A study of outbreaks of Aujeszky's disease in cattle. II. Further investigations on the routes of infection.

The probable routes of infection in 29 outbreaks of Aujeszky’s disease in cattle are discussed in the light of virological and epidemiological data, given in a preceding paper, and of histories of the individual outbreaks given in the present paper. The view was substantiated that anterior pruritus is mostly associated with infection by the respiratory route. In outbreaks with posterior pruritus the route of infection appeared to be a question of a more complex nature. With reference to cases examined later, it is concluded that perineal pruritus is often associated with vaginal infection. In a few cases there was evidence of virus transmission by man. Three cases with pruritus on a hind leg were suggestive of an alimentary infection. In many outbreaks with posterior pruritus, the route of infection remained obscure.