Molecular epidemiology of the 2001 Foot-and-mouth Disease epizootic in Argentina

GUIDO KÖNIG; ANDRÉS PEREZ; SOLEDAD GARCÍA NUÑEZ; LEANDRO BISCALDI; ENRIQUE ESCOBAR; CYRIL GAY; LUIS RODRIGUEZ; ELISA CARRILLO

Érice, Sicilia, Italia

Workshop; Open Session of the EuFMD Standing Technical Committee; The Global Control of FMD Tools, Ideas and Ideals; 2008

EuFMD Standing Technical Committee

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Introduction: An FMDV (Foot and Mouth Disease Virus) epizootic that affected the Argentine herd in 2000-2001 brought about devastating consequences for the country. Earlier VP1 nucleotide sequencing of a subset of samples and phylogenetic analysis of the epidemic led to a preliminary assessment of FMDV genetic variation and identified factors associated with nucleotide changes that occurred during the epidemic. The goals of a new project are to full sequence a set of FMDV isolates and to assess the evolution of the A Argentina 2001 FMDV strain, which is considered to be responsible for most of the outbreaks in Argentina in 2001. The purpose of this report is to share some of the early activities conducted as part of this initiative.   Materials and Methods: Isolates from a selected region of the country will be divided up based on FMD vaccination status prior to infection. Five overlapping PCR products will be amplified and sequenced. Raw data files will be assembled into a single contig and edited using SeqMan (DNAStar) and BioEdit programs. Bayesian regression techniques will be used to assess association between virus evolution, vaccination status (yes, no; type of vaccine used; time from vaccination), and selected epidemiological factors (attack rate, herd density, distance to closest outbreak).   Results: The district of Mar Chiquita, in the Province of Buenos Aires, has been selected as the study region. This district was chosen because it was estimated to have the highest attack rate during the 2001 epidemic and it has accessible high-quality epidemiological data. Sixty-six outbreaks were reported in the district from May through July, 2001. Forty-one samples from those outbreaks tested positive for FMDV and have been preserved until now. PCR protocols and sixty primers have been designed for amplification and sequencing of the A Argentina 2001 strain.   Discussion: A system has been developed to assess the evolution of the A Argentina 2001 strain of the FMDV. This system combines whole genome sequencing and epidemiological and phylogenetic data analysis and will be utilized over a year. Results are expected to become public by the end of 2009.