Molecular epidemiology of Foot-and-Mouth Disease in South America

MALIRAT V.

Buenos Aires

Otro; PROYECT-FMD SOUTH-SOUTH AND TRIANGULARARGENTINE FUND FOR HORIZONTAL COOPERATION (FO.AR); 2014

SENASA

Automatized genetic sequencing of viral genomes, allied to the use of bioinformatics is a valuable tool for constructing genetic databases necessary for establishing the relationships between existing and emerging strains in a way that allows tracing the evolutionary paths of the infectious agent. In this seminar, the establishment of the genetic database of strains of FMD virus of epidemiological relevance for the continent was presented. Paired comparisons of these sequences have allowed the construction of phylogenetic trees, considering the relevant evolutionary assumptions Phylogenetic analyzes have shown that, in all cases, only endogenous virus strains have circulated in the continent for the three serotypes that have circulated in the region (O, A and C). Particular attention has been given to the phylogenetic relationships that were established for the virus responsible for outbreaks areas already declared FMD-free. These studies demonstrated that all type O and A variants isolated during emergencies in the Southern Cone of South America between 2000-2006 are grouped into a single lineage within each type and show genetic similarity values ​​of at least 90% between them. They have also ruled out a vaccine origin of the outbreak.It has also been possible to establish that the strains present in the Southern Cone are not genetically related to those isolated in the Andean region, reflecting two independent livestock circuits. Variants isolated in the Andean region are not restricted to unique genetic lineages. These phylogenetic studies also assessed C virus recurrence in Amazonas, Brazil, in 2004 and were critical to establish that the outbreak was caused by endogenous strains of the Continent and not related to the strain used in vaccine production.