Control of classical swine fever epidemics under varying conditions--with special focus on emergency vaccination and...

In case of a classical swine fever outbreak in the European Union (EU), its control is based upon the culling of swine on infected farms, movement restrictions in the protection and surveillance zones, and contact tracing. Additionally, preventive culling may be carried out. Emergency vaccination and rapid PCR testing are discussed as alternatives to avoid this measure. An outbreak of classical swine fever and the success of its control are influenced by different factors. Using a spatial and temporal Monte-Carlo simulation model the control strategies 'Restriction Zone', 'Traditional Control', 'Emergency Vaccination', 'Test To Slaughter', 'Test To Control' and 'Vaccination in conjunction with Rapid Testing' were compared under various conditions. Farm density, compliance with movement restrictions and delay in the establishment of an emergency vaccination were analysed as influencing factors. It was found that all these factors had a significant influence on the number of infected and culled farms. In a low-density region, the basic measures are sufficient to control an epidemic, provided strict compliance with movement restrictions is adhered to. In a high-density region, additional measures are necessary. They can compensate non-strict compliance with movement restriction to a certain extent. In the high-density region, 'Emergency Vaccination' and 'Vaccination in conjunction with Rapid Testing' reached the same level of infected farms as 'Traditional Control', independent of the value of compliance with movement restrictions. However, in the case of an emergency vaccination, an early start to the vaccination campaign is essential for successful disease control.