Transmission network for foot-and-mouth disease epidemic in Mar Chiquita - Argentina: A spatial modeling analysis

Abstract

Foot-and-mouth disease (FMD) is a highly contagious viral disease with major implications for livestock production, food security, and economic stability. In this study, we investigate the transmission dynamics of the 2001 FMD outbreak in Mar Chiquita, Argentina, using a spatially explicit modeling framework. Transmission kernels based on inter-farm Euclidean distances are developed to estimate the probability of between-farm transmission and to reconstruct the likely transmission network. Several kernel formulations are evaluated, and parameters are estimated using maximum likelihood estimation techniques. We further assess the influence of isolation interventions by incorporating time-dependent kernel modifications that reflect reduced transmission risk following farm visits. Local transmission potential is quantified through farmspecific reproduction numbers, and transmission pathways are inferred using Markov Chain Monte Carlo (MCMC) simulations. Our results show that controlling geographic proximity alone does not reliably mitigate transmission risk and that delayed intervention can sustain epidemic spread. The reconstructed transmission network reveals spatial clusters of infections and temporal patterns consistent with field observations. These findings highlight the importance of timely isolation, active surveillance, and spatial risk assessment for effective outbreak control. HighlightsO_LISpatial transmission modeling captures FMD spread across 65 farms in Mar Chiquita, Argentina. C_LIO_LIDistance-based kernel functions estimated from epidemic data quantify between-farm infection risk. C_LIO_LIMCMC simulations reconstruct high-resolution farm-to-farm transmission networks. C_LIO_LIIntervention strategies (e.g., isolation) effectively reduce transmission probability and local R0. C_LI