[Classical swine fever in 1993 in Switzerland: molecular-epidemiologic characterization of the virus isolate]

RT-PCR followed by direct nucleotide sequencing of the amplified cDNA was carried out to analyse most of the 5' nontranslated region (5'NTR) of classical swine fever virus (CSFV) isolates from the five 1993 disease outbreaks in Switzerland. Sequence data were compared to other CSFV strains, and dendrograms were constructed in order to determine the phylogenetic relationship of the Swiss virus strains. Dendrograms formed by the analysis of different parts of the 5'NTR were compared. It was shown that all Swiss isolates were related to other CSFV strains involved in disease outbreaks in Europe in the 1990s. Two of the isolates were indistinguishable from a CSFV strain isolated from wild boar meat imported from China into Austria in 1993. The risk of introducing classical swine fever by improperly treated swill and, in particular by importing wild boar meat is discussed.