Bovine tuberculosis (bTB), widely considered a disease of livestock, can also affect large game species despite their poorly understood role in the epidemiology of the endemic state of the disease. The Idanha-a-Nova County, situated in the eastern region of central Portugal, is one of the most important regions for large game hunting activity. In order to investigate the role of large game and the presence of bTB in Idanha-a-Nova, 132 wild boar (Sus scrofa) and 339 red deer (Cervus elaphus) were inspected for bTB-compatible lesions (bTBCL) during the 2008-2009 hunting season. Tissue samples with bTBCL were collected and processed for bacteriological confirmation and spoligotyping of Mycobacterium bovis isolates. In wild boar, bTB lesions were single, mostly calcified (21/29, 72.4%) and situated in the mandibular lymph nodes. Lesions were more severe and largely non-calcified (36/ 40, 90%) in red deer. Wild boar presented a consistently higher bTB infection rate than the red deer; however, the difference was only significant in the southern B area. This area was significantly affected by bTB for both animal species (up to 72.7% in wild boar and 34.8% in red deer) and requires the urgent implementation of intervention measures to contain the disease. Wild boar may assume an important role in the emergence of new disease foci in distant areas that infected red deer cannot reach. Spoligotyping of M. bovis isolates grouped the strains into three clusters, revealing patterns common to wild boar, red deer, and also to local cattle, indicating possible transmission among different animal species.

Since April 2011, Portugal has implemented specific national legislation (Notice N.º1/2011), defining “Epidemiologic Risk Areas for Bovine Tuberculosis in Large Game” and mitigation measures in these areas, including Idanha-a-Nova county. A GIS project was created to record information that would allow us to analyse the spatial–temporal distribution, both for hunting bags and tuberculosis occurrence, in hunted wild boar and red deer in Idanha-a-Nova. Hunting bag and tuberculosis-like lesion data were recorded during post-mortem inspection across 11 hunting seasons, totalling 9844 animals. The difference in tuberculosis occurrence for these species was statistically significant in nearly all 11 seasons, with wild boars presenting approximately twice the occurrence of red deer. No significant difference was noted before and after the Notice N.º1/2011 implementation. These results, following GIS-based spatial analysis, enable us to state that both large game species displayed an irregular tuberculosis pattern for the 2006–2016 period, and we identified some specific areas of high risk for both species. Southern areas of the county may be considered the priority for intervention. This research demonstrates the potential of GIS tools to evaluate, in the field, the results and efficacy of legislation such as Notice N.º1/2011, and to ensure the correct implementation of cost-effective mitigation strategies for tuberculosis in large game species.

In the Iberian Peninsula, the prevalence of tuberculosis differs for each region and for different wild disease hosts and the region affected by a Mediterranean climate will be the most affected. The Mediterranean Iberic regions have a favourable ecosystem for the development of Mycobacterium tuberculosis complex agents, where habitat, population dynamics, and climate (especially drought) are important factors affecting the high prevalence of tuberculosis in the wild boar population. Our objective was to study the association between the Palmer Drought Severity Index (PDSI) and the occurrence of tuberculosis-like lesions (TBL) in wild boar during nine hunting seasons (2008/09 to 2016/17) in Idanha-a-Nova County. To this end, statistical analysis revealed a significant association (p < 0.05) between the occurrence of TBL in wild boar in Idanha-a-Nova County and the analysed risk factor—previous season with periods of drought—which indicated that, when one season experiences some periods of drought, the probability of TBL occurrence in wild boars was 1.2 (OR = 1.2) times higher in the next hunting season than when there were no periods of drought. Therefore, our study contributes to the discovery of a positive effect of periods of drought on the transmission of tuberculosis in Iberian wildlife.

Concerning large game in Portugal, there is an epidemiological risk area for tuberculosis where the pressure of tuberculosis infection in wild animals is high. Hunters and other people involved in managing carcasses (evisceration and/or initial examination) of these animals should be considered as a high-risk population for sporadic occupational zoonotic infection. This study aims to evaluate and indicate these stakeholders’ main risk practices. The survey was carried out in two phases: a first phase with an anonymous survey to hunters about self-consumption of game meat and carcass handling practices, and a second phase of evaluation in loco of the practices carried out at collection points after driven hunts. As the main results suggested in this study, bad practices and improper handling of hunted carcasses potentially infected with tuberculosis were marked in both phases of the survey, mostly related to the lack of recognition of tuberculosis-like lesions and the non-use of individual protection material, such as gloves and masks. It is evident that stakeholders are interested in learning more about how to perform initial examination properly and what kind of biosecurity measures can be adopted to minimize zoonotic infection risk.

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