Division 1

Genetic typing of classical swine fever virus isolates is achieved by determining the nucleotide sequence of portions of the virus genome, namely specific parts of the 5'noncoding region and/or of the E2 glycoprotein gene. The similarity of these sequences with those already obtained from previous virus isolates can indicate whether or not outbreaks of disease are caused by new or already recognised strains. This can support or refute hypotheses on transmission routes that have been provided by epidemiological tracing.

Genetic typing of classical swine fever virus isolates is of major importance to determine the source of disease. However, a close relationship between viruses obtained from different outbreaks is not an absolute proof for a direct epidemiological link.