Simulating the Spread of Foot-and-Mouth Disease in Densely Populated Areas as Part of Contingency Plans to Establish the Best Control Options.

Foot-and-mouth disease (FMD) is a highly contagious disease of livestock caused by the FMD virus (FMDV). It is not dangerous to humans but can cause severe disruption to the farming sector and hampers trade in animals and animal products. Given the characteristic of transmissibility of the virus, the legislation in force in the European Union requires that some control activities be initiated in peacetime: the so-called "emergency preparedness". As part of a research project on FMD, a dynamic transmission model was developed to test the effectiveness of the main control strategies in different livestock settings in Italy. This manuscript focuses on the control of the disease in densely populated livestock areas (DPLAs). Reduction in farm density was simulated to identify a threshold density compatible with disease control in the study area and to understand whether this was acceptable in terms of the sustainability of the livestock production system. Considering that in some municipalities the density of animals greatly exceeded the identified threshold, we adopted an original risk-based approach aimed at identifying farms which were most likely to play a central role in FMDV transmission. This approach has proven to be the most effective in controlling the spread of FMDV and can be proposed for practical applications where limited information on contacts between farms is available.