Antibodies against the Mycobacterium tuberculosis complex and Brucella spp. in captive and free-living European bison (Bison bonasus) in Poland.

BACKGROUND: The European bison (Bison bonasus), a symbol of Polish nature, is a protected species that requires active health monitoring. However, conservation efforts are made difficult by the zoonotic diseases such as brucellosis and tuberculosis. OBJECTIVE: The aim of this study was to screen the Polish European bison population for exposure to the Mycobacterium tuberculosis complex (MTC) and Brucella spp. METHODS: A total of 323 free-living and captive European bison from 13 localities were tested serologically for antibodies against the M. bovis P22 multi-protein complex (in-house ELISA) and against Brucella spp. (commercial ELISA). RESULTS: Antibodies against the MTC (P22) were detected in 7% (22/323) of the tested European bison. Anti-MTC antibody positivity was not significantly different by sex, age, and captive/free range status. Anti-MTC antibodies were found in six of 13 populations sampled, always in populations with larger sample sizes including the four free-living ones. Antibodies against Brucella spp. were detected in 36% (116/323) of the tested bison. While Brucella spp. antibody prevalence was not different by sex, it was significantly different by age (lower in adults) and captive/free-living status. Brucella spp. seroprevalence decreased with sample size and seropositive bison were found in 12 of 13 sampling populations. CONCLUSIONS: Our findings identify potential emerging threats to the European bison population and confirm the first serological response to P22 in European bison. As Poland is currently officially free of brucellosis and bovine tuberculosis, our results require careful interpretation. Further studies are needed to establish the presence of cross-reactions with atypical mycobacteria in the case of MTC and other bacteria (e.g. Yersinia enterocolitica O:9) in the case of Brucella spp.

Complementary roles of wild boar and red deer to animal tuberculosis maintenance in multi-host communities.

The contribution of wildlife species to pathogen maintenance in multi-host communities has seldom been quantified. To assess the relative contribution of the main wildlife hosts of animal tuberculosis (TB) to its maintenance, we estimated the basic reproduction number (R0) of Mycobacterium tuberculosis complex in wild boar and red deer at 29 sites in the Iberian Peninsula. Host abundance and true TB prevalence were estimated for each species at each site by sampling from distributions incorporating the uncertainty in the proportion of the population harvested each year, sensitivity, and specificity of the diagnostic methods, while excretion of mycobacteria was estimated using site-occupancy models. The distributions of these parameters were then used to estimate, at each site, the R0,wild boar (range 0.1 - 55.9, average 8.7, standard deviation 11.8), and the R0,red deer (0.1 - 18.9, 2.2, 3.9). Animal TB is maintained in epidemiological scenarios ranging from any single species acting as a maintenance host (the wild boar in 18 sites and the red deer in 5), to facultative multi-host disease (6 sites). The prevalence of TB in the red deer is likely an important driver of the epidemiology in multi-host communities. The wild boar was the main maintenance host of TB in most of the study sites and could have an epidemiological role linking the wildlife multi-host community and livestock.