Assessing epidemiological parameters and dissemination characteristics of the 2000 and 2001 foot-and-mouth disease outbreaks in Rio Grande do Sul, Brazil

Since 1998 the state of Rio Grande do Sul, Brazil, has been free of foot-and-mouth disease (FMD) with yearly mandatory vaccination, until the 2000 and 2001 reintroductions. This study gathers data from both outbreaks including official veterinary state service archives and field investigation reports to quantify epidemiological parameters such as epidemic duration, number of secondary infected farms and animals, and estimate the epidemic rate of growth. We apply a Bayesian latent variable approach to estimate the time-varying reproduction number and calculate new confirmed cases by infection date. Additionally, we utilized between-farm animal movements to reconstruct possible FMD transmission and characteristics of spread over the current at-risk population, by incorporating bovine movement data from 2018 to 2020 as standard to benchmark infected network parameters. The results were consistent with the reports generated by the official investigation of the outbreaks and the models and results presented in this study may be useful for assessing the transmission dynamics and support control measures in the future.