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In June 2019 the Health Protection Team in Yorkshire and Humber, England, was notified of cases of hepatitis A virus (HAV) infection in staff at a secondary school. Investigation revealed that an earlier case worked as a food handler in the school kitchen. Indirect transmission through food from the canteen was considered the most likely route of transmission. Cases were described according to setting of exposure. Oral fluid was obtained from students for serological testing. Environmental investigations were undertaken at settings where food handling was considered a potential transmission risk. Thirty-three confirmed cases were linked to the outbreak. All of those tested ( n = 31) shared the same sequence with a HAV IB genotype. The first three cases were a household cluster and included the index case for the school. A further 19 cases (16 students, 3 staff) were associated with the school and consistent with indirect exposure to the food handler. One late onset case could not be ruled out as a secondary case within the school and resulted in vaccination of the school population. Five cases were linked to a bakery where a case from the initial household cluster worked as a food server. No concerns about hygiene standards were noted at either the school or the bakery. Oral fluid samples taken at the time of vaccination from asymptomatic students ( n = 219, 11-16 years-old) showed no evidence of recent or current infection. This outbreak included household and foodborne transmission but limited (and possibly zero) person-to-person transmission among secondary school students. Where adequate hygiene exists, secondary transmission within older students may not occur.

Background: Surveillance programs undertaken in infants born to mothers with hepatitis B virus (HBV) provide an opportunity to analyze virological markers from the neonate and early infancy. These data inform on mechanisms of HBV transmission and how available interventions can be better used for control of HBV infections arising at the mother/child interface., Methods: Retrospective analysis of HBV serological markers was undertaken in dried blood spots collected from infants born to mothers infected with HBV. In addition, molecular analysis was performed in newborn blood spot cards, collected after birth, from infants identified as infected with HBV despite receiving prophylaxis., Results: Perinatal exposure could not account for all transmissions, with at least one-quarter (22%) of infants already infected in utero. All harbored a wild-type hepatitis B surface antigen (HBsAg), with identical sequences noted in the neonatal and early infancy samples. In contrast, in infants infected perinatally (43%), selection of viruses harboring amino acid changes in the HBsAg were common (80% of sequences) and divergent from the linked maternal sample., Conclusion: Currently considered to represent vaccine failure, it is likely that a proportion of HBV infections result from in utero acquisition. These infections are unlikely to be susceptible to postnatal prophylaxis, and current recommendations for maternal antiviral treatment may be too late to prevent transmission. Consideration should be given to the earlier use of antivirals during gestation to reduce the risk of intrauterine transmission together with completion of the immunization schedule also to reduce the perinatal risk of HBV transmission., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Objectives: We sought to evaluate clinically a hepatitis C virus (HCV) whole-genome, next-generation sequencing (NGS) pipeline that is agnostic to viral genotype., Methods: Performance of the NGS pipeline was assessed through comparison of results with Sanger sequencing (SS) of partial HCV genomes., Results: There was 98.7% (376/381) concordance for viral subtype between SS and NGS. The positive and negative per cent agreements for determination of resistance-associated substitutions were 97.8% (95% CI 92.5-99.4%) and 99.9% (95% CI 99.5-100.0%), respectively. The NGS pipeline was also able to detect novel subtypes, mixtures, recombinants, transiently occurring resistance mutations and distinguish re-infection with the same subtype from relapse., Discussion: Particular scenarios where NGS may be used include settings without universal access to pan-genotypic antiviral regimens, those infected with a 'rare' subtype or who have been failed by first-line therapy, and in cases of suspected re-infection., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

We report a national hepatitis A virus (HAV) outbreak linked to the consumption of Medjool dates. Twenty-nine cases of three genetically related sequences have been identified. Epidemiological investigations identified a suspected product (adjusted odds ratio: 47.36; 95% confidence interval: 1.79-1,256.07; p = 0.021). Microbiological testing has confirmed the presence of HAV on dates recovered from two cases and the product has been recalled. Date consumption is currently likely to be increased in connection with Ramadan, with potential ongoing contamination risk.

From July to August 2016, 4 homeless people who injected drugs (PWID) with acute or recent hepatitis C virus (HCV) infection were reported in Belfast. A multidisciplinary team including public health, homeless and addiction services undertook an investigation to identify risk behaviours and interrupt transmission chains. Recent HCV cases were defined as negative test within the previous year, or reported injecting for less than 1 year; acute cases had tested negative within the previous 6 months. Contacts in the injecting networks of cases were identified for testing. We undertook a cross-sectional survey using structured questionnaires to elicit risk behaviours for PWID and compare behaviours between self-reported hepatitis C positive and negative subjects. During the outbreak investigation until December 2017, 156 PWID were tested and 45 (29%) cases identified, including 7 (16%) recent and 13 (29%) acute infections. 68 PWID, including 12 cases, were interviewed. All respondents reported using heroin, with 76% injecting once or more daily. Sharing was reported for spoons (58%) and filters (53%), but also needles (27%) and syringes (29%). Hepatitis C positive individuals had higher odds to be injecting in public toilets (AOR 17, 95% CI 0.71-400, P < .05) when compared with hepatitis C negative individuals. Hepatitis C positive individuals were more likely to inject in public spaces, but all respondents indicated concerning risk behaviours. We recommend active surveillance with ongoing testing, expanding existing harm reduction programmes and access to bespoke services., (© 2019 John Wiley & Sons Ltd.)

IntroductionSequence-based typing of hepatitis A virus (HAV) is important for outbreak detection, investigation and surveillance. In 2013, sequencing was central to resolving a large European Union (EU)-wide outbreak related to frozen berries. However, as the sequenced HAV genome regions were only partly comparable between countries, results were not always conclusive.AimThe objective was to gather information on HAV surveillance and sequencing in EU/European Economic Area (EEA) countries to find ways to harmonise their procedures, for improvement of cross-border outbreak responses.MethodsIn 2014, the European Centre for Disease Prevention and Control (ECDC) conducted a survey on HAV surveillance practices in EU/EEA countries. The survey enquired whether a referral system for confirming primary diagnostics of hepatitis A existed as well as a central collection/storage of hepatitis A cases' samples for typing. Questions on HAV sequencing procedures were also asked. Based on the results, an expert consultation proposed harmonised procedures for cross-border outbreak response, in particular regarding sequencing. In 2016, a follow-up survey assessed uptake of suggested methods.ResultsOf 31 EU/EEA countries, 23 (2014) and 27 (2016) participated. Numbers of countries with central collection and storage of HAV positive samples and of those performing sequencing increased from 12 to 15 and 12 to 14 respectively in 2016, with all countries typing an overlapping fragment of 218 nt. However, variation existed in the sequenced genomic regions and their lengths.ConclusionsWhile HAV sequences in EU/EEA countries are comparable for surveillance, collaboration in sharing and comparing these can be further strengthened.

In August 2015 two community outbreaks of hepatitis A virus (HAV) occurred in sub-urban communities in Northern England. Each was managed by an independent outbreak control team. In outbreak one, mass vaccination was deployed targeting a residential area and two schools, while in outbreak two, vaccination was reserved for household-type contacts of cases. The highest vaccination uptake was achieved in the school settings (82% and 95%). These case studies illustrate the range of approaches that can be used and the factors that influence decision-making in response to a hepatitis A community outbreak. Both outbreaks likely started from importation(s) of HAV by returning travellers and spread through extended social networks and the local community. Vaccination strategies were selected based on hypotheses about transmission pathways, which were informed by evidence from oral fluid (OF) testing of asymptomatic contacts. More evidence about the effectiveness of mass vaccination in community outbreaks of hepatitis A in low endemicity settings is needed. Hepatitis A guidelines should include recommendations for the use of mass vaccination and OF testing in outbreaks., (Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.)

Background: We report on an outbreak of hepatitis A among men who have sex with men (MSM) in England and its associated healthcare resource burden, the strategies used to control the outbreak and the role of past and current hepatitis A vaccination policy and practice in England., Methods: National surveillance of hepatitis A, including reference laboratory confirmation and molecular sequencing, and a case questionnaire, was enhanced in 2017 to collect demographic and risk information, disease severity and healthcare utilisation. National Health Service (NHS) data was used to calculate associated healthcare costs., Results: During the outbreak period (July 2016 to January 2018), 670 confirmed cases were identified in England, caused by three distinct viral strains. The public health response included raising public and professional awareness, reinforcing vaccine recommendations for MSM, contact tracing for post-exposure vaccination, and mass community vaccination where spill-over of infection into the general population occurred. Hepatitis A vaccine was centrally procured to ensure sexual health clinics in England could offer vaccination to MSM. Outbreak associated healthcare costs were estimated to be approximately £1,500,000., Conclusions: While MSM are at increased risk of hepatitis A infection, inconsistent implementation of MSM vaccination policy in previous years led to an increasingly susceptible MSM population. The large number of cases, hospital admission rate and public health actions contributed to a significant healthcare burden. Recommending hepatitis A vaccination for MSM and clarifying commissioning responsibilities is essential to prevent future outbreaks.

The public health response to sporadic hepatitis A virus (HAV) infection, hepatitis A, can be complex especially when the index case is a child and no obvious source is identified. Identifying an infection source may avoid mass immunisation within schools when transmission is found to have occurred within the household. Screening of asymptomatic contacts via venepuncture can be challenging and unacceptable, as a result non-invasive methods may facilitate public health intervention. Enzyme-linked immunoassays were developed to detect HAV immunoglobulin M (IgM) and immunoglobulin G (IgG) in oral fluid (ORF). A validation panel of ORF samples from 30 confirmed acute HAV infections were all reactive for HAV IgM and IgG when tested. A panel of 40 ORF samples from persons known to have been uninfected were all unreactive. Two hundred and eighty household contacts of 72 index cases were screened by ORF to identify HAV transmission within the family and factors associated with household transmission. Almost half of households (35/72) revealed evidence of recent infection, which was significantly associated with the presence of children ⩽11 years of age (odds ratio 9.84, 95% confidence interval: 2.74-35.37). These HAV IgM and IgG immunoassays are easy to perform, rapid and sensitive and have been integrated into national guidance on the management of hepatitis A cases.

Between 1 June 2016 and 31 May 2017, 17 European Union (EU) and European Economic Area countries reported 4,096 cases associated with a multi-country hepatitis A (HA) outbreak. Molecular analysis identified three co-circulating hepatitis A virus (HAV) strains of genotype IA: VRD&#95;521&#95;2016, V16-25801 and RIVM-HAV16-090. We categorised cases as confirmed, probable or possible, according to the EU outbreak case definitions. Confirmed cases were infected with one of the three outbreak strains. We investigated case characteristics and strain-specific risk factors for transmission. A total of 1,400 (34%) cases were confirmed; VRD&#95;521&#95;2016 and RIVM-HAV16-090 accounted for 92% of these. Among confirmed cases with available epidemiological data, 92% (361/393) were unvaccinated, 43% (83/195) travelled to Spain during the incubation period and 84% (565/676) identified as men who have sex with men (MSM). Results depict an HA outbreak of multiple HAV strains, within a cross-European population, that was particularly driven by transmission between non-immune MSM engaging in high-risk sexual behaviour. The most effective preventive measure to curb this outbreak is HAV vaccination of MSM, supplemented by primary prevention campaigns that target the MSM population and promote protective sexual behaviour.

Background: It is believed that between 2% and 5% of infants born to hepatitis B virus (HBV)-infected mothers at a high risk of perinatal transmission will become persistently infected despite immunization starting at birth. We investigated factors associated with breakthrough infections., Methods: Sixty-nine samples from HBV-infected infants born between 2003 and 2015 were tested for HBV serological and molecular markers. Sequencing and epitope phenotyping were used to investigate alterations in hepatitis B surface antigen (HBsAg) sequence and antigenicity in infants and in mothers known to have transmitted and not to have transmitted virus to their infants., Results: Vaccine/hepatitis B immune globulin uptake was complete in the majority of HBV-infected infants. A minority (8 [12%]) had detectable plasma antibody to HBsAg at 12 months. Twenty-five of 68 (37%) infants harbored a virus with amino acid changes in the HBsAg "a" determinant, of which 13 displayed altered HBsAg antigenicity. Viral load was 30-fold higher in maternal samples from those who transmitted., Conclusions: Our data provide evidence to suggest that immune selection drives change at mother-infant transmission, resulting in the alteration of HBsAg antigenicity. These changes may play a role in immunization failure, but other factors including viral load may be more important. Continued monitoring of vaccine efficacy is essential.

From January to June 2018, two ongoing hepatitis A outbreaks affected travellers returning from Morocco and cases in Europe without travel history, resulting in 163 patients in eight European countries. Most interviewed travel-related cases were unaware of the hepatitis A risk in Morocco. Molecular analysis revealed two distinct hepatitis A virus (HAV) strains (subgenotype IA DK2018&#95;231; subgenotype IB V18-16428). Vaccination recommendations should be emphasised to increase awareness among non-immune travellers to Morocco and HAV-endemic countries.

Background: Hepatitis C virus (HCV) infection is a major health burden worldwide. A patient with no history of HCV infection while on a renal unit was found to seroconvert to HCV., Aim: To report the use of sequencing to postulate how transmission of HCV occurred in a healthcare setting, and how this guided our outbreak investigation., Findings: Based on infection control inspections the transmission event was surmised to be due to ward environmental contamination with blood and subsequent inoculation from intravenous interventions on the patient acquiring HCV. We discuss the interventions put in place in response to the outbreak investigation findings., Conclusion: Sequencing of healthcare-acquired HCV infections should be undertaken as routine practice in outbreak investigations., (Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Between July 2016 and January 2017, 37 confirmed cases of hepatitis A with two unique IA genotype strains primarily among men who have sex with men, were reported across eight areas in England and Northern Ireland. Epidemiological and laboratory investigations indicate that these strains may have been imported several times from Spain, with secondary sexual transmission in the United Kingdom. Local and national public health services are collaborating to control this ongoing outbreak., (This article is copyright of The Authors, 2017.)

This report describes an outbreak investigation starting with two closely related suspected food-borne clusters of Dutch hepatitis A cases, nine primary cases in total, with an unknown source in the Netherlands. The hepatitis A virus (HAV) genotype IA sequences of both clusters were highly similar (459/460 nt) and were not reported earlier. Food questionnaires and a case-control study revealed an association with consumption of mussels. Analysis of mussel supply chains identified the most likely production area. International enquiries led to identification of a cluster of patients near this production area with identical HAV sequences with onsets predating the first Dutch cluster of cases. The most likely source for this cluster was a case who returned from an endemic area in Central America, and a subsequent household cluster from which treated domestic sewage was discharged into the suspected mussel production area. Notably, mussels from this area were also consumed by a separate case in the United Kingdom sharing an identical strain with the second Dutch cluster. In conclusion, a small number of patients in a non-endemic area led to geographically dispersed hepatitis A outbreaks with food as vehicle. This link would have gone unnoticed without sequence analyses and international collaboration.

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.

HCV strains belonging to genotype 4 may be gaining endemicity across Continental Europe but the extent of their spread in the United Kingdom is unknown. Sera referred from patients attending hospitals in England between 2004 through 2008 were characterised. A total of 243 sera carried HCV genotype 4. The most common subtypes were 4a (33%) and 4d (35%). Compared to patients infected by 4d, those infected by 4a were 20 times more likely to be Middle Eastern than English, and those infected by non-4a/4d were older, tended to be female, and 50 or 12 times more likely to be Middle Eastern or South Asian, respectively, than English. Persons infected by 4d tended to be English rather than Middle Eastern or South Asian. One group of 4d strains clustered with strains reported from persons in Europe engaged in male homosexual activity. Surveillance of trends in the importation and subsequent spread of HCV genotype 4 and its subtypes is advocated., (© 2014 Wiley Periodicals, Inc.)

Background: Analysis of laboratory testing data collected through the Sentinel Surveillance programme has provided a method for identifying individuals who have recently acquired their hepatitis C virus (HCV) infection. Access to samples from these individuals provided a rare opportunity to undertake molecular characterization studies., Objectives: To describe the epidemiology and genetic diversity of hepatitis C in recent seroconverter infections and to predict how this will impact on HCV treatment and control., Study Design: One hundred and forty seven samples were available from individuals, identified to have recently acquired their HCV infection. Genotype determination with additional phylogenetic analysis was carried out on NS5B sequences. Analysis across the NS3 region investigated the presence of antiviral resistance mutations. Where possible, molecular data was linked to demographic and risk/behavioural factor information., Results: The majority of new infections occurred in males with a mean age of 37 years. The most commonly observed genotypes were 1a (49%) and 3a (42%) and injecting drug use (58%) was the most common risk factor. Genotype distribution differed between persons who inject drugs and those with other risk factors suggesting two possible epidemics. Phylogenetic analysis indicated possible transmission networks within specific risk groups. Amino acid changes associated with antiviral resistance were noted in the NS3 region in some samples., Conclusions: Continued surveillance of linked molecular, virological, demographic and epidemiological information on recently acquired infections will contribute to understanding the on-going HCV epidemic in England., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Hepatitis A virus (HAV) is considered one of the most important vaccine-preventable diseases in travelers. HAV spreads from person to person via the fecal-oral route and gives rise to an estimated 1.4 million cases worldwide each year. In developing countries with poor sanitary conditions people tend to be infected during childhood and have few symptoms, whereas in developed countries with good sanitary conditions fewer people develop immunity during childhood. This leads to susceptible populations of adults, who are also more prone to severe complications. Here we describe two confirmed cases of hepatitis A associated with a nursing home. The index case was a care worker who had recently traveled to a high-endemicity country, and the second case was a resident at the nursing home where the index case worked. Both cases had an identical genotype IIIA strain, consistent with a transmission event. Current policy does not include a requirement for hepatitis A vaccine in care workers who travel to high endemicity countries despite the fact that infected care workers can potentially spread the disease to elderly patients and other groups at risk of severe complications from HAV infection. We suggest that employers should consider hepatitis A vaccine upon employment; particularly in care workers who plan to visit areas where HAV is known to be endemic.

Objectives: To re-assess the prevalence and patient characteristics of hepatitis D virus (HDV) infection among hepatitis B patients in inner city London., Methods: All hepatitis B patients attending clinics over a 52 months period were tested for HDV antibody. All reactive samples were also tested for anti-HDV IgM and RNA. The characteristics of HDV seronegative patients first seen in the calendar year 2008 were compared with all HDV seropositive patients in the cohort., Results: Of 1048 hepatitis B patients, 11 had equivocal anti-HDV serology (1%) and 22 were HDV seropositive (2.1%, 95%CI 1.39-3.16%); 12 were anti-HDV IgM positive and 15 HDV RNA positive. No patient with equivocal anti-HDV serology had detectable HDV RNA. Five HDV seropositive patients were intravenous drug users (22.7%); 17/22 were from abroad with 11/22 (50%) from sub-Saharan Africa. HDV seropositive patients had poorer laboratory parameters and were more likely to have evidence of cirrhosis. Triple infected (HIV/HBV/HDV) patients were also more likely to have cirrhosis than HIV/HBV dually infected patients., Conclusions: The prevalence of HDV in hepatitis B patients in inner city London was about 2%. The role of migration from endemic countries should be recognised., (Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.)

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.

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.

Objectives: Hepatitis E virus (HEV) infection is an emerging infection in developed countries and is thought to be a porcine zoonosis. HEV can cause chronic infection and cirrhosis in the immunosuppressed, including patients with HIV infection. Little is known about HEV and HIV coinfection. The aim of the study was to document the incidence of chronic HEV coinfection in patients with HIV infection and to determine the anti-HEV seroprevalence and compare it with that of a control population., Methods: A cohort/case-control study was carried out in two teaching hospitals in southwest England. A total of 138 patients with HIV infection were tested for HEV using an immunoassay for anti-HEV immunoglobulin M (IgM) and IgG and reverse transcriptase-polymerase chain reaction (RT-PCR), and 464 control subjects were tested for anti-HEV IgG. Demographic, lifestyle and laboratory data were prospectively collected on each patient with HIV infection. The anti-HEV IgG seroprevalence in patients with HIV infection was compared with that in controls and demographic risk factors for HEV exposure were explored using logistic regression models., Results: There was no difference in anti-HEV IgG seroprevalence between the HIV-infected patients and controls. The only risk factor predictive of anti-HEV seropositivity was the consumption of raw/undercooked pork; sexual risk factors were unrelated. No patient with HIV infection had evidence of chronic coinfection with HEV CONCLUSIONS: Anti-HEV seroprevalence is similar in controls and patients with HIV infection. Risk factor analysis suggests that HEV is unlikely to be transmitted sexually. Chronic coinfection with HEV was absent, indicating that chronic HEV/HIV coinfection is not a common problem in this cohort., (© 2011 British HIV Association.)

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., (© 2010 Blackwell Publishing Ltd.)

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.

Between March and June 2008, 12 cases of hepatitis A were notified in Winchester. Cases were from a primary school and a nursery school with no direct linkage. Hepatitis A virus (HAV) RNA sequenced from nine cases confirmed the strain in both schools to be identical. The outbreak could have affected three other schools and a maternity unit and was controlled by immunization and screening of neonates in the maternity unit by dried blood spots. No neonates were infected and no further cases were reported until 5 months later when the index case's mother became infected with same strain of virus associated with the outbreak despite vaccination. Neither the source of the outbreak or the subsequent infection of the index case's mother was identified; however, with the timing of the cases continued transmission in the community by children with asymptomatic infection or a recurrent source cannot be ruled out.

Background: Identification of HCV genotype is a prerequisite for anti-viral treatment in England. Treatment length and sustained virological response rates vary by genotype. Therefore knowledge of circulating HCV genotypes is important for health-care providers., Objectives: To describe the HCV genotypes identified in English laboratories and to investigate changes over time; sub-analysis of young adults (15-24 years) to provide information on recently circulating genotypes., Study Design: Data from the national reference laboratory and 19 English laboratories participating in the sentinel surveillance of hepatitis testing study were analysed. Multinomial regression was used to investigate trends in genotypes identified between 2002 and 2007., Results: HCV genotypes were available for 18,031 individuals. The majority (89%) of people were genotypes 1 and 3; 3a was the single largest subtype. Half of people born between 1960 and 1989 were genotype 3a and the majority of South Asian people were genotype 3a. People born pre-1940 were nine times more likely to have genotype 1b than 3a. The proportion of 1b infections, relative to 3a, declined over time, but, after adjusting for birth cohort, this effect disappeared. There was no evidence of a relative change in 1a infections., Conclusions: This is the largest study of genotypes identified in England to date. Changes in genotypes over time were due to decreased genotyping of older individuals. As the population ages, the proportion of more difficult to treat genotypes may decline, leading to possible cost-savings for health-care providers, with a higher chance of achieving sustained virological response., (Copyright 2010 Elsevier B.V. All rights reserved.)

During 2002, an upsurge in frequency of hepatitis A outbreaks among injecting drug users was observed in England and Wales. As lack of risk factor information and the high mobility of the cases made linkage of outbreaks difficult, the relationship of nucleotide sequences in the VP1/2PA junction of the hepatitis A virus (HAV) genome amplified from serum of case-patients was investigated. A total of 204 HAV RNA positive sera obtained from a network of 23 laboratories were studied. Comparison of the sequences identified two principal strains: ES1 (n=95) belonging to type IB, and ES2 (n=72) to type IIIA. Of the remaining samples, 15 were type IA, 11 were type IB and 11 were type IIIA. ES1 predominated in Doncaster and other towns in Trent and northern England, and ES2 in the Midlands and southern England; the difference in geographical distribution between these two strains was significant (P<0.0001). In comparison to the sporadic cases, cases infected by either ES1 or ES2 tended to be younger, injecting drug users, people in contact with injecting drug users, or those with a history of incarceration in prisons or homelessness (P<0.0001). Cases infected by ES1 tended to be younger than those by ES2 (P<0.0001). The association of the outbreaks to two geographically restricted strains implicates two principal transmission pathways associated with injecting behavior. Identifying these routes may be conducive to preventing further outbreaks.

In 2005, 329 cases of hepatitis E virus infection were confirmed in England and Wales; 33 were confirmed indigenous infections, and a further 67 were estimated to be indigenous infections. Hepatitis E should be considered in the investigation of patients with hepatitis even if they have no history of travel.

Background: It has been proposed that hepatitis C virus (HCV)-infected patients with end-stage renal disease undergoing maintenance haemodialysis may lack HCV antibody (anti-HCV) despite chronic HCV viraemia. This carries important implications for the design of surveillance policies., Methods: To characterize the prevalence of antibody-negative/RNA-positive HCV infection, patients attending seven haemodialysis units underwent anti-HCV testing using a third-generation assay and HCV RNA testing using real-time PCR., Results: At screening, anti-HCV prevalence was 12/360 (3.3%; 95% CI 1.7-5.8%); 7/12 (58.3%) anti-HCV positive samples were HCV RNA positive. Among anti-HCV-negative samples, 2/348 (0.6%; 95% CI 0.2-2.1%) tested HCV RNA positive (genotype 1a). Retrospective testing of stored sera dated the infections to a period of holiday in the Indian subcontinent. The two infections were unrelated by HCV-NS5B sequencing. Only one of the two newly infected persons showed raised transaminases. Both developed anti-HCV within 8-13 weeks of follow-up. Prospective surveillance of travellers to resource-limited countries returning to the units showed a HCV incidence of 4/153 travel episodes (2.6%; 95% CI 0.7-6.6%) among 131 persons (3.1%; 95% CI 0.8-7.6%)., Conclusions: Among haemodialysis patients in the United Kingdom, antibody-negative/RNA-positive HCV status is associated with newly acquired infection, rather than lack of antibody responses in chronic HCV infection. There is a significant risk of HCV infection associated with travel to resource-limited countries. Given that transaminase levels may be normal, HCV RNA testing is recommended in patients re-entering a dialysis unit following haemodialysis in settings where suboptimal infection control policies pose a risk of exposure to blood-borne viruses.

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.

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.

Large outbreaks of hepatitis A have occurred in Denmark, Germany, the Netherlands, Norway, Spain, Sweden, and the United Kingdom during the period 1997-2005 affecting homosexual men. A collaborative study was undertaken between these countries to determine if the strains involved in these hepatitis A outbreaks were related genetically. The N-terminal region of VP1 and the VP1/P2A region of the strains were sequenced and compared. The majority of the strains found among homosexual men from the different European countries formed a closely related cluster, named MSM1, belonging to genotype IA. Different HAV strains circulated among other risk groups in these countries during the same period, indicating that specific strains were circulating among homosexual men exclusively. Similar strains found among homosexual men from 1997 to 2005 indicate that these HAV strains have been circulating among homosexual men for a long time. The homosexual communities are probably too small within the individual countries to maintain HAV in their population over time, whereas the homosexual communities across Europe are probably sufficiently large to sustain continued circulation of homologous HAV strains for years resulting in an endemic situation among homosexual men., ((c) 2007 Wiley-Liss, Inc.)

The prevalence of concurrent multitypic hepatitis C virus (HCV) infection is uncertain. A sensitive and specific approach to identifying minority HCV genotypes in blood is presented. Following serum extraction and reverse transcription PCR to amplify cDNA originating from the viral 5' noncoding region, the amplified product mixture was treated with genotype-specific restriction endonuclease to digest the dominant genotype. Residual amplicons were subjected to PCR cloning and then to real-time DNA sequencing using a Pyrosequencer to identify the remaining genotypes. Dilution experiments showed that minority genotypes may be detected when they represent 1:10,000 of the total population and in serum specimens with viral loads as low as 1,000 IU/ml. Of 37 patients with bleeding disorders and 44 injecting drug users, infection by more than one HCV genotype was found in 7 (19%) and 4 (9%) patients, respectively. The low rate of detection in people at high risk of repeated HCV infection suggests that multitypic HCV carriage is uncommon.

Background: Outbreaks of acute hepatitis B among inmates of 6 prisons in 3 regions of northern England occurring from 1992 through 1994 were found to be associated with a single hepatitis B virus (HBV) variant, which was carried by 20 of the 24 case patients. We instigated a study of cases of acute hepatitis B to trace the spread and prevalence of this variant., Methods: A denaturing gradient gel electrophoresis assay was optimized to detect the HBV variant, and cases of acute HBV infection in 3 regions in England occurring from 1990 through 1996 were screened for its presence. Samples from HBV-transmission incidents that were received for molecular investigation were also tested., Results: The variant was identified in 117 (41%) of the 266 cases of acute hepatitis examined in representative regions in England. In North Humberside, but not in southeast England or the West Midlands, a trend toward an increase in the prevalence of the variant was observed. Furthermore, the same variant was identified in the case patients or the individuals implicated in transmission in 11 (22%) of 51 transmission incidents occurring in England from 1997 through 2002. The spread of the variant was primarily associated with injection drug use., Conclusions: The finding of a single, genetically identical variant (over the 600 bp sequenced) occupying a large niche among the circulating viruses was unexpected. This finding has major implications for the use of DNA sequencing analysis in the investigation of chains of transmission. The study also highlights the need for better protection of at-risk groups through vaccination against HBV, a strategy that currently achieves poor coverage.

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.

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., (Copyright 1999 John Wiley & Sons, Ltd.)

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.

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.

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.

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.

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.