Animal Disease Contingency Modelling in the US

Improving outbreak preparedness for one of the world’s largest beef producers

The US is one of the world’s largest producers of beef, with around 93.6 million cattle across 882,000 farms, and with a market value of $77bn. As a result, protecting millions of cattle from potential disease outbreaks is a crucial part of the nation’s economic security, as well as a public health priority. Warwick researchers Dr Mike Tildesley and Professor Matt Keeling have been integral in helping the US Department of Agriculture (USDA) to develop the first national-scale model to simulate potentially devastating outbreaks of foot-and-mouth disease (FMD) and, later, bovine Tuberculosis (bTB) within the country.

Research funded by: US Department of Homeland Security, BBSRC

The challenge

FMD outbreaks have a catastrophic effect on farming and tourism, with the 2001 outbreak in the UK estimated to have cost £8bn. While previous outbreaks in the UK and Japan prompted modelling efforts, these retrospective models could not easily be adapted to active management of a disease outbreak in a country the size of the US. The US also faces unique challenges, as it does not track livestock movements and its largest farms are over 100 times the size of those in the UK.

Our approach

Working with collaborators in Colorado State University, Linköping University and the USDA, Tildesley and Keeling developed a framework which could for the first time ever simulate national scale spread of livestock disease. Warwick worked mainly on the US Disease Outbreak Simulation (USDOS ), which could model outbreaks in large cattle populations with limited information on shipments and locations of premises. Collaborators worked on the US Animal Movement Model (USAMM ), which models cattle shipments and feeds into USDOS. Further research and enhancements to USDOS enabled a number of benefits in the event of an outbreak:

• Faster simulation using a novel gridding methodology

• Extension of the model to cover bTB as well as FMD

• Highlighting the importance of local interventions

• Demonstrating optimal control policies are best selected early despite uncertainty

Our impact

USDOS and USAMM have enabled the USDA to develop better control policies in the event of outbreaks and to provide operational advice on animal health emergency management before, during and after an incident. Both models were formally transferred into the USDA for use by their risk analysts in 2019. Prior to this they were used to support the Federal Emergency Management Agency (FEMA) Food, Agriculture and Veterinary response exercise, with FEMA coordinating federal government disaster planning and response in the US. Both models were first cited in a foreign animal disease outbreak standard operating procedure (SOP) released by the USDA in 2014. This series of SOPs highlight essential activities in response to an outbreak, and were featured in the 2020 USDA Red Book on FMD response planning. In the US, it is estimated that an FMD outbreak could cost up to $14bn if contained to California, or up to $228bn as a result of a nationwide agroterrorism attack. Through USDOS, the University of Warwick has improved the ability for the country to plan for and respond to economically disastrous livestock disease outbreaks.

USDOS webpage

USAMM Shiny app