Caracterização epidemiológica da brucelose bovina no Estado do Espírito Santo / Epidemiological characterization of bovine brucellosis in Espírito Santo State, Southeast region of Brazil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

As result of a partnership joining the Ministry of Agriculture, Livestock and Food Supply (MAPA), the Animal and Plant Health Institute of the State of Espírito Santo (IDAF-ES) and the Department of Preventive Veterinary Medicine and Animal Health (VPS) of the Faculty of Veterinary Medicine and Zootechny (FMVZ) of the University of São Paulo (USP), a seroepidemiological survey of bovine brucellosis was conducted in State of Espírito Santo, Southeast region of Brazil. The State was stratified in two sampling strata according to the predominant farm enterprise and the operational capacity of the IDAF-ES to conducting the field work. The sampling was delineated for the determination of the prevalence of positive herds and seropositive animals for bovine brucellosis per sampling stratum. It was made a random selection of 300 herds (primary units) per sampling stratum, and inside the primary units, if the herd was constituted by up to 99 cows over 24 months of age, 10 cows of the same age (secondary units) were randomly sampled, or all existing cows if they did not totalize 10 cows; if the herd was constituted by more than 99 cows over 24 months of age, 15 cows of the same age were randomly sampled. A total of 5370 blood samples of cows from 636 herds distributed in the sampling strata were collected. On the occasion of the blood collection, an epidemiological questionnaire was applied in each herd and the geographical coordinates were obtained with a GPS. For the serological diagnosis, the Rose Bengal Test was applied as a screening method and the 2-mercaptoetanol test as a confirmatory method. Herds with at least one test-positive animal were considered positive. The following analyses were carried out: (a) determination of the prevalence of positive herds and eropositive animals; (b) identification of risk factors for bovine brucellosis; and (c) spatial clustering analysis of positive herds. The prevalence of positive herds and seropositive animals in the State of Espírito Santo were 9.00% [6.97% - 11.55%] and 3.53% [1.93% - 6.37%], respectively. In sampling stratum 1, the prevalence of positive herds and seropositive animals were 6.80% [4.47% - 10.21%] and 3.43% [1.33% - 8.57%], respectively. In sampling stratum 2, the prevalence of positive herds was 10.86% [7.86% - 14.84%] and the prevalence of seropositive animals was 3.69% [2.13% - 6.33%]. The risk factors for bovine brucellosis in State were utilization of artificial insemination (OR = 7.05) and intensive/semi-intensive management systems (OR = 2.98). In sampling stratum 1, herds with more than 15 cows over 24 months of age (OR = 5.18), which rent pasturage (OR = 2.85) and that use artificial insemination (OR = 6.76) presented larger chance of being positive. The risk factors for bovine brucellosis in sampling stratum 2 were: existence of more than 42 bovine in the herd (OR = 5.31), utilization of artificial insemination (OR = 11.72), purchase of bovine reproducers in exhibitions (OR = 16.7) and intensive/semi-intensive management systems (OR = 2.99). The vaccination of heifers between three and eight months of age was a protective factor against the disease in the sampling strata and in State. There was no tendency for spatial clustering of positive herds.

ASSUNTO(S)

epidemiology (control) bovinos epidemiologia (controle) brucelose animal animal brucellosis bovine

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