Spread and control of Aujeszky's disease (AD).

The review deals with practical aspects of control and eradication of Aujeszky's disease (AD) and the various factors concerned with it. These are resistance of virus to environmental conditions, amounts of virus necessary for infection, virus excretion, virus latency, mode of virus transmission, and vaccination. Notification of AD is a precondition of control. Several measures are necessary on the infected farm to prevent virus spread. Eradication can be done by slaughter of all the seropositive animals. However, until recently this is impossible in severely infected vaccinated areas on economic reasons. The development of glycoprotein-deleted vaccines now allows the differentiation between vaccinated and infected animals by ELISA. Thus, a combination of vaccination and removal of infected pigs is possible, resulting in a more economic way of expanded eradication.