Prevalence and prevention of paratuberculosis in North America.

The United States of America (U.S.) has made several attempts over the years to develop a producer accepted voluntary program. The focus of the U.S. Voluntary Bovine Johne's Disease Control Program (VBJDCP) is to provide producers with the tools to control Johne's disease on their farms and identify herds with a low risk for the presence of Mycobacterium avium subspecies paratuberculosis (MAP) infection. The VBJDCP includes an evaluation of producers' operations to identify practices that could allow the transmission of MAP among animals or between premises. Once risky practices havebeen identified, a herd management plan is developed to assist the producer in correcting risky practices. In addition to management changes, vaccination is a control tool allowed in the U.S. because it reduces the clinical signs of Johne's disease and the shedding of MAP. Testing is used in addition to management changes. While the classification component of the VBJDCP dictates the amount and type of testing herd owners are required to conduct, the education and management components of the VBJDCP does not specify testing protocols. The testing for control is intended to fit the needs and resources of producers and can be quite flexible. Management changes on the farm remain the key to control and programs cannot replace well thought out plans by producers that are specific to their resources, facilities, and operation.