Autochthonous infection with hepatitis E virus related to subtype 3a, France: a case report

Epidemiology of Hepatitis E in 2017 in Bavaria, Germany

In the last decade, the number of reported hepatitis E virus (HEV) infections in Germany, including Bavaria, has continued to rise. In order to identify risk factors associated with HEV infection, we investigated notified hepatitis E cases from Bavaria during 2017. The project "Intensified Hepatitis E Surveillance in Bavaria" included interviews with questionnaires, collection and genotyping of stool, serum and food samples. In addition, certain risk factors were examined in a sample comparison with healthy population using univariable analysis and logistic regression. In total, 135 hepatitis E cases from Bavaria were included in the analysis. Mean age for women was 46 (range 20-74) years and 47.5 (range 20-85) for men. 56 of the cases (41.5%) were asymptomatic. Among the symptomatic cases, both men and women were equally affected with symptoms like fever (16.3%), jaundice (18.8%) and upper abdominal pain (28.2%). 145 human samples (serum, stool) and 6 food samples were collected. 15.9% of the human samples (n = 23) were positive for HEV RNA by reverse-transcription quantitative real-time PCR (RT-qPCR). Identified risk factors significantly associated with hepatitis E were sausage consumption with odds ratio 9.6 (CI 1.3-70.1), fish with OR 2.2 (CI 1.1-4.4) and cat ownership with OR 1.9 (CI 1.3-3.0) in multivariable analyses. Further investigation is needed to confirm the role of fish in HEV transmission. Autochthonous HEV genotype 3 is prevalent in Bavaria and there could be more transmission routes contributing to the spread of HEV than previously known. Undercooked meat, offal, sausages, fish, shellfish and contact with animals and pets are possible sources for infection.

Immune dissociation during acute hepatitis E infection

OBJECTIVE

We report the immune response during a case of acute HEV response in a patient with an acute hepatitis E virus (HEV) genotype 3 infection in the Netherlands.

METHODS

Cytokine evaluation was performed via multiplex cytokine array for 65 immune markers in plasma during the different phases of hepatitis.

RESULTS

The patient initially presented with features typical of acute viral hepatitis, with detectable HEV RNA in blood. This evolved into a cholestatic disease following peripheral clearance of the virus, leading to the demise of the patient. Real time PCR revealed the presence of HEV in liver tissue, suggestive of active intrahepatic infection despite clearance in blood. During the phase of detectable HEV RNA in serum, there was a surge in T-cell-related immune mediators, as well as interferon alpha and interferon gamma-induced protein 10 (IP-10), characteristic of a viral infection. After clearance of the virus in the blood and development of cholestatic hepatitis, several inflammatory markers subsided, followed by an increase in immune factors related to anti-inflammatory activity, as well as monocyte/macrophage-related markers, likely due to the intrahepatic presence of the virus.

CONCLUSIONS

This report describes the dissociation of intra- and extra-hepatic immune responses during acute HEV infection. As shedding of the virus became solely intrahepatic, an immune profile reflective of the activity of hepatic resident cells was observed.

Genetically similar hepatitis E virus strains infect both humans and wild boars in the Barcelona area, Spain, and Sweden

Hepatitis E virus (HEV) is a hepatotropic virus, endemic in Europe where it infects humans and animals, with domestic pigs and wild boars as main reservoirs. The number of HEV-infected cases with unknown source of infection increases in Europe. There are human HEV strains genetically similar to viruses from domestic pigs, and zoonotic transmission via consumption of uncooked pork meat has been shown. Due to continuous growth of the wild boar populations in Europe, another route may be through direct or indirect contacts with wild boars. In the Collserola Natural Park near Barcelona, Spain, the wild boars have spread into Barcelona city. In Sweden, they are entering into farmlands and villages. To investigate the prevalence of HEV and the risk for zoonotic transmissions, the presence of antibodies against HEV and HEV RNA were analysed in serum and faecal samples from 398 wild boars, 264 from Spain and 134 from Sweden and in sera from 48 Swedish patients with HEV infection without known source of infection. Anti-HEV was more commonly found in Spanish wild boars (59% vs. 8%; p < 0.0001) while HEV RNA had similar prevalence (20% in Spanish vs. 15% in Swedish wild boars). Seven Swedish and three Spanish wild boars were infected with subtype 3f, and nine Spanish with subtype 3c/i. There were three clades in the phylogenetic tree formed by strains from wild boars and domestic pigs; another four clades were formed by strains from humans and wild boars. One strain from a Spanish wild boar was similar to strains from chronically infected humans. The high prevalence of HEV infections among wild boars and the similarity between wild boar HEV strains and those from humans and domestic pigs indicate that zoonotic transmission from wild boar may be more common than previously anticipated, which may develop into public health concern.

Patterns of mutation within an emerging endemic lineage of HEV-3a

The hepatitis E virus can cause chronic infections in immuno-suppressed patients, and cases have been on the rise globally. Viral mutations during such infections are difficult to characterize. We deep-sequenced viral populations from 15 immunocompromised patients with chronic HEV to identify the viral lineage and describe viral mutational hotspots within and across patients. A total of 21 viral RNA samples were collected between 2012 and 2017 from a single hospital in Singapore. Sequences covering a total of 3894 bp of the HEV genome were obtained. Phylogenetic analyses identified all sequences as belonging to the HEV-3a sub-clade and clearly indicate a unique local lineage. Deep sequencing reveals variable viral population complexity during infections. Comparisons of viral samples from the same patients spaced 2-19 months apart revealed rapid nucleotide replacements in the dominant viral sequence in both ribavirin treated and treatment-naive patients. Mutational hotspots were identified within ORF3 and the PCP/HVR domain of ORF1.

Molecular detection of hepatitis E virus in wild boar population in eastern Romania

In industrialized countries, Hepatitis E is a recognized zoonosis, with wild boar and swine representing the main reservoirs for zoonotic genotype HEV-3 in Europe. Data related to HEV infection in wild boar population in Romania are restricted to serological surveys. Therefore, our main goal was to determine the HEV prevalence in wild boar population and to characterize HEV strains circulating in Romania. Using TaqMan real-time RT-PCR assay, we analyzed the presence of RNA HEV in 45 liver samples and five spleen samples collected from 50 wild boars. Samples were collected during the 2013-2015 hunting seasons. Nine samples of 50 were tested positive for HEV RNA, resulting an overall prevalence of 18%. Phylogenetic analysis revealed that the isolates clustered in different HEV-3 monophyletic groups, depending on the sampling county. This is the first study signalling, based on molecular analysis, the presence of HEV in wild boar population from Romania. Also, in this study, we report the detection of HEV in splenic tissue from wild boar.

Hepatitis E Virus in Industrialized Countries: The Silent Threat

Hepatitis E virus (HEV) is the main cause of acute viral hepatitis worldwide. Its presence in developing countries has been documented for decades. Developed countries were supposed to be virus-free and initially only imported cases were detected in those areas. However, sporadic and autochthonous cases of HEV infection have been identified and studies reveal that the virus is worldwide spread. Chronic hepatitis and multiple extrahepatic manifestations have also been associated with HEV. We review the data from European countries, where human, animal, and environmental data have been collected since the 90s. In Europe, autochthonous HEV strains were first detected in the late 90s and early 2000s. Since then, serological data have shown that the virus infects quite frequently the European population and that some species, such as pigs, wild boars, and deer, are reservoirs. HEV strains can be isolated from environmental samples and reach the food chain, as shown by the detection of the virus in mussels and in contaminated pork products as sausages or meat. All these data highlight the need of studies directed to control the sources of HEV to protect immunocompromised individuals that seem the weakest link of the HEV epidemiology in industrialized regions.

Detection and Phylogenetic Analysis of the Hepatitis E Virus in a Canadian Swine Production Network

Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatitis E virus (HEV) genotype 3 in humans. The presence of HEV in swine herds has been reported, but its dissemination in pork production environments is still unknown. To investigate viral contamination sources in the swine industry, 452 environment and fecal samples, including samples from livestock transportation vehicles, were collected over a period of 11 months from ten farms and one slaughterhouse that together represent a single production network. Hepatitis E virus RNA was detected by nested RT-PCR in 32 samples from both inside and outside farm buildings, on trucks, and, mostly, from fomites collected in the slaughterhouse yard, such as on a utility vehicle. Phylogenetic analysis showed a wide diversity of HEV genotype 3 strains, similar to human and swine strains previously found. According to the results of this study, the movements of trucks and utility vehicles might play an important role in HEV dissemination on a slaughterhouse site and throughout an entire network.