Rapid implementation of movement controls at the county level play an important role in stopping or slowing the spread of a fast-spreading animal disease like foot-and-mouth disease (FMD), according to an article published in the March 2014 issue of PLOS ONE.
The article evaluates movement control options on a continental scale of an FMD-like epidemic in the United States and was prepared by the USDA Animal and Plant Health Inspection Service, Colorado State University, the University of Warwick (United Kingdom) and the Linköping University (Sweden). It is the first quantitative national-scale model of cattle movement.
PLOS ONEState-to-state cattle flows based on ICVI information. FMD is a highly contagious disease that affects cloven-hoofed animals, including cattle, and causes blisters along the hoofs and mouth. While FMD has not been present in the United States since 1929, efforts are continuously ongoing to prevent introduction of the rapidly-spreading disease because it is one of the most economically damaging animal diseases in the world. According to USDA, if an outbreak of FMD were to occur in the United States, the economic impact could reach into the billions of dollars in the first year unless it is detected and eradicated immediately.
The agency says that evaluating potential response strategies is challenging due to absence for the disease in the United States and “limited information on cattle movement.”
The authors of the article reviewed Interstate Certificates of Veterinary Inspection (ICVI) documents to develop a network of cattle movement in the country and combined that with information about the spread of an FMD-like virus to estimate that the largest outbreak in the United States could reach 40 percent of U.S. counties and infect more than 120,000 premises if uncontrolled. Upon detection of an infection, cattle shipments from the infected area are likely to be banned to prevent further spread. According to the article, with rapid detection, county-level movement bans, instead of state or national level bans, substantially reduce the epidemic extent, size and infection risk and state bans have little additional benefit. However, delayed detection favors the use of a state-level ban to reduce spread of the disease.
Since some livestock diseases, including FMD, affect other species, the article also noted that future data collection efforts in the United States should focus on the potential interaction between livestock industries and the interaction between long-distance movement and inter-specific local spread.
In addition to the need for more information related to cattle movement and implementing rapid and effective movement bans, USDA says targeted surveillance, vaccination strategies and other measures are currently being evaluated in to improve animal disease prevention and response plans. USDA works closely with state and local governments, other federal agencies, industry stakeholders and other emergency preparedness officials in development of preparedness plans.
The article is available on the PLOS ONE website.