Bovine Pestivirus: an underestimated problematic in central Italy.

The aim of this study was to investigate the spread of Bovine viral diarrhea virus (BVDV) and the preventive measures used in dairy herds in Central Italy. A total of 25 dairy herds located in four regions of Central Italy (Lazio, Umbria, Marche, Abruzzo) have been included in the study. Data about the herd management, the biosafety measures and the health problems have been analysed. Blood sera have been collected and tested for antibodies against BVDV with a commercial ELISA test. When possible, sera of cattle suspected to be persistently infected have been tested for BVDV antigen by a commercial direct ELISA test. In 24 out of 25 herds the animals were not vaccinated for BVD. In all farms, a history of respiratory and/or reproductive problems was recorded. Blood sera from 2035 unvaccinated animals and 314 vaccinated cattle were collected and analysed. Among the unvaccinated animals, 1491 (73.3 %) were seronegative and 544 (26.7%) were seropositive for BVDV. The percentages of seropositive animals were not dissimilar among herds located in different regions and ranged from 24.9 % to 28.7 %. Thirty-four (10.8 %) out of the 314 vaccinated animals were seronegative for BVDV. Further investigations have been permitted by the farmers only in the herd with vaccinated animals. Two vaccinated but seronegative cattle (a cow and her offspring) were positive for BVDV antigen by ELISA. This study shows that BVDV is widely spread in herds in Central Italy. The BVD vaccination was carried out only in 1 out of 25 farms, suggesting that farmers underestimate the economic losses due to pestiviruses in cattle. Persistently infected animals are an important source of BVDV for the other animals if not promptly detected and removed from the herd. Even if vaccination is expensive, the economic losses due to BVD can exceed the vaccination costs.