Abstract
Brucellosis remains one of the key zoonotic infections of veterinary, epidemiological and socio-economic importance for Kazakhstan. With the rapid recovery of the saiga antelope (Saiga tatarica) population to more than 4 million individuals, the need is increasing for scientifically grounded monitoring of infections common to wild and farm animals. The purpose of this study was to summarize previously partially published data from experimental and field studies of brucellosis in saigas conducted at KazRVI in 2000–2004, to compare them with the results of diagnostic monitoring in 2023, and to relate them to current epizootiological challenges. The retrospective component of the study included examination of blood sera from 704 free-ranging saigas, 145 newborn saiga calves, 25 clinically healthy calves kept in a stationary facility, and experimental infection of 9 saigas with virulent strains B. melitensis 565 and B. abortus 54. The current 2023 monitoring covered 20 saigas and 159 biological-material samples. It was established that the saiga is susceptible to B. melitensis and B. abortus; the serological response developed in a regular pattern, with earlier appearance of agglutinins and later formation of complement-fixing antibodies. Brucella cultures isolated after passage through the saiga organism retained their main morphological, cultural, staining, agglutinable and virulent properties. In 2023, no positive serological or bacteriological results were detected; however, the limited sample size does not exclude the need for regular risk-based surveillance. The obtained data substantiate the inclusion of the saiga in an interdepartmental brucellosis monitoring system in the One Health format.