Effectiveness of foot and mouth disease systematic mass vaccination campaigns in Argentina.

LEON, EMILIO; PEREZ AM; STEVENSON MA; ROBIOLO, BLANCA; MATTION, NORA; SEKI, CRISTINA; LA TORRE, JOSE; TORRES A; COSENTINO B; DUFFY, SERGIO

REVUE SCIENTIFIQUE ET TECHNIQUE DE L4OFFICE INTERNATIONAL DES EPIZOOTIES

OFFICE INT EPIZOOTIES

Año: 2014 vol. 33

0253-1933

The objective of this paper was to evaluate the effectiveness of systematic mass vaccination campaigns against foot and mouth disease (FMD) in Argentina. The analytical method used was based on the estimation of the proportion of protected animals and protected farms in vaccinated populations, as reflected by levels of antibodies measured by LP Elisa. The analysis was carried out in 42 Sanitary Units in Buenos Aires province using data collected from four cross-sectional studies, carried out in 2004, 2007, 2008, and 2011. Based on the correlation between serological titres and percentage of expected protection, cattle were assigned to one of two categories, referred to as non-adequately protected (percentage of expected protection < 75%) and adequately protected (percentage of expected protection ≥ 75%), respectively. The proportions of adequately protected cattle and significantly non-adequately protected farms were estimated and compared among sampled locations. Protection was variable among Sanitary Units; cattle 1-to-2 years of age showed higher levels of protection than 6-to-12 month old cattle, and the proportion of protected cattle was increased in the more recent studies. The results presented here will allow the National Animal Health Service to investigate in depth those districts in which protection was lower than the background protection in the region. Our proposal is that the methodology presented in this paper can be used to evaluate the effectiveness of vaccination campaigns in other countries or zones in which FMD systematic mass vaccination campaigns are conducted.