Gross lesions associated with Sarcocystis miescheriana in a wild boar hunted for human consumption: the importance of trained hunters to ensure animal health surveillance and food safety.

Sarcocystis is a genus of protozoa with a worldwide distribution infecting a wide range of animals, including humans. Wild boars can harbor at least two species of Sarcocystis, that is, the zoonotic Sarcocystis suihominis, using humans as definitive hosts, and Sarcocystis miescheriana, for which wild and domestic canids serve as definitive hosts. In Portugal, hunting holds significant economic and social importance, and wild boars are among the most appreciated hunted species. As the consumption of wild boar meat can expose humans to several foodborne pathogens, the presence of trained hunters can make a difference in ensuring animal health surveillance and food safety. Herein, we report the detection of macroscopic cystic lesions associated with S. miescheriana in a wild boar hunted for human consumption, resulting in carcass condemnation. To the best of the authors' knowledge, the presence of S. miescheriana in wild boar tissues has never been associated with macroscopic pathological alterations before. Although S. miescheriana cannot infect humans, carcasses affected by grossly visible pathological changes must be declared unfit for consumption. Therefore, our finding points out the potential economic damage associated with carcass rejection due to the presence of gross lesions associated with generalized sarcocystosis. Nonetheless, further studies are required to investigate these alterations that currently appear to be occasional findings.

Microscopic detection and molecular characterization of Sarcocystis miescheriana in wild boars (Sus scrofa): first report from Greece.

The genus Sarcocystis includes protozoan parasites with an indirect life cycle. Sarcocystis spp. can infect various animal species and humans, causing sarcocystosis, a parasitosis of economic importance and zoonotic concern. Wild boars can act as intermediate hosts for Sarcocystis miescheriana and the zoonotic Sarcocystis suihominis that infects humans by consumption of raw or undercooked infected swine meat. In the present study, the diaphragmatic muscle tissue of 123 wild boars hunted in Greece was examined to determine the frequency of Sarcocystis spp. The samples were examined by tissue compression and molecular techniques. Under light microscopy, 34 out of 123 (27.6%) wild boars tested positive for Sarcocystis spp., while a higher infection prevalence (75%) was revealed by multiplex PCR performed in 100 of the samples. The partial mtDNA cox1 gene (~ 1100 bp) of 20 samples tested positive for S. miescheriana by multiplex PCR was amplified and sequenced. Sarcocystis miescheriana was identified as the only species involved in these infections. This is the first study on the prevalence of Sarcocystis spp. in wild animals in Greece. Further, large-scale surveys are needed to assess the prevalence and species of this parasite in Greece and to design efficient control and preventive measures in a One Health perspective.

First report of Echinococcus granulosus genotype 1 in a wild boar (Sus scrofa) from China.

Echinococcosis is a worldwide disease endemic to the western region of China. In 2023, echinococcosis was detected in one of 27 wild boars (Sus scrofa) in Yili Prefecture, Xinjiang, northwestern China. Histopathological staining and full sequence mitochondrial (mt) analysis were used to determine the infection genotype. Echinococcus granulosus was detected in the wild boar liver, and the cystic lesion characteristics indicated the E. granulosus genotype (G1). This case is the first confirmation of wild boar serving as a transmitter for the G1 genotype of E. granulosus within China. These findings suggest that surveillance is needed to assess the risk of E. granulosus sensu lato transmission to humans and wild animals.

Occurrence and identification of lungworms in Iranian wild boars.

This study represents the first investigation into the occurrence and identification of Metastrongylus spp. in wild boars (Sus scrofa) in Iran, utilizing both molecular and morphological methods. Thirteen wild boars from Kerman Province were examined, with 92.3% found to be infected with at least one species of Metastrongylus. Mixed infections were observed in 38.46% of the animals. Morphological and molecular analyses confirmed the presence of M. pudendotectus and M. salmi, with prevalence rates of 76.9% and 53.9%, respectively. Histopathological examination revealed transverse and longitudinal sections of Metastrongylus parasites within the airways, causing partial to complete obstruction, interstitial pneumonia, and inflammatory responses. The study also highlights the public health significance of these parasites. The higher prevalence observed compared to earlier studies suggests changes in environmental conditions, host dynamics, or agricultural practices as possible factors, warranting further investigation. The findings underscore the need for comprehensive surveillance and control measures to mitigate the risk of zoonotic transmission, particularly in regions with significant wild and domestic swine populations. This study contributes to the understanding of Metastrongylus spp. distribution and their pathological impact, emphasizing the ecological importance of wild boars and the necessity for continued monitoring and research to prevent and control infections in both animal and human populations.

Analysis of seroprevalence data on Hepatitis E virus and Toxoplasma gondii in wild ungulates for the assessment of human exposure to zoonotic meat-borne pathogens.

Seroprevalence data for Toxoplasma gondii and Hepatitis E virus (HEV) in wild boar (Sus scrofa), roe deer (Capreolus capreolus), red deer (Cervus elaphus), mouflon (Ovis aries/musimon) and chamois (Rupicapra rupicapra) hunted/culled in northern Italy were used to fit seroprevalence distributions describing the exposure and co-exposure of the species to the two pathogens. The higher proportion of T. gondii and HEV seropositive animals was observed in wild boars with point estimate seroprevalence of 49% (N = 331) and 15% (N = 326) respectively. Data allowed comparisons by area (pre-Alpine Vs Alpine environment) for roe deer, red deer and mouflons. Contrasts between the distributions describing the uncertainty in seroprevalence suggest roe deer, red deer and mouflons have higher probability of being seropositive to T. gondii in pre-Alps. When considering HEV, few seropositive animals were detected and contrasts were symmetrically centred to zero for roe deer and red deer; mouflons shown higher probability of being seropositive in Alpine environment. HEV seropositive animals also included chamois (P = 5.1%, N = 97) in the Alpine districts, confirming circulation of HEV in remote areas. Evidence of HEV and T. gondii co-exposure was limited except for wild boars where it was observed in 30 samples representing 60% of the overall HEV-positive samples. Seroprevalence data of single infection and co-infection are extremely useful to investigate circulation of zoonotic pathogens in wild animals and estimate the foodborne risk of human exposure, however, these type of data do not directly translate into the presence/absence of the pathogen in seropositive and seronegative animals. At benefit of future development of quantitative risk assessments aiming at estimating the risk of human infection/co-infection via consumption of game meat, we developed and made available an online application that allows estimating the probability of the pathogen(s) being present as a function of seroprevalence data.

Prevalence of Alaria alata mesocercariae in wild boars from Brandenburg, Germany.

Since 2002, Alaria (A.) alata mesocercariae (AM) have been found during routine Trichinella inspection of wild boars in many European countries. To date, human infection with AM through consumption of undercooked or raw AM infested wild boar meat cannot be excluded. In Germany, data on the parasite's prevalence in wild boars are scarce. To better understand temporal and spatial fluctuations of this parasite, this study investigated the prevalence of AM in wild boars in the German federal state of Brandenburg during three hunting seasons from 2017 to 2020. In total, 28.3% (100/354, 95% CI: 23.3-33.3%) of all wild boars sampled in eight counties of Brandenburg were tested positive for AM by Alaria alata mesocercariae migration technique (AMT). AM were detected in wild boars from seven different counties. Samples from one county (Havelland) tested completely negative for AM (0/16). Prevalences of the seven AM positive counties of Brandenburg ranged from 11.5 (3/26, 95% CI: 2.5-30.1%) in Märkisch-Oderland to 64.1% (25/39, 95% CI: 47.2-78.8%) in Uckermark. An association between sex and A. alata positivity could not be determined. A statistically significant increase in frequency of older AM positive wild boars was observed (p = 0.001). For a nationwide assessment of the prevalence of A. alata in wild boars and the risk for consumers of ingesting viable AM by consumption of raw or undercooked AM infested wild boar meat, further long-term studies in different regions of Germany are needed.

Seroprevalence of Toxoplasma gondii and associated risk factors in domestic pigs raised from Cuba.

A cross-sectional study was carried out to determine the seroprevalence of Toxoplasma gondii and associated risk factors in pigs in the largest pork-producing region in Cuba. Serum samples from 420 pigs, including 210 sows and 210 post-weaning pigs, were tested for antibodies against T. gondii using a commercial indirect enzyme-linked immunosorbent assay. Anti-T. gondii antibodies were detected in 56 animals (13.3%, 95% CI: 10.1-16.6). A generalized estimating equations model revealed that the risk factors associated with higher seropositivity in pigs were altitude (higher in farm's location < 250 m above sea level (masl) versus ≥ 250 masl) and age (higher in sows compared to post-weaning pigs). The results indicated that this protozoan parasite is widely distributed on pig farms in the study area, which is a public health concern since the consumption of raw or undercooked pork meat products containing tissue cysts is considered one of the main routes of T. gondii transmission worldwide. Control measures should be implemented to reduce the risk of exposure to T. gondii in pigs in Cuba.

Macracanthorhynchus hirudinaceus in expanding wild boar (Sus scrofa) populations in Eastern Spain.

Prevalence and temporal evolution of the infection by the acanthocephalan Macracanthorhynchus hirudinaceus is studied in the Valencian Community (Eastern Spain), a region only recently fully colonized by the expanding native Eurasian wild boar (Sus scrofa). For 8 years, a total of 1486 wild boars were sampled in order to look for the parasite. The mean prevalence was 20.7% (95% CI, 18.6-22.8; 307/1486). We observed an increasing trend through time, both in the number of wild boars and affected districts. The prevalence of M. hirudinaceus rose in parallel to the annual capture of wild boars, and its presence has been expanding towards the East. A hotspot of M. hirudinaceus is located to the west of the study area, in Muela de Cortes Game Reserve, where 89.6% of the wild boars were positive for the infection, constituting one of the world's highest known prevalence areas.

Ticks on game animals in the fragmented agricultural landscape of western Poland.

Ticks (Acari: Ixodida) are well known external parasites of game animals that cause serious veterinary and medical problems. The occurrence and geographical distribution of different species of ticks in Western Poland have changed over the last decades. The purpose of the present study was to determine the species spectrum and prevalence of ticks parasitizing three species of game animals, the Eurasian wild boar Sus scrofa L., red deer Cervus elaphus L., and roe deer Capreolus capreolus (L.) in two hunting districts in Lubuskie Province. In addition, the distribution of ticks on the host's body and the intensity of infestation were determined. Ticks were collected from dead animals during the hunting seasons in 2013 and 2014, over the periods from May to June and from August to December. In total, 286 specimens were examined: 138 Eurasian wild boars, 8 red deers, and 140 roe deers. Altogether, 1891 ticks were collected. Three species of ticks were determined: Ixodes ricinus (L.), Dermacentor reticulatus (Fabricius, 1794), and Haemaphysalis concinna (C.L. Koch, 1844). H. concinna was recorded for the first time in Lubuskie Province.

First nationwide survey of the seroprevalence of Toxoplasma gondii in wild boars in Japan.

The increase in some wildlife species is of global concern. The utilization of wildlife meat as food and feed represents a potential source of food-borne pathogens; this is particularly a potential concern for the use of wild board as a food source in Japan. Regarding food safety and an animal infectious disease control, however, little is known about the infection level of zoonotic pathogens including Toxoplasma gondii (T. gondii) in wild boar populations in their natural habitats in Japan. A total of 1279 blood samples from 41 prefectures were collected from apparently healthy wild boars during the three hunting periods (September to February) of 2014-2015, 2015-2016, and 2017-2018. Out of these sera, 461 samples tested positive by a commercial indirect ELISA for T. gondii, and the total apparent and adjusted true seroprevalence were estimated to 36.0% (95% confidence interval [CI], 33.4-38.7) and 31.3% (95% CI, 33.1-38.9), respectively. The seroprevalence was significantly higher in yearlings and adults than in piglets (P < 0.05); however, no significant difference according to gender was noted. These results indicate the importance of adequate heating of wild boar meat before consumption to prevent transmission of T. gondii to humans. Furthermore, freezing meat for several days before cooking is recommended to reduce the risk of infection. In addition, although the incidence of toxoplasmosis in pig farms is relatively low in Japan, biosecurity measures against the felids and the varied intermediate hosts should be strengthened, especially, at the farms located in the wild boar habitats to prevent livestock infection.

Occurrence of Alaria alata in wild boars (Sus scrofa) in Poland and detection of genetic variability between isolates.

Alaria alata is a trematode included among several emerging zoonotic parasites. The mesocercarial larval stage of A. alata named Distomum musculorum suis (DMS) may potentially be infective for humans. In the past, DMS was often observed in wild boar meat during the official Trichinella inspection by artificial digestion before a more specific and effective detection method, the A. alata mesocercariae migration technique (AMT), was introduced. In the present study, the AMT method was used to screen 3589 tissue samples collected from wild boars hunted in Poland during the 2015-2019 period. The survey mainly focused on the southern part of Poland with the majority of samples coming from Malopolskie, Swietokrzyskie, and Dolnoslaskie provinces; samples from ten additional provinces were also included. The total prevalence was 4.2% with mean abundance of 4.7 DMS. Occurrence was dependent upon environmental conditions (i.e., wetland habitats and water reservoirs) rather than on sex of the host or season in which they were hunted. The recovered trematodes were identified as Alaria spp. according to their morphological features. Molecular analysis of 18S rDNA and COI genes confirmed the species identification to be A. alata and documented genetic variability among the isolates.

Lectin-Mediated Bacterial Modulation by the Intestinal Nematode Ascaris suum.

Ascariasis is a global health problem for humans and animals. Adult Ascaris nematodes are long-lived in the host intestine where they interact with host cells as well as members of the microbiota resulting in chronic infections. Nematode interactions with host cells and the microbial environment are prominently mediated by parasite-secreted proteins and peptides possessing immunomodulatory and antimicrobial activities. Previously, we discovered the C-type lectin protein AsCTL-42 in the secreted products of adult Ascaris worms. Here we tested recombinant AsCTL-42 for its ability to interact with bacterial and host cells. We found that AsCTL-42 lacks bactericidal activity but neutralized bacterial cells without killing them. Treatment of bacterial cells with AsCTL-42 reduced invasion of intestinal epithelial cells by Salmonella. Furthermore, AsCTL-42 interacted with host myeloid C-type lectin receptors. Thus, AsCTL-42 is a parasite protein involved in the triad relationship between Ascaris, host cells, and the microbiota.

Spinal cord toxoplasmosis in a young immunocompetent patient.

We report a case of spinal cord toxoplasmosis occurring as a primary infection in a 31-year-old immunocompetent man. Exhaustive immunologic and genetic investigations did not identify any immunodeficiency. The causative agent was a typical type 2 strain. In cases of spinal cord lesions, toxoplasmosis should be considered, even in an immunocompetent patient.

Non-invasive sampling in Itatiaia National Park, Brazil: wild mammal parasite detection.

BACKGROUND: Non-invasive sampling through faecal collection is one of the most cost-effective alternatives for monitoring of free-living wild mammals, as it provides information on animal taxonomy as well as the dynamics of the gastrointestinal parasites that potentially infect these animals. In this context, this study aimed to perform an epidemiological survey of gastrointestinal parasites using non-invasive faecal samples from carnivores and artiodactyls identified by stool macroscopy, guard hair morphology and DNA sequencing in Itatiaia National Park. Between 2017 and 2018, faeces from carnivores and artiodactyls were collected along trails in the park. The host species were identified through macroscopic and trichological examinations and molecular biology. To investigate the parasites, the Faust, Lutz and modified Ritchie and Sheather techniques and enzyme immunoassays to detect Cryptosporidium sp. antigens were used. RESULTS: A total of 244 stool samples were collected. The species identified were Chrysocyon brachyurus, Leopardus guttulus, Canis familiaris, Cerdocyon thous, Puma yagouaroundi, Leopardus pardalis, Puma concolor and Sus scrofa. There were 81.1% samples that were positive for parasites distributed mainly in the high part of the park. Helminths, especially eggs of the family Ascarididae, were more frequently detected in carnivore faeces (70.9%). Protozoa, especially Cryptosporidium sp., represented the highest frequency of infection in artiodactyl faeces (87.1%). This zoonotic protozoon was detected in eight mammalian species, including in a wild boar. High values of structural richness and Shannon and Simpson diversity indices were observed for the parasites, especially in the faeces of C. brachyurus. Significant differences in parasite diversity were observed between wild and domestic animals, such as C. brachyurus and C. familiaris, respectively, and between taxonomically distant species, such as C. brachyurus and S. scrofa. The highest values for parasite similarity were found among the species that frequented similar areas of the park, such as C. brachyurus and L. guttulus. CONCLUSIONS: The animals and parasite infections were identified through the combination of three techniques. High frequency parasite structures were diagnosed. Zoonotic protozoa were found and mainly occurred in samples from introduced species.

Clinical and epidemiological descriptions from trichinellosis outbreaks in Bulgaria.

Bulgaria is one of European countries where trichinellosis continues to be regularly diagnosed and registered. The clinical and epidemiological features of 72 cases of trichinellosis associated with five outbreaks caused by Trichinella spiralis and Trichinella britovi between 2009 and 2011, are described. At hospital admission, patients were often initially treated with antibiotics, without any improvement. A range of signs and symptoms were recorded, including: myalgia, elevated temperature, arthralgia, difficulty with movement, facial oedema, conjunctival hyperaemia, ocular haemorrhages, diarrhoea, skin rash, headache, and fatigue. Due to the variable clinical course of the disease, the diagnostic process for trichinellosis is often complex and difficult. This means the diagnosis may be established late for an appropriate treatment, potentially leading to a severe course of the disease with complications. Laboratory abnormalities were expressed by marked eosinophilia (97.2%), leucocytosis (70.8%), elevated serum creatine phosphokinase levels (82%), and antibody-positive results by ELISA and indirect hemagglutination. Patients were treated with albendazole (Zentel) 10 mg/kg for 7-10 days. In two outbreaks, the aetiological agent was T. spiralis, in one outbreak T. britovi, and an unknown Trichinella species in the fourth outbreak. The sources of infection were domestic pigs, probably fed with scraps and offal of wild game. In one outbreak, T. spiralis was also detected in brown rats trapped close to where the pig had been raised in the backyard. These epidemiological factors are relevant in considering implementation of targeted control programmes.

First molecular characterization of Sarcocystis miescheriana in wild boars (Sus scrofa) from Latvia.

Various muscle samples of wild boar (Sus scrofa) from Latvia were studied for the presence of Sarcocystis infection by means of morphological and molecular methods. Sarcocysts were detected in 122 out of 140 (87.1%) wild boar examined. According to the morphological appearance of sarcocysts, the observed cysts belonged to one morphological type and resembled Sarcocystis miescheriana. Twenty-three sarcocysts isolated from the muscles of Latvian wild boars were molecularly characterized at 18S rRNA, ITS1 and cox1. Additionally, eight sarcocysts obtained from Lithuanian wild boars were subjected to molecular analysis in order to compare intraspecific genetic variability. The amplified 18S rRNA region using newly designed primers is sufficiently variable to separate S. miecheriana from S. suihominis. All Latvian and Lithuanian isolates were confirmed belonging to S. miescheriana. No genetic variation was detected within 18S rRNA and ITS1. By contrast, the high intraspecific genetic variability of S. miescheriana was observed within cox1 since each newly obtained sequence represented a unique haplotype. The comparison made using S. miescheriana isolates from Italian and Japanese wild boar and Chinese domestic pig revealed the genetic similarity of the samples depending on their geographical distances. The current study provides the first detection of Sarcocystis infection in wild boars from Latvia and molecular characterization of S. miescheriana.

Genetic characterization and phylogenetic analysis of Sarcocystis suihominis infecting domestic pigs (Sus scrofa) in India.

A total of 57 tissue samples of domestic pigs (Sus scrofa) were collected from the meat outlets of five north Indian states and examined for sarcocystosis by histological and molecular methods. The genomic DNA extracted from five representative positive isolates was subjected to PCR amplification of the partial 18S rRNA gene followed by cloning and sequencing. Sequence analysis of the newly generated Indian isolates recorded 96.9-100.0% identity with published sequences of Sarcocystis suihominis. Two new haplotypes that have not been previously described manifested 99.5-100.0% nucleotide homology within themselves. In the phylogenetic analysis, Indian isolates of S. suihominis grouped together with S. suihominis originating from Italy, and they collectively formed a sister clade with Sarcocystis miescheriana within a clade containing various Sarcocystis spp. of ruminants having felids as final hosts. At the same time, this clade separated from a sister clade containing Sarcocystis spp. of bovid or cervid ruminants using canids as known or surmised definitive host. The current study established the phylogenetic relationship of Indian isolates of S. suihominis with various Sarcocystis spp. as well as with other taxa of Sarcocystidae family based on 18S rRNA gene for the first time.

A two-step morphology-PCR strategy for the identification of nematode larvae recovered from muscles after artificial digestion at meat inspection.

To ensure that meat from livestock and game is safe for human consumption, European legislation lays down rules for mandatory testing. Helminth larvae are a category of zoonotic foodborne pathogens that can contaminate meat. Among helminths, the only zoonotic nematode regulated in Europe regarding meat inspection is Trichinella spp.. It is precisely during Trichinella testing that other potentially zoonotic larvae can be found. Due to current lack of tools, their identification is often very complicated. Nematode larvae other than Trichinella, recovered from artificial digestions of pig and wild boar muscles from France and Germany, were subjected to a newly developed two-step identification scheme, which includes both morphological examination and molecular assays. The first step is a general orientation towards a broad taxonomic group; the second step consists of targeted identification based on the results of first step. Different parasites were identified, some of which were not zoonotic such as Metastrongylus spp. and Angiostrongylus vasorum, but others are known to be zoonotic such as Toxocara cati, Ascaris suum, and Uncinaria stenocephala. The strategy is efficient for the identification of nematode larvae recovered from muscles but could also be applied for larvae from other sources.

Description of a new species of Dermacentor Koch, 1844 (Acari: Ixodidae) from the mountains of Laos and Thailand.

Dermacentor pasteuri n. sp. (Acari: Ixodidae) is described based on adults ex wild boar and vegetation from Laos and Thailand. Adults of D. pasteuri n. sp. are similar to those of D. compactus Neumann, 1901, but can be distinguished by the shape of conscutum in the male, development of dorsal cornua in the female, size and shape of spurs on coxae and coloration of leg segments in both sexes.

Elimination of Taenia solium Transmission in Northern Peru.

BACKGROUND: Taeniasis and cysticercosis are major causes of seizures and epilepsy. Infection by the causative parasite Taenia solium requires transmission between humans and pigs. The disease is considered to be eradicable, but data on attempts at regional elimination are lacking. We conducted a three-phase control program in Tumbes, Peru, to determine whether regional elimination would be feasible. METHODS: We systematically tested and compared elimination strategies to show the feasibility of interrupting the transmission of T. solium infection in a region of highly endemic disease in Peru. In phase 1, we assessed the effectiveness and feasibility of six intervention strategies that involved screening of humans and pigs, antiparasitic treatment, prevention education, and pig replacement in 42 villages. In phase 2, we compared mass treatment with mass screening (each either with or without vaccination of pigs) in 17 villages. In phase 3, we implemented the final strategy of mass treatment of humans along with the mass treatment and vaccination of pigs in the entire rural region of Tumbes (107 villages comprising 81,170 people and 55,638 pigs). The effect of the intervention was measured after phases 2 and 3 with the use of detailed necropsy to detect pigs with live, nondegenerated cysts capable of causing new infection. The necropsy sampling was weighted in that we preferentially included more samples from seropositive pigs than from seronegative pigs. RESULTS: Only two of the strategies implemented in phase 1 resulted in limited control over the transmission of T. solium infection, which highlighted the need to intensify the subsequent strategies. After the strategies in phase 2 were implemented, no cyst that was capable of further transmission of T. solium infection was found among 658 sampled pigs. One year later, without further intervention, 7 of 310 sampled pigs had live, nondegenerated cysts, but no infected pig was found in 11 of 17 villages, including all the villages in which mass antiparasitic treatment plus vaccination was implemented. After the final strategy was implemented in phase 3, a total of 3 of 342 pigs had live, nondegenerated cysts, but no infected pig was found in 105 of 107 villages. CONCLUSIONS: We showed that the transmission of T. solium infection was interrupted on a regional scale in a highly endemic region in Peru. (Funded by the Bill and Melinda Gates Foundation and others.).