28th ANNUAL EASTERN FISH HEALTH WORKSHOP April 21-25, 2003 Atypical Spring Viremia Of Carp Virus Isolated From Carp Imported Into The United Kingdom:  Evidence For A Number Of Distinct Sub-Groups Keith Way, Kevin L Denham, Peter F. Dixon, Clare B. Longshaw, Alyson M. Sheppard, David M. Stone. The Centre for the Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Barrack Road, The Nothe, Weymouth, DT4 8UB, United Kingdom Spring Viremia of Carp virus (SVCv) is a rhabdovirus of the genus vesiculovirus that is recognised as an important pathogen of freshwater fish associated with major disease epizootics in cultured carp populations. The geographic range of SVC is generally considered to be restricted to the European continent (including Russia and some states of the former Soviet Union). However, in 1998, during routine virus screening of coldwater ornamental fish, SVCv was isolated from koi carp and goldfish imported into the United Kingdom (UK) from Asia. Further isolates were obtained in 2001 and 2002 from sites connected with imports of fish from Asia and also from carp imported illegally into the UK from Europe. These isolates showed different growth characteristics from that of typical SVCv and were difficult to identify using some immunodiagnostic tests. Only two of these isolates were associated with mortality in carp.  The reverse transcription-polymerase chain reaction method was applied to the detection and sequencing of a 426 nt fragment of the glycoprotein (G) gene of putative SVCv isolates. Subsequent phylogenetic analysis of the partial G gene sequence produced trees in which the isolates were assigned to four distinct sub-groups that were supported by bootstrap values of >99.3%. Isolates from Western Europe formed one sub-group and isolates from Russia and the former Soviet states were divided between two sub-groups. The isolates of Asian origin were assigned to a fourth distinct group along with two isolates associated with SVC outbreaks in the United States during 2002. These data further highlighted the genetic diversity that exists among SVCv isolates and suggested that analysis of this region of the SVCv G gene could be used as an epidemiological tool to identify the source of an SVCv isolate. Return to 28th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page