Following the 2001 outbreak of FMD, Defra imposed a 20-day standstill period prohibiting any livestock movements off-farm following the arrival of an animal. The 20-day rule caused significant difficulties for farmers. The Lessons Learned Inquiry, which reported in July 2002, recommended that the 20-day standstill remain in place pending a detailed cost-benefit analysis of the standstill regime. This was commissioned in September 2002.

Existing models were not appropriate for the particular types of modelling required, so, due to the short timescales and limited data available, a simplified approach was developed by Risk Solutions to assess the impact of different movement controls. This was an extremely challenging task due to the short timescales and limited data available to inform the model. Our approach was to involve as wide a range of experts as possible ensuring that the different assumptions and simplifications could be fully understood.

The resultant ‘silent spread’ model indicated that factors other than length of standstill, such as time to detection of disease, are much more important in determining the size of an outbreak. The work was highly influential in the Government’s decision to relax the 20-day movement control to 6 days, subject to certain commitments from the livestock industry. The report can be accessed via the Defra web site.