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.

Increase in hepatitis A in tourists from Denmark, England, Germany, the Netherlands, Norway and Sweden returning from Egypt, November 2012 to March 2013

Since November 2012, there has been an increase in reported cases of hepatitis A in tourists returning from Egypt in several European countries. As of 24 April, 80 HAV cases in travellers with symptom onset after 1 November 2012 visiting different areas in Egypt have been reported. Four cases from Norway, six cases from the Netherlands and five cases from England share an identical hepatitis A viral RNA sequence. This increase in cases suggests that vaccination recommendations for travellers to hepatitis A endemic countries should be reinforced.

A possible outbreak of hepatitis A associated with semi-dried tomatoes, England, July–November 2011

In October 2011, two primary cases of hepatitis A virus (HAV) infection with identical HAV genotype IB strains to those seen in other outbreaks associated with semi-dried tomatoes were reported in England. Both cases had consumed semi-dried tomatoes. Epidemiological investigations revealed two additional cases of genotype IB strains with different sequences who also reported having consumed semi-dried tomatoes. In November, five cases of HAV infection with closely related strains were identified in the Netherlands. A foodborne multiple-strain outbreak is suspected.

Measuring the incidence, prevalence and genetic relatedness of hepatitis C infections among a community recruited sample of injecting drug users, using dried blood spots

Monitoring hepatitis C virus (HCV) infection among injecting drug users (IDUs) in the community is complicated by difficulties in obtaining biological specimens and biases in recruitment and follow-up. This study examined the utility of dried blood spot (DBS) specimens from IDUs recruited using respondent-driven sampling (RDS). Active IDUs underwent a computer-assisted interview and provided a DBS sample, tested for HCV antibody (anti-HCV) and HCV-RNA. HCV incidence was estimated from the proportion of anti-HCV-negative subjects found HCV-RNA-positive and estimates of the duration of this state. Results were adjusted according to RDS derived sample weights. HCV-RNA testing was performed on 288 DBS samples; 173 were anti-HCV-positive (54% weighted), of which 70 (42%, 95%CI 34-50% weighted) were RNA-negative indicating cleared infection. Among the 115 anti-HCV-negatives, 14 were RNA-positive suggesting an incidence of 38-47 per 100pyrs. Incident infections were younger than anti-HCV-negative and prevalent infections: 25 vs. 29 and 34, respectively. Incidence was highest among individuals with poor needle exchange coverage. One hundred and fourteen were genotyped (60 1a, 46 3a): a cluster of 14 had homology of >98.5% including 10 incident infections. Public health surveillance of HCV among IDUs could be enhanced through the collection of DBS samples with appropriate recruitment approaches. DBS allow differentiation between individuals with cleared infections, ongoing infection and those recently infected. They also enable virus characterization at genotype and nucleotide level. This would allow surveillance to inform development of harm reduction interventions, and the international evidence base for these.

Hepatitis A outbreak predominantly affecting men who have sex with men in Northern Ireland, October 2008 to July 2009

We describe an outbreak of hepatitis A which evolved in Northern Ireland between October 2008 and July 2009, against a background of large concurrent hepatitis A outbreaks in various parts of Europe. Thirty-eight cases were defined as outbreak cases using a stratified case definition; 36 were males with a median age of 29 years and of the 28 males whose sexual orientation was known, 26 were men who have sex with men(MSM). Detailed descriptive epidemiology data collected through standardised questionnaires, together with sequencing of a 289 bp fragment of the VP1/2PA region of the virus, significantly aided the understanding of the spread of the outbreak when non-MSM cases occurred. The sequence of the outbreak strain, genotype IA, was indistinguishable from that involved in a large outbreak in the Czech Republic. Although seeded in a generally susceptible Northern Ireland population, the outbreak remained mostly contained in MSM, showing this sub-population to be the most vulnerable despite ongoing hepatitis A vaccination programmes in genito-urinary medicine clinics.

Hepatitis A outbreak predominantly affecting men who have sex with men in Northern Ireland, October 2008 to July 2009

We describe an outbreak of hepatitis A which evolved in Northern Ireland between October 2008 and July 2009, against a background of large concurrent hepatitis A outbreaks in various parts of Europe. Thirty-eight cases were defined as outbreak cases using a stratified case definition; 36 were males with a median age of 29 years and of the 28 males whose sexual orientation was known, 26 were men who have sex with men (MSM). Detailed descriptive epidemiology data collected through standardised questionnaires, together with sequencing of a 289 bp fragment of the VP1/2PA region of the virus, significantly aided the understanding of the spread of the outbreak when non-MSM cases occurred. The sequence of the outbreak strain, genotype IA, was indistinguishable from that involved in a large outbreak in the Czech Republic. Although seeded in a generally susceptible Northern Ireland population, the outbreak remained mostly contained in MSM, showing this sub-population to be the most vulnerable despite ongoing hepatitis A vaccination programmes in genito-urinary medicine clinics.

Infection with hepatitis C virus genotype 3--experience of a tertiary health care centre in south India

To analyse the response rate and the predictive values of virological, biochemical and histological factors on HCV antiviral therapy in HCV genotype 3 infected patients, we retrospectively studied 21 HCV genotype 3 infected patients, who underwent HCV antiviral therapy. Low (57%) sustained viral response (SVR) rate and significant association of SVR with normalization of alanine transaminase (ALT) levels were observed in our study. Absence of early viral response (EVR) showed high (80%) predictive value on SVR. Absence of EVR and normalisation of the ALT levels can predict the outcome of HCV antiviral therapy.

Emergence of occult minority genotype 2b hepatitis C infection in an HIV-1-co-infected patient treated for genotype 5a HCV infection with 48 weeks of pegylated-interferon-alpha 2b and ribavirin

An HIV-1/hepatitis C virus (HCV) co-infected patient with haemophilia received a 48-week course of pegylated interferon-alpha-2b and ribavirin therapy for genotype 5a HCV infection. Virological response was achieved at week 24. At the end of treatment, HCV RNA in serum was detected and identified to belong to genotype 2b, rather than genotype 5a. A sensitive method for identifying minority HCV genotypes in pre-treatment serum showed genotype 2b HCV carriage prior to treatment. Sequencing the interferon sensitivity-determining region of the HCV NS5A gene obtained from pre-, intra- and post-treatment sera revealed emergence of quasispecies bearing R-->K and M-->A/T mutations at codons 2222 and 2223, respectively. Occult presence of minority HCV subpopulations and their acquisition of mutations following therapy can result in poor treatment outcome.

Salivary human herpesvirus 8 shedding in renal allograft recipients with Kaposi's sarcoma

Renal allograft recipients in the Middle East are at high risk of developing Kaposi's sarcoma. This report describes the extent of oral human herpesvirus 8 shedding and the genomic diversity of the virus in five Saudi Arabian kidney transplantation patients in whom Kaposi's sarcoma had developed. PCR protocols were applied to amplify three fragments of the viral genome from whole-mouth saliva, parotid saliva, buccal and palatal exfoliates, plasma, peripheral blood leukocytes and biopsy of the Kaposi's sarcoma lesion, and to quantify the viral load in whole-mouth saliva. Viral DNA was detected in all plasma and biopsy samples, 80% of whole-mouth saliva, 20% of each of the other oral samples, and none of the leukocyte samples. The viral load in the cell-free fraction of whole-mouth saliva ranged between approximately 1.2 x 10(3) and 2.2 x 10(6) genome-copies/ml. Genotypically distinct viral strains were evident: intra-lesionally in 1 patient; intra-orally in one patient; between an oral sample and biopsy in two patients; and in four patients, between an oral sample and plasma, and between plasma and biopsy. Thus, in the patients studied, salivary shedding of human herpesvirus 8 was frequent and could be extensive, and they were prone to multiple infections. Measures to curtail salivary viral transmission to pre- and post-transplantation patients might reduce the incidence of post-transplantation Kaposi's sarcoma.

Selective transmission of hepatitis B virus after percutaneous exposure

In 3 clusters of postsurgical hepatitis B virus (HBV) infection, HBV DNA sequence mismatches were observed between the transmitting surgeons and the patients whom they infected. Sequence analysis of clones amplified from the C gene of HBV suggested that the mismatches were due to transmission of a minority variant in the circulation of each surgeon. Compared with 5 other transmitters from whom transmission of the dominant variant was demonstrated, the 3 surgeons who transmitted minority variants carried significantly more heterogeneous HBV populations. Transmission of minority variants was not correlated with the transmitters' hepatitis B antigen status, the presence of the position 1896 precore mutant, or the level of HBV viremia. In 1 cluster, a variant comprising <10% of the HBV population circulating in the transmitting surgeon established infection in all 3 patients who acquired HBV through him, which substantiates the phenomenon of true selection.

Natural and iatrogenic variation in hepatitis B virus

The existence of HBV as quasispecies is thought to be favoured by the infidelity of HBV RT, which would account for the emergence of the many natural mutants with point substitutions. RT infidelity may also underlie the hypermutation phenomenon. Indeed, the oft-reported point mutation in the preC gene that leads to failure of HBeAg synthesis may be driven by a hypermutation-related mechanism. The presence of mutants with deletions and insertions involving single nucleotides and oligonucleotides at specific positions in the genome, and of mutants with deletions of even longer stretches particularly in the C gene, suggests that other mutagenic mechanisms operate. Candidates include slippage during mispairing between template and progeny DNA strand, the action of cellular topoisomerase I, and gene splicing using alternative donor and acceptor sites. Natural substitutions, deletions or insertions involving the Cp/ENII locus in the X gene can significantly alter the extent of viral replicative activity. Similar mutations occurring at other locations of Cp/ENII, and at B-cell epitope sites of the S gene are associated with failure to detect serological markers of HBV infection. HBV variation can also arise from recombination between coinfecting strains. S gene mutations that become evident following HBIG administration and HBV vaccination are all point substitutions, as are mutations in functional RT domains of the P gene after treatment with viral RT-inhibitory drugs. Widespread and long-term use of prophylactic and therapeutic agents may potentially generate serologically occult HBV variants that might become difficult to eradicate.

Natural and iatrogenic variation in hepatitis B virus

The existence of HBV as quasispecies is thought to be favoured by the infidelity of HBV RT, which would account for the emergence of the many natural mutants with point substitutions. RT infidelity may also underlie the hypermutation phenomenon. Indeed, the oft-reported point mutation in the preC gene that leads to failure of HBeAg synthesis may be driven by a hypermutation-related mechanism. The presence of mutants with deletions and insertions involving single nucleotides and oligonucleotides at specific positions in the genome, and of mutants with deletions of even longer stretches particularly in the C gene, suggests that other mutagenic mechanisms operate. Candidates include slippage during mispairing between template and progeny DNA strand, the action of cellular topoisomerase I, and gene splicing using alternative donor and acceptor sites. Natural substitutions, deletions or insertions involving the Cp/ENII locus in the X gene can significantly alter the extent of viral replicative activity. Similar mutations occurring at other locations of Cp/ENII, and at B-cell epitope sites of the S gene are associated with failure to detect serological markers of HBV infection. HBV variation can also arise from recombination between coinfecting strains. S gene mutations that become evident following HBIG administration and HBV vaccination are all point substitutions, as are mutations in functional RT domains of the P gene after treatment with viral RT-inhibitory drugs. Widespread and long-term use of prophylactic and therapeutic agents may potentially generate serologically occult HBV variants that might become difficult to eradicate.

Failed postnatal immunoprophylaxis for hepatitis B: characteristics of maternal hepatitis B virus as risk factors

A retrospective case-control study was conducted to determine why some infants born full-term without obstetric intervention to hepatitis B e antigen (HBeAg)-seropositive mothers become infected by hepatitis B virus (HBV) despite having received passive-active immunoprophylaxis. Cases and controls comprised 12 hepatitis B surface antigen (HBsAg)-seropositive infants and 22 HBsAg-seronegative infants, respectively. Infants infected by putative vaccine-escape mutants were excluded. Risk factors, after adjustment for the level of maternal viremia, were the following allelic base changes in maternal HBV:C158, A328, G365, and A479 (P = .017, .005, .003, and .005, respectively). High-level maternal viremia (i.e., > or = 10(8) genome equivalents/mL) was a significant factor only after adjustment for G365 (P = .027). HBV DNA sequences recovered from one of the cases, the case's mother, and three infected contacts all had the high-risk mutations. Specific allelic mutations in maternal HBV and level of maternal viremia are potential predictors of vertical breakthrough infection.

Human herpesvirus 8 variants in sarcoid tissues

BACKGROUND

The cause of sarcoidosis is unknown, although mycobacteria have been implicated. We examined sarcoid tissues for human herpesvirus 8 (HHV-8) in addition to mycobacterial genomic sequences.

METHODS

Biopsy samples from 17 patients with sarcoidosis were studied (eight transbronchial, 27 lymph node, two skin, and two oral mucosa). We used tissues (n = 137) from 96 patients without sarcoidosis as negative controls. A nested PCR was applied to amplify a segment of open reading frame (ORF) 26 of the HHV-8 genome, and a heminested PCR was to amplify a segment of ORF 25 of HHV-8 and of the 16 S rRNA gene of mycobacteria. Differences in base sequences of the amplified fragments were resolved with single-strand conformation polymorphism and dideoxy sequencing.

FINDINGS

HHV-8 ORF 26 DNA was detected in significantly higher proportions of sarcoid than of non-sarcoid tissue samples from lung (8/8 vs 0/54; p < 0.0001), lymph nodes (26/27 vs 6/29; p < 0.0001), skin (2/2 vs 0/17; p = 0.006), and oral tissues (2/2 vs 1/13; p = 0.029). 31 (82%) of the 38 ORF 26 DNA-positive sarcoid specimens were also positive for ORF 25 DNA. For mycobacteria-like 16 S rRNA DNA, the proportion positive was significantly higher in sarcoid than non-sarcoid tissues for lymph node samples (11/27 vs 2/29; p = 0.003) but not for other tissues (lung 3/8 vs 22/54; skin 2/2 vs 15/17; and oral tissues 1/2 vs 0/13). Overall, the prevalence of HHV-8 ORF 26 sequences was higher in sarcoid tissues than in non-sarcoid tissues (p < 0.0001). When patients whose tissues were included in a masked phase of the study were treated as units of analysis, eight of eight sarcoidosis patients were positive for HHV-8 ORF 26 DNA, compared with three of 56 control patients (p < 0.0001); for mycobacteria-like sequences, three of eight sarcoidosis patients were positive, compared with four of 56 controls (p = 0.0464). The HHV-8 ORF 26 sequences, ten of which were unique, could be segregated into four groups according to peptide motifs. In seven of nine patients from whom biopsy samples were taken from various sites, different sequences were recovered. The mycobacterial sequences amplified from sarcoid tissues were also varied, but none was homologous to those of known species.

INTERPRETATION

Variant HHV-8 DNA sequences are found in a wide range of sarcoid but not non-sarcoid tissues. Mycobacteria-like 16 S rRNA sequences are more frequently present in sarcoid lymph nodes and not in other tissue types, but do not indicate infection by a particular mycobacterial species.

Low detection rate and maternal provenance of hepatitis B virus S gene mutants in cases of failed postnatal immunoprophylaxis in England and Wales

Hepatitis B virus (HBV) infection occurred despite full passive-active immunoprophylaxis in 20 of 321 infants born to mothers seropositive for hepatitis B e antigen. In 2 (12%) of 17 infected infants, mother-infant DNA sequence mismatches were found in a segment of the HBV S gene coding for antigenic determinants of the HBV surface antigen (HBsAg) amplified from sera by polymerase chain reaction (PCR). Point substitutions occurred in codons 120, 134, and 144 of the HBsAg polypeptide in the variant sequence of 1 infant and in codon 126 in the other; all were missense mutations. Mutant sequences could not be recovered from maternal sera by PCR cloning but were selectively generated using an amplification refractory mutation system. The frequency of potential vaccine escape mutants is therefore low, and these preexist maternally as minor variants.

Hepatitis B virus genomic heterogeneity: variation between quasispecies may confound molecular epidemiological analyses of transmission incidents

Nucleotide sequence variability studies were conducted on a 263-base pair fragment of the core-coding genomic region of hepatitis B virus (HBV), amplified by the polymerase chain reaction (PCR) from three surgeons with varying circulating levels of HBV, all of whom were thought to have transmitted HBV to their patients post-surgically. DNA sequencing was applied to amplicons obtained directly from serum and those cloned into plasmid vectors, and from single HBV molecules in serum separated by a limiting dilution procedure. In one surgeon, who had a titre of approximately 3 x 10(5) genome equivalents ml-1, the direct sequence was identical to none of 29 other sequences and differed by one base substitution from the sequence amplified from the single patient he infected. In another surgeon, who had a titre of approximately 2 x 10(6) genome equivalents ml-1, the direct sequence was identical to 17 of 36 (47%) sequences; however, the sequence common to all three infected patients was identical to a unique sequence in the surgeon that differed by three base substitutions from the direct sequence. By contrast, the direct sequence in the third surgeon, who had a titre of approximately 4 x 10(7) genome equivalents ml-1, was identical to 25 of 38 (66%) sequences, and to the sequence common to all 11 infected patients. Assessment of HBV DNA sequences directly amplified from clinical specimens may not be appropriate to studies of transmission in which the source of infection harbours a relatively dilute, heterogeneous mix of viral variants.

Detection of human herpesvirus-8 DNA in oral ulcer tissues of HIV-infected individuals

OBJECTIVE

To determine the frequency of detection of human herpesvirus-8 (HHV-8) in HIV-related oral ulcers.

DESIGN

Analysis of archived biopsy material.

METHODS

Nested polymerase chain reaction of DNA extracts.

RESULTS

HHV-8 DNA was detected in six of 10 oral ulcers of HIV-positive patients without oral Kaposi's sarcoma (KS) lesions and five of 11 oral KS lesions. The positive non-KS samples were derived from various oral sites.

CONCLUSIONS

In HIV-positive people, HHV-8 can infect oral tissues that are not affected by KS.

Presence of human herpesvirus 8 variants in the oral tissues of human immunodeficiency virus-infected persons

A 210-bp DNA segment specific to the human herpesvirus 8 (HHV-8) genome was amplified by nested polymerase chain reaction from 10 of 14 archived oral biopsy samples of HIV-positive patients in London who had no evidence of oral Kaposi's sarcoma (KS). Various oral sites were represented. Oral tissues from 20 general dental patients not known to be HIV-infected were negative. When DNA sequences of these products were compared with sequences derived from 5 oral KS tissues of AIDS patients in London and 10 skin biopsies of Italian patients with Mediterranean KS (total number of positive tissues = 25), 11 were found to be unique. DNA and predicted peptide motifs of these sequences were also different from those in 28 of 36 HHV-8-positive lesions previously reported from American and African patients. HHV-8 is tropic for the oral mucosa of HIV-infected persons, and HHV-8 variants, though diverse, may be geographically restricted.