Phylogenetic analysis and epidemiological history of Hepatitis E virus 3f and 3c in swine and wild boar, Italy

Hepatitis E Virus RNA Detection in Liver and Muscle Tissues Sampled from Home Slaughtered Domestic Pigs in Central Italy

Hepatitis E virus is a worldwide emerging foodborne pathogen; raw or undercooked meats and liver pork products can cause infection through the orofecal route. In Central-Southern Italy, small traditional farming method, associated with the possibility of environmental sharing with wild species, can facilitate HEV diffusion and persistence. The aim of this study was to determine HEV genotype and subtype in Marche region from home slaughtered domestic pigs involved in small and traditional food chains. A total of 236 liver and muscle tissues and 6 pooled salami samples were screened. Laboratory workflow started with homogenization, followed by RNA extraction. Nested reverse transcription PCR and qRT-PCR were used to amplify specific parts of overlapping open reading frames belonging to the HEV genome. A total of 42/236 (17.79%) liver and 8/236 (3.39%) diaphragm specimens were positive; none of the pooled salami specimens showed positive HEV signal. The discovered HEV3c presented high nucleotide similarities with ones amplified from wild boar populations hunted in the same province. Extensive farming methods and environmental sharing with wild animal species support cross-infection infections, as observed in the present study. Although salami resulted negative for HEV RNA detection, the effects of food technologies on viral loads remain unclear. Therefore, further scientific investigations coupled with efficacious standardized laboratory procedures will be the next challenge.

Evidence of Circulation and Phylogenetic Analysis of Hepatitis E Virus (HEV) in Wild Boar in South-East Italy

Hepatitis E virus (HEV) is an important cause of acute viral hepatitis in humans worldwide. The food-borne transmission of HEV appears to be a major route in Europe through the consumption of pork and wild boar meat. HEV epidemiology in wild boars has been investigated mainly in Northern and Central Italian regions, whilst information from Southern Italy is limited. We investigated the occurrence of HEV in wild boar in the Apulia and Basilicata regions (Southern Italy). Thirteen (10.4%) out of one hundred and twenty-five wild boar samples tested positive for HEV using a quantitative reverse transcription PCR. HEV prevalence was 12% in Apulia and 9.3% in Basilicata. Seven samples were genotyped, and different subtypes (c, f, m) of genotype 3 were identified. The complete genome of a 3m strain was determined, and the virus showed the highest nucleotide identity to a human HEV strain identified in France in 2017. These findings demonstrate the substantial circulation of HEV in the wild boar population in Italian Southern regions. Gathering information on the HEV strains circulating in different geographical areas is useful for tracking the origin of HEV outbreaks and assessing the epidemiological role of wild boar as a potential virus reservoir for domestic pigs.

Hepatitis E Virus in the Wild Boar Population: What Is the Real Zoonotic Risk in Portugal?

Hepatitis E virus (HEV) is an important zoonosis in wild boar. Reported zoonotic cases are mainly associated with the consumption of raw/undercooked meat and/or liver. This study aims to determine the occurrence of HEV in the Portuguese wild boar population. During the hunting season 2021/2022, 123-matched samples (liver, faeces, and blood) were collected from hunted wild boars throughout Portugal. An RT-PCR assay tested liver and faeces samples to detect HEV-RNA. From blood samples, an ELISA test was performed. Only one liver sample was positive for HEV (0,8%) and one other from faeces. A total of 34 sera were seropositive (26.7%). At the same time, in a survey of 106 hunters, 21 consumed/ate the liver of wild boars (19.8%). Only three recognised the possibility of consuming it undercooked. Contrary to previous studies in Portugal, the prevalence of HEV in liver and faeces is low, but the seropositivity is higher. But, when analyzing in detail, it could be observed that an HEV hotspot exists in the southeast of central Portugal and that it is a zoonotic risk for hunters of this region. The data of this study reinforce the importance of including HEV in surveillance programs for wildlife diseases to expand the potential zoonotic information.

Temporal changes in the genotypes of Paslahepevirus balayani in southern Spain and their possible link with changes in pig trade imports

Introduction

Paslahepevirus balayani (HEV) is an endemic zoonotic disease ranked as a major cause of acute hepatitis in Europe. Most infections occurring in Europe are due to the endemic several subtypes of genotype 3, through the consumption of raw or undercooked pork, observing a genotype geographical distribution pattern among countries Because of global changes in the pig and pork trading markets, subtype distribution might vary. We aimed to evaluate the temporal distribution of HEV genotypes in patients from southern Spain with acute hepatitis to determine whether these changes were related to the pig import trade during the study period between 2018 and 2022.

Methods

Prospective longitudinal study including patients with acute hepatitis from southern Spain between 2018 and 2022. HEV RNA and antibodies was tested in all patients. In patients with detectable HEV RNA, genotype was obtained. To determine the number of imported pigs and their origins, we checked the official data from the Spanish statistics on international trade of Spanish Minister of Industry during by country of origin during the same study period.

Results

A total of 659 patients with acute hepatitis were included in the study. Among them, 162 (24.5%) had at least one marker (IgM or RNA) of acute HEV infection. Among the 71 patients with detectable viral RNA, genotypes could be obtained for 58 (81.6%). The most prevalent HEV genotype was 3f (n = 48; 78.6%), showing a decreasing prevalence of over time, from 100% in 2018 to 70.6% in 2022. Since 2021, the emergence of other genotypes has been determined. A significant increase in the number of animals imported was observed since the beginning of the study. Denmark experienced a significant rise, from 0.03% in 2018 of total imports to 10.4% in 2022.

Conclusions

HEV molecular diversity is changing in Spain, could be linked to changes in fattening pig import origin.

The Role of Wildlife and Pests in the Transmission of Pathogenic Agents to Domestic Pigs: A Systematic Review

Wild animals and pests are important reservoirs and vectors of pathogenic agents that can affect domestic pigs. Rapid globalization, anthropogenic factors, and increasing trends toward outdoor pig production facilitate the contact between domestic pigs and wildlife. However, knowledge on the transmission pathways between domestic pigs and the aforementioned target groups is limited. The present systematic review aims to collect and analyze information on the roles of different wild animal species and pests in the spread of pathogens to domesticated pigs. Overall, 1250 peer-reviewed manuscripts published in English between 2010 and 2022 were screened through the PRISMA framework using PubMed, Scopus, and Web of Science databases. A total of 84 studies reporting possible transmission routes of different pathogenic agents were included. A majority of the studies (80%) focused on the role of wild boars in the transmission of pathogenic agents to pig farms. Studies involving the role of rodents (7%), and deer (6%) were the next most frequent, whereas the role of insects (5%), wild carnivores (5%), wild birds (4%), cats (2%), and badgers (1%) were less available. Only 3.5% of studies presented evidence-based transmission routes from wildlife to domestic pigs. Approximately 65.5% of the included studies described possible risks/risk factors for pathogens' transmission based on quantitative data, whereas 31% of the articles only presented a hypothesis or qualitative analysis of possible transmission routes or risk factors and/or contact rates. Risk factors identified include outdoor farms or extensive systems and farms with a low level of biosecurity as well as wildlife behavior; environmental conditions; human activities and movements; fomites, feed (swill feeding), water, carcasses, and bedding materials. We recommend the strengthening of farm biosecurity frameworks with special attention to wildlife-associated parameters, especially in extensive rearing systems and high-risk zones as it was repeatedly found to be an important measure to prevent pathogen transmission to domestic pigs. In addition, there is a need to focus on effective risk-based wildlife surveillance mechanisms and to raise awareness among farmers about existing wildlife-associated risk factors for disease transmission.

Hepatitis E Virus (HEV): Identification of Subtypes 3b and 3m in Wild Boar Population in Liguria Region, Italy

The wild boar is an important natural reservoir for the zoonotic transmission of the hepatitis E virus (HEV) around the world. In particular, HEV genotypes 3 and 4 are an emerging problem in industrialized countries, as the number of wild boars has increased, and their territory is ever closer to farms and populated areas. This study describes the HEV prevalence and geographic circulation among wild boar populations in the Ligurian region (Italy) during the period 2019-2022. Liver samples from 849 wild boars were analyzed for HEV RNA using real-time RT-PCR; positive samples were then subjected to sequencing and phylogenetic analysis. Overall, 6.7% of the wild boars were positive for HEV RNA; however, in the last two years, the percentage of positive animals almost doubled. Phylogenetic analysis showed that wild boar HEV sequences belonged to genotype 3 and clustered within subtypes 3a and 3c, and, for the first time in Italy, subtypes 3b and 3m were identified. Interestingly, 13 sequences could not be assigned to a recognized subtype. Furthermore, the results showed different circulations of identified subtypes across the territory. These findings increase the knowledge of HEV-3 heterogeneity in Italy and describe the role of wild boars in maintaining an active viral circulation in the environment.

Hepatitis E Virus Detection in Hunted Wild Boar Liver and Muscle Tissues in Central Italy

In different European countries, including Italy, hepatitis E virus (HEV) has been recognized as an emerging public health concern. Humans are infected through the orofecal route by the ingestion of contaminated uncooked or undercooked animal-origin foodstuffs. Wild boars (Sus scrofa) have gained a crucial role as viral reservoirs. HEV-3 is the most frequently identified genotype from hunted wild boar liver and muscle tissues. The Marche region, more specifically Ascoli Piceno province, is characterized by a rooted hunting tradition and related product consumption. In this research study, 312 liver and 296 muscle specimens were screened using biomolecular assays, and HEV RNA was detected from 5.45% and 1.35% of liver and muscle samples, respectively. Phylogenetic analysis revealed that positive animals were infected by genotype 3 subtype c. Based on the environmental pathogen characteristics, HEV has also evolved to guarantee its survival in a wild environment. Therefore, wild boars and ruminants have a key role in its persistence. Epidemiological data regarding HEV circulation have resulted as necessary, and biomolecular analysis represents an important means of monitoring and establishing preventive measures. A multidisciplinary approach could provide a wide perspective regarding HEV and infectious implications on human, animal, and environmental health.

Hepatitis E virus detection in hunted wild boar (Sus scrofa) livers in Central Italy

Hepatitis E virus (HEV) is a zoonotic pathogen, responsible for numerous cases of infection in humans. Transmission occurs through the orofecal route, and ingestion of contaminated foods represents an important risk factor for final consumer's health. Wild animal species, in particular wild boar (Sus scrofa), are the main virus reservoirs; liver is the target organ, from which, through the hematic diffusion, HEV reaches different tissues and organs, as muscular one. The hygienic-sanitary critical issues connected with game meat food chain in general, and particularly wild boar, with special regards to any geographical area where this animal species can be directly in contact with humans, domestic ones (i.e., domestic pig), and other wild reservoirs (i.e., wild ruminants), finds favorable environmental conditions, have induced us to conduce the present scientific investigation. During the hunting season 2019/2020, a total of 156 wild boar livers were collected from provided plucks at slaughterhouse in Ascoli Piceno. Nested RT-PCR was used for the viral RNA detection. Results demonstrated a positivity of 5.12% (8/156), and the circulation in the screened area of genotype 3 subtype c, which is frequently identified in Central Italy. HEV sanitary relevance and the emerging role of any food chains in its transmission impose further detailed studies. The molecular screening of hunted wild boars' livers can provide important information about virus's circulation in wild animal populations in a specific area.

Molecular Identification and Characterization of a Genotype 3 Hepatitis E Virus (HEV) Strain Detected in a Wolf Faecal Sample, Italy

Hepatitis E virus (HEV) infection is a major health problem worldwide. In developed countries, zoonotic transmission of HEV genotypes (Gt) 3 and 4 is caused by the ingestion of raw or undercooked meat of infected pigs and wild boars, the main reservoirs of HEV. However, additional animals may harbour HEV or HEV-related strains, including carnivores. In this study, we investigated the molecular epidemiology of orthohepeviruses in wild canids by screening a total of 136 archival faecal samples, collected from wolves (42) and red foxes (94) in Northwestern Italy. Orthohepevirus RNA was identified in a faecal specimen, collected from a wolf carcass in the province of La Spezia (Liguria Region, Italy). The nearly full-length (7212 nucleotides) genome of the strain HEV/81236/Wolf/2019/ITA (GenBank accession no. MZ463196) was determined by combining a sequence-independent single-primer amplification (SISPA) approach with the Oxford Nanopore Technologies sequencing platform. Upon phylogenetic analysis, the HEV detected in wolf was segregated into clade HEV-3.1, displaying the highest nucleotide (nt) identity (89.0-93.3%) to Gt3 strains belonging to subtype c. Interestingly, the wolf faecal sample also contained porcine astrovirus sequences, endorsing the hypothesis of a dietary origin of the HEV strain due to preying habits.

Hepatitis E Virus (HEV) Spread and Genetic Diversity in Game Animals in Northern Italy

Hepatitis E virus (HEV) is the causative agent of hepatitis E, an emerging public health infection which has an increasing incidence across Europe. Because of the apparent lack of species barriers, HEV was characterized as a zoonotic agent. Swine are recognized as the main reservoir, but HEV is also found in wild animals such as ungulates, lagomorphs, and bats. Our work aimed at detecting the HEV presence in wild fauna in two hunting areas of Northern Italy (Parma and Sondrio areas) with different environmental and anthropic characteristics to investigate its possible role as reservoir. Liver samples were collected from wild boars, red deer, roe deer and chamois, and viral identification was carried out by One-Step RT Real-time PCR. Positive samples were genotyped, and phylogenetic analysis was performed. The virus was found only in the wild boar population, with different prevalence and subtypes in the two areas (14% HEV3a and 1.2% close to HEV3f in Parma and Sondrio, respectively). Wild ruminants seem otherwise to pose a marginal risk. Given the high pig farm density in the Parma area, and expansion of the wild boar population, continuous monitoring of the strains circulating in wildlife is crucial.