Hepatitis E in high-income countries

Prevalence of Toxoplasma gondii, Hepatitis E Virus, and Salmonella Antibodies in Meat Juice Samples from Pigs at Slaughter in Switzerland

ABSTRACT

Toxoplasma gondii, hepatitis E virus (HEV), and Salmonella are zoonotic foodborne pathogens that may be transmitted to humans through the consumption of raw or undercooked pork. The aim of this study was to determine the seroprevalence of anti-T. gondii, anti-HEV, and anti-Salmonella antibodies from healthy pigs at slaughter in Switzerland. From August to September 2020, the diaphragm muscle of Swiss fattening pigs was collected in three Swiss abattoirs from 188 farms. Two randomly chosen pig carcasses per farm were selected. On the basis of the slaughter data, we noted the production system and the canton of origin, comparing indoor (n = 120) and free-range (n = 68) farming and regional allocation. The meat juice of these samples was analyzed for pathogen-specific antibodies by using commercial enzyme-linked immunosorbent assay kits. The seroprevalences were 1.3% for T. gondii, 71.8% for the HEV, and 5.3% for Salmonella, respectively. Comparing the origins, the results of many cantons were not meaningful due to the low number of samples. No regional accumulations were found for T. gondii and HEV. The results showed that 2.1% of the farms had least one T. gondii-seropositive animal, 80.3% had at least one HEV-seropositive animal, and 8.5% had at least one Salmonella-seropositive animal, respectively. The seropositivity of T. gondii was higher in free-range pigs than in indoor pigs, whereas anti-Salmonella antibodies were more common in pigs from indoor farming than in outdoor pigs. The seroprevalence of anti-HEV antibodies was similar in free-range and indoor farming pigs. Compared with studies from 2012, the seroprevalence of T. gondii has decreased, whereas the seroprevalence of the HEV has increased and is highly prevalent among fattening pigs in Switzerland. The low seroprevalence of Salmonella has remained stable in recent years.

HIGHLIGHTS

Detection of Hepatitis E Virus RNA in Raw Cured Sausages and Raw Cured Sausages Containing Pig Liver at Retail Stores in Switzerland

Hepatitis E virus (HEV) is the causative agent of an acute and self-limiting hepatitis and is increasingly detected in food products containing pork. In this study, 102 raw sausages containing pig liver (mortadella di fegato) and 18 raw pork sausages (salami type sausage) collected at retail level in a region of southern Switzerland were screened for the presence of HEV by quantitative real-time reverse transcription PCR. HEV was detected in 12 (11.8%) of 102 mortadella di fegato products but not in any of the salami sausages. Viral loads in the mortadella di fegato sausages ranged from log HEV 2.3 to 5.7 genome copies per gram of food product. This study identifies mortadella di fegato type sausages made with raw pig liver as a potential source of HEV infection in humans.

Hepatitis E: A Literature Review

Hepatitis E is the fifth known form of human viral hepatitis. Although not very common in our clinical practice, the incidence in Western countries is increasing. Infection with the hepatitis E virus (HEV) may be related to acute illness, liver failure, chronic hepatitis and cirrhosis. HEV itself is an RNA virus, with eight described genotypes (HEV 1-8), four of which more commonly affect humans and have, thus, been better studied. Besides liver manifestations, genotype 3 is also related to extra-hepatic manifestations, such as neurological, renal and rheumatological. Evolution to chronic disease occurs especially in patients who underwent transplantation, have hematological malignancies requiring chemotherapy, or have infection with the human immunodeficiency virus. The diagnosis may be difficult because of the low availability of tests and due to low sensibility and specificity. The acute form of illness does not have to be treated, but the chronic one does. We present here a literature review of hepatitis E and the relation between chronic hepatitis E and transplantation.

Potential Approaches to Assess the Infectivity of Hepatitis E Virus in Pork Products: A Review

The zoonotic transmission of hepatitis E, caused by the hepatitis E virus (HEV), is an emerging issue. HEV appears common in pigs (although infected pigs do not show clinical signs), and evidence suggests that a number of hepatitis E cases have been associated with the consumption of undercooked pork meat and products. Little information is available on whether cooking can eliminate HEV, since there is currently no robust method for measuring its infectivity. HEV infectivity can be clearly demonstrated by monitoring for signs of infection (e.g., shedding of virus) in an animal model. However, this approach has several disadvantages, such as lack of reproducibility and unsuitability for performing large numbers of tests, high costs, and not least ethical considerations. Growth in cell culture can unambiguously show that a virus is infectious and has the potential for replication, without the disadvantages of using animals. Large numbers of tests can also be performed, which can make the results more amenable to statistical interpretation. However, no HEV cell culture system has been shown to be applicable to all HEV strains, none has been standardized, and few studies have demonstrated their use for measurement of HEV infectivity in food samples. Nonetheless, cell culture remains the most promising approach, and the main recommendation of this review is that there should be an extensive research effort to develop and validate a cell culture-based method for assessing HEV infectivity in pork products. Systems comprising promising cell lines and HEV strains which can grow well in cell culture should be tested to select an assay for effective and reliable measurement of HEV infectivity over a wide range of virus concentrations. The assay should then be harnessed to a procedure which can extract HEV from pork products, to produce a method suitable for further use. The method can then be used to determine the effect of heat or other elimination processes on HEV in pork meat and products, or to assess whether HEV detected in any surveyed foodstuffs is infectious and therefore poses a risk to public health.

Identification of a Novel Hepatitis E Virus Genotype 3 Strain Isolated from a Chronic Hepatitis E Virus Infection in a Kidney Transplant Recipient in Switzerland

Hepatitis E virus genotype 3 (HEV-3) is the causal pathogen of chronic hepatitis E. We report here the full-length genome sequence of an HEV-3 strain, isolated from a kidney transplant recipient in Switzerland (SW/16-0282). This HEV-3 strain showed less than 88% homology compared to known strains, suggesting a new HEV-3 strain.

Markers for Ongoing or Previous Hepatitis E Virus Infection Are as Common in Wild Ungulates as in Humans in Sweden

Hepatitis E virus (HEV) is a human pathogen with zoonotic spread, infecting both domestic and wild animals. About 17% of the Swedish population is immune to HEV, but few cases are reported annually, indicating that most infections are subclinical. However, clinical hepatitis E may also be overlooked. For identified cases, the source of infection is mostly unknown. In order to identify whether HEV may be spread from wild game, the prevalence of markers for past and/or ongoing infection was investigated in sera and stool samples collected from 260 hunted Swedish wild ungulates. HEV markers were found in 43 (17%) of the animals. The most commonly infected animal was moose (Alces alces) with 19 out of 69 animals (28%) showing HEV markers, followed by wild boar (Sus scrofa) with 21 out of 139 animals (15%), roe deer (Capreolus capreolus) with 2 out of 30 animals, red deer (Cervus elaphus) with 1 out of 15 animals, and fallow deer (Dama dama) 0 out of 7 animals. Partial open reading frame 1 (ORF1) of the viral genomes from the animals were sequenced and compared with those from 14 endemic human cases. Phylogenetic analysis revealed that three humans were infected with HEV strains similar to those from wild boar. These results indicate that wild animals may be a source of transmission to humans and could be an unrecognized public health concern.

Advances in hepatitis E - II: Epidemiology, clinical manifestations, treatment and prevention

INTRODUCTION

Infection with hepatitis E virus (HEV) is the commonest cause of acute hepatitis worldwide. This infection, with fecal-oral transmission, was previously thought to be limited to humans residing in developing countries with poor sanitation, spreading via contaminated drinking water. In recent years, our understanding of epidemiology and clinical spectrum of this infection have changed markedly.

AREAS COVERED

This article reviews the epidemiology, including routes of transmission, and clinical manifestations of HEV infection around the world. In addition, recent findings on transmission-associated HEV infection, extrahepatic manifestations of hepatitis E and chronic infection with HEV, and treatment and prevention of this infection are discussed. Expert commentary: HEV infection has two distinct epidemiologic forms and clinical patterns of disease: (i) acute epidemic or sporadic hepatitis caused by fecal-oral (usually water-borne) transmission of genotype 1 and 2 HEV from a human reservoir in areas with poor hygiene and frequent water contamination, and (ii) infrequent sporadic hepatitis E caused by zoonotic infection, possibly from an animal source through ingestion of undercooked animal meal, of genotype 3 or 4 virus. In disease-endemic areas, pregnant women are at a particular risk of serious disease and high mortality. In less-endemic areas, chronic infection with HEV among immunosuppressed persons is observed. HEV can also be transmitted through Transfusion of blood and blood products. Ribivirin treatment is effective in chronic hepatitis E. Two efficacious vaccines have been tried in humans; one of these has received marketing approval in its country of origin.

Liver Failure due to Acute Viral Hepatitis (A-E)

BACKGROUND

Viral hepatitis is still one of the key causes of acute liver failure (ALF) in the world.

METHODS

A selective literature search of the PubMed database was conducted, including current studies, reviews, meta-analyses, and guidelines. We obtained an overview of ALF due to viral hepatitis in terms of epidemiology, course, and treatment options.

RESULTS

Most fulminant viral courses are reported after infection with hepatitis A, B, and B/D, but not with hepatitis C. Hepatitis E is also known to cause ALF but has not gained much attention in recent years. However, more and more autochthonous hepatitis E virus infections have been recently observed in Europe. Reactivation of hepatitis B virus (HBV) under immunosuppressive conditions, such as after intensive chemotherapy, is also an increasing problem. For most viral-induced cases of ALF, liver transplantation represented the only therapeutic option in the past. Today, immediate treatment of HBV-induced ALF with nucleotide or nucleoside analogs is well tolerated and beneficially affects the course of the disease.

CONCLUSION

Although numbers in Western European countries are decreasing rapidly, reliable diagnostic screening for hepatitis A-E is necessary to identify the etiology and to determine those most at risk of developing ALF.

Hepatitis E Virus Infection as a Possible Cause of Acute Liver Failure in Europe

BACKGROUND & AIMS

In Western countries, infection with the hepatitis E virus (HEV) is considered to be rare and imported from endemic regions. However, the prevalence of HEV infection has increased among adults in central Europe. HEV infection can cause acute liver failure (ALF), but there have been only a few confirmed cases of HEV-associated ALF in Europe. We investigated the number of cases of indeterminate ALF associated with HEV infection.

METHODS

We performed a retrospective analysis of 80 patients diagnosed with ALF or acute hepatitis at the University Hospital Essen in Germany from November 2006 through December 2013. Clinical data were collected from the hospital databases; archived sera were tested for IgG and IgM against HEV, as well as HEV RNA.

RESULTS

Sera from 12 patients (15%) tested positive for IgG against HEV IgG; 7 of these samples did not test positive for HEV IgM or HEV RNA. Sera from 64 patients (80%) did not test positive for IgG or IgM against HEV or HEV RNA. Sera from 8 patients (10%) tested positive for HEV RNA (only 4 of these were positive for HEV IgG) and had clinical findings to support acute HEV infection.

CONCLUSIONS

In a hospital in Germany, approximately 10% to 15% of patients with ALF had evidence for HEV infection. Serologic tests for IgG against HEV are insufficient to identify or exclude HEV infection; tests for HEV RNA also should be performed on patients with ALF of ambiguous etiology.

Transmission, diagnosis, and management of hepatitis E: an update

Hepatitis E virus (HEV) infection is an important public health concern in many developing countries, causing waterborne outbreaks as well as sporadic autochthonous hepatitis. HEV is mainly transmitted by the fecal–oral route in endemic areas through drinking of contaminated water. However, zoonotic transmission from animal reservoirs to humans has also been suggested. Three additional routes of HEV transmission have been proposed to occur: blood borne, human to human, and vertical transmission from mother to child. Acute HEV infection is usually diagnosed by detecting specific anti-HEV antibodies. However, the performance of the available assays in different settings is not optimal. Analysis of HEV ribonucleic acid in biologic specimens such as stools, serum, and liver biopsy by using nucleic acid amplification techniques is also employed. Nonetheless, additional consensus regarding the best technologies suitable for serosurveys and diagnosis of acute HEV infection is also needed. This review article summarizes the current status of HEV infection end epidemiology with particular emphasis in transmission, diagnosis, and clinical management.

Seroprevalence of hepatitis E virus in domestic pigs and wild boars in Switzerland

Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6-21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV-specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars.

Identification of a novel picornavirus in healthy piglets and seroepidemiological evidence of its presence in humans

In this study, we describe a novel porcine parechovirus-like virus (tentatively named PLV-CHN) from healthy piglets in China using 454 high-throughput sequencing. The complete genome of the virus comprises 6832 bp, encoding a predicted polyprotein of 2132 amino acids that is most similar to Ljungan virus (32% identity). A similar virus that belongs to a novel Picornaviridae genus, named swine pasivirus 1 (SPaV-1), was reported during the preparation of this paper. Sequence analysis revealed that PLV-CHN and SPaV1 shared 82% nucleotide identity and 89% amino acid identity. Further genomic and phylogenetic analyses suggested that both SPaV1 and PLV-CHN shared similar genomic characteristics and belong to the same novel Picornaviridae genus. A total of 36 (20.0%) fecal samples from 180 healthy piglets were positive for PLV-CHN by RT-PCR, while no fecal samples from 100 healthy children and 100 children with diarrhea, and no cerebrospinal fluid samples from 196 children with suspected viral encephalitis, was positive for the virus. However, Western blot and enzyme-linked immunosorbent assays using recombinant PLV-CHN VP1 polypeptide as an antigen showed a high seroprevalence of 63.5% in the healthy population. When grouped by age, the antibody-positivity rates showed that the majority of children under 12 years of age have been infected by the virus. It was suggested that PLV-CHN, SPaV1, or an as-yet-uncharacterized virus can infect humans early in life. Thus, investigation of the role of this novel virus is vital.

Hepatitis e: epidemiology and natural history

Hepatitis E is a disease caused by infection with hepatitis E virus (HEV). The virus has four genotypes, named 1 to 4, with one shared serotype. Genotypes 1 and 2 infect only humans, whereas genotypes 3 and 4 primarily infect several mammalian animals, with occasional transmission to humans. Evidence of infection with HEV has been found in most parts of the world, with two distinct epidemiological patterns. In areas with high disease endemicity, primarily developing countries in Asia and Africa, the disease occurs as outbreaks and as sporadic cases of acute hepatitis, and is caused exclusively by infection with genotypes 1 or 2 HEV, which is acquired through fecal-oral route, usually through contamination of water supplies. The disease in these areas occurs most commonly in young adults, and is particularly severe in pregnant women and persons with pre-existing chronic liver disease; chronic infection has not been reported. In areas with lower endemicity, which are mainly developed areas with robust water supply and sanitation systems, occasional sporadic cases of locally-acquired genotype 3 or 4 HEV infection are observed. The affected persons are often elderly and have other coexisting illnesses. The reservoir of infection in these areas is believed to be in animals, such as pigs, wild boar and deer, with zoonotic transmission to humans, possibly through consumption of undercooked meat. Also, in these areas, persistent HEV infection has been well documented among immunosuppressed persons such as organ transplant recipients, and is believed to lead to chronic liver injury, including liver cirrhosis. Further work is needed to better understand the biological basis underlying these widely-differing epidemiological patterns.

Advances in hepatitis immunization (A, B, E): public health policy and novel vaccine delivery

PURPOSE OF REVIEW

This review offers an update on hepatitis A, B and E vaccines based on relevant literature published in 2011-2012. Hepatitis A and B vaccines have been commercially available for years; however, the development of the hepatitis E vaccine is still facing some challenges.

RECENT FINDINGS

Current scientific evidence shows that both hepatitis A and B vaccines confer long-term protection. These data supported the updated recommendations from the WHO on hepatitis A and B vaccines and the respective booster policy. In addition, a single-dose hepatitis A vaccination programme may be an option for some intermediate endemic countries, as far as the epidemiological situation is further monitored. Recent data illustrate the co-administration of hepatitis A with infant vaccines, as well as the interchangeability with other hepatitis A vaccines. Two genetically engineered hepatitis E vaccines are currently in development, showing more than 95% protective efficacy.

SUMMARY

Follow-up of vaccinated individuals confirms the long-term protection offered by the hepatitis A as well as hepatitis B vaccines. Data confirm the safety and immunogenicity profile of both vaccines, also when used in patient groups. The first data on the hepatitis E vaccine look promising, but questions on cross-protection, long-term efficacy and safety and immunogenicity in pregnant women and children less than 2 years remain unanswered.

Seroprevalence of anti-hepatitis E virus and anti-Salmonella antibodies in pigs at slaughter in Switzerland

Hepatitis E virus (HEV) and Salmonella bacteria are zoonotic pathogens that can be acquired by foodborne transmission because food animals, for example pigs, are recognized as a reservoir. The objectives of this study were to determine the seroprevalence of anti-HEV immunoglobulin G (IgG) and anti-Salmonella antibodies from healthy pigs at slaughter in Switzerland, a country with a good health status of pig herds (e.g., eradication of enzootic pneumonia) compared with those of many countries in the European Union, and a rate of importation of live pigs that is very low (<1%). Based on pooled (diaphragm muscles from 3 to 5 animals per producer) meat juice samples, 120 (60%) of 200 and 8 (4%) of 200 samples were positive for anti-HEV IgG and anti-Salmonella antibodies, respectively. HEV seems to be highly prevalent among fattening pigs in Switzerland, whereas the low seroprevalence of anti-Salmonella IgG has not changed in recent years.

A member of a new Picornaviridae genus is shed in pig feces

During a study of the fecal microbiomes from two healthy piglets using high-throughput sequencing (HTS), we identified a viral genome containing an open reading frame encoding a predicted polyprotein of 2,133 amino acids. This novel viral genome displayed the typical organization of picornaviruses, containing three structural proteins (VP0, VP3, and VP1), followed by seven nonstructural proteins (2A, 2B, 2C, 3A, 3B, 3C(pro), and 3D(pol)). Given its particular relationship with Parechovirus, we propose to name it "Pasivirus" for Parecho sister clade virus, with "Swine pasivirus 1" (SPaV1) as the type species. Fecal samples collected at an industrial farm from healthy sows and piglets from the same herd (25 and 75, respectively) with ages ranging from 4 to 28 weeks were analyzed for the presence of SPaV1 by one-step reverse transcription (RT)-PCR targeting a 3D region of 151 bp. SPaV1 was detected in fecal samples from 51/75 healthy piglets (68% of the animals) and in none of the 25 fecal samples from healthy sows, indicating that SPaV1 circulates through enteric infection of healthy piglets. We propose that SPaV1 represents the first member of a novel Picornaviridae genus related to parechoviruses.

Detection of IgM and IgG against hepatitis E virus in serum and meat juice samples from pigs at slaughter in Bavaria, Germany

Hepatitis E virus (HEV) is an emerging foodborne pathogen with domestic and wild pigs (and likely other species such as deer or rabbits) recognized as reservoir. Pathogenesis in pigs usually leads to an asymptomatic course of disease. Since there is no enzyme-linked immunosorbent assay (ELISA) kit for the detection of anti-HEV antibodies in pigs commercially available, the objective of this study was to assess the seroprevalence in fattening pigs at slaughter and at herd level using a newly developed ELISA based on genotype (GT) 1 and GT 3 in Bavaria, Germany. Based on 516 serum and 198 meat juice samples collected from different herds at four different Bavarian slaughterhouses, the overall seroprevalence of anti-HEV IgG in serum and meat juice samples was 68.6% and 67.6%, respectively. Analyzing the serum for the presence of anti-HEV IgM, 36/516 (7%) were positive for anti-HEV IgM. At herd level, most of the herds were seropositive for anti-HEV antibodies. The present study shows that HEV is widespread among the Bavarian pig population and that some pigs might test positive for anti-HEV IgM even at the age of slaughter. Also, meat juice serves as an equivalent matrix to serum to test for anti-HEV antibodies in pigs.

Hepatitis E Virus seroprevalence and chronic infections in patients with HIV, Switzerland

We screened 735 HIV-infected patients in Switzerland with unexplained alanine aminotransferase elevation for hepatitis E virus (HEV) immunoglobulin G. Although HEV seroprevalence in this population is low (2.6%), HEV RNA can persist in patients with low CD4 cell counts. Findings suggest chronic HEV infection should be considered as a cause of persistent alanine aminotransferase elevation.

Hepatitis E Virus seroprevalence and chronic infections in patients with HIV, Switzerland

We screened 735 HIV-infected patients in Switzerland with unexplained alanine aminotransferase elevation for hepatitis E virus (HEV) immunoglobulin G. Although HEV seroprevalence in this population is low (2.6%), HEV RNA can persist in patients with low CD4 cell counts. Findings suggest chronic HEV infection should be considered as a cause of persistent alanine aminotransferase elevation.

First case of anti-ganglioside GM1-positive Guillain-Barré syndrome due to hepatitis E virus infection

A 51-year-old previously healthy woman presented with Guillain-Barré syndrome (GBS) and elevated liver enzymes. Further diagnostic investigations showed the presence of an acute hepatitis E infection associated with anti-ganglioside GM1 antibodies. After treatment with intravenous immunoglobulins, the patient made a rapid recovery. Here, we report the first case of GBS due to acute hepatitis E virus (HEV) infection associated with the presence of anti-ganglioside GM1 antibodies. We also review available literature on the association between acute HEV infection and GBS.

Hepatitis E virus in domestic pigs and surface waters in Slovenia: prevalence and molecular characterization of a novel genotype 3 lineage

A novel hepatitis E virus (HEV) genotype 3 lineage was identified in Slovenian pig herds. Stool samples from six Slovenian pig farms were collected and tested for the presence of HEV RNA. Of 85 individual samples 15 (20.3%) were positive for HEV RNA of which 2/38 (5.3%), 6/21 (28.6%) and 7/26 (26.9%) were from suckling, weanling and fattening pigs, respectively. Additionally, 51 pooled porcine stool samples were tested in one of the biggest pig farm and the estimated infection rate of individual pig was calculated, resulting in 7.8%, 10.6% and 24.2% for suckling, weanling and fattening pigs, respectively. The majority of HEV positive porcine samples were from the same pig farm. Out of 17 Slovenian patients with confirmed recent hepatitis E in the period 1999-2011, the serum samples of 10 patients were tested and 3 samples turned out to be HEV RNA positive. Furthermore, 60 surface water samples were tested throughout the country, of which 2 (3.3%) were positive for HEV RNA, one of them in the near vicinity of a pig farm. All HEV strains were analysed at 5' ORF1 and 5' ORF2 regions and both genome regions confirmed that Slovenian HEV strains represent a distinct genotype 3 lineage, diverse from all other genotype 3 lineages available in GenBank and described in the literature to date. All but one HEV strains detected in pigs in Slovenia represent a monophyletic branch in phylogenetic trees, with a high degree of sequence identity. One human HEV strain belonged to genotype 1 and two to genotype 3 but did not match the new genotype 3 lineage detected in Slovenian pig herds.

Clinical presentation of hepatitis E

Hepatitis E is a form of acute hepatitis, which is caused by infection with hepatitis E virus. The infection is transmitted primarily through fecal-oral route and the disease is highly endemic in several developing countries with opportunities for contamination of drinking water. In these areas with high endemicity, it occurs as outbreaks and as sporadic cases of acute hepatitis. The illness often resembles that associated with other hepatotropic viruses and is usually self-limiting; in some cases, the disease progresses to acute liver failure. The infection is particularly severe in pregnant women. Patients with chronic liver disease and superimposed HEV infection can present with severe liver injury, the so-called acute-on-chronic liver failure. In recent years, occasional sporadic cases with locally acquired hepatitis E have been reported from several developed countries in Europe, United States, and Asia. In these areas, in addition to acute hepatitis similar to that seen in highly endemic areas, chronic hepatitis E has been reported among immunosuppressed persons, in particular solid organ transplant recipients. HEV-infected mothers can transmit the infection to foetus, leading to premature birth, increased fetal loss and hypoglycaemia, hypothermia, and anicteric or icteric acute hepatitis in the newborns. Occasional cases with atypical non-hepatic manifestations, such as acute pancreatitis, hematological abnormalities, autoimmune phenomena, and neurological syndromes have been reported from both hyperendemic and non-endemic regions. The pathogenesis of these manifestations remains unclear.

First report of an autochthonous hepatitis E virus genotype 3 infection in a 5 month old female child in Germany

Hepatitis E virus (HEV) is well-known to cause endemic outbreaks of hepatitis in tropical countries, mostly caused by HEV genotypes 1 or 2 and transmitted from humans to humans via the fecal-oral route. In contrast, HEV genotypes 3 or 4 are commonly encountered as sporadic cases in a non-endemic setting; these autochthonous cases are transmitted from animals to humans and commonly affect elderly male subjects. We report a five-month-old caucasian girl presenting with diarrhea, emesis, and elevated ALT. Surprisingly, acute infection with Hepatitis E virus (HEV) genotype 3 was laboratory-confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing. Thirteen months later, RT-PCR for HEV from stool tested negative whereas anti-HEV IgG in serum tested positive. Neither HEV RNA nor anti-HEV antibodies could be detected in stool or serum of the parents. To our knowledge, this is the first pediatric case of a HEV infection in Germany. Thus, HEV should be included into the differential diagnosis of pediatric infectious liver and bowel disease.

Spatial configuration of hepatitis E virus antigenic domain

Hepatitis E virus (HEV) is a human pathogen that causes acute hepatitis. When an HEV capsid protein containing a 52-amino-acid deletion at the C terminus and a 111-amino-acid deletion at the N terminus is expressed in insect cells, the recombinant HEV capsid protein can self-assemble into a T=1 virus-like particle (VLP) that retains the antigenicity of the native HEV virion. In this study, we used cryoelectron microscopy and image reconstruction to show that anti-HEV monoclonal antibodies bind to the protruding domain of the capsid protein at the lateral side of the spikes. Molecular docking of the HEV VLP crystal structure revealed that Fab224 covered three surface loops of the recombinant truncated second open reading frame (ORF2) protein (PORF2) at the top part of the spike. We also determined the structure of a chimeric HEV VLP and located the inserted B-cell tag, an epitope of 11 amino acids coupled to the C-terminal end of the recombinant ORF2 protein. The binding site of Fab224 appeared to be distinct from the location of the inserted B-cell tag, suggesting that the chimeric VLP could elicit immunity against both HEV and an inserted foreign epitope. Therefore, the T=1 HEV VLP is a novel delivery system for displaying foreign epitopes at the VLP surface in order to induce antibodies against both HEV and the inserted epitope.