Spatio-temporal Dynamics of Foot-and-Mouth Disease Virus in South America

TL;DR

This study analyzes the spatiotemporal spread and evolutionary history of foot-and-mouth disease virus serotypes A and O in South America, revealing distinct patterns and key factors influencing their dispersal.

Contribution

It combines environmental, epidemiological, and genetic data to elucidate the different dynamics of FMDV serotypes A and O in South America, providing insights for control strategies.

Findings

Serotype A emerged around 1930, serotype O around 1990.

Serotype A has a higher rate of evolution than serotype O.

Two main viral flow networks identified: Venezuela-Colombia-Ecuador and Brazil-Uruguay-Argentina.

Abstract

Although foot-and-mouth disease virus (FMDV) incidence has decreased in South America over the last years, the pathogen still circulates in the region and the risk of re-emergence in previously FMDV-free areas is a veterinary public health concern. In this paper we merge environmental, epidemiological and genetic data to reconstruct spatiotemporal patterns and determinants of FMDV serotypes A and O dispersal in South America. Our dating analysis suggests that serotype A emerged in South America around 1930, while serotype O emerged around 1990. The rate of evolution for serotype A was significantly higher compared to serotype O. Phylogeographic inference identified two well-connected sub networks of viral flow, one including Venezuela, Colombia and Ecuador; another including Brazil, Uruguay and Argentina. The spread of serotype A was best described by geographic distances, while trade of live cattle was the predictor that best explained serotype O spread. Our findings show that the two serotypes have different underlying evolutionary and spatial dynamics and may pose different threats to control programmes. Key-words: Phylogeography, foot-and-mouth disease virus, South America, animal trade.