Wild Boar Shot Research Articles

Trichinella findings in Germany from 2013 to 2023 indicate an increased prevalence in wild boar (Sus scrofa) population

In Germany, Trichinella spp. are mainly detected in the sylvatic cycle. Here, the affected animal species are wild boar, fox, badger, raccoon dog, wolf, raccoon and golden jackal. The predominantly detected species are T. spiralis, followed by T. pseudospiralis and T. britovi. Due to legal requirements in Germany, all hunted wild boars and other susceptible animals must be examined for Trichinella spp. if their meat is intended for human consumption. In recent years, an increase in the number of Trichinella-positive wild boar shot in Germany has been registered and the prevalence of positive wild boar scaled up from 0.002% to 0.005% between 2013 and 2023. Regarding regional distribution, most Trichinella findings in wild boar have been registered in the North-Eastern part of Germany. Here, the federal states Western-Pomerania, Brandenburg and Saxony that are bordering to Poland are particularly affected. The increase in positive wild boar may be associated with the spread of raccoon dogs and wolves in these regions. Thus, measures are required to prevent the spread of Trichinella among wild animals and to follow the systematic meat inspection in susceptible wild animals intended for food especially wild boar.

Molecular and biological properties of the African swine fever virus (Asfarviridae: Asfivirus) isolate ASF/Tatarstan 20/WB-12276

Up-to-date data and full characterization of circulating ASFV isolates play a crucial role in virus eradication and control in endemic regions and countries. The aim of the study was to evaluate and characterize the molecular and biological properties of the ASFV isolate ASF/Tatarstan 20/WB-12276, conduct phylogenetic analysis, and compare the results with isolates circulating in Europe and Asia. For bioassay, eight heads of the Large White pigs weighing 15-20 kg/head were used. Detection of specific anti-ASFV antibodies by ELISA and immunoperoxidase method. Detection of ASFV genome was performed by qPCR. Isolation of ASF/Tatarstan 20/WB-12276 and determination of titer were performed in pig spleen cell culture. Sequencing was carried out by the Sanger method. The virus was characterized as highly virulent and capable of causing acute to subacute forms of ASF. Phylogenetic analysis revealed substitutions in the genome of the ASF/Tatarstan 20/WB-12276 isolate (IGR/I73R-I329L and I267L markers) that supported the clustering of the studied variant with isolates prevalent in most of Europe and Asia. For the first time, the molecular and biological properties of the ASF/Tatarstan 20/WB-12276 virus isolate taken from a wild boar shot on the territory of the Republic of Tatarstan were studied and analyzed.

Infection of a Free-Living Wild Boar (Sus scrofa) with a Bacterium from the Mycobacterium kansasii Complex.

Simple SummaryMycobacteriosis is a collective term for diseases caused by nontuberculous mycobacteria. Wild animals are a frequent source of mycobacteria infection in farm animals and humans; therefore, it is important to monitor the presence of these pathogens in free-living mammals. We isolated bacterium belonging to Mycobacterium kansasii complex from a submandibular lymph node obtained from a wild boar. This mycobacterium is a common cause of severe human lung diseases and is rarely responsible for animal diseases; therefore, its presence in the wild animal population is of great concern. The animal was apparently healthy, and we did not find any internal organ lesions despite the abundant growth of tissue-isolated bacteria on media. Thanks to our research, the specificity of wild boar mycobacteriosis caused by MKC will be better known.The most numerous group of bacteria in the genus Mycobacterium is the nontuberculous mycobacteria. Currently, over 200 species of bacteria have been classified as belonging to this group, of which approximately 30 are pathogenic to humans and animals. Mycobacterium kansasii complex numbers among these pathogenic species. The submandibular lymph nodes of a wild boar shot by a hunter were examined in order to confirm or exclude infection with bacteria of the genus Mycobacterium. In culture, a bacterial isolate was obtained after 12 days of incubation on Petragnani and Stonebrink media. A multiplex PCR clearly indicated that the isolate was a nontuberculous mycobacterium. The results of species identification attempts via both molecular biology methods and mass spectrometry confirmed that the isolated strain belonged to MKC. The described case of a wild boar infection with MKC is the first documented case in Poland and only the second in Europe, and in confirming the presence of this pathogen among free-living animals, this report implies that MKC is of great concern. Our research elucidates some specifics of wild boar mycobacteriosis and may be used to instill awareness in the public of the dangers of dressing hunt prey or consuming its meat in ignorance of safe procedures, which can contribute to the transmission of the pathogen to humans.

An approach to assess stress in response to drive hunts using cortisol levels of wild boar (Sus scrofa)

Hunting can easily be linked to stress in wildlife. Drive hunts performed two to three times in one area during the respective hunting period, are thought to decrease the pressure hunting places on wildlife. Nevertheless, the expression of cortisol—one of the main mammalian stress hormones—is considered to have negative impacts on animals’ well-being if expressed excessively, which may occur during some (especially repeated) hunting events. We explored the effect of drive hunts on cortisol levels in wild boar in Lower Saxony, Germany, compared these cortisol levels to reference values given by a similar study, and investigated the effect of age, sex, and pregnancy. Blood collected from wild boar shot on drive hunts was analysed using a radioimmunoassay. As expected, we observed elevated cortisol levels in all samples, however, we still found significant differences between age groups and sexes, as well as an influence of pregnancy on cortisol levels. The effect of drive hunts on cortisol levels appears to be weaker than predicted, while the effects of other variables, such as sex, are distinct. Only half of the evaluated samples showed explicitly increased cortisol levels and no significant differences were found between sampling months and locations. Group living animals and pregnant females showed significantly higher cortisol levels. The impact of hunting is measurable but is masked by natural effects such as pregnancy. Thus, we need more information on stress levels in game species.

Future distribution of wild boar in a highly anthropogenic landscape: Models combining hunting bag and citizen science data

Wild boar is one of the most widespread mammals of the world and in many regions wild boar populations continue to expand. Especially in highly anthropogenic landscapes, increasing numbers of wild boar lead to a rising number of contacts with human activities causing human-wildlife impacts. In the heavily fragmented landscape of Flanders (northern Belgium) where the wild boar re-appeared in 2006 after more than half a century of absence, it is crucial to get a better understanding of the probable further distribution of wild boar in order to assess potential impacts in the near future. Wild boar occurrences have been collected by two citizen science programs: through an online observation platform and based on the reported locations of wild boar shot by hunters. This allowed us to construct a MaxEnt habitat suitability model. We constructed a new approach to define background manipulation to correct for sampling bias due to uneven sampling effort or due to areas in which hunting is not allowed based on the construction of bias files using this information. Model outcomes based on this new approach for background manipulation were compared with the known method of spatial thinning. All model outcomes were found comparable reflecting the utility of our new approach when limited data are available and spatial thinning would result in insufficient data for modelling. Our MaxEnt models show that coniferous forest, deciduous forest, maize, scrub and other low cover play a key role in increasing the habitat suitability for wild boar. Built up areas and the extent of habitat diversity only had a minor influence on habitat suitability reflecting wild boars’ behavioural flexibility to adapt to human-dominated landscapes. Unoccupied suitable habitat is mainly found in the centre of Flanders, although highly scattered. Habitat suitability in the West of Flanders was limited.

Analysis of Estonian surveillance in wild boar suggests a decline in the incidence of African swine fever

African swine fever (ASF) in wild boar populations is difficult to control. In affected areas, samples from all wild boar shot and found dead are investigated. The use of laboratory tests allows estimating the duration of the infection in affected animals. The study aimed to test the hypothesis that the stage of the epidemic in different areas of Estonia can be assessed on the basis of prevalence estimates. ASF surveillance data of Estonian wild boar were used to estimate prevalences and compare them between the East and West of Estonia. The temporal trend of the estimated prevalence of ASF virus positive animals and of the estimated seroprevalence of wild boar showing antibodies against ASFV was analyzed. Due to the potential influence of population density on the course of ASF in wild boar, also population density data (number of wild boar/km2) were used to investigate the relationship with laboratory test results. In areas, where the epidemic had already lasted for a long time, a small number of new cases emerged recently. The prevalence of samples that were only seropositive was significantly higher in these regions as compared to areas, where the epidemic is in full progress. The observed course of the disease could be the beginning of an ASF endemicity in this region. However, the results may also indicate that ASF has started to subside in the areas that were first affected in Estonia.

Antimicrobial Resistance in Escherichia coli Isolated from Wild Animals in Poland.

Antimicrobial resistance was tested in Escherichia coli isolated from feces (n = 660) of red deer, roe deer, fallow deer, European bison, and wild boar shot in regional forests in Poland during two winter hunting seasons. Indicator E. coli (n = 542) was resistant against 11 of 14 tested compounds, mostly sulfamethoxazole, streptomycin, ampicillin, trimethoprim, and tetracycline (1.3-6.6% range). No significant differences were observed between boar and ruminant isolates. Most of deer and bison isolates showed no resistance. Selective screening of wildlife samples revealed 1.7% prevalence of cephalosporin-resistant E. coli found mostly in wild boars. They produced extended-spectrum beta-lactamases (blaCTX-M-1, blaCTX-M-15) and plasmid-mediated AmpC-type cephalosporinase (blaCMY-2). The majority of the isolates originated from boars shot in a narrow time frame and space; therefore, common antimicrobial selection pressure in the environment was assumed. Three E. coli isolates carried plasmid-mediated quinolone resistance genes (qnrS1/S3). No transferable colistin resistance mechanisms were found in two resistant E. coli. Transferability of resistance was proved in a single pAmpC-positive isolate carrying IncI1-alpha 95 kb plasmid. No cephalosporin-resistant E. coli harbored pathogenicity markers; therefore, they might be considered a vector of resistance determinants, but not a pathogen themselves.

Fatty acid and microbiological profile of the meat (longissimus dorsi muscle) of wild boar (Sus scropha scropha) hunted in Tuscany

The aim of this work is to study the influence of gender, age and hunting period on the fatty acid composition of the longissimus dorsi muscle excised from 42 wild boars hunted on a farm located in Tuscany. A sub-sample of 22 muscles was used for the study of the microbiological profile of wild boar meat. The results show that gender had an effect only on C16:1 n7, which was higher in females (p ≤ .05). Slaughtering age influenced more parameters, thus resulting in a higher content of C6:0, C18:2, C20:1 and n6/n3 ratio in meat from adults (p ≤ .05) and in a higher percentage of C16:0 (p ≤ .05) in meat from young animals. The hunting month greatly influenced the meat quality because, in addition to the single fatty acids, it significantly modified the MUFA, PUFA, PUFA/SFA and n6/n3 ratio, underlining the great difference between meat of wild boar shot in October – November vs December – January. Ether extract was higher in sub-adults than in young animals (p ≤ .01) but was not influenced by gender and hunting month. Regarding the microbiological analyses, Salmonella spp. was only detected in one sample, while Yersinia enterocolitica was not detected at all. Data on the presence of pathogenic bacteria confirmed health risk for the consumer comparable to that associated with meat obtained from farm animals, while data on microbial loads (total aerobic mesophilic and psychrotrophic counts, Enterobacteriaceae, Escherichia coli) did not highlight any specific criticality.

Transferable integrons of Gram-negative bacteria isolated from the gut of a wild boar in the buffer zone of a national park

The aim of this study was to determine the presence of integron-bearing Gram-negative bacteria in the gut of a wild boar (Sus scrofa L.) shot in the buffer zone of a national park. Five Gram-negative strains of Escherichia coli, Serratia odorifera, Hafnia alvei and Pseudomonas sp. were isolated. Four of these strains had class 2 integrase (intI2), and one harbored class 1 integrase (intI1). The integron-positive strains were multiresistant, i.e., resistant to at least three unrelated antibiotics. All of the integrons were transferred to E. coli J-53 (RifR) in a conjugation assay. The results showed that a number of multiresistant, integron-containing bacterial strains of different genera may inhabit a single individual of a wild animal, allowing the possibility of transfer of antimicrobial resistance genes.

Increase in crop damage caused by wild boar (Sus scrofa L.): the “refuge effect”

The occurrence of crop damage by wild boars raised dramatically in the last decades, implying an increase in social conflicts, expenditures for compensation and a risk to natural ecosystems. Many researchers have explained this phenomenon by considering wild boar biology, behaviour and abundance. Little or no attention has been devoted to wildlife management and the agricultural mosaic. We hypothesised that the agricultural structure of the landscape and wildlife management planning, including hunting, can play a relevant role in causing crop damage. We studied a Mediterranean area in central Italy that is characterised by a patchy agriculture, dividing the surface into hexagons. A large number of terrain parameters were calculated at the large (hexagons) and local (buffer) scale, including the topography, land use and agricultural management. We also considered wildlife variables such as the number of wild boar shot down, hunting management and the legal status of the wild boar. The terrain and management data for each hexagon were submitted to a generalised binomial stepwise multiple logistic regression. The resultant model demonstrated an accuracy of 0.76, a misclassification rate of 0.24 and an odds ratio of 10.41. The most important variables selected by the regression were the woods in the area where hunting was banned (P < 0.001), a 1-km buffer of intensively cultivated farmland close to the woods where hunting was banned (P < 0.001), a 1-km buffer of intensively cultivated farmland along the river (P < 0.05), the forest edge (P < 0.001), and the mean number of wild boar that were shot (P < 0.05). In this study, we proved that an important factor in explaining crop damage is the “refuge effect” (a buffer close to the wooded areas where hunting was banned) and the 1-km buffer along possible dispersion routes.

Age-related Toxoplasma gondii seroprevalence in Dutch wild boar inconsistent with lifelong persistence of antibodies.

Toxoplasma gondii is an important zoonotic pathogen that is best known as a cause of abortion or abnormalities in the newborn after primary infection during pregnancy. Our aim was to determine the prevalence of T. gondii in wild boar to investigate the possible role of their meat in human infection and to get an indication of the environmental contamination with T. gondii. The presence of anti-T. gondii antibodies was determined by in-house ELISA in 509 wild boar shot in 2002/2003 and 464 wild boar shot in 2007. Most of the boar originated from the “Roerstreek” (n = 673) or the “Veluwe” (n = 241). A binormal mixture model was fitted to the log-transformed optical density values for wild boar up to 20 months old to estimate the optimal cut-off value (−0.685) and accompanying sensitivity (90.6%) and specificity (93.6%). The overall seroprevalence was estimated at 24.4% (95% CI: 21.1–27.7%). The prevalence did not show variation between sampling years or regions, indicating a stable and homogeneous infection pressure from the environment. The relation between age and seroprevalence was studied in two stages. Firstly, seroprevalence by age group was determined by fitting the binary mixture model to 200 animals per age category. The prevalence showed a steep increase until approximately 10 months of age but stabilized at approximately 35% thereafter. Secondly, we fitted the age-dependent seroprevalence data to several SIR-type models, with seropositives as infected (I) and seronegatives as either susceptible (S) or resistant (R). A model with a recovery rate (SIS) was superior to a model without a recovery rate (SI). This finding is not consistent with the traditional view of lifelong persistence of T. gondii infections. The high seroprevalence suggests that eating undercooked wild boar meat may pose a risk of infection with T. gondii.

Should legislation regarding maximum Pb and Cd levels in human food also cover large game meat?

Game meat may be contaminated with metals and metalloids if animals reside in anthropogenically polluted areas, or if ammunition used to kill the game contaminates the meat. Muscle tissue from red deer and wild boar shot in Ciudad Real province (Spain) in 2005–06 was analysed for As, Pb, Cu, Zn, Se and Cd. Samples were collected from hunting estates within and outside an area that has been historically used for mining, smelting and refining various metals and metalloids. Meat destined for human consumption, contained more Pb, As and Se (red deer) and Pb (boar) when harvested from animals that had resided in mined areas. Age related accumulation of Cd, Zn and As (in deer) and Cd, Cu and Se (in boar) was also observed. Two boar meat samples contained high Pb, at 352 and 2408 μg/g d.w., and these were likely to have been contaminated by Pb ammunition. Likewise, 19–84% of all samples (depending on species and sampling area) had Pb levels > 0.1 μg/g w.w., the EU maximum residue level (MRL) for farm reared meat. Between 9 and 43% of samples exceeded comparable Cd limits. Such data highlight a discrepancy between what is considered safe for human consumption in popular farmed meat (chicken, beef, lamb), and what in game may often exist. A risk assessment is presented which describes the number of meals required to exceed current tolerable weekly intakes (PTWIs) for Pb and Cd, and the potential contribution of large game consumption to such intake limit criteria.

Utility for production of massaged products of selected wild boar muscles originating from wetlands and an arable area

Percentages of muscle fibre types, area of intramuscular fatty tissue (IMF) and changes in hardness, rheological properties as well as mean fibre cross-sectional area (CSA), and endomysium thickness of muscles from wild boars hunted in two different ecosystems (arable area vs. wetlands) were evaluated. Three muscles: Biceps femoris (BF), Semimembranosus (SM), and Longissimus (L) subjected to massaging (or not) for 4h were studied. Fibre type percentage and structural elements: mean muscle fibre cross-sectional area (CSA), endomysium thickness, and amount of intramuscular fat (IMF) were measured using a computer image analysis programme. Fibre properties of muscles from wild boars originating from arable areas did not differ from those of wild boars from wetlands. Muscles of wild boars hunted in the arable area of the forest contained significantly higher amounts of intramuscular fat and lower values of hardness, viscous and elastic moduli than the corresponding muscles of animals from the marshy area. Of the muscles tested, BF with its higher percentage of red fibres and fibre CSA, thicker endomysium and lower amount of IMF compared to SM and L muscles, was tougher and more elastic and viscous than the other two muscles. Muscle massaging resulted in an increase in the fibre CSA and decrease in thickness of the endomysium and as a consequence reduced hardness and augmented the viscous and elastic modules of the muscles. Muscles with higher amounts of intramuscular fat, lower values of textural parameters and percentage of red fibres as well as smaller structural elements showed higher susceptibility to massaging. Muscles from animals hunted on wetlands compared to those from wild boar shot on the arable land and BF compared to SM and L, were slightly less susceptible to mechanical tenderization.

Somatic variability in wild boar (Sus scrofa L.) in different areas of Central Italy

A survey of wild boar shot during two consecutive years (hunting seasons 2002–2004) was carried out in order to evaluate which somatic measurements are most significant in identifying and discriminating among different morphotypes in central Italy. Biometric data from 688 wild boars was collected in three different areas of central Italy, two in Viterbo and one in the Province of Rieti. The following somatic measurements were individually recorded for each specimen: head-body length, height at withers, hind-foot length, ear length, ear-snout distance and ear-shoulder distance. Body weight was registered, and age was estimated from tooth eruption and wear. The animals were divided into three age classes; young (aged less then 12 months), sub-adults (aged between 12 and 36 months), and adults (36 months and older). After a preliminary ANOVA procedure, which did not give satisfactory results, a statistical analysis was performed using a canonical discriminant procedure, given an a priori classification (geographical area) and several quantitative variables (somatic measurements and weight). The separation between areas was estimated calculating the squared distance of Mahalanobis. The data referring to all 688 specimens was subjected to factor analysis. The results of the canonical discriminant analysis highlight the existence of two distinct groups within all three age classes. There is a statistically significant difference between the southern-Maremma (SM) vs the Apennine (A) and sub-Apennine (SA) areas, for young (P<0.0001), sub-adults (P<0.001) and adults (P<0.001). The difference between the A and SA areas was significant only for sub-adults (P<0.05). The first canonical variable account for 92.5, 92.7 and 89.9% of the total variance for the three age classes respectively, but this is unequally correlated with the original variables suggesting that the separation between the two areas is due to differences in conformation rather than in body size. On the basis of the discriminant analysis large part of the animals were correctly categorised in the sampling areas. As regards the factor analysis results for the adult group, the first three common factors are able to explain 78, 92, and 64% of the covariance for the data of the SM, A and SA groups respectively. These results suggest that, for the SM group, a differentiation among morphotypes may be possible on the basis of a few somatic measurements. These results confirm the need for biochemical and genetic studies to identify if the different morphotypes refer to the autochthonous wild boar strain.

Antibodies to Selected Viral Disease Agents in Wild Boars from the Czech Republic

Blood samples were collected from wild boar (Sus scrofa) shot during the hunting season from 1999 to 2005 in the Czech Republic. Sera were tested by enzyme-linked immunosorbent assay for the presence of antibodies against classical swine fever virus (CSFV), swine vesicular disease virus (SVDV), Aujeszky's disease virus (ADV), and bovine viral diarrhea virus (BVDV). Indirect fluorescence antibody test was used for detection of antibodies against porcine circovirus type 2 (PCV-2) and transmissible gastroenteritis virus (TGEV). Antibodies against ADV, BVDV, PCV-2, and TGEV were detected in 30% (101 of 338), 1% (2 of 352), 43% (57 of 134), and 1% (1 of 134) of wild boars, respectively. Sera of 6,471 and 362 tested wild boars were negative for the presence of antibodies against CSFV and SVDV, respectively. This is the first survey of TGEV antibodies in wild boars and the first serologic survey of viral diseases in wild boars in the Czech Republic. Wild boars in the Czech Republic may act as a potential reservoir of ADV and thus have a role in the epidemiology of this disease.

Epidemiological survey of swine influenza A virus in selected wild boar populations in Germany

The aim of this study was to evaluate the epidemiological situation of swine influenza virus (SIV) infections in different wild boar populations in Germany based on a serological surveillance in some Bundeslaender (federal states) in connection with virological investigations in wild boar shot in Northern Germany (Mecklenburg-Western Pomerania, district of Nordvorpommern). Altogether, 1245 sera from wild boar were tested using the hemagglutination inhibition test. The established seroprevalence rate was low (on average 5.2%). Antibodies were only detected against the subtypes H1N1 and H3N2 showing differences between wild boar populations and age classes. The virological investigation of samples derived from lungs of wild boar shot in Mecklenburg-Western Pomerania, district of Nordvorpommern ( n = 242), revealed that the virus prevalence (two virologically positive animals, 0.8%) was very low. Based on serological typing, the isolated SIV was identified as subtype H3N2. Molecular biological investigations of the hemagglutinin (HA) and neuraminidase (NA) genes confirmed this result. This study suggests that SIV infections in wild boar seem to be no serious threat for domestic pigs.

Monitoring of Classical Swine Fever in Wild Boar (Sus scrofa) in Slovenia

Classical swine fever (CSF) is a highly contagious multi-systemic haemorrhagic viral disease of pigs. Not only domestic pigs, but also wild boar appear to play a crucial role in the epidemiology of CSF. Spleen (n = 739) and blood coagulum (n = 562) sampled from wild boars (Sus scrofa) shot in 2002, and serum samples from 746 wild boar shot in 2003 and 2004, were tested throughout Slovenia. In 2002, 17 samples were positive on enzyme-linked immunosorbent assay (ELISA) test for antibodies against classical swine fever virus (CSFV). Positive ELISA test was confirmed by a virus neutralization test. All other samples were negative. This is the first report that describes the epidemiology of CSFV from 2002 on, and the monitoring of the wild boar population in Slovenia at present.

Oral immunisation of wild boar against classical swine fever in Baden-Württemberg: development of the seroprevalences based on the hunting bag

Oral immunisation of wild boar against classical swine fever (CSF) in the German federal state of Baden-Wurttemberg has been evaluated on the basis of the seroprevalence rates after application of an improved immunisation procedure consisting of three double vaccinations per year (in spring, summer and autumn). The seroprevalence in the vaccination area increased continuously until the third immunisation campaign (72.4% seropositive animals). Later, a decrease of the seroprevalence rates was detected, especially in young boars. Although in the infected area the seroprevalences were higher, in principle, the same trend could be found in the surveillance zone. The development of the monthly seroprevalence rates of young boars during the first year of their life showed that the new immunisation procedure had a positive effect on their immunisation rate. Fifty percent and more of the wild boar shot at the age of 6–12 months were antibody positive. Neutralising antibody titre levels were the same in young boars (on average 812 ND50) and in sub-adults (on average 997 ND50). Individual antibody positive animals may be detected for more than 2 years after completion of the vaccination programme.

Serosurveillance of wild deer and wild boar after the epidemic of foot-and-mouth disease in the Netherlands in 2001

Blood samples from 140 wild deer and 208 wild boar shot in the aftermath of the epidemic of foot-andmouth disease in the Netherlands in 2001 were examined for antibodies to...

A long-term survey of pseudorabies virus infections in European wild boar of western Germany

In a long-term study, a total of 1,112 European wild boar (Sus scrofa) shot in the southern part of North Rhine Westphalia between 1993 and 2000 were investigated for the infection with pseudorabies virus (PRV). Of 929 sera tested during the 7 year observation period -92 (9.4%) had PRV-specific antibodies with an overall seroprevalence in the south west of North Rhine Westphalia of 11.4%. A total of 473 tissues and 516 mucosal swabs collected between 1996 and 2000 from wild boar originating from those districts were tested for the presence of PRV using virus isolation in cell culture. In 2000, 4 viruses were isolated from the tonsils of piglets and juvenile wild boar shot in the district of Bonn, which were identified as type Ip PRV. When tonsils and lungs were additionally tested in a glycoprotein D-specific PCR, 14 (4.0%) and 2 (1.6%) were positive. Virus isolation and PCR results suggest that PRV might be mainly transmitted by wild boar piglets. The results also indicate that PRV-infections have been endemic in wild boar populations in the south west of North Rhine Westphalia for several years. Based on present knowledge, the area covered by this study appears to be part of a larger, coherent endemic area comprising wild boar populations in neighbouring regions of western Germany. Recently, PRV was eradicated in the domestic pigs in North Rhine Westphalia resulting in a recognition as an officially Aujesky's disease free region within the EU. As in other regions, so far, PRV infections in the wild boar population appear not to affect the domestic pig population.