Development of foot-and-mouth disease transmission simulator: Japan simulation model of animal infectious diseases-FMD, JSMIN-FMD

Foot-and-mouth disease (FMD) is a highly contagious and economically important disease of cloven-hoofed animals. Epidemiological modeling has been recognized as a useful tool for studying the spread of the disease under different environments and control measures. In this study, we developed an FMD transmission simulator (Japan simulation model of animal infectious diseases simulator FMD, JSMIN-FMD), which is a user-friendly simulation system, allowing decision makers to use for evaluation of the effectiveness and efficacy of control strategies upon the simulated outbreaks. This simulator employs a stochastic spatially explicit individual-based model to generate between-farm transmission in a selected area. To run the simulator, farm data including farm sizes, animal species, and geographical locations, is required. Parameters concerning the transmission process and control measures are also necessary. The transmission process is composed of two parts, namely transmission before the movement restrictions and that after movement restrictions. Long-distance transmissions were generated reflecting the movement of animals, humans, and vehicles in the area. The default setting parameters of these movement patterns such as the frequency and distance of movements were based on the survey results conducted in the livestock farming areas. Estimation of the movement distance is also available based on the farm density in the simulated area by a developed algorithm. Local spread was produced by transmission kernels estimated from the previous FMD epidemics in Japan in 2010 and those in Europe in 2001. Control measure scenarios include prompt culling, preemptive culling, and vaccination. For simulating these scenarios, culling or vaccinating capacities and prioritization of farms to be culled or vaccinated can be defined in advance. Simulation outputs include graphs and tables on epidemic size, economic impact, and required human resources as well as maps showing the way of the disease spread. The simulator could provide practical help for decision makers to understand how the disease spread and how best to control the disease in planning control strategies against FMD.