  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.
