REINTRODUCTION OF FOOT-AND-MOUTH DISEASE IN ARGENTINA: CHARACTERIZATION OF THE ISOLATES AND DEVELOPMENT OF TOOLS FOR THE CONTROL AND ERADICATION OF THE DISEASE

Authors: MATTION, NORA - CEVAN-CONICET, ARGENTINA; KONIG, GUIDO - INTA-CICVYA, ARGENTINA; CRISTINA, SEKI - CEVAN-CONICET, ARGENTINA; SMITSAART, ELIANA - BIOGENESIS SA ARGENTINA; MARADEI, EDUARDO - SENASA, ARGENTINA; ROBIOLO, BLANCA - CEVAN-CONICET, ARGENTINA; DUFFY, SERGIO - INTA-CICVYA, ARGENTINA; LEON, EMILIO - INTA-CICVYA, ARGENTINA; Piccone, Maria; SADIR, ANA - INTA-CICVAYA, ARGENTINA; BOTTINI, RODOLFO - SENASA, ARGENTINA; CONSENTINO, BERNARDO - SENASA, ARGENTINA; FALCZUK, ABRAHAM - SENASA, ARGENTINA; MARESCA, RICARDO - SENASA, ARGENTINA; PERIOLO, OSVALDO - SENASA, ARGENTINA; BELLINZONI, RODOLFO - BIOGENESIS SA, ARGENTINA; ESPINOZA, ANA - BIOGENESIS SA, ARGENTINA; LA TORRE, JOSE - CEVAN-CONICET, ARGENTINA; PALMA, EDUARDO - INTA-CICVYA, ARGENTINA

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2004
Publication Date: 10/22/2004
Citation: Mattion, N., Konig, G., Cristina, S., Smitsaart, E., Maradei, E., Robiolo, B., Duffy, S., Leon, E., Piccone, M.E., Sadir, A., Bottini, R., Consentino, B., Falczuk, A., Maresca, R., Periolo, O., Bellinzoni, R., Espinoza, A., La Torre, J., Palma, E. 2004. Reintroduction of foot-and-mouth disease in argentina: characterization of the isolates and development of tools for the control and eradication of the disease. Vaccine. (2004) 22: 4149-4162.

Interpretive Summary: In 2000, Argentina, which had only recently gained recognition as being free from FMD without vaccination, suffered the re-introduction of the disease. The outbreak was explosive and spread rapidly throughout the central and eastern provinces. This paper described the antigenic and molecular characterization of foot and mouth disease virus type A and O strains isolated during the epidemic and the control methods that eliminated the disease. At present, Argentina continues serological surveillance activities and a national vaccination program.

Technical Abstract: This paper describes the antigenic and molecular characterization of foot-and-mouth virus (FMDV) strains isolated during the 2000-2002 epidemic in Argentina, and the strategy implemented for disease control. Two different FMDV serotypes, O and A, were involved. Of the various field isolates studied, two distinct O1 lineages (strains Corrientes/00 and Misiones/00) and two serotype A lineages (A/Argentina/00 and /Argentina/01prototypes) were identified. The genome sequences of these strains were compared with sequences of previous regional isolates and sequences of vaccine strains. O1 strains were found to be related to regional strains while serotype A strains were found to be more distanced from them. The updating of the antigenic composition of the vaccines used in the emergency was a key issue, since the outbreaks stopped shortly after the implementation of the vaccination programs. TheO1 strains quickly disappeared from the field following strict control measures and the use of vaccines containing O1/Campos strain. However, in the case of the A serotype strains, the situation was different, since the use of a vaccine containing strain A24/Cruzeiro yielded acceptable levels of protection only after re-vaccination. Therefore, the new field strains A/Argentina/00 and A/Argentina/01 were incorporated into the vaccine, leading to an effective control of the disease. Viral circulation greatly diminished, as indicated by the significant reduction in the number of outbreaks and in the number of animals with antibodies against non-structural proteins. Satisfactory levels of protective antibodies were subsequently detected in the cattle population (above 75% protection). The absence of outbreaks after January 2002 indicated that the epidemic was controlled.