Level of endoparasite infection in free-living wild boars in relation to carcass weight and sex

Research into the determination of intestinal parasitic levels in free-living animals can provide knowledge enabling action to be taken to improve their health status. The aim of the study was to determine the relationship between the carcass weight of wild boars and the degree of endoparasite infection. The research was performed on 165 culled wild boars, from which a representative group (n = 50) was separated and divided according to sex (males n = 24, females n = 26) and age (2-3 years). Separate weight groups were defined for males (< 70 kg, n = 6; 70-80 kg, n = 9; > 80 kg, n = 9) and females (< 45 kg, n = 10; 45-60 kg, n = 10; > 60 kg, n = 6). Oesophagostomum spp., Ascaris suum, Trichuris suis, Eimeria spp. and Strongyloides ransomi were observed and defined in the study population. A statistically significant effect of the overall infection on carcass weight was obtained (F = 9.96; P ≤ 0.01). In the case of overall infection, a more than 7 kg lower carcass weight was observed in infected males. A carcass weight over 15 kg lower was noted for overall infection of females (F = 38.47; P ≤ 0.01), for which average EPG was 2946.67 ± 6485.31 with a median of 400 (50-25 300). Correlations were proven between sex and the average number of Eimeria spp. oocysts, and carcass weight for males (r = –0.84, P ≤ 0.05). In the case of females, correlations were noted between carcass weight and infection by nematodes (r = –0.63, P ≤ 0.05). Studies have shown that there is a need to monitor the environment in order to improve the condition of free-living animals.

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.

Detection and characterisation of porcine circoviruses in wild boars in northeastern Serbia

The objective was to expand and update the knowledge on the presence and genotype diversity of porcine circoviruses 2 and 3 (PCV2 and PCV3) in the wild boar populations from the hunting grounds in northeastern Serbia. The presence of PCV3 was not determined, and PCV2 was confirmed in 40.32% of the organ samples from 124 wild boars hunted from 2018 to 2019, indicating their significance in virus circulation since traditional pig farms with irregular PCV2 vaccination strategies are widespread in this region. The most prevalent genotype was PCV2d, followed by PCV2b and PCV2a in 55.6%, 38.9%, and 5.5% of the examined samples, respectively. Nucleotide sequences of the detected strains were homogenous within the genotype and clustered within the subgroups PCV2d-2, PCV2b-1A/B, and PCV2a-2D with high identity to European, Chinese, and Serbian domestic pig sequences suggesting their origin. Wild boars presented with no clinical or pathological signs of infection, implying that these animals might be less susceptible to disease, particularly since the cofactors present in pig farming systems that support the disease development are absent in the wild. The high PCV2 detection frequency demonstrates the importance of wildlife monitoring to track virus population dynamics, especially in regions with free-range pig farming in order to plan adequate disease control strategies.

Prevalence and antimicrobial resistance of Salmonella spp. isolated from free-ranging wild boars in the State of São Paulo, Brazil

ABSTRACT: European wild boars (Sus scrofa) are considered exotic invasive species worldwide. Invasions of wild boars are a growing public health concern, as wild boars may represent an important reservoir of zoonotic pathogens, including bacteria of the genus Salmonella. The aim of this study was to determine the prevalence and serovars of Salmonella spp. in free-ranging wild boars legally hunted in the state of São Paulo, Brazil, and the susceptibility of those Salmonella spp. to antimicrobials. Fecal samples and mesenteric lymph nodes were acquired from 63 wild boars. The prevalence of Salmonella spp. in free-ranging wild boars was 9.5 % (6/63; confidence interval: 4.4 % - 19.2 %). Six serovars were isolated: S. enterica subsp. enterica ser. 4,5,12:-:1,2, S. enterica ser. Cerro, S. enterica ser. Madelia, S. enterica ser. Typhimurium, S. enterica ser. I (4,5,12:i:-) and S. enterica ser. Muenster. Analysis of antimicrobial resistance of Salmonella spp. showed that the majority of serovars were fully susceptible to the tested antimicrobials. Only S. enterica ser. Typhimurium and S. enterica ser. Muenster showed a resistance pattern to at least one antimicrobial analyzed. To our knowledge, this study is the first report the prevalence and serovars of Salmonella spp. in free-ranging wild boars in the State of São Paulo, Brazil. Results indicate a low prevalence with variability of Salmonella serovars, with some pattern of antimicrobial resistance. This study highlights the potential role of wild boars as carriers of Salmonella and could pose a risk to wild and domestic animals as well as humans.

Passive surveillance of African Swine Fever (ASF) in wild boars as an effective tool for prevention, control and eradication of ASF: A new approach

The latest recommendations of the European Commission and the scientific opinions of the EFSA and other bodies define the passive surveillance of ASF in wild boars as a key means of epidemiological surveillance and a basic tool for the eradication of the ASF virus from the natural environment in the areas where this disease occurs, especially in the early stage of its development. The key to eradication is the management of the wild boar population and its reduction to a low and controlled number, so as to diminish the virus pressure in the environment and lessen the risk to pig farms. Wild boar hunting should take place in a planned manner that is adapted to the epizootic situation (as part of centrally managed hunting and sanitary culling). The most intensive hunting should take place in ASF-free areas, with the use of tailored methods and the latest technologies. Periodic hunting moratoria and restrictions on any activity in newly infected zones are necessary. This approach provides for phased eradication of the infectious agent by culling or capturing wild boars, as well as identifying and safely removing their carcasses and remains. When passive ASF surveillance in wild fauna is undertaken, data on the incidence of the disease in wild boars are obtained by the Veterinary Inspectorate without its active participation. The inspectorate is notified of any suspicion or occurrence of the disease, including discoveries of carcasses of animals of susceptible species. Then it acts according to an established plan including clinical examination of suspected or sick animals, anatomopathological examinations and sample collection for laboratory tests. The article describes the use of passive ASF surveillance in wild boars as a tool to prevent, control and combat ASF in Poland.

Porcine circovirus 2 and 3 in wild boars in Southern Brazil

ABSTRACT: Porcine circovirus 2 (PCV2) has a considerable economic impact on the pork industry worldwide for more than two decades. In 2016, a new circovirus, porcine circovirus 3 (PCV3), was described; since then, it has been reported to be associated with diseased or even in clinically healthy swine in several countries. Considering the importance of wild boars as reservoirs of swine pathogens and the extensive distribution of these animals in Rio Grande do Sul and throughout the national territory, we searched for PCV2 and PCV3 in twenty-six wild boars coupled with necropsy and histologic examination of the sampled animals. Using PCR, 182 tissue samples were analyzed, including the heart, kidneys, liver, lung, lymph nodes, spleen, and tonsils. PCV2 and PCV3 were detected in 57.7% (15/26) and 15.4% (4/26) of wild boars, respectively. Furthermore, co-infection with PCV2 and PCV3 was detected in one of these animals, with PCV2 or PCV3 DNA detection in multiple organs. Histological examination showed mild to moderate and multifocal lymphoplasmacytic interstitial nephritis distributed randomly throughout the renal cortex, apparently unrelated to PCV2 or PCV3 detection. The wild boar population in Brazil is extensive, indicating the presence of a larger number of swine pathogen hosts. In the present study, more than half of the wild boars harbored PCV2; and although less frequently, PCV3 was also detected. Therefore, free-living wild boars can serve as reservoirs of swine circoviruses in southern Brazil.

A Preliminary Study on Antimicrobial Susceptibility of Staphylococcus spp. and Enterococcus spp. Grown on Mannitol Salt Agar in European Wild Boar (Sus scrofa) Hunted in Campania Region—Italy

The importance of wild boar lies in its role as a bioindicator for the control of numerous zoonotic and non-zoonotic diseases, including antibiotic resistance. Mannitol Salt Agar (MSA) is a selective medium used for isolation, enumeration, and differentiation of pathogenic staphylococci. Other genera such as Enterococcus spp. are also salt tolerant and able to grow on MSA. The present study focused on the identification, by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS), of bacteria grown on MSA isolated from the nasal cavities of 50 healthy wild boars hunted in Campania Region (southern Italy) in the year 2019. In addition, the antimicrobial resistance phenotype of the isolated strains was determined by disk diffusion method. Among genus Staphylococcus, coagulase-negative Staphylococcus (CoNS) were the most common isolated species, with Staphylococcus xylosus as the most prevalent species (33.3%). Furthermore, Enterococcus spp. strains were isolated, and Enterococcus faecalis was the species showing the highest frequency of isolation (93.8%). For staphylococci, high levels of resistance to oxacillin (93.3%) were recorded. Differently, they exhibited low frequencies of resistance to tested non-β-lactams antibiotics. Among enterococci, the highest resistances were observed for penicillin (93.7%), followed by ampicillin (75%), and ciprofloxacin (68.7%). Interestingly, 43.7% of the isolated strains were vancomycin-resistant. In conclusion, this study reports the phenotypic antibiotic resistance profiles of Staphylococcus spp. and Enterococcus spp. strains isolated from nasal cavities of wild boars hunted in Campania Region, highlighting that these wild animals are carriers of antibiotic resistant bacteria.

Territorial pattern between outbreaks of ASF among wild and domestic pigs in Ukraine

The article presents the results of the analysis of the epizootic situation in Ukraine regarding African swine fever among domestic and wild pigs from 2012 to 2020 and identifies the main sources of virus spread as well as weak links in the biological safety system of farms. When studying the statistical material of the Food and Agriculture Organization of the United Nations (FAO) and the State Service of Ukraine on Food Safety and Consumer Protection regarding animal morbidity, revealed a territorial pattern between the outbreaks of African swine fever among wild boars and domestic pigs of private farms and pig-breeding complexes, and proved the involvement of the European boar in the epizootic process as a natural reservoir and mobile focus of infection. Calculated the number of outbreaks of African swine fever among wild boars and domestic pigs within the same region and district, and studied the sequence of the emergence of foci on limited territories. Analyzed the natural focality of the disease, the probability of infection transmission to the domestic pig farm sector, and the role of infected objects in the spread of the virus among wild animal populations. From 2012 to 2020 inclusive, according to FAO statistics, 537 cases of African swine fever were recorded in Ukraine, 21.7 % of which were associated with wild boars. In 2017 and 2018, the role of the European wild boar in the epizootic process is best reflected, when 10.9 % (2017) and 20.4 % (2018) of outbreaks of African swine fever among domestic animals recorded in the same administrative districts, where during a year this desiase was detected among wild pigs. When analyzing statistical data of the recent years, the effectiveness of introducing more detailed monitoring of African swine fever among wild boars using modern laboratory methods and improving biosafety measures in the private sector and directly on hunting grounds has been proved. Further research is based on predicting the dynamics of the spread of African swine fever in Ukraine and the role of wild boar in this epizootic process. In addition, the role of wild boar in the spread of African swine fever in other countries and the most effective foreign methods of disease control and prevention will be analyzed.