Contact person: Patrick Presi
Duration: Jan. 2009 - Dec. 2011
With an antibody prevalence of about 70% and approximately 1% persistently infected (PI) animals in the year 2000, BVD was widespread in Switzerland, causing serious economic losses. To eradicate the disease, the whole Swiss cattle population was tested for virus in a short period of time between January 2008 and January 2009. Antigen-positive animals identified by ELISA or rRT-PCR methods were slaughtered, and movement restrictions were applied to avoid new herd infections. In total, 1.7 Millions animals were tested and 14’000 PI animals identified and slaughtered. Beginning in 2009, all new-born calves will be systematically tested.
In 2010 a national surveillance program will start in order to control and maintain the BVD free status. This surveillance program should allow an early detection of infected animals, to avoid a new spread of the BVDV.
This project aims at comparing different surveillance strategies using a stochastic model developed using the language and environment for statistical computing R. Besides testing for antigen in all newborn calves, additional methods in consideration are blood testing of young calves for antibodies starting in 2010; milk testing of young heifer for antibodies starting in 2011; combination of both approaches; integration of risk factors associated with the herd, the sampling period, or the sampling location, to target sampling to animals at higher risk.
The model will help decision makers to better allocate resources to maintain the presence of BVDV at a negligible level in the Swiss livestock as well as identify missed animals during the eradication program.
