Luiz Max Carvalho1, Nuno Rodrigues Faria2, Guido Konig3, Marc A. Suchard4,5 Philippe Lemey6, Waldemir de Castro Silveira7, Guy Baele6
1 - School of Applied Mathematics, Getulio Vargas Foundation, Brazil.
2 - Department of Zoology, University of Oxford, Oxford, United Kingdom.
3 - Institute of Agrobiotechnology and Molecular Biology, INTA-CONICET, Buenos Aires, Argentina.
4 - Departments of Biomathematics and Human Genetics, David Geffen School of Medicine at UCLA, University of California, Los Angeles, United States of America.
5 - Department of Biostatistics, UCLA Fielding School of Public Health, University of California, Los Angeles, United States of America.
6 - Department of Microbiology and Immunology, Rega Institute -- KU Leuven, Leuven, Belgium. 7 - Research and Development Division, Trimatrix Applied Biotechnology Ltd, Rio de Janerio, Brazil.
Abstract (arXiv)
Despite the decrease in incidence of foot-and-mouth disease virus (FMDV) 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 employ modern phylodynamic methods to merge epidemiological and genetic data and reconstruct spatiotemporal patterns and determinants of the dispersal of the two most prevalent FMDV serotypes A and O in South America, while accounting for temporal and spatial sampling bias. We find that serotypes A and O differ in their temporal pattern of population dynamics, with serotype A displaying more temporal oscillation. Spatially, we traced the origins of the 2011 Paraguay outbreak to Argentina and Brazil. Overall, we find that FMDV spread seems to happen mostly through transnational borders, with few long range transmissions, such as a well-supported link between Argentina and Peru for serotype A. We also found the trade of different livestock (pigs for serotype A and cattle for serotype O) to be associated with viral spread, providing a possible explanation for this pattern of spread. Our results showcase the usefulness of phylodynamic methods to the study and surveillance of FMDV in South America.
Key-words: Phylogeography, foot-and-mouth disease virus, South America, animal trade.