In WP3, the objective is to validate and optimise STOC-FREE DATA and STOC-FREE MODEL that are developed in WP1 and WP2 in case studies that are conducted by all partners.
Case example: BVD
Several European countries have implemented national or regional surveillance, control, or eradication programmes for endemic infections of cattle which are currently not regulated at EU level. Programmes aiming to control and eradicate these infections may bring tangible benefits to farmers, processors, the wider public and national economies. Nevertheless, such programmes also create difficulties for trade, particularly of live animals, between member states where differences exist in either the presence or absence of such programmes. Additionally, the statuses attained by the programmes (control/eradication ongoing or freedom achieved) create difficulties for trade due to the risks of impairing progress with control/eradication or re-introducing infection where freedom has been achieved.
Bovine viral diarrhoea (BVD) caused by BVD virus, is a good example of such a disease and has therefore been chosen as an example disease for the development of the STOC free framework in this project.
BVDV is recognised to be an economically important pathogen of cattle and to be endemic in countries without systematic control and eradication efforts. The infection is primarily maintained and spread by persistently infected (PI) calves, which are generated as a result of in utero infection following exposure of their dams. These PI animals shed high levels of virus throughout their lifetime, and their movement between herds is recognised to be the principal means by which infection can be transferred. Trade of PI animals between member states also poses particular risks to ongoing, or completed eradication programmes.
A number of member states have initiated or completed national or regional eradication programmes for BVDV. While these have a common goal, they follow a variety of pathways to achieve this. For example, some focus primarily on testing and assigning the subsequent BVDV free status at herd level, while individual animals are the unit of interest in others. Some BVDV programmes have already achieved freedom, other programmes are still underway but have made good progress, and a third group of BVDV programmes are in their early stages. There are control programmes that are implemented on a voluntary basis and others that are compulsory and supported by legislation. The risks associated with movement of cattle between areas with different programmes and statuses is therefore an ongoing concern for both farmers and programme managers and for this reason BVD has been chosen as the model disease for this project.
The countries in our consortium reflect the variation in both BVDV programme design and prevalence, with a variety of programmes in place and disease statuses ranging from endemic to free, which have generated considerable amounts of data that are available to develop a framework to determine the confidence of freedom of infection at different levels of aggregation for BVD.
When completed, this framework will also be applicable to other infectious cattle diseases.