Genetic heterogeneity of classical swine fever virus in Central Europe.

The aim of this work was to genetically characterize Central European isolates of classical swine fever virus (CSFV) and to evaluate the applicability of molecular analysis in the epizootiology of CSFV infections. Thirty four viruses, derived from Central European pigs or wild boar, were examined. All of these viruses were detected by each of three sets of oligonucleotide primers which had been designed for the specific RT-PCR amplification of different genomic regions. Comparative sequence analysis of the PCR products showed that they were of a genetic type common in Western Europe. Further discrimination of virus isolates was possible, into subgroups that largely coincided with their regions of origin in Poland, Slovakia, Hungary and Estonia. The discriminatory ability of the technique was improved by the analysis of a composite dataset consisting of all of the sequence data from all of the viruses. Using this approach we were able to distinguish between all of the viruses and to group them in a manner that precisely matched their geographical origins, apart from a single Estonian isolate which grouped with viruses from Eastern Poland.