Hepatitis E virus infects brain microvascular endothelial cells, crosses the blood-brain barrier, and invades the central nervous system.

Hepatitis E virus (HEV) is an important but understudied zoonotic virus causing both acute and chronic viral hepatitis. A proportion of HEV-infected individuals also developed neurological diseases such as Guillain-Barré syndrome, neuralgic amyotrophy, encephalitis, and myelitis, although the mechanism remains unknown. In this study, by using an in vitro blood-brain barrier (BBB) model, we first investigated whether HEV can cross the BBB and whether the quasi-enveloped HEV virions are more permissible to the BBB than the nonenveloped virions. We found that both quasi-enveloped and nonenveloped HEVs can similarly cross the BBB and that addition of proinflammatory cytokine tumor necrosis factor alpha (TNF-α) has no significant effect on the ability of HEV to cross the BBB in vitro. To explore the possible mechanism of HEV entry across the BBB, we tested the susceptibility of human brain microvascular endothelial cells lining the BBB to HEV infection and showed that brain microvascular endothelial cells support productive HEV infection. To further confirm the in vitro observation, we conducted an experimental HEV infection study in pigs and showed that both quasi-enveloped and nonenveloped HEVs invade the central nervous system (CNS) in pigs, as HEV RNA was detected in the brain and spinal cord of infected pigs. The HEV-infected pigs with detectable viral RNA in CNS tissues had histological lesions in brain and spinal cord and significantly higher levels of proinflammatory cytokines TNF-α and interleukin 18 than the HEV-infected pigs without detectable viral RNA in CNS tissues. The findings suggest a potential mechanism of HEV-associated neuroinvasion.

Hepatitis E virus RNA-dependent RNA polymerase is involved in RNA replication and infectious particle production.

BACKGROUND AND AIMS: Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis worldwide. Its positive-strand RNA genome encodes three open reading frames (ORF). ORF1 is translated into a large protein composed of multiple domains and is known as the viral replicase. The RNA-dependent RNA polymerase (RDRP) domain is responsible for the synthesis of viral RNA. APPROACH AND RESULTS: Here, we identified a highly conserved α-helix located in the RDRP thumb subdomain. Nuclear magnetic resonance demonstrated an amphipathic α-helix extending from amino acids 1628 to 1644 of the ORF1 protein. Functional analyses revealed a dual role of this helix in HEV RNA replication and virus production, including assembly and release. Mutations on the hydrophobic side of the amphipathic α-helix impaired RNA replication and resulted in the selection of a second-site compensatory change in the RDRP palm subdomain. Other mutations enhanced RNA replication but impaired virus assembly and/or release. CONCLUSIONS: Structure-function analyses identified a conserved amphipathic α-helix in the thumb subdomain of the HEV RDRP with a dual role in viral RNA replication and infectious particle production. This study provides structural insights into a key segment of the ORF1 protein and describes the successful use of reverse genetics in HEV, revealing functional interactions between the RDRP thumb and palm subdomains. On a broader scale, it demonstrates that the HEV replicase, similar to those of other positive-strand RNA viruses, is also involved in virus production.

Risk of transfusion-transmitted hepatitis E virus infection from pool-tested platelets and plasma.

BACKGROUND AND AIMS: Immunocompromised patients are at risk of chronic hepatitis E which can be acquired by blood transfusions. Currently, screening of blood donors (BDs) for HEV RNA with a limit of detection (LOD) of 2,000 IU/ml is required in Germany. However, this may result in up to 440,000 IU of HEV RNA in blood products depending on their plasma volume. We studied the residual risk of transfusion-transmitted (tt) HEV infection when an LOD of 2,000 IU/ml is applied. METHODS: Highly sensitive individual donor testing for HEV RNA on the Grifols Procleix Panther system (LOD 7.89 IU/ml) was performed. HEV loads were quantified by real-time PCR. RESULTS: Of 16,236 donors, 31 (0.19%) were HEV RNA positive. Three BDs had viral loads between 710 and 2,000 IU/ml, which pose a significant risk of tt hepatitis E with any type of blood product. Eight BDs had viral loads of >32 to 710 IU/ml, which pose a risk of tt hepatitis E with platelet or plasma transfusions because of their higher plasma volume compared to red blood cell concentrates. Eight of these 11 potentially infectious BDs were seronegative for HEV, indicating a recent infection. Only 8 of 31 donors had viral loads >2,000 IU/ml that would also have been detected by the required screening procedure and 12 had very low HEV loads (<32 IU/ml). CONCLUSIONS: Screening of BDs with an LOD of 2,000 IU/ml reduced the risk of tt HEV infection by about 73% for red blood cell concentrates but by just 42% for platelet and fresh frozen plasma transfusions. Single donor screening (LOD <32 IU/ml) should lead to an almost 100% risk reduction. LAY SUMMARY: Immunocompromised patients, such as solid organ or hematopoietic stem cell recipients, are at risk of chronic hepatitis E, which can be acquired via blood transfusions. The risk of transfusion-transmitted hepatitis E in these patients may not be sufficiently controlled by (mini-)pool hepatitis E virus RNA screening of blood donors. Single donor screening should be considered to improve the safety of blood products.

Assessment of Knowledge, Attitude, and Practice among Saudi Residents Regarding Hepatitis E Virus.

Global data, including those from Saudi Arabia, that examined public knowledge, attitudes, and practices (KAP) toward hepatitis E virus (HEV) are limited. This study examined KAP levels of the general population in Saudi Arabia toward HEV. A cross-sectional study was conducted among 768 participants. An Arabic electronic questionnaire that contained demographic data and had 35 questions was used to measure KAP of the participants concerning HEV. Collected data were analyzed at a significance level of 0.05. A total of 768 individuals participated in the study, of whom 16.3% (N = 125) were males and 83.7% (N = 643) were females. Study subjects were 18 years and above. Most of the participants were Saudi citizens (95.6%; N = 734), and from Western Saudi Arabia (76.4%; N = 587). Thirty-four percent (N = 261) of the participants had not heard of HEV, and 48% were aware that yellowish skin or eyes are the most important sign of hepatitis. The level of participants' knowledge about HEV was low (39.5%). However, positive attitudes and practices were apparent and tended to aim at how to avoid becoming infected with HEV. In conclusion, the level of HEV-related knowledge among the participants was low, and their practices and attitudes were aimed at avoiding HEV infection. Awareness campaigns are required to increase the public's HEV-related knowledge.

Uterine Injury Caused by Genotype 4 Hepatitis E Virus Infection Based on a BALB/c Mice Model.

To evaluate whether uterine injury caused by hepatitis E virus (HEV) infection is responsible for adverse pregnancy outcomes. HEV-infected female BALB/c mice were coupled with healthy male BALB/c mice at 0, 7, 14, 21, and 91 dpi to explore the uterine injury caused by HEV infection. Mice were euthanized after 10 days of copulation, and uteruses were collected for HEV RNA and antigen detection and histopathological analysis. Inflammatory responses; apoptosis; and estrogen receptor ɑ (ER-ɑ), endomethal antibody (ERAb), cytokeratin-7 (CK7), vimentin (VIM), and vascular endothelial growth factor (VEGF) expression levels were evaluated. After 10 days of copulation, miscarriage and nonpregnancy, as well as enlarged uteruses filled with inflammatory cytokines, were found in HEV-infected mice. HEV RNA and antigens were detected in the sera and uteruses of HEV-infected mice. Significant endometrial thickness (EMT) thinning, severe inflammatory responses, and aggravated apoptosis in the uteruses of HEV-infected mice that experienced miscarriage might contribute to adverse pregnancy outcomes. Furthermore, significantly suppressed ER-ɑ expression and increased ERAb, CK7, VIM, and VEGF expression levels were found in the uteruses of HEV-infected mice that had miscarried. However, uterine damage recovered after complete HEV clearance, and impaired fertility was improved. EMT injury, severe inflammatory responses, and aggravated apoptosis in the uterus caused by HEV infection are responsible for poor pregnancy outcomes.

Hepatitis E Outbreak in the Central Part of Italy Sustained by Multiple HEV Genotype 3 Strains, June-December 2019.

In European countries, autochthonous acute hepatitis E cases are caused by Hepatitis E Virus (HEV) genotype 3 and are usually observed as sporadic cases. In mid/late September 2019, a hepatitis E outbreak caused by HEV genotype 3 was recognized by detection of identical/highly similar HEV sequences in some hepatitis E cases from two Italian regions, Abruzzo and Lazio, with most cases from this latter region showing a link with Abruzzo. Overall, 47 cases of HEV infection were finally observed with onsets from 8 June 2019 to 6 December 2019; they represent a marked increase as compared with just a few cases in the same period of time in the past years and in the same areas. HEV sequencing was successful in 35 cases. The phylogenetic analysis of the viral sequences showed 30 of them grouped in three distinct molecular clusters, termed A, B, and C: strains in cluster A and B were of subtype 3e and strains in cluster C were of subtype 3f. No strains detected in Abruzzo in the past years clustered with the strains involved in the present outbreak. The outbreak curve showed partially overlapped temporal distribution of the three clusters. Analysis of collected epidemiological data identified pork products as the most likely source of the outbreak. Overall, the findings suggest that the outbreak might have been caused by newly and almost simultaneously introduced strains not previously circulating in this area, which are possibly harbored by pork products or live animals imported from outside Abruzzo. This possibility deserves further studies in this area in order to monitor the circulation of HEV in human cases as well as in pigs and wild boars.

Generation of a Bactrian camel hepatitis E virus by a reverse genetics system.

Bactrian camel hepatitis E virus (HEV) is a novel HEV belonging to genotype 8 (HEV-8) in the Orthohepevirus A species of the genus Hepevirus in the family Hepeviridae. HEV-8 cross-transmits to cynomolgus monkeys and has a potential risk for zoonotic infection. Until now, neither a cell-culture system to grow the virus nor a reverse genetics system to generate the virus has been developed. To generate replication-competent HEV-8 and to establish a cell-culture system, we synthesized capped genomic HEV-8 RNAs by in vitro transcription and used them to transfect into PLC/PRF/5 cells. A HEV-8 strain, HEV-8M2, was recovered from the capped HEV-8 RNA-transfected cell-culture supernatants and subsequently passaged in the cells, demonstrating that PLC/PRF/5 cells were capable of supporting the replication of the HEV-8, and that a cell-culture system for HEV-8 was successfully established. In addition to PLC/PRF/5 cells, A549 and Caco-2 cells appeared to be competent for the replication, but HepG2 C3/A, Vero, Hela S3, HEp-2C, 293T and GL37 cells were incompetent. The HEV-8M2 strain was capable of infecting cynomolgus monkeys by an intravenous inoculation, indicating that HEV-8 was infectious and again carried a risk for zoonotic infection. In contrast, HEV-8 did not infect nude rats and BALB/c nude mice, suggesting that the reservoir of HEV-8 was limited. In addition, the replication of the HEV-8M2 strain was efficiently abrogated by ribavirin but not by favipiravir, suggesting that ribavirin is a drug candidate for therapeutic treatment of HEV-8-induced hepatitis. The infectious HEV-8 produced by a reverse genetics system would be useful to elucidate the mechanisms of HEV replication and the pathogenesis of type E hepatitis.

Mechanism of Cross-Species Transmission, Adaptive Evolution and Pathogenesis of Hepatitis E Virus.

Hepatitis E virus (HEV) is the leading cause of acute hepatitis worldwide. While the transmission in developing countries is dominated by fecal-oral route via drinking contaminated water, the zoonotic transmission is the major route of HEV infection in industrialized countries. The discovery of new HEV strains in a growing number of animal species poses a risk to zoonotic infection. However, the exact mechanism and the determinant factors of zoonotic infection are not completely understood. This review will discuss the current knowledge on the mechanism of cross-species transmission of HEV infection, including viral determinants, such as the open reading frames (ORFs), codon usage and adaptive evolution, as well as host determinants, such as host cellular factors and the host immune status, which possibly play pivotal roles during this event. The pathogenesis of hepatitis E infection will be briefly discussed, including the special forms of this disease, including extrahepatic manifestations, chronic infection, and fulminant hepatitis in pregnant women.

Resolution of hepatitis E virus infection in CD8+ T cell-depleted rhesus macaques.

BACKGROUND & AIMS: HEV is a significant cause of acute hepatitis globally. Some genotypes establish persistent infection when immunity is impaired. Adaptive immune mechanisms that mediate resolution of infection have not been identified. Herein, the requirement for CD8+ T cells to control HEV infection was assessed in rhesus macaques, a model of acute and persistent HEV infection in humans. METHODS: Rhesus macaques were untreated or treated with depleting anti-CD8α monoclonal antibodies before challenge with an HEV genotype (gt)3 isolate derived from a chronically infected human patient. HEV replication, alanine aminotransferase, anti-capsid antibody and HEV-specific CD4+ and CD8+ T cell responses were assessed after infection. RESULTS: HEV control in untreated macaques coincided with the onset of a neutralizing IgG response against the ORF2 capsid and liver infiltration of functional HEV-specific CD4+ and CD8+ T cells. Virus control was delayed by 1 week in CD8+ T cell-depleted macaques. Infection resolved with onset of a neutralizing IgG antibody response and a much more robust expansion of CD4+ T cells with antiviral effector function. CONCLUSIONS: Liver infiltration of functional CD8+ T cells coincident with HEV clearance in untreated rhesus macaques, and a 1-week delay in HEV clearance in CD8+ T cell-depleted rhesus macaques, support a role for this subset in timely control of virus replication. Resolution of infection in the absence of CD8+ T cells nonetheless indicates that neutralizing antibodies and/or CD4+ T cells may act autonomously to inhibit HEV replication. HEV susceptibility to multiple adaptive effector mechanisms may explain why persistence occurs only with generalized immune suppression. The findings also suggest that neutralizing antibodies and/or CD4+ T cells should be considered as a component of immunotherapy for chronic infection. LAY SUMMARY: The hepatitis E virus (HEV) is a major cause of liver disease globally. Some genetic types (genotypes) of HEV persist in the body if immunity is impaired. Our objective was to identify immune responses that promote clearance of HEV. Findings indicate that HEV may be susceptible to multiple arms of the immune response that can act independently to terminate infection. They also provide a pathway to assess immune therapies for chronic HEV infection.

An outbreak of acute jaundice syndrome (AJS) among the Rohingya refugees in Cox's Bazar, Bangladesh: Findings from enhanced epidemiological surveillance.

In the summer of 2017, an estimated 745,000 Rohingya fled to Bangladesh in what has been described as one of the largest and fastest growing refugee crises in the world. Among numerous health concerns, an outbreak of acute jaundice syndrome (AJS) was detected by the disease surveillance system in early 2018 among the refugee population. This paper describes the investigation into the increase in AJS cases, the process and results of the investigation, which were strongly suggestive of a large outbreak due to hepatitis A virus (HAV). An enhanced serological investigation was conducted between 28 February to 26 March 2018 to determine the etiologies and risk factors associated with the outbreak. A total of 275 samples were collected from 18 health facilities reporting AJS cases. Blood samples were collected from all patients fulfilling the study specific case definition and inclusion criteria, and tested for antibody responses using enzyme-linked immunosorbent assay (ELISA). Out of the 275 samples, 206 were positive for one of the agents tested. The laboratory results confirmed multiple etiologies including 154 (56%) samples tested positive for hepatitis A, 1 (0.4%) positive for hepatitis E, 36 (13%) positive for hepatitis B, 25 (9%) positive for hepatitis C, and 14 (5%) positive for leptospirosis. Among all specimens tested 24 (9%) showed evidence of co-infections with multiple etiologies. Hepatitis A and E are commonly found in refugee camps and have similar clinical presentations. In the absence of robust testing capacity when the epidemic was identified through syndromic reporting, a particular concern was that of a hepatitis E outbreak, for which immunity tends to be limited, and which may be particularly severe among pregnant women. This report highlights the challenges of identifying causative agents in such settings and the resources required to do so. Results from the month-long enhanced investigation did not point out widespread hepatitis E virus (HEV) transmission, but instead strongly suggested a large-scale hepatitis A outbreak of milder consequences, and highlighted a number of other concomitant causes of AJS (acute hepatitis B, hepatitis C, Leptospirosis), albeit most likely at sporadic level. Results strengthen the need for further water and sanitation interventions and are a stark reminder of the risk of other epidemics transmitted through similar routes in such settings, particularly dysentery and cholera. It also highlights the need to ensure clinical management capacity for potentially chronic conditions in this vulnerable population.

Hepatitis E virus infection and waste pickers: A case-control seroprevalence study.

Whether waste pickers are a risk group for hepatitis E virus (HEV) infection is largely unknown. This study aimed to determine the association between HEV exposure and the occupation of waste pickers and the work characteristics of waste pickers. An age-and gender-matched case-control seroprevalence study of 86 waste pickers and 86 control subjects of the general population was performed. We determined anti-HEV IgG antibodies in sera of cases and controls using a commercially available enzyme-linked immunoassay. The McNemar's test was used to assess the association between HEV seropositivity and the occupation of waste picker. The association between HEV seropositivity and work characteristics of waste pickers was assessed by bivariate and logistic regression analyses. Anti-HEV IgG antibodies were detected in 14 (16.3%) of the 86 waste pickers and in 8 (9.3%) of the 86 control subjects (McNemar's pair test: odds ratio (OR) = 13.0; 95% confidence interval (CI): 0.73-230.77; p = .02). Bivariate analysis showed that HEV exposure was associated with an ill status (p = .01) and reflexes impairment (p = .009). Logistic regression analysis showed that HEV seropositivity was associated with increasing age (OR = 6.52; 95% CI: 1.95-21.78; p = .002) and raising pigs (OR = 12.01; 95% CI: 1.48-97.26; p = .02). This is the first age- and gender-matched case-control study on the association between HEV infection and the occupation of waste picker. Waste pickers represent a risk group for HEV infection. Factors associated with HEV seropositivity found in this study may help in the design of optimal planning to avoid HEV infection.

Hepatitis E viral infection regulates estrogen signaling pathways: Inhibition of the cAMPK-PKA-CREB and PI3K-AKT-mTOR signaling pathways.

Hepatitis E virus (HEV) infection has become a global concern with high mortality rates among pregnant women, especially those in their third trimester of pregnancy. Estrogen plays an important role in mediating the body, regulating physiological and pathological processes. Estrogen is activated by binding to estrogen receptors (ERs) and mediates rapid signaling events by pathways that involve transmembrane ERs. Our previous study had confirmed that high estrogen levels during pregnancy are associated with high HEV titers. However, the association between HEV infection and estrogen signaling pathways remains unclear. In the present study, the regulation of estrogen signaling pathways by HEV infection was evaluated. Results demonstrated that HEV infection significantly inhibits the cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways, but is independent of the Ras-Raf-MEK-ERK signaling pathway. In summary, the increasing estrogen levels and highly activated ERα during pregnancy aggravates HEV replication. The exacerbation of HEV replication, in turn, inhibits ERα expression and suppresses both cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways.

The histologic presentation of hepatitis E reflects patients' immune status and pre-existing liver condition.

Infection with the hepatitis E virus (HEV) is one of the main causes of acute hepatitis worldwide. Given that, the histopathology of hepatitis E is relatively poorly characterized, and it is unclear what exactly determines its remarkable variability. The aim of our study was a systematic analysis of hepatitis E histology, especially with regard to the clinical setting. Fifty-two liver samples (48 biopsies, 1 liver explant, 3 autopsy livers) from 41 patients with molecularly proven hepatitis E (28 HEV genotype (gt) 3, three gt 1, one gt 4 and 9 undetermined gt) were systematically evaluated for 33 histopathologic features. Following one approach, the biopsies were assigned to one of five generic histologic patterns. In another approach, they were subjected to hierarchical clustering. We found that 23/41 (56%) patients were immunocompromised, whereas 18 (44%) had no known immunosuppression. Five patients (12%) had pre-existing liver disease (LD). The histopathologic spectrum ranged from almost normal to acute, chronic, and steato-hepatitis to subtotal necrosis, and was thus distributed across all five generic patterns. Hierarchical clustering, however, identified three histopathologic clusters (C1-C3), which segregated along the immune status and pre-existing LD: C1 comprised mostly patients with pre-existing LD; histology mainly reflected the respective LD without pointing to the additional hepatitis E. C2 comprised mostly immunocompetent patients; histology mainly displayed florid hepatitis. C3 comprised mostly immunocompromised patients; histology mainly displayed smoldering hepatitis. Accordingly, C1-C3 differed markedly with respect to their clinical and histopathologic differential diagnoses. Hierarchical clustering suggests three groups with distinct histopathologies, indicating biologically different manifestations of hepatitis E. The association of histopathologic changes with the patient's immune status and pre-existing LD plausibly explains the diversity of hepatitis E histopathology, and suggests that these factors are the crucial underlying determinants. We expect our results to improve patient management by guiding the clinico-pathologic diagnosis of hepatitis E.

Virus-Host Cell Interplay during Hepatitis E Virus Infection.

The molecular interplay between cellular host factors and viral proteins is a continuous process throughout the viral life cycle determining virus host range and pathogenesis. The hepatitis E virus (HEV) is a long-neglected RNA virus and the major causative agent of acute viral hepatitis in humans worldwide. However, the mechanisms of liver pathology and clinical disease remain poorly understood for HEV infection. This review summarizes our current understanding of HEV-host cell interactions and highlights experimental strategies and techniques to identify novel host components required for the viral life cycle as well as restriction factors. Understanding these interactions will provide insight into the viral life cycle of HEV and might further help to devise novel therapeutic strategies and antiviral targets.

A systematic review of the epidemiology of Hepatitis E virus infection in South - Eastern Asia.

Hepatitis E virus (HEV) infection is an emerging zoonotic viral disease, with an increasingly international public health challenge. Despite the concerns that the global disease burden may be underestimated. Therefore, evaluation of the disease epidemiology in South - eastern Asia through a systematic review will assist in unraveling the burden of the disease in the subregion. A priori protocol was prepared for the systematic review and followed by a literature search involving five electronic databases. Identified publications were screened for high quality studies and the elimination of bias and relevant data extracted. A total of 4157 citations were captured, and only 35 were included in the review. A wide range of HEV seroprevalence was recorded from 2% (urban blood donors in Malaysia) to 77.7% (lowland communities in Lao PDR). Sporadic HEV infection and epidemics were also detected in the subregion. Indicating hyperendemicity of the disease in South - eastern Asia.

Infectivity and pathogenicity of different hepatitis E virus genotypes/subtypes in rabbit model.

The pathogenicity of each hepatitis E virus (HEV) genotypes/subtypes may be different. This study aimed to investigate the infectivity and pathogenicity of different HEV genotypes/subtypes from different mammalian sources especially human in rabbits, and to assess whether rabbits are an appropriate animal model to study different HEV genotypes/subtypes. Thirty-seven rabbits were randomly divided into nine groups and inoculated with eight different HEV strains, including human-derived HEV3b (hHEV-3b), hHEV-4a, hHEV-4d and hHEV-4h, swine-derived HEV4d (sHEV-4d) and sHEV-4h, rabbit-derived HEV3 (HEV-3ra) and camel-derived HEV8. HEV RNA, antigen, anti-HEV and alanine aminotransferase (ALT) in serum or/and feces were monitored weekly. One rabbit from each group was euthanized at seven weeks post inoculation and the liver specimens were taken for histopathological analysis and immunofluorescence staining of HEV ORF2 proteins. hHEV-4d, sHEV-4d and HEV-3ra infections were successfully established in rabbits and typical acute hepatitis symptoms were observed, including viraemia/antigenemia, fecal virus/antigen shedding, elevated ALT level and liver histopathological changes. One rabbit infected with HEV-3ra showed chronic infection. hHEV-4d and sHEV-4d are less infectious and pathogenic than HEV-3ra in rabbits. hHEV-3b and HEV8 only caused inapparent infection in rabbits as 60% (3/5) and 20% (1/5) of the rabbits seroconverted to anti-HEV, respectively. No obvious signs of HEV infection in rabbits inoculated with hHEV-4a, hHEV-4h and sHEV-4h. The infectivity and pathogenicity of different HEV genotypes/subtypes in rabbits is different, which may be related to the species specificity of HEV. Rabbit can be used as an animal model for the study of HEV-3ra and more importantly human HEV-4d.

A Cell Culture Model for Producing High Titer Hepatitis E Virus Stocks.

Hepatitis E virus is the leading cause of liver cirrhosis and liver failure with increasing prevalence worldwide. The single-stranded RNA virus is predominantly transmitted by blood transfusions, inadequate sanitary conditions and contaminated food products. To date the off-label drug ribavirin (RBV) is the treatment of choice for many patients. Nonetheless, a specific HEV treatment remains to be identified. So far, the knowledge about the HEV life cycle and pathogenesis has been severely hampered because of the lack of an efficient HEV cell culture system. A robust cell culture system is essential for the study of the viral life cycle which also includes the viral pathogenesis. With the method described here one can produce viral titers of up to 3 x 106 focus forming unit/mL (FFU/mL) of non-enveloped HEV and up to 5 x 104 FFU/mL of enveloped HEV. Using these particles, it is possible to infect a variety of cells of diverse origins including primary cells and human, as well as animal cell lines. The production of infectious HEV particles from plasmids poses an infinite source, which makes this protocol exceedingly efficient.

¿Afectación hepática en la listeriosis? Considere una coinfección por virus E de la hepatitis / Liver involvement in listeriosis? Think of a hepatitis E virus coinfection

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Identification and pathogenicity of a novel genotype avian hepatitis E virus from silkie fowl (gallus gallus).

Hepatitis E virus (HEV) is a public health concern because of its zoonotic potential; however, the host species spectrum and the genetic diversity of HEV in many birds are unknown. In the present study, a novel genotype avian HEV was isolated from a bird, silkie fowl, and designated CHN-GS-aHEV (GenBank No. MN562265). The genome of CHN-GS-aHEV was analyzed in comparison with other avian HEVs' and the pathogenicity in silkie fowl was characterized. The results show that the CHN-GS-aHEV shares about 81 % identity with known avian HEV in chickens, ORF3 shares the highest identity (85.1 %-88.0 %) at the nucleotide level, while ORF2 shares the highest identity (96.5 %-98.0 %) at the amino acid level, indicating that the CHN-GS-aHEV belongs to a new genotype avian HEV. The pathogenicity study showed that silkie fowl experimentally infected with the CHN-GS-aHEV demonstrated seroconversion, viremia, fecal virus shedding, liver lesions, and increased ALT level. Furthermore, ultrastructural changes in hepatocyte cells by transmission electron microscopy were characterized by the loss of mitochondrial cristae and swollen mitochondria and endoplasmic reticulum in the infected birds, suggesting that these two organelles may play a significant role in HEV replication. Overall, this study reports the complete genome characterization of a novel avian HEV and successful experimental infection in silkie fowl, and may be serving as a prominent indicator for additional avian HEV detection in other species.