Viral hemorrhagic septicemia virus infection in yellow perch, Perca flavescens, in Lake Erie Michelle Kane-Sutton a , Bryan Kinter a,1 , Patricia M. Dennis b,2 , Joseph F. Koonce a, ⁎ ,1 a Case Western Reserve University, Department of Biology, 10900 Euclid Avenue Cleveland, OH 44106-7080, USA b Cleveland Metroparks Zoo, 4200 Wildlife Way Cleveland, OH 44109, USA abstract article info Article history: Received 22 December 2008 Accepted 14 October 2009 Communicated by Tim Johnson Index words: VHSV Infection period Spawning Yellow perch Viral hemorrhagic septicemia virus (VHSV) infects wild and hatchery fish in Europe, Japan, and the Great Lakes and Pacific regions of North America. The virus was associated with a large die-off of yellow perch, Perca flavescens, in Lake Erie in 2006. To determine the infection pattern of VHSV, we sampled yellow perch during the spring, summer, and fall of 2007 and 2008 in the central basin of Lake Erie during routine sampling by the Ohio Division of Wildlife with bottom trawls in nearshore, mid-depth, and offshore locations near the Chagrin River. The Ohio Department of Agriculture's Diagnostic Laboratories and the U.S. Fish and Wildlife Service's La Crosse Fish Health Center tested for VHSV from homogenized samples obtained from yellow perch kidney, spleen, and brain. At each lake sample location, we also measured temperature, dissolved oxygen, and conductivity. In both years, we found yellow perch infected with VHSV during a three- week period starting in the last week of spawning to early June. A high proportion of adult male and female yellow perch tested positive for VHSV during the infection period in our sample population. Infection appeared to be associated with temperatures between 12 and 18 °C and with significantly higher yellow perch densities during spawning. No large mortalities of yellow perch were observed during the VHSV infection period in 2007 and 2008. © 2009 Elsevier B.V. All rights reserved. Introduction Viral hemorrhagic septicemia virus (VHSV) is a fish pathogen that has been present in the Great Lakes since at least 2003 (USDA, 2006). VHSV is an enveloped negative-strand RNA virus belonging to the Novirhabdovirus genus of the Rhabdovirdae family (Einer-Jensen et al., 2004). The virus is transmitted horizontally by urine and female sex products and in some cases orally by feeding as seen in feeding young northern pike infected trout (Meyers and Winton, 1995, Lorenzen et al., 2000; Wolf, 1988). Gills were thought to be the main portal of infection to fish (Meyers and Winton, 1995, Lorenzen et al., 2000; Wolf, 1988), however, a recent study (Harmache et al., 2006) showed that fin bases are the major portal for Novirhabdovirus infection in salmonids. Depending on the species, strain and genotype, wild versus aquaculture fish, and geographical location the virus is associated with an adult fish death rate of 25–75%, while close to a 100% death rate in juvenile fish such as rainbow trout. Strains of European species at low temperatures in freshwater and Pacific herring are more susceptible to isolates of Genotype IVa (Meyers and Winton, 1995; Wolf, 1988). Because of the detrimental effect VHSV infection can have on certain species in freshwaters there has been substantial concern about the effect of the virus on the health of fish populations in Lake Erie. VHSV was first successfully isolated in cell culture in 1962 Denmark and showed to be the etiological agent of VHSV (Wolf, 1988). Since its first detection in Denmark, researchers sequenced and mapped VHSV into four genotypes, three European (I–III) and one North American (IV) (Snow et al., 1999; Einer-Jensen et al., 2004). The North American (IV) has been subdivided into two sublineages, IVa and IVb (Elsayed et al., 2006). To this date, all isolates of VHSV from fish in the Great Lakes region have been identified as belonging to IVb sublineage while all isolates from fish from the west coast of North America belong to the IVa sublineage (Elsayed et al., 2006). The source of the virus in the Great Lakes is uncertain, but tissue samples collected from mummichog, Fundulus heteroclitus, three spined stickleback, Gasterosteus aculeatus aculeatus, striped bass, Morone saxatlis, and brown trout, Salmo trutta trutta, in Eastern Canada near Nova Scotia and New Brunswick tested positive for VHSV between 2000 and 2004 (Gagne et al., 2007). In 2003, muskellunge, Esox masquinongy, tested positive for VHSV in Lake St. Clair, MI, USA (Elsayed et al., 2006). Since 2003, the Ontario Ministry of Natural Resources reported a large fish kill of freshwater drum infected with VHSV in the Bay of Quinte in Lake Ontario in the spring of 2005 (USDA, Journal of Great Lakes Research 36 (2010) 37–43 ⁎ Corresponding author. Tel.: +1 216 368 3561. E-mail addresses: michelle.kane@case.edu (M. Kane-Sutton), kinter.6@osu.edu (B. Kinter), pmd@clevelandmetroparks.com (P.M. Dennis), joseph.koonce@case.edu (J.F. Koonce). 1 Tel.: +1 216 368 3557. 2 Tel.: +1 216 635 2520. 0380-1330/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jglr.2009.11.004 Contents lists available at ScienceDirect Journal of Great Lakes Research journal homepage: www.elsevier.com/locate/jglr