Characterisation of Aujeszky's disease viruses isolated from domestic animals and from a wild boar (Sus scrofa) in Italy between 1972 and 1995.

Following the isolation of a group I Aujeszky's disease virus from a wild boar in 1993, an investigation was carried out on 30 Italian Aujeszky's disease viruses (ADV's), isolated over a 23-yr period in 12 Italian regions, by means of restriction endonuclease analysis. All strains isolated between 1972 and 1984 belong to group I. From 1984 onwards group II isolates (II and II intermediate) replace group I isolates. The isolation of a group I virus in 1993 from a wild boar supports the hypothesis that ADV's may persist for several years in wild boar populations and that wild boars should therefore be considered reservoirs of Aujeszky's disease virus.