Análise retrospectiva dos fatores associados à distribuição da tuberculose bovina no estado do Rio de Janeiro

Abstract

The objectives of this study were to determine the prevalence, to identify the associated factors, to analyze the historical tendency and the distribution of the bovine tuberculosis (BT) in 209 herds in the State of Rio de Janeiro, corresponding to the period from 1959 to 1989. For such, a epidemiological retrospective study was performed, analyzing the data of the demand of the Laboratory of IPEACS and Embrapa - PNPSA. The data bank was elaborated based on BT results, production indicators, management and other information referring to the farms and to the herds. The association among the presence of BT and the variables as: herd s aptitude, animal density, productivity, suckling system, suckling period, veterinary assistance, size of the herds, milk production, criterion for purchase, handling of manure, newborn management, mortality of calves. The region of the State were analyzed by the c2 test with correction of Yates, when necessary. In the bivariate analysis, the variables herd s aptitude, animal density, productivity, suckling system, suckling period, veterinary assistance had values of p £ 0,20, the multivariate analysis was submitted to generalized linear model. The historical tendency was evaluated by linear regression. The prevalence rate of BT on farms was 49,8% and it was presented in seven of the eight regions of the State, with significant differences (p = 0,03). The model that better explained the occurrence of BT in the herds included the variables: density, herd s aptitude, productivity, suckling system, suckling period as well as the interactions density x productivity, density x suckling system and productivity x suckling period. The increasing historical tendency of BT, with accentuated annual variations, could be due to the different motivations to the search of diagnostic. The economical organization of the production system was determinat in the occurrence of BT it could be evidenced by the variables that better explained its presence and its distribution in the analyzed population.