Prevalence Of Hepatitis E Virus Research Articles

Prevalence and molecular characterization of hepatitis E virus (HEV) from wild rodents in Hubei Province, China

Hepatitis E, caused by the hepatitis E virus (HEV), is a global public health issue. Low similarity between the gene sequences of mouse and human HEV led to the belief that the risk of human infection was low. Recent reports of chronic and acute hepatitis E caused by murine HEV infection in humans in Hong Kong have raised global concerns. Therefore, it is crucial to investigate the epidemiology and prevalence of HEV in China. We comprehensively analyzed different rodent HEV strains to understand rocahepevirus occurrence in Hubei Province, China. The HEV positivity rate for was 6.43% (73/1136). We identified seven near-full-length rocahepevirus strains and detected rat HEV antigens in tissues from different mouse species. HEV has extensive tissue tropism and a high viral load in the liver. We highlight the genetic diversity of HEVs in rodents and underscore the importance of paying attention to their variation and evolution.

Porcine-derived pancreatic enzyme replacement therapy may be linked to chronic hepatitis E virus infection in cystic fibrosis lung transplant recipients

ObjectivesIn high-income countries hepatitis E virus (HEV) is an uncommonly diagnosed porcine-derived zoonoses. After identifying disproportionate chronic HEV infections in persons with cystic fibrosis (pwCF) postlung transplant, we sought to...

Water-Based Epidemiological Investigation of Hepatitis E Virus in South Africa.

Hepatitis E virus (HEV) is an emerging zoonotic pathogen that exhibits great host diversity. The primary means of transmission of the virus in low- and middle-income countries is contaminated water, often due to a lack of access to proper sanitation, which leads to faecal contamination of water sources. Environmental surveillance is an important tool that can be used to monitor virus circulation and as an early warning system for outbreaks. This study was conducted to determine the prevalence and genetic diversity of HEV in wastewater, surface water (rivers and standpipe/ablution water), and effluent from a piggery in South Africa. A total of 536 water samples were screened for HEV using real-time reverse transcription-polymerase chain reaction. Overall, 21.8% (117/536) of the wastewater, river, and ablution water samples tested positive for HEV, whereas 74.4% (29/39) of the samples from the piggery tested positive. Genotyping revealed sequences belonging to HEV genotypes 3 (98%, 53/54) and 4 (2%, 1/54), with subtypes 3c, 3f, and 4b being identified.

Detection of Rat Hepatitis E Virus in Pigs, Spain, 2023.

We identified rat hepatitis E virus (HEV) RNA in farmed pigs from Spain. Our results indicate that pigs might be susceptible to rat HEV and could serve as viral intermediaries between rodents and humans. Europe should evaluate the prevalence of rat HEV in farmed pigs to assess the risk to public health.

Molecular Epidemiology of Hepatitis E Virus Genotypes in Blood Donors in Peshawar, Khyber Pakhtunkhwa

Background: Hepatitis E virus (HEV), an RNA virus, poses a significant global health threat, affecting 2.3 billion people annually, causing 70,000 deaths, over 50% of acute viral hepatitis cases. In Pakistan, HEV prevalence is high among pregnant women (26%), with a mortality rate of 26 to 30%. Blood transmission is a leading source of sporadic HEV infection.
 Methodology: The blood specimens were investigated with HEV to detect anti- IgM and IgG antibodies. Anti HEV IgM positive specimens confirmed the incidence of viral RNA by Polymerase chain reactions. The positive cases containing viral RNA were subjected to sequencing of ORF2.
 Result: A total of 3480 blood specimens were screened serologically by ELISA for the existence of anti HEV IgM and anti-HEV IgG antibodies. Of these 3480 samples, 170 (4.9%) were confirmed positive when screened for HEV antibodies among study population, there was a statistically significant difference observed between males and females (p=0.00001).  From 170 positive samples, 60 (1.72 %) were positive for having anti-HEV IgM antibodies in plasma, whereas 110 (3.16 %) were found with anti-HEV IgG antibodies. Among 60 (1.72 %) IgM-positive samples, 18 (0.51 %) were confirmed positive by PCR for the presence of HEV-RNA. Genotype 1 was observed in all 18 HEV RNA-positive samples.  
 Conclusion: The findings of this study underscore the urgency of implementing HEV screening protocols before blood donation. The risk of transmission through blood products is evident, with 4.9% of screened blood specimens exhibiting HEV antibodies. Therefore, the National Blood Transfusion Regulatory Authority must incorporate HEV screening as a routine procedure in Pakistan.

Seroprevalence of the Hepatitis E Virus in Indigenous and Non-Indigenous Communities from the Brazilian Amazon Basin.

Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis in tropical regions. In Brazil, HEV G3 is the only genotype detected to date. Reports on HEV prevalence are heterogeneous. We aimed to compare the prevalence of anti-HEV among three populations living in the Brazilian Amazon basin. Two cross-sectional studies were conducted in urban, rural, and Yanomami indigenous areas. Plasma samples from 428 indigenous and 383 non-indigenous subjects were tested for anti-HEV IgG using enzyme-linked immunosorbent assays. The overall prevalence of anti-HEV was 6.8% (95%CI: 5.25-8.72), with 2.8% (12/428) found in the Yanomami areas, 3% (3/101) in an urban area, and 14.2% (40/282) in a rural area. Multivariate logistic analysis indicated that patients aged 31-45 years or ≥46 years are more likely to present anti-HEV positivity, with a respective aOR of 2.76 (95%CI: 1.09-7.5) and 4.27 (95%CI: 1.58-12.35). Furthermore, residence in a rural area (aOR: 7.67; 95%CI: 2.50-33.67) represents a relevant risk factor for HEV infection. Additional studies detecting HEV RNA in fecal samples from both humans and potential animal reservoirs are necessary to comprehensively identify risk factors associated with HEV exposure.

Monitoring of hepatitis E virus in wastewater can identify clinically relevant variants.

Hepatitis E virus (HEV) is prevalent worldwide and can cause persistent infection with severe morbidity. Antiviral treatment approaches can lead to the emergence of viral variants encoding escape mutations that may impede viral clearance. The frequency of these variants remains unknown in the human population as well as environment due to limited comprehensive data on HEV diversity. In this study, we investigated the HEV prevalence and diversity of circulating variants in environmental samples, that is, wastewater and rivers from North-Rhine Westphalia, Germany. HEV prevalence could be determined with 73% of samples tested positive for viral RNA via qRT-PCR. Using high-throughput sequencing, we were able to assess the overall genetic diversity in these samples and identified the presence of clinically relevant variants associated with drug resistance. In summary, monitoring variants from environmental samples could provide valuable insights into estimating HEV prevalence and identifying circulating variants that can impact treatment outcome.

High Prevalence of Hepatitis E IgM Antibody among Pregnant Women in Their Second and Third Trimester in Southwest Nigeria

Background: Background: Pregnant women with Hepatitis E virus (HEV) infection, particularly those in the second or third trimester, are at increased risk of acute liver failure, fetal loss, and mortality; but unfortunately, routine HEV screening is yet to be introduced for pregnant women in Nigeria and many developing nations. This study was conducted to determine HEV prevalence and the associated risk factors among pregnant women unaware of their HEV status in three states of the southwestern geopolitical zone in Nigeria. Methods: Two hundred and thirty-two consenting pregnant women aged 18 -55 years from Lagos, Oyo, and Osun state were recruited for the study and screened for HEV IgM antibodies using DIAPRO HEV IgM ELISA KIT (Milanno-Italy). Sociodemographic data and risk factors were obtained using a structured questionnaire, and data were analyzed using SPSS version 23. Results: An overall HEV prevalence rate of 9.9% was observed among pregnant women in Southwest Nigeria. State-specific prevalence of 14.7%, 8.5%, and 6.7% was observed in Oyo, Lagos, and Osun, respectively. HEV prevalence increased with increase in trimester of pregnancy, with more than 80% of the HEV prevalence found among women in their second and third trimester. All the HEV prevalence occurring in women of active childbearing age (≤ 40 years) and among low-income earners. None of the risk factors considered was found to have a statistical correlation with HEV prevalence. Conclusion: High HEV prevalence in the second and third trimesters was reported in southwest Nigeria. We advocate routine screening of pregnant women for HEV IgM antibody for prompt HEV detection and proper HEV management to forestall HEV complications in pregnancy.

Prevalence of hepatitis E virus genotype 4 of probable human origin in Tibetan pigs from the Qinghai-Tibetan Plateau, China.

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. In 2018-2022, we investigated the presence of HEV RNA in 1233 stool samples collected in the Qinghai-Tibetan Plateau, including humans (16), Tibetan pigs (624), yaks (312), sheep (267), and dogs (14). HEV RNA was only detected in Tibetan pig faecal samples (18.27%, 114/624). To perform molecular characterization of HEV strains in Tibetan pigs, we obtained 21 complete HEV genome sequences between 2018 and 2022. Sequence comparisons showed that 21 HEV strains from Tibetan pigs shared the mean nucleotide identities with the reference HEV strains ranging between 82.9% and 94.9% and 89.3% and 92.1% similarities with human HEV strains. Phylogenetic analysis confirmed that all HEV strains were genotype 4, closely related to human HEV strains. Sequence recombinant analysis showed five potential recombinant strains identified in this study, of which SWU/D18/2018 (GenBank No. MK410044) was recombinant with human and swine HEV strains, located 6509-6878 nt from the recombination point. Based on the Bayesian evolutionary trees, we found that most HEV strains diverged later than human HEV (16 Tibetan pig HEV strains diverged later than 1979, and seven human HEV strains diverged earlier than 1979). Therefore, we speculated that the prevalence of HEV 4 in Tibetan pigs possibly originated from humans in the Qinghai-Tibetan Plateau.

Exploring hepatitis E virus seroprevalence and associated risk factors among the human population in Tandil, Buenos Aires, Argentina.

Hepatitis E virus (HEV) infection is a common cause of acute clinical hepatitis worldwide and is emerging as a disease in Argentina. It is primarily transmitted through contaminated water and food, following the fecal-oral route. Furthermore, is a zoonotic disease with swine as the primary reservoir. Prevalence of HEV infection in humans in several regions of Argentina remains unknown. (i) Determine the seroprevalence of HEV among the human population in Tandil, Buenos Aires, Argentina; (ii) Evaluate its association with demographic, socioeconomic and other risk exposures variables, and (iii) Describe and analyze spatial patterns related to HEV infection. From August 2020 to July 2021, serum samples were collected from 969 individuals aged 1-80 years. Seroprevalence and 95% Confidence Interval was determined. To assess the factors associated with the presence of anti-HEV antibodies, associations between the variables and seropositivity were evaluated through bivariate and multivariate analysis. Spatial scanning for clusters of positivity was carried out. Factors associated with these clusters were also assessed. Anti-HEV antibodies were detected in 4.64% (IC 95% 3.27-6.02) of samples. Dark urine was associated with seropositivity (p = 0.02). Seropositivity was linked with the presence of natural water courses near their households (p = 0.02); the age (p = 0.04); and previous travel to Europe (p = 0.04). A spatial cluster of low rates of HEV seropositivity was detected, with greater distance of the households to water courses associated to the cluster, and male sex inversely associated to it. This study is the first study to investigate the prevalence of HEV in the population from Tandil, Buenos Aires, Argentina. Considering HEV infection in the differential diagnosis in individuals presenting acute hepatitis is highlighted. The incorporation of HEV testing into blood screening policies should be mandatory. Factors related to the infection and spatial patterns of high and low risk were determined, and should be considered when implementing specific preventive measures.

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.

First Seroepidemiological Investigation of Hepatitis E Virus Infection in Backyard Pigs from Northeastern India: Prevalence and Associated Risk Factors.

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis globally, with zoonotic potential, and pigs are considered the major reservoir. To determine the seroprevalence of HEV infection in pigs reared in backyard conditions in the northeastern region of India, blood samples were collected from 400 pigs from five northeastern states (80 samples from each state) and tested for IgG antibodies against HEV using an ELISA assay. Questionnaires on farm characteristics and management practices were completed, and risk factors associated with HEV were studied using univariate and multivariate analysis. The apparent seroprevalence of HEV infection was 51% (46.1-55.9, 95% CI), with a true prevalence of 52.98% (47.22-58.75, 95% CI). The risk factors significantly associated with higher HEV seropositivity were as follows: lack of disinfection (OR 4.65), feeding swill (restaurant and bakery waste) (OR 2.55), failure to follow the all-in-all-out production system (OR 3.47), and medium holding size (OR 9.83), which refers to mixed rearing of younger and older age groups. This study demonstrates that HEV is widespread among pigs reared in northeastern India. The risk factor analysis conducted in this study provides valuable insights into the prevalence of HEV in the region.

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.

Meta-analysis and moderator analysis of the seroprevalence of hepatitis E in South-Eastern Asia

By 2030, the World Health Organization wants to decrease viral hepatitis incidence and mortality by 90% and 65%, respectively. One of the agents responsible for the increased burden of viral hepatitis is the hepatitis E virus (HEV). This emerging pathogen is prevalent worldwide causing both acute and chronic infection. The rising risk profile of HEV has become a source of increased global public health concern. Despite this challenge, South-Eastern Asia (SEA), where many at-risk people are found, lacks uniform HEV prevalence data. Therefore, a meta-analysis was conducted to assess the overall prevalence of hepatitis E in SEA. Using R statistical software, a random effect model was used to estimate the logit-transformed prevalence. Moderator analyses were used to investigate the potential sources of variation. Thirty-two studies comprising 29,944 with 6806 anti-HEV antibody-positive individuals were evaluated. The overall HEV seroprevalence in SEA was 21% (95% confidence interval [CI]: 17–27) with high heterogeneity. At the country level, Laos has the highest prevalence estimate of 39% (CI: 16–69). Also, the studied population, year of publication, duration of sampling, and diagnostic method are significant HEV prevalence predictors accounting for 22.61% of the observed heterogeneity. The high HEV prevalence found in this study necessitates coordinated national and regional efforts to combat this emerging disease.

Infection Dynamics and Genomic Mutations of Hepatitis E Virus in Naturally Infected Pigs on a Farrow-to-Finish Farm in Japan: A Survey from 2012 to 2021.

Hepatitis E virus (HEV) causes acute or chronic hepatitis in humans. Pigs are the primary reservoir for zoonotic HEV genotypes 3 and 4 worldwide. This study investigated the infection dynamics and genomic mutations of HEV in domestic pigs on a farrow-to-finish pig farm in Japan between 2012 and 2021. A high prevalence of anti-HEV IgG antibodies was noted among pigs on this farm in 2012, when the survey started, and persisted for at least nine years. During 2012-2021, HEV RNA was detected in both serum and fecal samples, indicating active viral replication. Environmental samples, including slurry samples in manure pits, feces on the floor, floor and wall swabs in pens, and dust samples, also tested positive for HEV RNA, suggesting potential sources of infection within the farm environment. Indeed, pigs raised in HEV-contaminated houses had a higher rate of HEV infection than those in an HEV-free house. All 104 HEV strains belonged to subgenotype 3b, showing a gradual decrease in nucleotide identities over time. The 2012 (swEJM1201802S) and 2021 (swEJM2100729F) HEV strains shared 97.9% sequence identity over the entire genome. Importantly, the swEJM2100729F strain efficiently propagated in human hepatoma cells, demonstrating its infectivity. These findings contribute to our understanding of the prevalence, transmission dynamics, and genetic characteristics of HEV in domestic pigs, emphasizing the potential risks associated with HEV infections and are crucial for developing effective strategies to mitigate the risk of HEV infection in both animals and humans.

Age and Gender Trends in the Prevalence of Markers for Hepatitis E Virus Exposure in the Heterogeneous Bulgarian Population.

The prevalence of hepatitis E virus (HEV) in the Bulgarian population remains underestimated. The aim of the present study was to evaluate age and gender trends in HEV prevalence in the heterogeneous Bulgarian population. Stored serum samples from blood donors and different patient sub-populations-kidney recipients (KR), patients with Guillain-Barre syndrome (GBS), Lyme disease (LD), patients with liver involvement and a clinical diagnosis other than viral hepatitis A and E (non-AE), hemodialysis (HD) and HIV-positive patients (HIV)-were retrospectively investigated for markers of past and recent/ongoing HEV infection. The estimated overall seroprevalence of past infection was 10.6%, ranging from 5.9% to 24.5% for the sub-populations evaluated, while the seroprevalence of recent/ongoing HEV infection was 7.5%, ranging from 2.1% to 20.4%. The analysis of the individual sub-populations showed a different prevalence with respect to sex. In regard to age, the cohort effect was preserved, as a multimodal pattern was observed only for the GBS sub-population. Molecular analysis revealed HEV 3f and 3e. The type of the population is one of the main factors on which the anti-HEV prevalence depends, highlighting the need for the development of guidelines related to the detection and diagnosis of HEV infection with regard to specific patient populations.

Prevalence of hepatitis E virus and its association with adverse pregnancy outcomes in pregnant women in China.

Hepatitis E virus (HEV) infection has become a global concern, especially in pregnant women. However, the association between HEV prevalence and age, gravidity and parity of pregnant women remains unclear. Pregnant women (n=19,762) were enrolled for HEV prevalence and associated adverse pregnancy outcomes investigation in Qujing City, Yunnan Province of China from May 2019 to December 2020. The seroprevalence of HEV was 11.6% (2,297/19,762; 95% CI:11.2%-12.1%). About 11.4% (2,247/19,762; 95% CI:10.9%-11.8%) were positive for anti-HEV IgG antibody, 0.1% (22/19,762; 95% CI:0.1%-0.2%) were positive for anti-HEV IgM antibody, and 0.1% (28/19,762; 95% CI:0.1%-0.2%) were positive for both anti-HEV IgM and IgG antibodies. Sixty-one out of 2,297 anti-HEV-antibodies-positive pregnant women were positive for HEV RNA. Phylogenetic analysis revealed that all HEV isolates from pregnant women belong to genotype 4. Age, gravidity and parity are associated with increased prevalence of HEV. Pregnant women positive for HEV-IgG antibody bear a higher risk for an adverse pregnancy history and liver injury with elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels than anti-HEV-negative pregnant women. Furthermore, seropositive pregnant women suffered a higher adverse maternal outcomes risk (crude odds ratio [cOR]=1.29; 95% CI: 1.16-1.43; adjusted odds ratio [aOR]=1.40, 95% CI: 1.25-1.55 for anti-HEV-IgG-positive pregnant women and cOR=1.38, 95% CI: 1.02-1.86; aOR=1.43, 95% CI: 1.05-1.95 for anti-HEV-IgM-positive pregnant women) and fetal outcomes risk (cOR=1.80, 95% CI: 1.61-2.01; aOR=1.77, 95% CI: 1.57-1.99) than anti-HEV-negative pregnant women. Adverse pregnancy outcomes of HEV infection are aggravated by age, gravidity and parity. In this study, we demonstrated high prevalence of HEV in pregnancy women in China, and HEV infection can cause various adverse maternal and neonatal outcomes.

Prevalence of Hepatitis A Virus and Hepatitis E Virus Infection in the Patients Presenting with Acute Viral Hepatitis in Eastern India: A Cross-sectional Study

Introduction: Enterically transmitted Hepatitis A Virus (HAV) and Hepatitis E Virus (HEV) are the most common cause of Acute Viral Hepatitis (AVH) and a major health concern in developing nations like India. Both viruses cause AVH and are spread predominantly through the faecal-oral pathway, most commonly through contaminated water. Aim: To estimate the prevalence of HAV and HEV infection in patients presenting with AVH. Materials and Methods: An analytical cross-sectional study was undertaken in Indira Gandhi Institute of Medical Sciences, Bihar. The study was conducted over a period of 24 months from November 2019 to October 2021. All patients presenting with AVH were included as study participants. The blood samples were subjected to test anti-HAV and anti-HEV positivity. Prevalence of HAV and HEV was calculated taking total cases of AVH as denominator. Patients with confirmed infection with HCV, HBV and any other cause of hepatitis were excluded from the study. Templates were generated in an Microsoft Excel spreadsheet and analysis of data was done using Statistical Package of the Social Sciences software (SPSS) version 20.0. Quantitative data were presented as frequency and percentages. Results: A total of 682 patients presented with acute hepatitis. The AVH patients comprised 467 males (68.5%) and 215 (31.5%) females with the mean age 39.6±18.87 years. The current study reports the seroprevalence of 9.18% HAV and 8.35% of HEV. A total of 4 patients tested positive for coinfection with HAV and HEV. Most of the HAV patients belonged to an age group less than or equal to 12 years (25,58.1%) and none were more than 60 years. However, none of the HEV patients were children and most of them were aged between 13 to 60 years (46,92%). A male preponderance among HAV (28,65.1%), and HEV (38,76%) was noted. Conclusion: Low seroprevalence was noted, with infection more common in younger age group and male patients. Further studies and vaccination along with surveillance system strengthening are warranted.

Ethnic differences in hepatitis A and E virus seroprevalence in patients attending the Emergency Department, Paramaribo, Suriname.

Hepatitis A virus (HAV) and hepatitis E virus (HEV) have enteric modes of transmission and are common causes of acute hepatitis in low- and middle-income countries. HEV is also characterised as a zoonotic infection and is prevalent in high-income countries. Data on HAV and HEV prevalence in Suriname, a middle-income country in South America, are scarce. Serum samples of 944 and 949 randomly selected patients attending the Emergency Department at the Academic Hospital of Paramaribo, the capital of Suriname, were analysed for anti-HAV antibodies (anti-HAV) and anti-HEV antibodies (anti-HEV), respectively. Determinants of anti-HAV and anti-HEV positive serology were evaluated using multivariable logistic regression. Anti-HAV prevalence was 58.3% (95% CI 55.4 to 61.4%) and higher prevalence was independently associated with belonging to the Tribal or Indigenous population and older age. Anti-HEV prevalence was 3.7% (95% CI 2.6 to 5.0%) and higher prevalence was associated with Tribal and Creole ethnicity and older age. In Suriname, exposure to HAV is consistent with a very low endemic country and exposure to HEV was rare. Both viruses were more prevalent in specific ethnic groups. As anti-HAVantibodies were less frequently found in younger individuals, they could be susceptible to potential HAV outbreaks and might require HAV vaccination.

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.