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An analysis was made that calculated the risk of disease for premises in the most heavily affected parts of the county of Cumbria during the foot-and-mouth disease epidemic in the UK in 2001. In over half the cases the occurrence of the disease was not directly attributable to a recently infected premises being located within 1.5 km. Premises more than 1.5 km from recently infected premises faced sufficiently high infection risks that culling within a 1.5 km radius of the infected premises alone could not have prevented the progress of the epidemic. A comparison of the final outcome in two areas of the county, south Penrith and north Cumbria, indicated that focusing on controlling the potential spread of the disease over short distances by culling premises contiguous to infected premises, while the disease continued to spread over longer distances, may have resulted in excessive numbers of premises being culled. Even though the contiguous cull in south Penrith appeared to have resulted in a smaller proportion of premises becoming infected, the overall proportion of premises culled was considerably greater than in north Cumbria, where, because of staff and resource limitations, a smaller proportion of premises contiguous to infected premises was culled.

This paper presents a detailed analysis of the application of contiguous culling in Cumbria between May 1 and September 30, during the outbreak of foot-and-mouth disease in 2001. The analysis shows that the application of veterinary risk assessment and judgement identified and removed groups of susceptible stock which were at risk of direct transmission of infection and avoided infected animals being left that might have spread the disease. When compared with an automatic contiguous cull, fewer culls were made and some of these were reduced in scale, providing economies in the use of resources. The data suggest that farms contiguous to an infected premises faced a 5 per cent risk of infection by direct transmission and a 12 per cent risk of infection by indirect transmission.

During the foot-and-mouth disease epidemic in the UK in 2001, two major control policies were the rapid identification of cases and the culling of animals on infected premises and on dangerous contact premises. Dangerous contact premises were divided into two groups, premises contiguous to an infected premises and non-contiguous premises. In England, the largest numbers of geographically clustered infected premises were in Cumbria, the South West (Somerset, Devon and Cornwall) and the Settle/Clitheroe area straddling the Yorkshire-Lancashire border. In each of these clusters, the rate of spread of the disease, the average time from the first lesion to slaughter on infected premises, and the intensity of culling of contiguous premises and non-contiguous premises were calculated for seven-day periods. Linear regression analysis was used to look for relationships between these factors and the rate of spread of the disease. The average time from the first lesion to slaughter had a statistically significant relationship in two of the three clusters and the intensity of culling of non-contiguous premises had a significant relationship in one. The intensity of culling of contiguous premises had no significant relationship in any of the three clusters.