A Study of the Progress of the Aujeszky's Disease Control Programme in Italy Using Survival Analysis

Abstract

A 3-year study (1997-2000) was performed on 294 swine herds from Italy, where a National Programme of Control of Aujeszky's Disease (AD) based on compulsory vaccination has been operative since 1997. Aim of the study was to evaluate the progress of this control programme using a survival approach applied to gE-seropositive herds at the beginning of the programme. The cumulative proportion of herds still gE-seropositive at the end of the study was 0.57. No significant difference in the probability of becoming gE-seronegative during the study period was found between herds of different type (breeding versus farrow-to-finish) whereas significant differences were seen between herds from different areas. The Cox's proportional hazards regression, performed on data from 79 herds, showed that the only risk factor significantly associated with a higher probability of becoming gE-seronegative is again the geographical location. Other risk factors considered in the analysis were: type of enterprise, type of replacement of animals, herd size, pig and pig herds densities around the farm, distance from the nearest pig herd and year of beginning of the vaccination with a gE-deleted vaccine.

A Serological Survey of Selected Pathogens in Wild Boar in Slovenia

“…Aujeszky's disease is an economically important disease of pigs, for which several European countries (Elbers et al., 2000; Müller et al., 2003, 2005; Martini et al., 2003) and the USA (Hahn et al., 1997; Corn et al., 2004) have implemented national program for elimination of the disease. The prevalence of antibodies against ADV found in the present study (31%) is higher than that reported from Eastern (8.9%) and Western (9.9%) Germany (Müller et al., 1998; Lutz et al., 2003), France (5.5%) (Albina et al., 2000), Italy (30%) (Capua et al., 1997) and lower than that reported from south‐central part of Spain (56%) (Gortazar et al., 2002), Croatia (54%) (Župančić et al, 2002), Tunisia (54%) (Jridi et al., 1996) and Corsica with prevalence up to 61% (Albina et al., 2000).…”