Genetic relatedness of hepatitis A virus strains recovered from different geographical regions

Hepatitis A virus genotype and its correlation with the clinical outcome of acute hepatitis A in Korea: 2006-2008

Korea has recently experienced a nationwide outbreak of hepatitis A. This study aimed to investigate hepatitis A virus (HAV) genotypes and to compare clinical features between patients infected with HAV genotype IA and those with genotype IIIA. From September 2006 to August 2008, 595 patients with symptomatic hepatitis A were enrolled prospectively in four hospitals in Korea. Among them, 556 patients participated in this study by providing serum or stool samples for genotypic analysis. HAV RNA was detected in 499 patients (89.7%). Major genotypes included IA (n = 244, 48.9%) and IIIA (n = 244, 48.9%), and the remaining genotype was IB (n = 11, 2.2%). From September 2006 to August 2007, the distribution of genotypes IA and IIIA were 64.6% and 35.6%, respectively, which changed to 42.3% and 54.6%, respectively, from September 2007 to August 2008, indicating change of circulating HAV genotypes in the study period from IA to IIIA. Major patterns of amino acid substitution in the VP3/VP1 junction region were observed at position 512 (P → L) in genotype IA and at 520 (R → K) in genotype IIIA. Patients with genotype IIIA infection showed significantly higher aminotransferase levels, prothrombin time, and leukocyte count, with more severe symptoms than those with genotype IA at the time of admission. These results suggest the occurrence of a change of circulating HAV genotypes in recent community-wide outbreaks of hepatitis A in Korea, and genotype IIIA infection, compared with genotype IA infection, might show more severe clinical manifestations.

Complete coding sequence and molecular analysis of hepatitis A virus from a chimpanzee with fulminant hepatitis

BACKGROUND

Hepatitis A virus (HAV) infects both humans and non-human primates, in experimentally infected chimpanzees is typically milder than in humans. In 1982, Abe and Shikata reported a first case of a chimpanzee with fulminant hepatitis caused by spontaneous HAV infection, and the underlying mechanisms of the disease remain unknown.

METHODS

To characterize denoted CFH-HAV, we conducted cloning and near full-length sequence analysis.

RESULTS

Phylogenetic analyses of VP1-2A and complete sequence comparison between various genotypes and the sample sequence showed clustering in genotype IB. Based on BLAST analysis, the sequence was most closely related to the wild-type (HM175/WT) isolate. Amino acid and nucleic acid similarities were 99.8% and 94.41%, respectively.

CONCLUSIONS

The chimpanzee may have been infected with human HAV genotype IB. The substitutions in VP2, VP4, 2B, 2C, and 3D, which may enhance virus proliferation, contributed to disease severity culminating in fulminant hepatic failure.

Hepatitis A among men who have sex with men in Barcelona, 1989-2010: insufficient control and need for new approaches

Background

Men who have sex with men (MSM) are a known group at risk for hepatitis A and outbreaks among this group are frequent. In Barcelona, vaccination for MSM has been recommended since 1994. In 1998 a vaccination campaign among preadolescents was implemented and an immunization program in gay bathhouses began in 2004. Objective: to asses the incidence of hepatitis A in adults in Barcelona from 1989 to 2010 and to evaluate the outbreaks among MSM including all genotypes involved.

Methods

All cases of acute hepatitis A among young adults notified to the Public Health Agency of Barcelona from 1989 to 2010 were included for analyses. We calculated the annual incidence rate and the incidence ratio male-to-female (M:F) as a marker for MSM. Spearman's coefficient was used to evaluate trends. We also evaluated the outbreaks among MSM and compared their characteristics using Chi-squared and ANOVA test. Fragment amplification of the VP1/P2A region was used for genetic analysis.

Results

The median annual incidence for the period of study was 4.7/100000 among females and 11.7/100000 among males. The rate of hepatitis A for adult woman decreased over time (Spearman' coefficient = -0.63, p = 0.002), whereas there was no decrease for adult men (Spearman' coefficient = 0.097, p = 0.67). During the study period the M:F ratio increased (Spearman' coefficient = 0.73, p < 0.001).

Three large outbreaks among MSM were detected. When comparing outbreaks, there was a decrease in the percentage of bathhouse users (from 47% to 19%, p = 0.0001) and sex workers (from 6.5% to 0%) while the percentage of HIV infected individuals did not change significantly (range: 21%-28%, p = 0.36). The isolated strains were closely related to those circulating in Europe.

Conclusions

Annual incidences remain high among MSM without tendency to decrease. More strategies which effectively reach the whole MSM community are needed.

Genetic analysis of hepatitis A virus strains that induced epidemics in Korea during 2007-2009

Hepatitis A virus is one of the most prominent causes of fecally transmitted acute hepatitis worldwide. In order to characterize the viral agents causing an outbreak in Korea (comprising North and South Korea) from June 2007 to May 2009, we collected specimens and performed genotyping of the VP1/P2A and VP3/VP1 regions of hepatitis A virus. We then used a multiple-alignment algorithm to compare the nucleotide sequences of the 2 regions with those of reference strains. Hepatitis A virus antibodies were detected in 64 patients from 5 reported outbreaks (North Korea, June 2007 [n = 11]; Jeonnam, April 2008 [n = 15]; Daegu, May 2008 [n = 13]; Seoul, May 2009 [n = 22]; and Incheon, May 2009 [n = 3]). We found 100% homology between strains isolated from the Kaesong Industrial Region and Jeonnam. While those strains were classified as genotype IA strains, strains from Seoul and Incheon were identified as genotype IIIA strains and showed 98.9 to 100% homology. Genotype IIIA was also dominant in Daegu, where strains were 95.7 to 100% homologous. All hepatitis A virus strains isolated from the Kaesong Industrial Region, Jeonnam, Seoul, and Incheon belonged to a single cluster. However, strains from Daegu could be classified into 2 clusters, suggesting that the outbreak had multiple sources. This study indicates that hepatitis A virus strains of 2 different genotypes are currently cocirculating in Korea. Moreover, it documents an increasing prevalence of genotype IIIA strains in the country.

Epidemiological and genetic analyses of a diffuse outbreak of hepatitis A in Japan, 2010

BACKGROUND

Hepatitis A virus (HAV) is still one of the most common causative agents of acute hepatitis in Japan. Although a relatively small number of annual acute hepatitis A cases (approximately 100-150, 0.78-1.17 per million) were recently reported, a larger number of cases (346, 2.71 per million) were reported in 2010.

OBJECTIVES

To investigate the causes of the 2010 HAV resurgence in Japan by using molecular epidemiological and genetic analyses.

STUDY DESIGN

HAV specimens were obtained from 61 cases from 22 different prefectures. These viral specimens were genotyped by PCR amplification and sequencing of the VP1/2A region of HAV genome.

RESULTS

Phylogenetic analysis revealed that 61 HAV strains could be divided into three genotypes: IA (44 cases), IB (1 case) and IIIA (16 cases). The IA genotype consisted of two genomic sub-lineages. The sequences of one of the two IA sub-lineages (corresponding to 31 cases) were very similar, 26 of these 31 isolates had 100% identity. The other IA sub-lineage corresponded to strains endemic to Japan. The sequences of Japanese IIIA strains were similar to those of strains that caused a large epidemic in the Republic of Korea from 2007 to 2009.

CONCLUSIONS

The resurgence of HAV in 2010 can be attributed to importation of two newly emerged HAV genotypes.

Outbreak of hepatitis A in an extended family after importation by non-immune travellers

The incidence of hepatitis A in England has declined in recent years, but travel-related cases and imported infections remain a challenge. We report an outbreak of hepatitis A in an extended family where two primary cases were infected while in Pakistan and two secondary cases were infected in England. All four were infected by the same genotype IIIA virus. Testing of the children in the extended family by dried blood spots (DBS) determined that three had evidence of recent past infections (anti-HAV IgM positive), one had a current asymptomatic infection (anti-HAV IgM and HAV RNA positive) and one was incubating the virus (anti-HAV IgM negative, HAV RNA positive). HAV RNA from the DBS was identical to the adult cases. This outbreak demonstrates secondary spread of hepatitis A by asymptomatic children after importation from abroad and highlights the importance of preventing travel-associated hepatitis A infection.

Major human Hepatitis A virus genotype in Hong Kong marine waters and detection by real-time PCR

Marine waters from seven sites around Hong Kong with varying levels of sewage pollution were analyzed for Hepatitis A virus (HAV) by PCR cloning and DNA sequencing of the highly variable VP1/2A junction of the HAV genome. Phylogenetic analysis of 10 PCR clones from each of the HAV-positive marine sites indicated that human HAV genotype IB is the most widely distributed type in Hong Kong waters. A sensitive and quantitative TaqMan-based PCR method targeting the 5'-noncoding region (5'-NCR) of HAV was used to quantify HAV particles in marine water samples along with the total Escherichia coli counts being enumerated on TBX medium for comparison. Our results showed that no correlation of any significance between HAV and E. coli counts was observed which underscores the inadequacy in using E. coli as a sanitary standard to predict the levels of HAV in marine waters.

The evolution of infectious agents in relation to sex in animals and humans: brief discussions of some individual organisms

The following series of concise summaries addresses the evolution of infectious agents in relation to sex in animals and humans from the perspective of three specific questions: (1) what have we learned about the likely origin and phylogeny, up to the establishment of the infectious agent in the genital econiche, including the relative frequency of its sexual transmission; (2) what further research is needed to provide additional knowledge on some of these evolutionary aspects; and (3) what evolutionary considerations might aid in providing novel approaches to the more practical clinical and public health issues facing us currently and in the future?

Hemocytes are sites of enteric virus persistence within oysters

The goal of this study was to determine how enteric viruses persist within shellfish tissues. Several lines of novel evidence show that phagocytic blood cells (hemocytes) of Eastern oysters (Crassostrea virginica) play an important role in the retention of virus particles. Our results demonstrated an association of virus contamination with hemocytes but not with hemolymph. Live oysters contaminated overnight with hepatitis A virus (HAV) and murine norovirus (MNV) had 56% and 80% of extractable virus associated with hemocytes, respectively. Transfer of HAV-contaminated hemocytes to naïve (virus-free) oysters resulted in naïve oyster meat testing HAV positive for up to 3 weeks. Acid tolerance of HAV, MNV, poliovirus (PV), and feline calicivirus (FCV) correlated with the ability of each virus to persist within oysters. Using reverse transcription-PCR (RT-PCR) to evaluate persistence of these viruses in oysters, we showed that HAV persisted the longest (>21 days) and was most acid resistant, MNV and PV were less tolerant of acidic pH, persisting for up to 12 days and 1 day, respectively, and FCV did not persist (<1 day) within oysters and was not acid tolerant. This suggests that the ability of a virus to tolerate the acidic conditions typical of phagolysosomal vesicles within hemocytes plays a role in determining virus persistence in shellfish. Evaluating oyster and hemocyte homogenates and live contaminated oysters as a prelude to developing improved viral RNA extraction methods, we found that viruses were extracted more expediently from hemocytes than from whole shellfish tissues and gave similar RT-PCR detection sensitivities.

Characterization of outbreak hepatitis a isolates in five Tunisian childcare centers

In the present study, epidemiological survey and molecular characterization of hepatitis A virus during an outbreak in five Tunisian childcare centers in El-Mahres during October and November 2006 were carried out. Five well-water and five drinking water samples were included in the present study. Serological investigation and molecular characterization were carried out. All patients were IgM seropositive and the viral genome was detected in all clinical and well-water samples whereas it was not detected in drinking water from the five childcare centers. Sequence analysis showed that all Tunisian strains belong to sub-genotype IA. The genetic profile of the VP1/2A junction showed that the outbreak isolates underwent an amino acid substitution which was absent in virus’s strains detected previously in Tunisia. Further studies need to be conducted to evaluate the emergence of the virus’s strains in clinical and water samples and more epidemiological data need to be collected about the risk factors which may contribute to acute hepatitis.

Hepatitis a virus vaccine escape variants and potential new serotype emergence

Six hepatitis A virus antigenic variants that likely escaped the protective effect of available vaccines were isolated, mostly from men who have sex with men. The need to complete the proper vaccination schedules is critical, particularly in the immunocompromised population, to prevent the emergence of vaccine-escaping variants.

Exposure to multiple subgenotypes of hepatitis A virus during an outbreak using matched serum and saliva specimens

Matched serum and saliva samples were collected simultaneously from 124 subjects exposed during a hepatitis A virus (HAV) outbreak at a daycare center in Rio de Janeiro, Brazil. All samples were tested for IgM and total anti-HAV antibodies by enzyme immunoassay (EIA). HAV was detected by nested PCR in serum, saliva, and water samples employing primers for the VP1/2A region of the viral RNA; all positive products were then sequenced. The viral load of the matched samples was determined by real-time PCR using the TaqMan system. HAV-RNA was identified by nested PCR in 37.7% of the saliva samples, 29% of the serum samples, and one drinking water sample. The mean HAV viral load was similar in the serum and saliva specimens (10(3)  copies/ml). HAV genotypes IA and IB were detected in both specimen types, and the water sample isolate was classified as genotype IB, indicating the existence of more than one source of infection at the daycare center. In six infected patients, a different HAV subgenotype was found in their serum than in their saliva, and this unusual pattern of mixed HAV infection was investigated further by molecular cloning followed by nucleotide sequencing. All clones derived from the saliva samples belonged to subgenotype IB and shared 96.5-100% identity. However, clones derived from their corresponding serum sample belonged to subgenotype IA and shared 90.5-100% identity. This study showed the important role that non-invasive saliva samples can play in the molecular epidemiological analysis of a hepatitis A outbreak.

What factors determine the severity of hepatitis A-related acute liver failure?

The reason(s) that hepatitis A virus (HAV) infection may progress infrequently to acute liver failure are poorly understood. We examined host and viral factors in 29 consecutive adult patients with HAV-associated acute liver failure enrolled at 10 sites participating in the US ALF Study Group. Eighteen of twenty-four acute liver failure sera were PCR positive while six had no detectable virus. HAV genotype was determined using phylogenetic analysis and the full-length genome sequences of the HAV from a cute liver failure sera were compared to those from self-limited acute HAV cases selected from the CDC database. We found that rates of nucleotide substitution did not vary significantly between the liver failure and non-liver failure cases and there was no significant variation in amino acid sequences between the two groups. Four of 18 HAV isolates were sub-genotype IB, acquired from the same study site over a 3.5-year period. Sub-genotype IB was found more frequently among acute liver failure cases compared to the non-liver failure cases (chi-square test, P < 0.01). At another centre, a mother and her son presented with HAV and liver failure within 1 month of each other. Predictors of spontaneous survival included detectable serum HAV RNA, while age, gender, HAV genotype and nucleotide substitutions were not associated with outcome. The more frequent appearance of rapid viral clearance and its association with poor outcomes in acute liver failure as well as the finding of familial cases imply a possible host genetic predisposition that contributes to a fulminant course. Recurrent cases of the rare sub-genotype IB over several years at a single centre imply a community reservoir of infection and possible increased pathogenicity of certain infrequent viral genotypes.

Scientific Opinion on an update on the present knowledge on the occurrence and control of foodborne viruses

A review of the biology, epidemiology, diagnosis and public health importance of foodborne viruses was performed. Data needs to support a risk assessment were also identified. In addition possible control options and their anticipated impact to prevent or reduce the number of foodborne viral human infections were identified, including the scientific reasons for and against the establishment of food safety criteria and process hygiene criteria for viruses for certain food categories. Food may be contaminated by virus during all stages of the food supply chain, and transmission can occur by consumption of food contaminated during the production process (primary production, or during further processing), or contaminated by infected food handlers. Transmission of zoonotic viruses (e.g. HEV) can also occur by consumption of products of animal origin. Viruses do not multiply in foods, but may persist for extended periods of time as infectious particles in the environment, or in foods. At the EU-level it is unknown how much viral disease can be attributed to foodborne spread. The relative contribution of different sources (shellfish, fresh produce, food handler including asymptomatic shedders, food handling environment) to foodborne illness has not been determined. The Panel recommends focusing controls on preventive measures to avoid viral contamination rather than trying to remove/inactivate these viruses from food. Also, it is recommended to introduce a microbiological criteria for viruses in bivalve molluscs, unless they are labelled "to be cooked before consumption". The criteria could be used by food business operators to validate their control options. Furthermore, it is recommended to refine the regulatory standards and monitoring approaches in order to improve public health protection. Introduction of virus microbiological criteria for classification of bivalve molluscs production areas should be considered. A virus monitoring programme for compliance with these criteria should be risk based according to the findings of a sanitary survey.

Immunological and molecular epidemiological characteristics of acute and fulminant viral hepatitis A

BACKGROUND

Hepatitis A virus is an infection of liver; it is hyperendemic in vast areas of the world including India. In most cases it causes an acute self limited illness but rarely fulminant. There is growing concern about change in pattern from asymptomatic childhood infection to an increased incidence of symptomatic disease in the adult population.

OBJECTIVE

In-depth analysis of immunological, viral quantification and genotype of acute and fulminant hepatitis A virus.

METHODS

Serum samples obtained from 1009 cases of suspected acute viral hepatitis was employed for different biochemical and serological examination. RNA was extracted from blood serum, reverse transcribed into cDNA and amplified using nested PCR for viral quantification, sequencing and genotyping. Immunological cell count from freshly collected whole blood was carried out by fluorescence activated cell sorter.

RESULTS

Fulminant hepatitis A was mostly detected with other hepatic viruses. CD8+ T cells count increases in fulminant hepatitis to a significantly high level (P = 0.005) compared to normal healthy control. The immunological helper/suppressor (CD4+/CD8+) ratio of fulminant hepatitis was significantly lower compared to acute cases. The serologically positive patients were confirmed by RT-PCR and total of 72 (69.2%) were quantified and sequenced. The average quantitative viral load of fulminant cases was significantly higher (P < 0.05). There was similar genotypic distribution in both acute and fulminant category, with predominance of genotype IIIA (70%) compared to IA (30%).

CONCLUSIONS

Immunological factors in combination with viral load defines the severity of the fulminant hepatitis A. Phylogenetic analysis of acute and fulminant hepatitis A confirmed genotypes IIIA as predominant against IA with no preference of disease severity.

Genotyping of acute hepatitis a virus isolates from China, 2003-2008

Hepatitis A virus (HAV) is usually transmitted by an oral-fecal route and is prevalent not only in developing countries but also in developed countries. In the present study, the phylogenetic characterization of the VP1/2A junction region (321 nucleotides) of China HAV isolates was examined. Anti-HAV IgM-positive serum samples were collected from 8 provinces, including 20 cities or counties in China from 2003 to 2008; 337 isolates from 406 HAV patients' serum samples were amplified by RT-PCR, sequenced at the VP1/2A junction region and aligned with the published sequences from GenBank to establish phylogenetic analysis. All China HAV isolates in this study belonged to genotype I, with 98.8% (333/337) of samples clustering in sub-genotype IA and 1.2% (4/337) in sub-genotype IB. In addition, sub-genotype IA isolates clustered into four groups (92.7-100% nucleotide identity), and the samples collected from all China HAV isolates in this investigation showed 87.5-100% nucleotide identity, but the amino acids in this region were more conserved (95.2-100% identity). Few unique amino acid changes could be deduced (VP1-253: Glu → Gly; 2A-34: Pro → Ala; 2A-33: Leu → Phe). Genetically identical or similar HAV strains existed in some investigated areas in China during different years, suggesting that an indigenous strain has been circulating in those regions. This report provides new data on the genetic relatedness and molecular epidemiology of HAV isolates from China as well as the distribution of sub-genotype IA and IB in this part of the world.

Analysis of synonymous codon usage in hepatitis A virus

BACKGROUND

Hepatitis A virus is the causative agent of type A viral hepatitis, which causes occasional acute hepatitis. Nevertheless, little information about synonymous codon usage pattern of HAV genome in the process of its evolution is available. In this study, the key genetic determinants of codon usage in HAV were examined.

RESULTS

The overall extent of codon usage bias in HAV is high in Picornaviridae. And the patterns of synonymous codon usage are quite different in HAV genomes from different location. The base composition is closely correlated with codon usage bias. Furthermore, the most important determinant that results in such a high codon bias in HAV is mutation pressure rather than natural selection.

CONCLUSIONS

HAV presents a higher codon usage bias than other members of Picornaviridae. Compositional constraint is a significant element that influences the variation of synonymous codon usage in HAV genome. Besides, mutation pressure is supposed to be the major factor shaping the hyperendemic codon usage pattern of HAV.

Presence of enteric hepatitis viruses in the sewage and population of Greater Cairo

In Egypt, the disease burden of viral hepatitis is one of the heaviest worldwide. We conducted a survey of hepatitis A virus (HAV) and hepatitis E virus (HEV) in patients and sewage in Cairo. Our data showed that HAV (genotype IB) was predominant over HEV (genotype 3) and was circulating in the population and the environment.

Factors for predicting positive results for anti-HAV IgM retesting among initially seronegative patients

BACKGROUND AND AIMS

The standard diagnostic tool for acute hepatitis A is detection of anti-hepatitis A virus (HAV) immunoglobulin M (IgM). However, a negative result for anti-HAV IgM can be obtained in the early phase of infection. Among clinically suspicious seronegative patients, diagnosis of hepatitis A is sometimes recorded on retesting.

PATIENTS AND METHODS

This study included patients who had attended the Kyung Hee University East-West Neo Medical Center from November 2006 to October 2008. We evaluated 27 patients (15 men, 12 women) who had undergone repeated anti-HAV IgM testing.

RESULTS

Thirteen patients were diagnosed with hepatitis A after retesting, and 14 with non-hepatitis A (non-HA). High initial cutoff index (COI) for anti-HAV IgM (≥0.5), low serum total bilirubin (<1.4 mg/dl), and low platelet count (<165 × 10(3)/μl) were related to a positive result for anti-HAV IgM retesting, although this association was not statistically significant on multivariate analysis. In the HA group, 7 of 13 patients had an initial COI for anti-HAV IgM of >0.5 compared with none of 14 patients in the non-HA group.

CONCLUSIONS

Initial COI for anti-HAV IgM, serum total bilirubin, and platelet count were helpful for predicting positive results for retesting among initially seronegative patients.

First full-length genomic sequence of a hepatitis A virus isolated in Argentina shows recombination between subgenotypes IA and IB

A hepatitis A virus (HAV) recovered in Argentina from a stool sample of a sick child in the year 2006 (HAV-Arg/06) was entirely sequenced. Phylogenetic analysis included the HAV-Arg/06 sequence in subgenotype IA, either considering the usual VP1-2A variable junction fragment or the full length nucleotide sequence. Interestingly, a recombination event with subgenotype IB, involving a portion of the 2C-3A nonstructural proteins coding region (nucleotides 4961-5140) was detected using specific software. Only subgenotype IA strains have been detected in Argentina or Uruguay, whereas subgenotype IA and IB strains have been reported to circulate in Brazil. Although recombination has been given an important role in the evolution of picornaviruses, there have been only a few reports of its involvement in the evolution of HAV, probably due to the limited number of complete HAV sequences available. This study constitutes the first report of a full-length HAV sequence in Argentina and the third in South America, after the sequence of the IA isolate HAV5 from Uruguay and the IB isolate HAF-203 from Brazil. The availability of new sequence data covering the complete HAV genome will help establish a more consistent genetic relatedness among HAV isolates and the role of recombination in its evolution.

[Genetic diversity of a rare hepatitis A virus genotype]

PURPOSE OF THE STUDY

Very few is known on genotype II hepatitis A virus (HAV) since it is rarely isolated. From 2002 to 2007, the French observatory of HAV identified six sub-genotype IIA strains of which one from a patient having travelled to West Africa. To investigate the possible African origin of sub-genotype IIA, we determined its prevalence among French travellers in 2008 and characterised its genetic variability.

PATIENTS AND METHODS

The 2008 mandatory notification records were screened for travel to Africa. Viral genotype was determined on the nucleotide sequencing of the VP1/2A junction region. The P1 region coding for capsid proteins was used to compare the genetic diversity of IIA isolates to those of other genotypes.

RESULTS

In 2008, five out of 54 patients returning from West Africa were infected by IIA strains and an additional "autochthonous" case was identified. Two more African cases were identified in 2009. A total of 14 IIA isolates (eight African and six "autochthonous") were analysed. Nucleotide and amino-acid variability of IIA sequences was lower than that of the other genotypes. Phylogenetic analysis revealed the clustering of two "autochthonous" cases with African isolates whereas the other ones belonged to a different lineage.

CONCLUSION

Most IIA strains isolated in France are imported by travellers returning from West Africa. However, the unexplained contamination mode of some "autochthonous" cases suggests another geographical origin to discover or a French reservoir to explore.

Inhibitory effects on HAV IRES-mediated translation and replication by a combination of amantadine and interferon-alpha

Hepatitis A virus (HAV) causes acute hepatitis and sometimes leads to fulminant hepatitis. Amantadine is a tricyclic symmetric amine that inhibits the replication of many DNA and RNA viruses. Amantadine was reported to suppress HAV replication, and the efficacy of amantadine was exhibited in its inhibition of the internal ribosomal entry site (IRES) activities of HAV. Interferon (IFN) also has an antiviral effect through the induction of IFN stimulated genes (ISG) and the degradation of viral RNA. To explore the mechanism of the suppression of HAV replication, we examined the effects of the combination of amantadine and IFN-alpha on HAV IRES-mediated translation, HAV replicon replication in human hepatoma cell lines, and HAV KRM003 genotype IIIB strain replication in African green monkey kidney cell GL37. IFN-alpha seems to have no additive effect on HAV IRES-mediated translation inhibition by amantadine. However, suppressions of HAV replicon and HAV replication were stronger with the combination than with amantadine alone. In conclusion, amantadine, in combination of IFN-alpha, might have a beneficial effect in some patients with acute hepatitis A.

Epidemiology of hepatitis A in Finland in 1990-2007

The seroepidemiology of hepatitis A virus (HAV) for the period 1990-2007 and the molecular epidemiology for the period 1994-2007 in Finland were studied. The incidence of hepatitis A has been very low since 1990, at 0.3-3.6/100,000 inhabitants, excluding two outbreaks in 1994-1995 and 2002-2003, both of which were connected to intravenous drug use. Serum samples (3,217) collected in the period 1997-1998 were tested for hepatitis A antibodies to assess the percentage of seropositive Finns. More than 50% of Finns aged over 55 were seropositive for hepatitis A, while less than 5% of those aged under 40 were seropositive. In addition, patient samples (52,012) from the period 1990 to 2007 were assessed for antibodies against HAV. In these samples the proportion of acute HAV infections stayed at around 2% per year (excluding outbreaks), whereas the overall seropositivity for hepatitis A increased from some 30% to 45%, which was most likely due to increased vaccinations. For molecular epidemiology, samples from 1994 to 2007 were analyzed by RT-PCR and sequencing. The results showed that most of the strains (82%) of HAV were of genotype IA but with an increasing number of genotypes IB and IIIA appearing during the last years of the study. All the cases seemed to be travel related and there was no endemic strain circulating in Finland. The low seroprevalence, especially in younger age groups, makes the population vulnerable to infection, which can be compensated for by increasing the number of vaccinations.

Nucleotide variability and translation efficiency of the 5' untranslated region of hepatitis A virus: update from clinical isolates associated with mild and severe hepatitis

Mutations in the internal ribosome entry site (IRES) of hepatitis A virus (HAV) have been associated with enhanced in vitro replication and viral attenuation in animal models. To address the possible role of IRES variability in clinical presentation, IRES sequences were obtained from HAV isolates associated with benign (n = 8) or severe (n = 4) hepatitis. IRES activity was assessed using a bicistronic dual-luciferase expression system in adenocarcinoma (HeLa) and hepatoma (HuH7) cell lines. Activity was higher in HuH7 than in HeLa cells, except for an infrequently isolated genotype IIA strain. Though globally low, significant variation in IRES-dependent translation efficiency was observed between field isolates, reflecting the low but significant genetic variability of this region (94.2% +/- 0.5% nucleotide identity). No mutation was exclusive of benign or severe hepatitis, and variations in IRES activity were not associated with a clinical phenotype, indirectly supporting the preponderance of host factors in determining the clinical presentation.

Epidemiology and genetic characterization of hepatitis A virus genotype IIA

Three hepatitis A virus (HAV) genotypes, I, II, and III, divided into subtypes A and B, infect humans. Genotype I is the most frequently reported, while genotype II is hardly ever isolated, and its genetic diversity is unknown. From 2002 to 2007, a French epidemiological survey of HAV identified 6 IIA isolates, mostly from patients who did not travel abroad. The possible African origin of IIA strains was investigated by screening the 2008 mandatory notification records of HAV infection: 171 HAV strains from travelers to West Africa and Morocco were identified. Genotyping was performed by sequencing of the VP1/2A junction in 68 available sera. Entire P1 and 5' untranslated regions of IIA strains were compared to reference sequences of other genotypes. The screening retrieved 5 imported IIA isolates. An additional autochthonous case and 2 more African cases were identified in 2008 and 2009, respectively. A total of 14 IIA isolates (8 African and 6 autochthonous) were analyzed. IIA sequences presented lower nucleotide and amino acid variability than other genotypes. The highest variability was observed in the N-terminal region of VP1, while for other genotypes the highest variability was observed at the VP1/2A junction. Phylogenetic analysis identified 2 clusters, one gathering all African and two autochthonous cases and a second including only autochthonous isolates. In conclusion, most IIA strains isolated in France are imported by travelers returning from West Africa. However, the unexplained contamination mode of autochthonous cases suggests another, still to be discovered geographical origin or a French reservoir to be explored.

Clinical implications of hepatitis A virus ribonucleic acid detection and genotyping in acute liver failure in children in Argentina

OBJECTIVES

To investigate the detection of hepatitis A virus ribonucleic acid in patients with acute liver failure and to assess if the results have any clinical implications for the evolution of acute liver failure in children. Hepatitis A infection, a vaccine-preventable disease, is an important cause of acute liver failure in children in Argentina. Universal vaccination in 1-yr-old children was implemented in June 2005.

DESIGN

Observational study in which patients were divided into Group 1 consisting of positive hepatitis A virus ribonucleic acid and Group 2 consisting of negative hepatitis A virus ribonucleic acid.

SETTING

Pediatric intensive care unit in National Pediatric Hospital "Dr. J. P. Garrahan," Buenos Aires, Argentina.

PATIENTS

Thirty-three patients with the diagnosis of acute liver failure secondary to hepatitis A virus infection and admitted to the Garrahan Pediatric Hospital between September 2003 and September 2005 were enrolled in the study. Twenty of these children were admitted to the pediatric intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples for total ribonucleic acid detection and genotyping were obtained from serum and/or stools on admission. We found positive hepatitis A virus ribonucleic acid in 13 patients and negative hepatitis A virus ribonucleic acid in 20 patients. The following clinical variables were evaluated: time of evolution, hospital stay, admission to the pediatric intensive care unit, pediatric intensive care unit stay, time on mechanical ventilation, criteria for orthotopic liver transplantation, and mortality. Characterization of the isolates did not reveal differences related to genotype; all cases were IA. No statistical significance was found as to the variables. However, positive hepatitis A virus ribonucleic acid showed lower percentages of pediatric intensive care unit admissions, criteria for orthotopic liver transplantation, number of orthotopic liver transplantation, and mortality than the group of patients with negative hepatitis A virus ribonucleic acid.

CONCLUSIONS

Hepatitis A virus genotyping studies did not show any particularities, all cases were IA and, thus, apparent associations between genotype and the clinical presentation of acute liver failure could not be found.

Internal ribosomal entry-site activities of clinical isolate-derived hepatitis A virus and inhibitory effects of amantadine

AIM

Little is known about specific naturally-occurring internal ribosomal entry site (IRES) activities of hepatitis A virus (HAV). We examined these activities using the bicistronic reporter assay and the effects of antiviral amantadine against their activities.

METHODS

Six HAV IRES clones from three patients with fulminant hepatitis and three with self-limited acute hepatitis were obtained. The activities of their IRES were analyzed using bicistronic reporter assay in hepatocyte- and non-hepatocyte-derived cell lines, and the potential efficaciousness of the amantadine was examined.

RESULTS

One clone from fulminant hepatitis had a deletion in domains III-IV of HAV IRES had higher IRES activities than HM175 in HLE and Huh-7 cells. In Huh-7 cells, amantadine is effective for inhibiting HAV IRES activities, and especially fulminant hepatitis-derived ones.

CONCLUSION

HAV IRES derived from clinical isolates have various activities. Bicistronic reporter assay using clinical isolates may be another useful tool for testing antiviral activities like those of amantadine and the new acridines and hydrazones recently reported.

High prevalence of antibodies against hepatitis A virus among captive nonhuman primates

Hepatitis A virus (HAV) can infect not only humans but also several other nonhuman primates. This study has been conducted to evaluate the comprehensive anti-HAV seroprevalence in captive nonhuman primate populations in Thailand. The prevalence of antibodies against HAV in 96 captive nonhuman primates of 11 species was evaluated by competitive enzyme immunoassay (EIA). HAV antibodies were found in 64.7% (11/17) of macaques, 85.7% (6/7) of langurs, 28.4% (10/35) of gibbons, and 94.6% (35/37) of orangutans. However, anti-HAV IgM was not found in any sera. These results indicate that the majority of captive nonhuman primates in Thailand were exposed to HAV. It is possible that some of the animals were infected prior to capture.

Hepatitis A virus: serology and molecular diagnostics

The diagnosis of hepatitis A virus (HAV) infection is based on the detection of anti-HAV IgM. Shortcomings of this serological approach include the persistence of IgM after normalization of liver enzymes or its detection during polyclonal activation of the immune system due to unrelated viral infection or autoimmune diseases. Molecular diagnosis of HAV along with anti-HAV IgG avidity measurement are helpful in case of positive IgM where laboratory evidence of acute hepatitis is absent and there is no epidemiologic link to other cases. Molecular epidemiology allows us to determine whether viruses from different locations are related to each other and provides further understanding of viral epidemiology by identifying sources and transmission modes. It has been demonstrated that the rapid turnover of HAV strains in low-endemicity countries is caused by their introduction by travelers. Growing sequence databases allow for the identification of geographic origin of viral strains. Collaboration between surveillance laboratories, including database sharing, should be promoted for deeper investigation of outbreaks and improved prevention approaches.

Environmental surveillance and molecular characterization of human enteric viruses in tropical urban wastewaters

AIMS

To study the prevalence and genotypes of waterborne pathogenic viruses in urban wastewaters in the tropical region.

METHODS AND RESULTS

Viruses in wastewaters collected at three water reclamation plants in Singapore were studied by molecular methods. Over a 6-month sampling period, adenoviruses, astroviruses and both norovirus genogroups I (GI) and II (GII) were detected in 100% of the sewage and secondary effluent. Enteroviruses and hepatitis A viruses (HAV) were found in 94 and 78% of sewage, and 89 and 28% of secondary effluent, respectively. By using quantitative real-time PCR, estimated concentrations of astrovirus in the sewage were 1-2 orders of magnitude higher than those for adenovirus, noroviruses GI and GII. Genotyping of environmental isolates revealed multiple genotypes of GI and GII noroviruses. Coxsackieviruses A, astrovirus type 1 and adenovirus type 41 were prevalent. Norovirus GII/4 and coxsackievirus A24 isolates in wastewaters were closely related to respective outbreak strains isolated previously in Singapore.

CONCLUSIONS

This study showed the widespread occurrence of all tested enteric virus groups in urban wastewaters. Genetic diversity of astroviruses, enteroviruses and noroviruses in the tropical region was observed.

SIGNIFICANCE AND IMPACT OF THE STUDY

The high prevalence and great genetic diversity of human enteric viruses in urban wastewaters strongly supports the need of further comprehensive studies for evaluating the public health risk associated with viral pathogens in water environments.

Epidemiology of hepatitis A virus infections, Germany, 2007-2008

Communicating vaccination recommendations may help reduce infections.

Full length genomes of genotype IIIA Hepatitis A Virus strains (1995-2008) from India and estimates of the evolutionary rates and ages

With the changing epidemiology, outbreaks of Hepatitis A Virus (HAV) have been reported from different parts of India. To characterize HAV strains circulating in India (1995-2008), 6 full genome sequences of the predominant genotype, IIIA, were determined. Further, applying the Bayesian Markov Chain Monte Carlo (MCMC) framework to the full genomes of Indian HAV strains as well as other global strains (human as well as simian), we derived the mean nucleotide substitution rate and evolutionary timescales with emphasis on the age of genotype III and IIIA strains. The genomic length of all the 6 HAV isolates was 7464 nt excluding the poly A tract. Phylogenetic analysis confirmed that all the Indian isolates were close to Nor-21 (AJ299464) and HMH (AY644337) of subgenotype IIIA. The ORF of the isolates when compared within genotype III at amino acid level showed a highly conserved pattern. Under the best fit expansion population relaxed molecular clock model, the estimated mean substitution rate of the HAV full genomes (human and simian strains) was 1.73 x 10(-4) substitutions/site/year based on which the earliest transmission of HAV from simian to humans is estimated to have occurred about 3564 years ago. The mean substitution rate within human HAV full genomes under the same model was estimated to be 1.99 x 10(-4) substitutions/site/year. With this the mean age of genotype III strains was estimated to be 592 years while that of genotype IIIA was estimated to be 202 years. The time to the most common recent ancestor (tMRCA) of the Indian genotype IIIA isolates was calculated to be 116 years.

Molecular epidemiology of hepatitis A virus in the South-East area of Gyeonggi-do in Korea

PURPOSE

Hepatitis A virus (HAV) has been a leading cause of acute hepatitis in Korea. The reported genotypes of acute hepatitis A in Korea are the subgenotype IA and IB. The aim of the present study is to investigate HAV genotypes in the south-east area of Gyeonggi-do in Korea.

MATERIALS AND METHODS

From June 2004 to June 2006, 46 acute hepatitis A patients were enrolled prospectively. All had sporadic acute hepatitis A patients. All suspected cases of acute hepatitis A were tested for IgM anti-HAV antibodies. We sequenced 168 bp of nucleotides of the putative VP1/P2A junction and determined the HAV genotype with reverse transcriptase polymerase chain reaction. The clinical and laboratory results of all patients were recorded.

RESULTS

HAV-ribonucleic acid (RNA) was detected in 41 samples out of 46 samples. Among the 41 samples, 25 (60%) were shown to have subgenotype IIIA and the other 16 (40%) were subgenotype IA. Several amino acid substitutions were found.

CONCLUSION

In these HAV sporadic cases, IIIA and IA were identified, and this may reflect co-circulation of various genotypes in Korea. This study provides valuable new data on the genetic distribution of HAV and important information to help design appropriate public health measures.

Acute hepatitis a virus infection presenting with multiorgan dysfunction: a case report

Introduction

Acute hepatitis due to hepatitis a virus is usually a benign self-limiting disease conferring lifelong immunity. However, few cases have been reported in literature with fulminant hepatitis. We report this extremely rare case with multiorgan dysfunction including liver failure, hepatic encephalopathy, renal failure, pleural effusion, pericardial effusion and hematologic dysfunction as a sequale of this infection in an otherwise healthy male at the age of 18.

Case presentation

An 18 years old Pakistani male presented with two days history of fever, cough, headache and vomiting. His condition gradually deteriorated and on day 7 developed multiorgan dysfunction. Initially Immunoglobulin M anti hepatitis a virus was borderline 1.40 but repeated titers one week later confirmed the diagnosis of acute hepatitis a virus infection.

Conclusion

This original case report highlights the importance of focusing first uncommon manifestations of common illnesses while diagnosing difficult cases. Moreover this case also adds knowledge to the limited available data regarding complications and predictors of prognosis.

Characterization of anti-idiotypic antibodies mimicking antibody- and receptor-binding sites on hepatitis A virus

Two anti-idiotypic monoclonal antibodies (mAb2s; named 94-2 and 94-7), were generated from a BALB/c mouse immunized with human monoclonal anti-hepatitis A virus (HAV) neutralizing antibody KF94. We characterized the properties of the mAb2s and determined interactions between mAb2s, KF94 and HAV using enzyme-linked immunosorbent assay, immunofluorescence assay and HAV infectivity assay. Inactivated HAV inhibited mAb2 binding to KF94, indicating that the mAb2s mimicked the HAV neutralization site that was complementary to the paratope of KF94. MAb2 94-7 competed with an anti-HAV cellular receptor antibody for binding to HAV-susceptible cells and partially blocked virus infection. We speculated that mAb2 94-7 mimicked a portion of the HAV receptor-binding site. The ability to generate mAb2 implies that HAV receptor-binding sites are exposed on the surface of HAV, permitting antibody access.

Hepatitis A outbreaks in China during 2006: application of molecular epidemiology

BACKGROUND

In China, hepatitis is a huge public health problem. Outbreaks of hepatitis A are the most frequent cause of acute hepatitis, and to date, few epidemiologic investigations or molecular surveillance studies have been performed.

MATERIALS AND METHODS

In 2006, two major outbreaks of hepatitis A occurred, one in Guigang City, southern China, and the other in Hetian City, northwestern China. Field and molecular epidemiologic investigations were conducted.

RESULTS

In Guigang, a single outbreak occurred in a school; 35 patients and 25 asymptomatic individuals were infected with 1 strain of hepatitis A virus (HAV). A case-control study showed that contaminated water was the likely transmission source. In Hetian, the epidemic of hepatitis A consisted of sporadic, small outbreaks involving as many as 20 wild HAV strains. A molecular epidemiology approach allowed us to identify two groups infected by individual HAV strains. Further fieldwork and a case-control study showed that ice cream was the suspected transmission source in one group. Our molecular epidemiology study showed that genetic variability between the HAV strains isolated from Guigang and Hetian and previously reported HAV strains was at least 4.3%.

CONCLUSION

Contaminated water and suspected ice cream were associated with outbreaks of hepatitis A. Viral genetic analysis may advance field investigations in complex situations.

Molecular characterization of hepatitis A virus isolated from acute gastroenteritis patients in the Seoul region of Korea

Hepatitis A virus (HAV) is a major public health problem throughout the world. As a result of declining HAV endemic in Korea, an increasing number of children and adolescents have become susceptible to HAV infection. HAV is related with sanitation conditions of the environment and is transmitted via the fecal-oral route, either through person-to-person contact or by contaminated water and food. The present study has been carried out to determine the phylogenetic analysis and circulating patterns of HAV strains detected from hospitalized patients with acute gastroenteritis (AGE) in the Seoul region of Korea. In total, 2,782 stool specimens from hospitalized patients with AGE collected in October 2006 to September 2007 in Seoul were tested for HAV. A pair comparison of the nucleic acid sequence of a 159-bp base region at the putative VP1/2A junction of 85 Seoul isolates revealed that the most common HAV strain circulating in the region during 2006-2007 was subgenotype IA. HAV phylogenetic studies can provide important information on the genetic characteristics of HAV from AGE patients who may subsequently become the source of infection in Korea.

Molecular characterization of hepatitis A virus isolates from Goiânia, Gioás, Brazil

Hepatitis A virus (HAV) infection is a public health problem worldwide and the virus has been classified into six genotypes. In Brazil, the only genotype that has been found is genotype I, predominately from subgenotype IA. Here, the HAV genotypes were analyzed of 18 isolates circulating between 1996-2001 in Goiânia, state of Goiás, Brazil. Viral RNA was extracted from 18 serum samples and amplified (RT-PCR/nested-PCR), followed by the genomic sequencing of the VP1/2A junction region of the HAV genome. Sequences of 168 nucleotides were compared and analyzed using the BLAST N, Clustal X and PAUP v. 4.10b programs. All samples were classified as genotype I, with 10 belonging to subgenotype IA and eight to subgenotype IB. The subgenotype IA isolates showed greater diversity than the subgenotype IB isolates at the nucleotide level. Elevated identity values were found between isolates obtained in this study and those from other regions of the world, including Brazil, highlighting the high conservation among different isolates of this virus. However, changes in the HAV subgenotype circulation could also be observed during the evaluated period.

A microarray based approach for the identification of common foodborne viruses

An oligonucleotide array (microarray) incorporating 13,000 elements representing selected strains of hepatitis A virus (HAV), human coxsackieviruses A and B (CVA and CVB), genogroups I and II of Norovirus (NV), and human rotavirus (RV) gene segments 3,4,10, and 11 was designed based on the principle of tiling. Each oligonucleotide was 29 bases long, starting at every 5th base of every sequence, resulting in an overlap of 24 bases in two consecutive oligonucleotides. The applicability of the array for virus identification was examined using PCR amplified products from multiple HAV and CV strains. PCR products labeled with biotin were hybridized to the array, and the biotin was detected using a brief reaction with Cy3-labeled streptavidin, the array subjected to laser scanning, and the hybridization data plotted as fluorescence intensity against each oligonucleotide in the array. The combined signal intensities of all probes representing a particular strain of virus were calculated and plotted against all virus strains identified on a linear representation of the array. The profile of the total signal intensity identified the strain that is most likely represented in the amplified cDNA target. The results obtained with HAV and CV indicated that the hybridization profile thus generated can be used to identify closely related viral strains. This represents a significant improvement over current methods for virus identification using PCR amplification and amplicon sequencing.

Simian hepatitis A virus derived from a captive rhesus monkey in India is similar to the strain isolated from wild African green monkeys in Kenya

A simian hepatitis A virus (HAV) was identified retrospectively in a faecal sample from a rhesus monkey in India, inoculated in 1995 with a faecal suspension from a suspected patient of non-A to E hepatitis. The monkey was in captivity for 2 years in one of the experimental primate facilities in western India before being moved to the National Institute of Virology, Pune for experimentation. Phylogenetic analysis based on a partial sequence of the 5' noncoding region placed this virus in genotype V, the only other member being the AGM-27 strain recovered in 1986 from African green monkeys in Kenya. The source of infection of the monkey remains unclear. The full genome was amplified in nine fragments and sequenced. The genome of the Indian simian HAV (IND-SHAV) is 7425 nucleotides long including the poly-A tail of 14 nucleotides at the 3' end. At the nucleotide and amino acid levels, IND-SHAV was 99.8 and 100% identical with AGM27, respectively.