Molecular epidemiology of foot-and-mouth disease in South America

MALIRAT, V.; COSTA, E.V; BERGMANN I.E.

Viña del Mar, Chile

Simposio; 10 Simposio Internacional de Epidemiología y Economía Veterinaria, ISVEE 10; 2003

International Society for Veterinary Epidemiology and Economics

Based on the progress observed in South America in the epidemiological situation of foot-and-mouth disease, as a consequence of the Hemispheric Program for the Eradication, implemented in 1988, the need for rapid and precise methods capable of identification and characterization of the viral agent involved, and even the putative identification of the sources of disease dissemination in the field has become evident. During the past decade, molecular biology methods have evolved allowing a more precise evaluation of the degree of relationship between viral variants that reaches levels of comparison of elementary genetic structures. The nucleotide sequence of genomic regions with important informative content is being increasingly used for phylogenetic evolutionary studies that contribute to the epidemiological knowledge of this disease. These studies have even allowed revealing viral evolutionary patterns of the different serotypes as well as the origin of viruses responsible for recent outbreaks. In this paper we summarized the construction and systematization of the genetic database of foot-and-mouth disease prototype strains for South America, and the phylogenetic analysis derived, including other strains of epidemiological importance for the continent. More than 80 variants were analyzed, corresponding to the three serotypes that were registered in South America, (O, A and C) from 1947 to 2003. Based on these analyses it has been possible to determine different evolutionary lineages, all belonging to topotypes endogenous of the region. This database has also been used as the basis to analyze the strains responsible for the sanitary emergencies that took account of the Southern Cone of South America between the years of 2000-2003, as well as strains circulating actually in other regions of the continent. The analysis of the circulating strains, for the two currently present types, O and A, have shown different lineages circulating in the two different livestock circuits (Southern Cone and Andean Area), where there is no evident interaction