Latent tuberculosis infection in cattle
The genome of mycobacterium tuberculosis (MBT) was detected in the milk of cows from conditionally tuberculosisfree herds that did not react and gave an uncertain reaction to tuberculin in 53.3 % 66.7 % of cases, specific antibodies in 40.7 % and 57.1 %, MBT antigens in 25 % and 22.2 % of samples, and non-acidfast forms of MBT were detected from 92.3 % and 66.7 % of the studied milk samples heated at 98 oC. Taking into account the absence of signs of active disease, this indicated a latent tuberculosis infection in some cows that did not respond to tuberculin and that the tuberculin test did not reflect the real situation in the herd. To eliminate tuberculosis infection, it is necessary to use alternative methods for determining direct and indirect markers of tuberculosis infection and the development of a new system of antituberculosis measures that take into account the high probability of transmission of modified forms of MBT through the placenta and with milk.