Fasciola hepatica in wild boar (Sus scrofa) from Italy

Fasciola hepatica is a trematode infecting ruminants worldwide, occasionally reported in a wide range of animal species, including humans. According to the WHO, fasciolosis is recognized as a re-emerging neglected tropical disease, responsible for endemic and epidemic outbreaks in humans. Although the main hosts of the parasite are represented by cattle, sheep and goats, wildlife may be involved in its circulation. Here we firstly report F. hepatica in a wild boar from Italy (southern area) and characterize it both morphologically and molecularly. The nad1 gene analysis of specimens analyzed, revealed a high genetic similarity with those of humans from Iran and Peru, as well as a close phylogenetic relationship to those in ruminants from Brazil, Ecuador and Egypt. Considering the increase in the wild boar populations in urban and peri-urban areas, a potential role of this ungulate in the circulation of this zoonotic trematode is suggested.     

A systematic study of brain base arteries in the wild boar (Sus scrofa scrofa)

This study aimed at describing and systematizing the arteries of the base of the brain of the wild boar (Sus scrofa scrofa). Thirty-three heads were used, of which 30 were injected with latex, and three with acrylic dental resin through the common carotid arteries. The brain carotid artery arose from the rostral epidural rete mirabile, and divided into a rostral and a caudal branch. The rostral branch gave off the middle cerebral artery and then continued as rostral cerebral artery. The latter branched into lateral rhinal, internal ethmoidal and medial rhinal arteries. The rostral cerebral artery joined its contralateral homologue, becoming the single rostral inter-hemispheric artery. The caudal branch emitted the caudal cerebral artery and the tectal arteries, and then fused with the branch of the opposite antimere, joining the basilar artery. The rostral cerebellar arteries derived from this point. The basilar artery originated from the anastomosis between the arteries derived from the caudal epidural rete mirabile of each antimere. The basilar artery extended rostrally, giving off as main collateral branch the caudal cerebellar artery. The basilar artery presented a significant decrease in diameter before joining the caudal branches of the brain carotid arteries. The cerebral arterial circle was rostrally and caudally closed.     

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.     

Epidemiological study on porcine circovirus type 2 (PCV2) infection in the European wild boar (Sus scrofa)

Porcine circovirus type 2 (PCV2) is considered as the causative agent of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs, where the virus is ubiquitous as evidenced by serological surveys. We present the results of the first nationwide sero-survey on the presence of PCV2 antibodies in European wild boars, and report the first PMWS case in a wild boar from Spain. Sera from 656 hunter harvested wild boars from 45 different geographical sites and 22 additional imported animals were analysed by means of an immunoperoxidase monolayer assay (IPMA). We also examined the tissues from 55 healthy and one diseased wild boars for the presence of PCV2 nucleic acid and PMWS lesions by in situ hybridisation and histopathology, respectively. Additionally, abundance estimates of wild boars and field interviews were carried out on 30 sampling sites. The prevalence of medium to high PCV2 serological titres among the examined wild boars was 47.89 +/- 1.9%. Seropositive wild boars appeared in all but one of the geographical regions analysed. Seroprevalence and titre of PCV2 antibodies were closely related to the management of the wild boar populations. Wild boars from intensively managed, farm-like populations had higher prevalence than wild boars living in more natural situations. The effect of wild boar abundance and management on PCV2 antibody prevalence was further evidenced by the high correlation existing between the relative abundance estimates of animals and the percentage of wild boars with medium to high levels of PCV2 antibodies. PCV2 nucleic acid was detected in the tissues of three wild boars. One of these was diagnosed as PMWS. The results, in addition to information on piglet mortalities, suggest a potential role of PMWS in piglet mortality in intensively managed wild boar populations.     

Morphological and morphometric features of knee joint in wild boar (Sus scrofa)

In the study, it was aimed to reveal the structure of the knee joint anatomically and morphometrically in the wild pig known as the ancestor of the domestic pig. In the study, the left and right knee joints of mature 10 wild boars were used as material. For this purpose, the materials were fixed with 10% formaldehyde solution. Macroanatomical and morphometrical examinations of bones, menisci and ligaments involved in joint formation were performed after fixation. Trochlea and condyles of femur were examined, and various measurements were made. Trochlear labia were found to be the same size, and the condyles did not show a significant difference in size. The shape of lateral condyle of the tibia was trapezoid, and the shape of medial condyle was triangular. Moreover, the lateral intercondylar tubercule was higher according to the medial one. The presence of a shallow groove on the tibial tuberosity was detected. It was found that the width difference between apex and base was more pronounced on the anterior and lateral surface of the patella. Joint surface of the fibula was found to be flat in all materials. The menisci were ‘C’ shape, but the medial meniscus is more convex than the lateral one. It was observed that the outer edges were thick, while the inner edges were thin. Ligaments of the knee joint were well developed. When the findings of the study were compared with the literature, domestication seemed to have no significant effect in terms of the morphologic properties of the knee joint of wild boar.     

First isolation of Trichinella britovi from a wild boar (Sus scrofa) in Belgium

Since 1992, when the European Union Council Directive requires that wild boars (Sus scrofa) hunted in EU for commercial purpose should be examined for Trichinella, the infection has not been detected in wild boars from Belgium, despite serological evidence of the presence of anti-Trichinella antibodies in wildlife and previous reports of Trichinella larvae in this host species. In November 2004, Trichinella larvae were detected in a wild boar hunted near Mettet, Namur province (Southern Belgium). Larvae were identified as Trichinella britovi by polymerase chain reaction methods. This is the first report of the identification of Trichinella larvae from Belgium at the species level. The detection of T. britovi in wildlife in Belgium is consistent with findings of this parasite in other European countries and confirms the need to test game meat for Trichinella to prevent its transmission to humans.     

Long-term monitoring of classical swine fever in wild boar (Sus scrofa sp.) using serological data

In the European Community, epizootics of classical swine fever (CSF) in the wild boar (Sus scrofa) are compulsorily monitored because transmission may occur between wild boars and domestic pigs, causing heavy economic losses to the pork industry. The estimation of incidence in populations of wild boars is generally based on viroprevalence. However, viral isolation becomes rare when the incidence is low because the virus cannot be detected for more than a few weeks following infection. On the contrary, seroprevalence is detectable at low incidence levels, because antibodies can be detected for the lifetime of the infected animal. We thus attempted to analyse the long-term evolution of CSF incidence using serological data. The data came from France, where CSF had been monitored from 1992 to 2002, and where the virus has not been detected since 1997. We assumed that the overall seroprevalence would estimate the proportion of immune wild boars, that seroprevalence in juveniles would approximate incidence and that seroprevalence in different age classes would show the evolution of incidence in a given cohort. Spatial and temporal trends of incidence and seroprevalence were explored using logistic modelling and the spatial trend was analysed using polynomial regression. In 1992, incidence peaked in the northern area. After 1993, incidence decreased but remained the highest in the northern area. After 2000, no seropositive juvenile was observed, suggesting the extinction of the epizootic. Our results support the reliability of serological monitoring since it allowed a longer detection of viral transmission and provided more information on the spatio-temporal evolution of incidence than did viral isolation. We advocate that the highest persistence of infection in northeastern France is not independent from infection persistence in Reinland-Pfalz (Germany). Such persistence may be due to favourable local conditions and/or the social organisation of wild boars.     

Systemic AA-amyloidosis in a European wild boar (Sus scrofa) suffering from generalized tuberculosis

Summary An adult female wild boar (Sus scrofa) was found moribund in Cabaneros National Park (central Spain). The animal had a markedly emaciated carcass, with body weight of 25.9 kg. At necropsy, most of the parenchymatous organs had widespread variably sized granulomas. Generalized tuberculosis was confirmed by PCR detection of Mycobacterium bovis in the mandibular lymph node. Large amounts of a hyaline, pale eosinophilic material were observed in liver, kidney and intestine. Congo red staining and green birefringence identified amyloid, which was further classified as AA type based on immunohistochemical results. It is speculated that the abundant serum amyloid A derivatives deposited in the tissues as AA-amyloid may be associated with the generalized tuberculosis. This is the first report of amyloidosis in the European wild boar.     

Study of lobation and vascularization of the lungs of wild boar (Sus scrofa)

The purpose of this study was to describe the anatomy of the lungs of wild boars for comparison with those of domestic swine. It was found that the right lung of the wild boar is divided into four lobes: cranial, median, caudal and accessory, whereas the left lung is divided into two lobes: cranial and caudal. In 93.4% of the cases, right pulmonary artery separates into the ascendant, descendant, median, accessory and caudal branches. In 73.3% of the cases, left pulmonary artery separates most frequently to form three branches to the cranial lobe, whereas the median lobe is generally supplied by only one arterial branch. There is a single pattern of bronchial distribution: in the right lung a tracheal bronchus leads to the cranial lobe, where it separates into the cranial and caudal bronchi and there are also bronchi to the median, caudal and accessory lobes. In the left lung, the large bronchus separates to form two branches, one of which further separates to form two branches to the cranial lobe whereas the other forms a single branch to the caudal lobe.     

The first description of gastric Helicobacter in free-ranging wild boar (Sus scrofa) from Poland

Specimens of gastric mucosa of 17 free-ranging wild boars (Sus scrofa) shot in the Central Poland during 2007/2008 hunting season were investigated for the presence of Helicobacter species. Histopathology, Helicobacter genus-specific 16S rRNA PCR, and DNA sequence analysis were employed. In PCR analysis the presence of Helicobacter's DNA was detected in one stomach. Obtained sequence analysis showed its relatedness to Helicobacter heilmannii type 2. In histopathology of the PCR-positive sample the presence of tightly coiled spiral bacteria was detected on the surface of the antral mucosa, in gastric pits and lumen of the upper parts of antral glands. Potential pathologic significance of the presence of Helicobacter in the stomach of free-ranging wild boars was obscured by the parasitic invasion-caused gastritis, and remains unknown.     

Trichinella spiralis in wild boars (Sus scrofa)

During the period 1.7. 1972--31.6. 1977 muscle samples from 137 wild boars were examined for Trichinella spiralis. Larvae of T. spiralis were demonstrated in 4 animals. The major part (83) of the wild boars examined, including the 4 positive ones, originated from one particular game park. The rate of infection with T. spiralis in the game park concerned was 4.8%. Calculated on the basis of the total of animals examined, the rate of infection was 2.9%.     

Trichinella spiralis and Trichinella pseudospiralis mixed infection in a wild boar (Sus scrofa) of Germany

A wild boar (Sus scrofa) from the island Usedom in Mecklenburg-Western Pomerania (north-east Germany) was detected as Trichinella-positive during routine meat inspection. Encapsulated and non-encapsulated larvae were detected in the muscle tissue by trichinoscopy. In the diaphragm, 922 larvae per g were detected by artificial digestion. Muscle larvae displayed two different sizes of about 700 and 1100 microm. By a multiplex PCR analysis, larvae with a large size were identified as Trichinella spiralis, whereas those of a smaller size were identified as Trichinella pseudospiralis. This is the first finding of a mixed infection of T. spiralis and T. pseudospiralis in a naturally infected animal and it supports the tendency of more frequent detection of the non-encapsulated species T. pseudospiralis in Europe.     

Immunohistochemical characterization of Kisselev nodules (ectopic lymphoid follicles) in wild boar (Sus scrofa L.)

This paper describes the histopathological features and cellular distribution of T lymphocytes (CD3), B cells (CD79), follicular dendritic cells (FDC) and macrophages (alpha-1-antitrypsin, lysozyme) in lymphoid aggregates (Kisselev nodules) found in the lung, kidney and liver of wild boar (Sus scrofa L.). The distribution of immunoreactive cells, tested for antibodies, was similar to that found in the cortex of lymph nodes: lymphoid follicles with germinal centers mainly consisting of CD79⁺ B cells with sparse interfollicular tissue (CD3⁺ T lymphocytes). This finding and the association of these structures with helminthic infections suggests that local humoral immunity is central to the organism’s response to parasitic challenge. The presence of follicular dendritic cells confirms the high degree of organization of these lymphoid-like structures. The role of other pathogenic factors and the induction of chronic inflammatory reaction in these ectopic lymphoid sites is also discussed.     

Porcine lymphotropic herpesvirus (Gammaherpesvirinae) DNA in free-living wild boars (Sus scrofa Linnaeus, 1758) in Brazil

BackgroundSuid gammaherpesvirus 3, 4, and 5 (porcine lymphotropic herpesvirus – PLHV-1, -2, and -3) are viruses that infect domestic and feral pigs.ObjectivesThis study examined the presence of PLHV DNA in biological samples from free-living wild boars circulating in a Brazilian geographical region with a high density of commercial domestic pigs.MethodsLung samples of 50 free-living wild boars were collected by exotic wildlife controller agents between 2017 and 2019 in the state of Paraná, southern Brazil. Lung and spleen fragments were obtained from six fetuses collected by hysterectomy post mortem from a pregnant sow. A polymerase chain reaction (PCR) assay using consensus primers (pan-herpesviruses) was performed to detect PLHV DNA. The samples showing positive results for PLHV DNA were submitted to single-round PCR assays with the specific primers for identifying PLHV-1 (213-S/215-As), PLHV-2 (208-S/212-As), and PLHV-3 (886s/886As). The specificity of the species-specific PCR products was assessed by nucleotide sequencing of the amplicons.ResultsForty-eight (96%) of the 50 lung samples analyzed were positive for PLHV by PCR using pan-herpesvirus primers. In 33 (68.75%) of the positive samples, at least two PLHV species were identified simultaneously. The DNA of PLHV-1, -2, and -3 was found in free-living wild boars of all ages, but not in the fetuses, even though they were from a sow that tested positive for all three viruses.ConclusionThese viruses are endemic to the population of feral pigs in the Brazilian region evaluated, as well as in domesticated pigs.     

Molecular detection of Leptospira spp. in wild boar (Sus scrofa) hunted in Liguria region (Italy)

Leptospirosis is a re-emerging and widespread zoonosis, worldwide distributed, due to a wide variety of wild and domestic animal species able to act as natural or accidental hosts. During last years, in Europe, as in Italy, wild boar (Sus scrofa) population is increased. This animal represents a reservoir for different etiological agents, such as Leptospira. The aim of this investigation was to evaluate the prevalence of Leptospira spp. in wild boar hunted in Liguria region (Italy) during two-year hunting seasons. From 611 hunted wild boar, kidneys were collected. DNA was extracted from each organ and different targets were used to detect pathogenic (lipL32 gene), intermediate (16S rRNA gene) and saprophytic (23S rRNA gene) Leptospira by Taqman-based RealTime-PCR assays. Overall, kidneys were sampled from 282 adults, 155 sub-adults and 174 young wild boar (in total 314 males and 298 females). By RealTime PCR 77 kidneys were positive and, among these, 74 resulted positive for pathogenic (96.10%) and 3 (3.90%) for intermediate Leptospira. No significant differences in pathogenic Leptospira infection ratio were detected between male (11.50%) and female (12.75%). Only 13 sub-adult animals (8.39%) resulted infected by pathogenic Leptospira; 23 young animals (13.22%) and 38 adult animals (13.47%) were positive. The results of this study confirmed the importance of wild boar in the epidemiology of leptospirosis, which is able to infect other animal species (domestic and wild) including humans. Rarely, intermediate Leptospira could be able to infect wild boar with a renal localization that can contribute to their shedding and circulation.