Preventive strategy for BVDV infection in North America.

Despite 60 years of vaccination, bovine viral diarrhea virus (BVDV) infections remain a source of significant economic loss for producers in the United States. Control program design in the United States varies by region based on the incidence of BVDV, density of animal populations, animal movement, contact with wildlife populations, level of producer compliance, variation among circulating BVDV strains, prevalent type of production unit or industry and support offered by state institutions. The Upper Peninsula BVDV Eradication Program in Michigan, the Montana BVD-PI Herd Biosecurity Project, the Washington State BVDV Testing program and the Alabama Voluntary BVD Control Program illustrates four different regional approaches. All four programs are voluntary rather than government mandated and a large component of each was the identification and removal of animals persistently infected with BVDV. The Washington, Montana and Alabama programs focus on herd screening to eliminate PI's but did not have eradication as a goal. The Michigan program was unique in that its goal was to eradicate BVDV from a defined geographic region. While the Washington, Alabama and Montana programs were beneficial to individual producers they did not have a significant impact on the prevalence of BVDV. In contrast, the Michigan program has reduced incidence of herds harboring PI animals in the region. Organizers of all four programs noted that compliance with control programs was directly linked to education and the presence of a support network composed of fellow producers, engaged veterinarians and knowledgeable diagnosticians.