elsewhere in Ontario. The Ontario Ministry of Natural Resources and Forestry (OMNRF) collected a variety of fish species from Southern Ontario water bodies as part of its continuing surveillance program for mortality events and reportable aquatic pathogens. Healthy fish caught for surveillance and fish from noted mortality events were collected for diagnostic purposes. All fish that were collected for either purpose that yielded suitably preserved material were tested using a RT-qPCR assay. Samples were collected from 35 water bodies mostly in southern Ontario. A total of 1432 fish were assayed between 2008 and 2012 Journal of Great Lakes Research 43 (2017) 127–131 ⁎ Corresponding author. E-mail address: emisk@uoguelph.ca (E. Misk). 1 Present address: Elanco Animal Health Inc., Victoria, PEI C0A 2G0, Canada. http://dx.doi.org/10.1016/j.jglr.2017.03.017 0380-1330/© 2017 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved. 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