Epizootiological characteristics of Bovine tuberculosis in South Bačka district [Serbia] | Epizootiološke karakteristike tuberkuloze goveda u Južnobačkom okrugu [Srbija]

Bovine tuberculosis caused by Mycobacterium bovis is a chronicle, infective disease associated with formation of specific inflammatory granulomas. Infection usually remains subclinical for a long period, but even when the clinical are present, they are not pathognomic. Bovine tuberculosis can spread to humans through inhalation of infectious droplets and by ingestion of raw milk, and on the rare occasion through consumption of meat products. Since the disease remains a great economic concern for cattle production operations and due to its zoonotic nature, most of the countries initiated a program for the control and eradication of tuberculosis in domestic animals. In South Bačka region (SBD) three tuberculous foci were detected on the territory of Žabalj, Novi Sad and Titel municipality. The first 11 reactors were detected in the year 2004 during the diagnostic examination that was conducted according to the Program of Measures for infectious disease survaillance. The number of animals with a positive reaction to the intradermal tuberculin test was 113, 54 and 142, in 2006, 2007 and 2008, respectively. The diagnosis was further confirmed by gama-interferon test, gross pathology and histopathological examination, and definitively confirmed by M. bovis isolation from the lymph node and lung lesions. The number of estimated tuberculin reactors was 320, located in six settlements and 37 husbandries. The percent of infected animals in some herds ranged from 11.10 to 59.18%. The objective of this investigation was to determine the routes of infection and to identify risk factors that contributed to the tuberculosis breakdown in the tuberculous hot spots. An epizootiological evaluation revealed that the high herd prevalence and high animal incidence of bovine TBC in South Bačka region was associated with the following factors: lack of TBC diagnosis in pastured animals in swampy areas for a long period, grazing areas are often flooded resulting in bad quality fodder and cattle malnutrition, presence of other domestic animals on the pastures, co-mingling of animals from different herds is frequent, common water through, presence of different wild animal species on pasture (as a potential reservoir of the disease), uncontrolled movement and illegal trade of infected animals, natural breeding as well as overpopulation in the sheds during winter housing.