date:Oct 18, 2013
linical signs, when present, do not entirely cover the period of virus excretion. Consequently, an absence of clinical signs cannot be used as evidence of absence of virus excretion. At farm level SIV infections can be maintained with a continuous introduction of susceptible pigs. Therefore, the risk of spread from holdings can remain high for an extended period of time even after cessation of clinical signs. This takes place particularly when susceptible pigs continuously enter the fattening un