Wild Boar Carcasses Research Articles

Occurrence of Campylobacter in Faeces, Livers and Carcasses of Wild Boars Hunted in Tuscany (Italy) and Evaluation of MALDI-TOF MS for the Identification of Campylobacter Species

A total of 193 wild boars hunted in Tuscany, an Italian region with a high presence of wild ungulates, were examined to assess the occurrence of Campylobacter species in faeces, bile, liver and carcasses, with the aim of clarifying their contribution to human infection through the food chain. Campylobacter spp. were found in 44.56% of the animals, 42.62% of the faecal samples, 18.18% of the carcass samples, 4.81% of the liver tissues and 1.97% of the bile samples. The Campylobacter species genotypically identified were C. coli, C. lanienae, C. jejuni and C. hyointestinalis. The prevalent species transpired to be C. coli and C. lanienae, which were isolated from all the matrices; C. jejuni was present in faeces and liver, while C. hyointestinalis only in faeces. Identification was carried out by matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS) on 66 out of 100 isolates identified genotypically, and the technique yielded unsatisfactory results in the case of C. lanienae, which is responsible for sporadic human disease cases. The level of Campylobacter spp. contamination of meat and liver underlines the need to provide appropriate food safety information to hunters and consumers.

Composting of Wild Boar Carcasses in Lithuania Leads to Inactivation of African Swine Fever Virus in Wintertime

African swine fever (ASF) continues to spread and persist in the Eurasian wild boar population. The infection pressure resulting from infected carcasses in the environment can be a major contributor to disease persistence and spread. For this reason, it is crucial to find a safe and efficient method of carcass disposal under different circumstances. In the presented study, we investigated open-air composting of carcasses under winter conditions in northeastern Europe, i.e., Lithuania. We can demonstrate that the ASF virus (ASFV) is inactivated in both entire wild boar carcasses and pieces thereof in a time- and temperature-dependent manner. Composting piles reached up to 59.0 °C, and ASFV was shown to be inactivated. However, the ASFV genome was still present until the end of the 112-day sampling period. While further studies are needed to explore potential risk factors (and their mitigation), such as destruction of composting piles by scavengers or harsh weather conditions, composting seems to present a valid method to inactivate the ASFV in wild boar carcasses where rendering or other disposal methods are not feasible. In summary, composting provides a new tool in our toolbox of ASF control in wild boar and can be considered for carcass disposal.

ОХОТА НА КАБАНОВ И ЕЕ РОЛЬ В РАСПРОСТРАНЕНИИ АЧС

African Swine fever (ASF) remains a serious economic threat to pig production around the world, affecting only animals of the Suidae family. The lack of effective treatment and vaccines makes the control of the disease particularly difficult and expensive. Only implementation of strict quarantine measures and a properly chosen eradication strategy remain the only methods to control the disease. ASF also circulates in the wildlife for a long time, persisting in the wild boar carcasses and spreading with infected animals to the new territories. Under natural conditions, the virus spreads slowly with the wild boars, but the intervention of hunters and the extraction of potentially infected meat can significantly accelerate the process. Particular emphasis is placed on the role of dead wild boars killed by ASF and the migration of susceptible wild animals. They are considered as the main source and factor in the maintenance of the ASF virus in the wild. In connection with this problem, the question of the role of hunting in the spread of ASF remains relevant. In order to reveal this issue, the article discusses the behavior of wild susceptible animals, hunting features worldwide, and the impact of hunting on the social behavior of wild boars, the role of hunting and hunters both in the containment and in the spread of ASF. The main attention of the article is focused on the importance of the cohesive work of each stakeholder group in the elimination of ASF. The choice of a strategy to control ASF in the wild and the long term support of joint efforts to implement it is the key to restoring the well-being of the area and preventing the introduction of the virus into farms and households.

Pathology of African Swine Fever in Wild Boar Carcasses Naturally Infected with German Virus Variants.

In 2020, African swine fever (ASF) was first identified in German wild boar, reaching a case number of about 4400 to date. Upon experimental infection, pathology is well documented; however, data on field infections are scarce in domestic pigs and not available from wild boar, respectively. Although the ASF viral genome is considered exceptionally stable, a total of five lineages with 10 distinct virus variants of genotype II have emerged in Eastern Germany. To investigate the pathology in naturally infected wild boar and to evaluate virus variants II, III and IV for their virulence, wild boar carcasses were obtained from three different outbreak areas. The carcasses underwent virological and pathomorphological investigation. The animals revealed characteristic ASF lesions of the highest severity accompanied by bacterial infections in several cases. In particular, wild boar infected with variant IV from Spree-Neiße (SN) district showed lower viral genome loads and total viral antigen scores, but simultaneously tended to reveal more chronic lesions. Our findings indicate a protracted course of the disease at least after infection with variant IV, but need confirmation under standardized experimental conditions. There is a strong need to monitor differences in the virulence among variants to identify potential attenuation that might complicate diagnosis. In addition, veterinarians, hunters and farmers need to be made aware of less acute courses of ASF to consider this as an important differential to chronic classical swine fever.

Effects of Spray Application of Lactic Acid Solution and Aromatic Vinegar on the Microbial Loads of Wild Boar Carcasses Obtained under Optimal Harvest Conditions

Solutions of lactic acid 2% and aromatic vinegar were investigated for microbial load reduction on the surfaces of wild boar carcasses. The animals were hunted and processed according to production specifications to obtain the best hygiene for carcasses. The solutions were sprayed on carcass surfaces after skinning, and sites of 5 × 5 cm were sampled 2 h and 48 h post-treatment, with the carcasses under refrigeration conditions. The values of the microbial loads were lower for lactic-acid-treated sites, compared with control, after both 2 and 48 h. Nonetheless, the differences in the microbial loads were only higher than 1 Log/CFU 25 cm2 for the aerobic colony count. The aromatic vinegar resulted in lower values than in controls only after 48 h for the aerobic colony count, Staphylococcus count, and Lactobacillus count, with values always below 1 Log/CFU 25 cm2. The implementation of a lactic acid solution could represent a valuable strategy to reduce microbial growth on wild boar carcasses, thus becoming a relevant critical control point in this peculiar and niche meat production process.

Changes in Estimating the Wild Boar Carcasses Sampling Effort: Applying the EFSA ASF Exit Strategy by Means of the WBC-Counter Tool

African swine fever (ASF) is a devastating disease, resulting in the high mortality of domestic and wild pigs, spreading quickly around the world. Ensuring the prevention and early detection of the disease is even more crucial given the absence of licensed vaccines. As suggested by the European Commission, those countries which intend to provide evidence of freedom need to speed up passive surveillance of their wild boar populations. If this kind of surveillance is well-regulated in domestic pig farms, the country-specific activities to be put in place for wild populations need to be set based on wild boar density, hunting bags, the environment, and financial resources. Following the indications of the official EFSA opinion 2021, a practical interpretation of the strategy was implemented based on the failure probabilities of wrongly declaring the freedom of an area even if the disease is still present but undetected. This work aimed at providing a valid, applicative example of an exit strategy based on two different approaches: the first uses the wild boar density to estimate the number of carcasses need to complete the exit strategy, while the second estimates it from the number of wild boar hunted and tested. A practical free access tool, named WBC-Counter, was developed to automatically calculate the number of needed carcasses. The practical example was developed using the ASF data from Sardinia (Italian island). Sardinia is ASF endemic from 43 years, but the last ASFV detection dates back to 2019. The island is under consideration for ASF eradication declaration. The subsequent results provide a practical example for other countries in approaching the EFSA exit strategy in the best choices for its on-field application.

The impact of wildfire and mammal carcasses on beetle emergence from heathland soils

Abstract Wildfires alter the composition of insect communities due to fire‐induced mortality, and the post‐fire vegetation and soil conditions also affect the initial re‐colonisation and subsequent local emergence of adults from burnt soils. However, the impact of wildfires on re‐colonisation and emergence of carrion‐associated scavenging species from soils has previously been neglected. We established an experiment in an unmanaged heathland area that was affected by a severe wildfire in 2017 by adding wild boar carcasses to burnt and unburnt areas 204 days after the wildfire. Adult beetles were then collected with emergence tents at paired sites with and without carcasses and in burnt and unburnt areas from 27 April to 10 August 2018. The wildfire did not significantly affect the diversity or abundance of soil‐emerging beetles. Community composition in the burnt area differed significantly from the unburnt area with higher numbers of Staphylinidae and lower numbers of phytophagous beetle families (Curculionidae and Elateridae) emerging from soils, probably reflecting the structurally simpler vegetation and reduced litter one year after the wildfire. Scavenging beetles generally colonise mammal carcasses in burnt areas to the same extent as in unburnt areas, but the post‐fire conditions favoured some species with very specialised habitat preferences. A few rare species of conservation concern almost exclusively occurred in the burnt area and in most cases in combination with the presence of a carcass. This result highlights the joint importance of heathland wildfires and carcass resources for species conservation in beetle communities.

Hygiene evaluation and microbiological hazards of hunted wild boar carcasses

Within the European Union, different legal requirements must be applied in relation to the circumstances in which wild boar meat is supplied for human consumption. The present study performed from October to December 2019 in the Campania region aimed to monitor microbial contamination on 36 wild boar carcasses eviscerated in premises registered according to the EU Regulation 852/04 (19 animals) and hunters' private houses (17 animals). From each carcass, four areas (ham, back, jowl, and belly), were swabbed using cellulose sponges and analysed for the enumeration of mesophilic bacteria, Enterobacteriaceae and E. coli using the respective culture ISO methods. Real-time PCR was used for the detection of Salmonella spp., Yersinia enterocolitica, Campylobacter spp., and pathogenic E. coli. The presence of pathogenic bacteria was also evaluated in 36 meat samples to better understand the public health risks related to its consumption. Additionally, the presence of Y. enterocolitica was assessed on 36 tonsil samples since, in swine, this pathogen is frequently isolated in this organ. According to the limits settled by the EU Regulation 2073/2005 for pork, carcasses collected from registered premises resulted in more satisfactory mesophilic counts (<4.0 log10 CFU/cm2) than carcasses collected from non-registered premises (Registered premises = 7 carcasses, 36.8% vs Hunters' private houses = 3 carcasses, 17.7%). However, the satisfactory Enterobacteriaceae counts (<2.0 log10 CFU/cm2) were similar at registered and non-registered premises (Registered premises = 3 carcasses, 15.8% vs Hunters' private houses = 3 carcasses, 17.7%). Of the four investigated areas, the jowl and belly showed the highest level of contamination, however the observed differences were not significant (p > 0.05). The overall percentage of wild boars positive per at least one of the enteric pathogens tested was 79.0% (15 out of 19 animals) in registered premises and 82.4% (14 out of 17 animals) in private houses. Pathogenic E. coli was detected in 27 carcasses (75.0%), suggesting that wild boar could play a role as reservoir host and that the meat can cause public health concerns. In conclusion, in the present study an overall high bacterial level was observed on wild boar carcasses, and therefore the need for better slaughter hygiene was demonstrated. Based on the data, the meat resulting from private domestic slaughter may be of lower hygienic quality. The absence of a significant difference observed in the present study may be due to limited sample size and therefore further research should be performed.

Epidemiological analyses of African swine fever in the European Union: (September 2020 to August 2021).

This report provides a descriptive analysis of the African swine fever (ASF) Genotype II epidemic in the affected Member States in the EU and two neighbouring countries for the period from 1 September 2020 to 31 August 2021. ASF continued to spread in wild boar in the EU, it entered Germany in September 2020, while Belgium became free from ASF in October 2020. No ASF outbreaks in domestic pigs nor cases in wild boar have been reported in Greece since February 2020. In the Baltic States, overall, there has been a declining trend in proportions of polymerase chain reaction (PCR)‐positive samples from wild boar carcasses in the last few years. In the other countries, the proportions of PCR‐positive wild boar carcasses remained high, indicating continuing spread of the disease. A systematic literature review revealed that the risk factors most frequently significantly associated with ASF in domestic pigs were pig density, low levels of biosecurity and socio‐economic factors. For wild boar, most significant risk factors were related to habitat, socio‐economic factors and wild boar management. The effectiveness of different control options in the so‐named white zones, areas where wild boar densities have been drastically reduced to avoid further spread of ASF after a new introduction, was assessed with a stochastic model. Important findings were that establishing a white zone is much more challenging when the area of ASF incursion is adjacent to an area where limited control measures are in place. Very stringent wild boar population reduction measures in the white zone are key to success. The white zone needs to be far enough away from the affected core area so that the population can be reduced in time before the disease arrives and the timing of this will depend on the wild boar density and the required population reduction target in the white zone. Finally, establishing a proactive white zone along the demarcation line of an affected area requires higher culling efforts, but has a higher chance of success to stop the spread of the disease than establishing reactive white zones after the disease has already entered in the area.

First description of Eucoleus garfiai (Gallego and Mas-Coma, 1975) in wild boar (Sus scrofa) in Italy

Eucoleus garfiai (syn. Capillaria garfiai) is a nematode infecting lingual tissue of domestic and wild swine. Prevalence data for this parasite are scant and often related to accidental findings, occurring only in Japan and a few European countries. In this study, an epidemiological survey was performed in order to identify E. garfiai in wild boar from the Campania region, southern Italy. A total of 153 wild boar carcasses were inspected over the course of two hunting seasons (2019–2020). Histological examinations were performed on tongue samples fixed and stained with haematoxylin and eosin. The scraping of dorsal tongue tissue was carried out to collect adult worms for parasitological examination. Out of 153 wild boars, 40 (26.1%, 95% CI: 19.8–33.6%) tested positive for helminths and/or eggs in tongue tissues. Parasites were identified morphologically and identification was confirmed by molecular analysis of the 18S rRNA gene, showing a 99% nucleotide match with E. garfiai sequences available in literature. No statistically significant differences were found according to age, sex nor hunting province. Our findings agree with previous histopathological data confirming the low pathogenic impact of this nematode. The present study represents the first report of E. garfiai in wild boar from Italy.

Combining hunting and intensive carcass removal to eradicate African swine fever from wild boar populations

African Swine Fever (ASF) is a highly lethal viral disease, which affects different species of wild and domestic suids. After its human-caused introduction in Georgia in 2007, the ASF virus has found a new ecological reservoir in the large and continuous wild boar (Sus scrofa) populations of Eurasia, spreading both eastward and westward. ASF has also breached into the intensive pork meat production system. Although the disease has no zoonotic potential, its consequences on wild boar populations and the economic losses for the pig industry have been dramatic. As no vaccine or effective medical treatment is available to reliably protect wild boar or domestic pigs against ASF, eradication efforts are mainly based on intensive wild boar hunting and on removing a significant portion of the infected wild boar carcasses, which are the main environmental virus reservoir. Both strategies have produced poor results, so far, and ASF is becoming endemic. We compared wild boar hunting and carcass removal as alternative and combined strategies for the eradication of ASF in its endemic state, using a spatially explicit individual-based model, which incorporated the demography and spatial dynamics of a wild boar population, the spatial epidemiology of ASF in its endemic phase, and a management system acting for the eradication of the disease from the population. When no eradication effort was simulated, ASF exhibited a clear and strong tendency to persist and remain endemic in the wild boar population. Both hunting and carcass removal, when used alone, provided either a low power to remove the virus from the population, or required unrealistic field effort. The best performing scenario corresponded to the combined use of a 30% annual hunting rate and of an intensive carcass removal, during a 2-month period in late winter (February-March). Eradicating ASF from wild boar populations remains a hard task. Managers should promote a drastic increase in the effort dedicated to systematically identify and remove as many infected wild boar carcasses as possible from the affected areas, with at least 5–15 carcasses removed for each 100 hunted wild boar.

Meat Fatty Acid Composition of Wild Boars Hunted in Romania in Relationship to Gender and Age-Class.

Simple SummaryGame meat has a good nutritional profile; wild boar, in particular, has lower fat, high protein, and higher iron content than meat from other domesticated animals. The present study aimed to assess the carcass characteristics and chemical composition and also to investigate the effect of gender and age on the intramuscular fatty acid profile of wild boar meat harvested during the 2010–2017 winter hunting seasons in the Frasin District hunting area (Romania). The age-class factor influenced the carcass traits (p ≤ 0.05), but not the yield, although overall, adults were heavier and had a better yield compared to the younger specimens (77.36 vs. 74.79 kg). The differences induced by gender for carcass traits and dressing yield were present but not statistically significant (p > 0.05). For the chemical composition of wild boar meat, the percentages of protein, fat, ash, and water did not present significant differences (p > 0.05) within the factors applied (gender, age-class). Regarding the studied effects, results showed that the wild boars’ age-class significantly influenced (p ≤ 0.001) the amount of meat total fat, with the adults having the highest fat content than subadults (7.60% vs. 4.52%). As for the fatty acid profile, a high ratio of PUFA/SFA (P/S: polyunsaturated fatty acids/saturated fatty acids) and n-6/n-3 PUFA was present in the meat, showing good functional properties for human health.The present study evaluates the influence of gender and age-class on the carcass traits, meat chemical composition, and fatty acid profiles of randomly hunt-harvested wild boars from Romania’s Frasin District hunting area, which is an important part of the stock density management strategy. Only 76 wild boars were chosen to participate in the experimental design from a total of 94 wild boars hunted over seven winter seasons, based on two main criteria: right carcass part intact and animal health status (suitable for human consumption) as determined by the veterinary health notice issued by the Food Safety Authority, with all wild boars being evaluated before slaughtering. After sanitary inspection and within the first 24 h postmortem, meat samples were taken in duplicate from the right side of wild boar carcasses (m. Biceps femoris). The aim of this study was to compare the carcass characteristics, chemical composition, and fatty acid profile of wild boar Biceps femoris muscle obtained from the right side of carcasses, as well as the effects of gender, age-class, and their interaction on these traits, in a context where venison is frequently regarded as organic food by consumers due to the natural habitat in which wild animals live. The age of the animals had an effect on the postmortem undressed warm and cold carcass weights (p ≤ 0.05). Considering the proximal chemical composition, only the intramuscular fat (IMF) content was higher in adult meat samples compared to young animals. C18:1 n-9 was the most abundant fatty acid in wild boar meat, followed by C16:0, C18:2 n-6, and C18:0. For IMF content, gender, age class, and their interaction influenced mainly MUFA fatty acids, in particular C16:1 n-9, C20:1 n-9 and C22:1 n-9, and also PUFA fatty acids C18:3 n-6, C20:3 n-3, C20:4 n-6, C20:5 n-3, C22:4 n-6, and C22:5 n-6. The appropriate amounts of individual fatty acids in the muscles of the wild boars translate into a ratio of P/S acids that promotes health as a bio-alternative resource of meat.

Targeting the search of African swine fever-infected wild boar carcasses: A tool for early detection.

This study analyses the temporal and spatial distribution of found dead African swine fever (ASF)-positive wild boar carcasses from 2017 to January 2021 in affected European countries: Bulgaria, Estonia, Germany, Hungary, Latvia, Lithuania, Romania, Poland, Serbia and Slovakia. During this period, a total of 21,785 cases were confirmed in 19,071 unique locations. The temporal analysis of aggregated cases per month evidenced that most countries located in southern latitudes showed a higher number of cases between January and April, whereas in northern latitudes there was no clear temporal pattern. The space-time K-function evidenced a space-time clustering in the ASF-positive wild boar carcasses, which was most prominent within distances of 2 km and within 1week. A Bayesian hierarchical spatial model was calibrated to evaluate the association between the probability of finding ASF-positive wild boar carcasses and landscape factors (i.e. the presence of a path and paved road), land use and wild boar abundance. Results showed the highest likelihood of finding ASF-positive wild boar carcasses in areas of transition between woodland and shrub, green urban areas and mixed forests. The presence of a path and a higher abundance of wild boar also increased slightly the odds of finding an ASF-positive dead wild boar. In summary, this paper aims to provide recommendations to design a search strategy to find ASF-infected wild boar carcasses, which is a crucial activity in the management of the disease, not just for surveillance purposes (i.e. the early detection of an introduction and the regular monitoring to understand the epidemiology and dynamics), but also for control, namely the disposal of infected carcasses as a virus source.

Update on the development of an app (adaptation of iMammalia) for early reporting of wild boar carcasses by a warning system

Citizen science (CS) has been increasingly used in wildlife disease surveillance since it can facilitate the detection and recovery of carcasses of target species used as sentinels of infection. This report updates on the improvement of an app adapted from iMammalia (MammalNet project) for early reporting carcasses of wild boar with a warning system. This app has a great potential for improving wildlife disease surveillance (carcass reporting), such as for ASF. The app has been expanded in the context of ENETWILD project during the second part of 2021 to several countries in their respective languages: Italy, Greece, Serbia, Montenegro, Kosovo, Bosnia-Herzegovina, North Macedonia, Albania, and the latest to incorporate, Portugal. The ENETWILD project has generated alliance with FAO to promote the use of iMammalia in the Balkans to collect data in gap areas about the distribution of wild boar, to document the presence of carcasses of dead animals. The technical improvements that have been made to meet the needs of iMammalia to report the presence of wild boar carcasses correspond to the possibility of recording different parameters, such as sex, age, whether the dead animal has been hunted or not, or the degree of decomposition observed. The possibility of generating warnings to notify these records in real time to wildlife and/or sanitary services will be implemented in 2022. To date, iMammalia collected 14,393 mammal observations all over Europe, 797 of which corresponds to wild boar. A total of 1,270 observations correspond to animals found dead (5.53%), 30 out of which are wild boar, which, in some cases, were later diagnosed as ASF positive (e.g. in Serbia). We finally summarize the next step of ENETWILD in relation to iMammalia promotion, including an online workshop to provide an overview of disease surveillance systems in Europe, and to propose changes, including the promotion of CS.

Effect of time and temperature before chilling on the hygiene of carcasses in wild boar hunted in central Italy.

The interest in certified game meat chains highlights the need for the evaluation and the management of factors affecting carcass hygiene along the peculiar steps of the production. The effects of time and temperature before chilling were specifically evaluated on aerobic colony count and Enterobacteriaceae count in hunted wild boar carcasses. Thirty wild boars were considered in two process steps where the hunted animal are still not chilled: after evisceration and just before chilling. Environmental temperature, carcass temperature and the elapse time between the two-step considered were registered. Furthermore, surface microbial loads were analyzed on the inner part of the carcasses. The mean time between the two sampling steps was 6 hours with an average environmental temperature of 20.49°C. A carcass temperature 9.6°C drop was observed during this period. In this lap of time aerobic colony count and Enterobacteriaceae count increased of 0.68 Log CFU/cm2 and 1.01 Log CFU/cm2 respectively, with a moderate correlation with the time but not with the temperature delta. The results reveal that the temperature conditions in central Italy hunting areas were not able to quickly reduce the carcass temperature and therefore the time between carcass evisceration and chilling should not exceed 6 hours.

ЭПИЗООТИЯ АФРИКАНСКОЙ ЧУМЫ СВИНЕЙ НА СЕВЕРЕ ИТАЛИИ: СТРАТЕГИЯ БОРЬБЫ

The article provides information on the ASF epizootic, and control measures taken. The most likely reason for the introduction of the disease, considering the distance from the nearest foci of the disease, is the anthropogenic factor. The unregulated growth of the wild boar population against the background of poorly controlled movement of pig products from affected areas leads to an increased risk of the virus introduction into the population of the wild susceptible animals. The control strategy adopted by the competent authorities of Italy includes a zonal principle for the selection and implementation of a set of measures. The main control approaches are depopulation of pigs in the unprotected pig sector (PSF), restriction of wild boar migration with the help of fences, as well as active search and removal of carcasses of wild boars, followed by local depopulation of wild boar in the infected zone, reduction of its density in the threatened zone along with measures aimed at early detection of the disease, and enhanced biosecurity measures.

Mycobacterium Tuberculosis and Avium Complex Investigation among Malaysian Free-Ranging Wild Boar and Wild Macaques at Wildlife-Livestock-Human Interface.

Simple SummaryThis study targeted a small epidemiological area of a selected wildlife-livestock-human interface in Selangor to detect important veterinary and public health mycobacteria in free-ranging wild boar (Sus scrofa) and wild macaques (Macaca fascicularis) using a combination of diagnostic methods, tuberculosis-like lesion (TBLL) detection and nucleic acids detection by conventional and molecular analyses. Conventional PCR on wild boar tissues showed that 75% (9/12) of the lymph node samples were positive for Mycobacterium bovis (95% CI: 46.8–91.1). For macaques, 33.3% (10/30) were positive for Mycobacterium avium (95% CI: 19.2–51.2).Wild animals are considered reservoirs, contributing to the transmission of emerging zoonotic diseases such as tuberculosis (TB). A cross-sectional study was conducted by opportunistic sampling from fresh carcasses of free-ranging wild boar (n = 30), and free-ranging wild macaques (n = 42). Stained smears from these tissues were tested for acid-fast bacilli (AFB) with Ziehl–Neelsen staining. Mycobacterial culture was conducted using Lowenstein–Jensen media and Middlebrook 7H11 agar media. Polymerase chain reaction (PCR) was performed through the detection of the 16S rRNA gene, with multiple sets of primers for the detection of Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium complex (MAC). In wild boars, 30% (9/30; 95% Confidence Interval: 16.7–47.9%) of examined samples showed gross tuberculosis-like lesions (TBLLs). Multiple nodular lesions that were necrotic/miliary with cavitation were found in the submandibular lymph nodes, tonsils, lungs, kidney and liver, while single nodular lesions were found in the mediastinal lymph nodes, spleen and mesenteric lymph nodes. Conventional PCR on the submandibular lymphoid tissues of wild boar (nine samples with TBLLs and three non-TBLL samples) showed that 75% (9/12) were positive for Mycobacterium bovis (95% CI: 46.8–91.1), and 91% (CI: 64.6–98.5) were positive for Mycobacterium avium. For macaques, 33.3% (10/30) were positive for M. avium (95% CI: 19.2–51.2) but negative for MTBC.

Efficacy of attractants for detecting eastern spotted skunks: an experimental approach

Estimates of abundance and occupancy are essential for wildlife management, particularly for species of conservation concern such as eastern spotted skunks Spilogale putorius. Most studies of eastern spotted skunks rely on limited evidence for best monitoring practices, and while many studies use attractants to increase detections, previous studies have not tested attractants against a control of no attractant to determine their effectiveness. We tested two common attractants (sardines and fatty acid tablets) and one uncommon attractant (wild boar carcasses) against a control of no attractant to determine if any attractant increased detections of eastern spotted skunks or changed their temporal activity. Based on our model, sardines and wild boar carcasses improved detections by three and eight times that of the control, respectively. Further, for every 100 trap nights, we detected eastern spotted skunks 10.67 times with wild boar carcasses, 1.02 times with sardines, 0.53 times with fatty acid tablets and 0.44 times with no attractant. Wild boar carcasses also substantially decreased latency to detection, with skunks detected two times faster than at other attractants and almost three times faster than at the control. Eastern spotted skunks were most active in the early morning before sunrise, and their temporal activity did not vary significantly by attractant. This study is the first to use an experimental framework to test attractants for eastern spotted skunks, and our results showed that choice of attractant matters. Large animal carcasses, although rarely used, may be most effective for detecting eastern spotted skunks, while fatty acid tablets were no different than the control, and we recommend against their use in future studies. Monitoring plans should incorporate our results as increasing detections is essential to understanding the abundance, range and demographics of eastern spotted skunks.

Evaluation of the Presence of ASFV in Wolf Feces Collected from Areas in Poland with ASFV Persistence.

African swine fever (ASF), caused by a DNA virus (ASFV) belonging to genus Asfivirus of the Asfarviridae family, is one of the most threatening diseases of suids. During last few years, it has spread among populations of wild boars and pigs in countries of Eastern and Central Europe, causing huge economical losses. While local ASF occurrence is positively correlated with wild boar density, ecology of this species (social structure, movement behavior) constrains long-range disease transmission. Thus, it has been speculated that carnivores known for high daily movement and long-range dispersal ability, such as the wolf (Canis lupus), may be indirect ASFV vectors. To test this, we analyzed 62 wolf fecal samples for the presence of ASFV DNA, collected mostly in parts of Poland declared as ASF zones. This dataset included 20 samples confirmed to contain wild boar remains, 13 of which were collected near places where GPS-collared wolves fed on dead wild boars. All analyzed fecal samples were ASFV-negative. On the other hand, eight out of nine wild boar carcasses that were fed on by telemetrically studied wolves were positive. Thus, our results suggest that when wolves consume meat of ASFV-positive wild boars, the virus does not survive the passage through intestinal tract. Additionally, wolves may limit ASFV transmission by removing infectious carrion. We speculate that in areas where telemetric studies on large carnivores are performed, data from GPS collars could be used to enhance efficiency of carcass search, which is one of the main preventive measures to constrain ASF spread.

Enterobacteriaceae and Salmonella contamination of wild boar (Sus scrofa) carcasses: comparison between different sampling strategies

During 2020, a total of 64 wild boar carcasses were tested for Enterobacteriaceae count (EBC), Salmonella and Yersinia enterocolitica in the abdominal region (i) within 5 h after hunting in the game collection point and (ii) before dressing and processing in the game-handling establishment (GHE) (49 carcasses—average time interval between (i) and (ii): 4.3 days). Because of COVID-19 restrictions, 15 carcasses were transported to a near slaughterhouse (average time interval between (i) and (ii): 2.3 days). Mesenteric lymph nodes (MLNs) were collected and tested for Salmonella and Y. enterocolitica. Results are shown in relation to sampling A (49 carcasses—GHE) and sampling B (15 carcasses—slaughterhouse). Sampling A: EBC median values were (i) 2.51 log10 CFU/cm2 and (ii) 2.79 log10 CFU/cm2. EBC increase between (i) and (ii) was statistically significant (p = 0.001). Salmonella prevalence on carcasses varied from (i) 2.0 to (ii) 6.1%. Sampling B: EBC median values were (i) 3.1 log10 CFU/cm2 and (ii) 3.32 log10 CFU/cm2. EBC increase between (i) and (ii) was not statistically significant (p = 0.191). Salmonella prevalence on carcasses varied from (i) 6.7 to (ii) 0.0%. The prevalence (sampling A + B) of lymphatic Salmonella carriers was 7.8% (5/64). From carcasses and/or MNLs, the serovars Enteritidis, Typhimurium, Agama, Zaiman and Diarizonae O:50 (z) were detected. Y. enterocolitica was never isolated. Long chilling periods prior to wild game processing should be avoided, and carcasses should be tested at GHE rather than after shooting to proper reflect the microbial load of wild boar meat entering the food chain.