Jürgen J. Wenzel

Test performance characteristics of Anti-HEV IgG assays strongly influence hepatitis E seroprevalence estimates.

Hepatitis E virus (HEV) seroprevalences of 0.3%-53% were reported from industrialized countries. Because these estimates may be influenced by detection assays, this study compares 3 frequently used tests for HEV detection: the MP Diagnostics HEV immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), the Axiom Diagnostics HEV IgG enzyme immunoassay (EIA), and the Mikrogen recomLine HEV IgG assay. Sera from 200 healthy healthcare workers and 30 individuals with acute HEV infection were analyzed. Among the healthy individuals, HEV IgG was found in 4.5% by the MP Diagnostics assay, in 29.5% by the Axiom Diagnostics assay, and in 18% by the Mikrogen assay. Among individuals with acute HEV infection, positive results were obtained for 83.3%, 100%, and 96.7%, respectively. Thus, the 3 assays show clear differences in diagnostic sensitivity.

Detection of hepatitis E virus (HEV) from porcine livers in Southeastern Germany and high sequence homology to human HEV isolates

BACKGROUND Hepatitis E virus (HEV) has been identified as an emerging cause of infectious hepatitis over the last years in developed countries. In contrast to travel associated hepatitis E, zoonotic sources of infection are suspected for autochthonous cases in Europe. OBJECTIVE Since pigs are known reservoirs of HEV, we tested porcine livers sold as food in Southeastern Germany for the presence of hepatitis E virus RNA. STUDY DESIGN We purchased 200 porcine liver samples in 81 butcher shops and grocery stores in Regensburg, Germany. Nucleic acid preparations were tested for the presence of HEV RNA by quantitative real-time PCR (RT-qPCR). HEV isolates from positive samples were characterized by partial sequencing of ORF1 and ORF2 regions in the HEV genome and by phylogenetic analysis. RESULTS Specimens from eight (4%) of 200 purchased pig livers had detectable HEV RNA amounts. Sequence determination and phylogenetic analysis allowed two novel isolates to be classified as HEV genotype 3, subgenotype 3a (swR437) and 3c (swR269), respectively. Both novel swine HEV isolates showed high sequence homology to isolates obtained from patients with acute HEV infection from the same geographic region. CONCLUSIONS These results support the suggested role of undercooked pig products in food as a source of zoonotic HEV infection for humans. It remains to be clarified if this mechanism of transmission is responsible for the surprisingly high anti-HEV IgG prevalence recently observed in some European countries and the USA.

Hepatitis E Virus Seroprevalence among Adults, Germany

We assessed hepatitis E virus (HEV) antibody seroprevalence in a sample of the adult population in Germany. Overall HEV IgG prevalence was 16.8% (95% CI 15.6%–17.9%) and increased with age, leveling off at >60 years of age. HEV is endemic in Germany, and the lifetime risk for exposure is high.

Prevalence of hepatitis E virus-specific antibodies in humans with occupational exposure to pigs

Due to the increasing number of non-travel-associated hepatitis E virus (HEV) infections observed in several industrialised countries including Germany, there is a substantial interest in the characterisation of risk factors and transmission routes relevant to autochthonous HEV infections. Autochthonous cases are believed to be the result of a zoonotic HEV transmission from pigs, wild boars and deer. Recently, a high prevalence of HEV-specific antibodies in the German domestic pig population has been demonstrated. Thus, one may assume a higher prevalence of HEV-specific antibodies in humans with occupational exposure to pigs. In this study, sera obtained from 24 slaughterers, 14 meat inspectors, 46 pig farmers and 22 veterinarians were tested for the presence of HEV-specific antibodies using a line immunoassay. For comparison, sera obtained from 116 age- and gender-matched blood donors were also included. Twenty eight per cent (28.3%; 30/106) of the swine-exposed humans and 15.5% (18/116) of the blood donors without contact to pigs exhibited IgG-antibodies determined as reactive (i.e. borderline or positive) against HEV. Thus, an increased risk of HEV infection in humans occupationally exposed to pigs and particularly for slaughterers (41.7%; 10/24) was demonstrated.

Seroprevalence study in forestry workers from eastern Germany using novel genotype 3- and rat hepatitis E virus-specific immunoglobulin G ELISAs

Hepatitis E virus (HEV) is the causative agent of an acute self-limiting hepatitis in humans. In industrialized countries, autochthonous cases are linked to zoonotic transmission from domestic pigs, wild boar and red deer. The main route of human infection presumably is consumption of contaminated meat. Farmers, slaughterers and veterinarians are expected to be risk groups as they work close to potentially infected animals. In this study, we tested four Escherichia coli-expressed segments of the capsid protein (CP) of a German wild boar-derived HEV genotype 3 strain for their diagnostic value in an indirect immunoglobulin G (IgG) ELISA. In an initial validation experiment, a carboxy-terminal CP segment spanning amino acid (aa) residues 326–608 outperformed the other segments harbouring aa residues 112–608, 326–660 and 112–335. Based on this segment, an indirect ELISA for detection of anti-HEV IgG antibodies in human sera was established and validated using a commercial line immunoassay as reference assay. A total of 563 sera from forestry workers of all forestry offices of Brandenburg, eastern Germany and 301 sera of blood donors from eastern Germany were surveyed using these assays. The commercial test revealed seroprevalence rates of 11% for blood donors and 18% for forestry workers. These rates are in line with data obtained by the in-house test (12 and 21%). Hence, the in-house test performed strikingly similar to the commercial test (sensitivity 0.9318, specificity 0.9542). An initial screening of forestry worker and blood donor sera with a corresponding CP segment of the recently discovered Norway rat-associated HEV revealed several strong positive sera exclusively in the forestry worker panel. Future investigations have to prove the performance of this novel IgG ELISA in large-scale seroepidemiological studies. In addition, the observed elevated seroprevalence in a forestry worker group has to be confirmed by studies on groups of forestry workers from other regions. The epidemiological role of ratHEV in human disease should be assessed in a large-scale study of risk and non-risk groups.

The human ABC transporter pseudogene family: Evidence for transcription and gene-pseudogene interference

BackgroundPseudogenes are an integral component of the human genome. Little attention, however, has so far been paid to the phenomenon that some pseudogenes are transcriptionally active. Recently, we demonstrated that the human ortholog of the rodent testis-specific ATP-binding cassette (ABC) transporter Abca17 is a ubiquitously transcribed pseudogene (ABCA17P). The aim of the present study was to establish a complete inventory of all ABC transporter pseudogenes in the human genome and to identify transcriptionally active ABC transporter pseudogenes. Moreover, we tested the hypothesis that a regulatory interdependency exists between ABC transporter pseudogenes and their parental protein coding equivalents.ResultsSystematic bioinformatic analysis revealed the existence of 22 ABC transporter pseudogenes within the human genome. We identified two clusters on chromosomes 15 and 16, respectively, which harbor almost half of all pseudogenes (n = 10). Available information from EST and mRNA databases and RT-PCR expression profiling indicate that a large portion of the ABC transporter pseudogenes (45%, n = 10) are transcriptionally active and some of them are expressed as alternative splice variants. We demonstrate that both pseudogenes of the pseudoxanthoma elasticum gene ABCC6, ABCC6P1 and ABCC6P2, are transcribed. ABCC6P1 and ABCC6 possess near-identical promoter sequences and their tissue-specific expression profiles are strikingly similar raising the possibility that they form a gene-pseudogene dual transcription unit. Intriguingly, targeted knockdown of the transcribed pseudogene ABCC6P1 resulted in a significant reduction of ABCC6 mRNA expression levels.ConclusionThe human genome contains a surprisingly small number of ABC transporter pseudogenes relative to other known gene families. They are unevenly distributed across the chromosomes. Importantly, a significant portion of the ABC transporter pseudogenes is transcriptionally active. The downregulation of ABCC6 mRNA levels by targeted suppression of the expression of its pseudogene ABCC6P1 provides evidence, for the first time, for a regulatory interdependence of a transcribed pseudogene and its protein coding counterpart in the human genome.

Transfusion-transmitted hepatitis E in Germany, 2013

The reported IgG seroprevalence against hepatitis E virus (HEV) in German blood donations is 6.8%, and HEV RNA detected in 0.08%, but documented evidence for HEV transmission is lacking. We identified two donations from a single donor containing 120 IU HEV RNA/mL plasma and 490 IU/mL. An infectious dose of 7,056 IU HEV RNA was transmitted via apheresis platelets to an immunosuppressed patient who developed chronic HEV. Further, transmission was probable in an immunocompetent child.

Large and prolonged food-borne multistate hepatitis A outbreak in Europe associated with consumption of frozen berries, 2013 to 2014.

In May 2013, Italy declared a national outbreak of hepatitis A, which also affected several foreign tourists who had recently visited the country. Molecular investigations identified some cases as infected with an identical strain of hepatitis A virus subgenotype IA. After additional European Union/European Economic Area (EU/EEA) countries reported locally acquired and travel-related cases associated with the same outbreak, an international outbreak investigation team was convened, a European outbreak case definition was issued and harmonisation of the national epidemiological and microbiological investigations was encouraged. From January 2013 to August 2014, 1,589 hepatitis A cases were reported associated with the multistate outbreak; 1,102 (70%) of the cases were hospitalised for a median time of six days; two related deaths were reported. Epidemiological and microbiological investigations implicated mixed frozen berries as the vehicle of infection of the outbreak. In order to control the spread of the outbreak, suspected or contaminated food batches were recalled, the public was recommended to heat-treat berries, and post-exposure prophylaxis of contacts was performed. The outbreak highlighted how large food-borne hepatitis A outbreaks may affect the increasingly susceptible EU/EEA general population and how, with the growing international food trade, frozen berries are a potential high-risk food.

Decline in hepatitis E virus antibody prevalence in southeastern Germany, 1996‐2011

In the past decade, an increasing frequency of acute hepatitis E was noted in Germany and other European countries. Moreover, a high prevalence (17%) of hepatitis E virus (HEV) immunoglobulin G antibodies (anti‐HEV) was recently found in the adult German population. Although this suggests an emerging pathogen, reports from other countries gave hints to a completely new aspect: a possible decrease in anti‐HEV prevalence during the last decades. To investigate the time trends of hepatitis E in southeastern Germany, we performed anti‐HEV testing in sera taken from adults in 1996 and 2011. Surplus serum specimens stored during routine operations of our diagnostic laboratory were used. The sample comprised two sets of 1,092 sera taken in 1996 and 2011, each with 182 specimens in six age groups from 20‐79 years. Testing was performed using an HEV IgG enzyme immunoassay (EIA, Axiom Diagnostics), and the recomLine HEV IgG immunoblot (Mikrogen). A significant difference in anti‐HEV prevalence was observed between the two groups: 50.7% of individuals tested positive in the 1996 group as compared to 34.3% in 2011 (EIA, P < 0.001). Results by immunoblot analysis were 20.5% (1996) versus 14.5% (2011), P < 0.001. Differences were found in all age groups and were more pronounced for the 20‐39‐year age group. Conclusion: The prevalence of anti‐HEV has decreased significantly in the past decades in southeastern Germany. The phenomenon of HEV being an emerging pathogen is thus most probably due to an increasing awareness of the disease. (Hepatology 2014;60:1180–1186)

Prevalence of nucleic acid sequences specific for human parvoviruses, hepatitis A and hepatitis E viruses in coagulation factor concentrates.

Background and Objectives  Due to their high resistance to inactivation procedures, nonenveloped viruses such as parvovirus B19, human bocavirus (HBoV), human parvovirus 4 (PARV4), hepatitis A (HAV) and hepatitis E virus (HEV) pose a particular threat to blood products. Virus transmission to patients treated with blood products presents an additional burden to disease. We determined the frequency and the amount of nucleic acid specific for nonenveloped viruses in recently manufactured preparations of commercial coagulation factor concentrates.