| risk factors for aujeszky's-disease seropositivity of swine herds of a region of northern italy. | vaccination programs to control aujeszky's-disease virus (adv) using ge-deleted vaccines are being considered in several european countries. knowledge of factors influencing adv-seropositivity for vaccinated herds might contribute to the success of these programs. a multivariable analysis of adv-seropositivity in 1248 swine herds (332 farrow-to-finish, 260 farrow-to-feeder and 656 finishing herds) in the emilia-romagna region of italy revealed that (1) high pig density (number of pigs in a 6-km ... | 2002 | 12114009 |