APPLICATION OF GENETIC METHODS TO STUDY THE RELATIONSHIP BETWEEN CLASSICAL SWINE FEVER OUTBREAKS

Eleven viruses isolated between 1993 and 1997 from outbreaks of classi cal swine fever in the neighbouring countries of Slovakia, The Czech R epublic and Austria were compared after partial sequencing of the NS5B and E2 genes. Viruses collected from South-Central and West Slovakia were indistinguishable during a period of four years, even when associ ated with outbreaks of variable severity. Outbreaks that occurred in t he Czech Republic in 1996 involved two types of virus, one of which wa s related to the Slovakian outbreaks, and the other to Austrian outbre aks. The results show that the molecular-genetic approach can reveal e pizootiological relationships between outbreaks that would not otherwi se be apparent. Furthermore, the relative genetic stability of the cla ssical swine fever virus in the field, means that quite small sequence differences can have epizootiological significance.