Surveillance plans were carried out in Italy from 1995 to 2003, with the main aim of controlling the possible circulation of low-virulence classical swine fever viral strains. The repetition
of a serological monitoring programme over several years, with constantly negative results, can prove the absence of the infection while increasing the degree of confidence. In our case, in 2003, after eight repetitions of the surveillance plan, the probability that there was at least one infected farm reached 0.006%. Therefore, on the basis of the results of the sampling carried out from 1995 to 2003, we may state that there is no endemic infection, even because of a low virulence virus, in
continental Italy.