Non-A hepatitis B virus genotypes in antenatal clinics, United Kingdom

Viral hepatitis B and C in HIV-exposed South African infants

Background

Whilst much attention is given to eliminating HIV mother-to-child transmission (MTCT), little has been done to ensure the same for hepatitis B virus (HBV) transmission. The introduction of HBV immunization at six weeks of age has reduced HBV horizontal transmission in South Africa. However, in order to eliminate HBV MTCT, further interventions are needed. The risk of hepatitis C virus (HCV) MTCT in HIV-infected (HIV+) African women is not yet well described. This study aimed to determine the rate of HBV and HCV vertical transmission in HIV-exposed infants in South Africa.

Methods

Serum samples from infants enrolled in an isoniazid prevention study (P1041) were screened for HBV and HCV serology markers; screening was performed on samples collected at approximately 60 weeks of age of the infants. HBV DNA was quantified in HBsAg positive samples and HBV strains characterized through gene sequencing. All HCV antibody samples with inconclusive results underwent molecular testing.

Results

Three of 821 infants were positive for both HBsAg and HBV DNA. All HBV strains belonged to HBV sub-genotype A1. The rtM204I mutation associated with lamivudine resistance was identified in one infant, a second infant harboured the double A1762T/G1764A BCP mutation. Phylogenetic analysis showed clustering between mother and infant viral genomic sequences. Twenty-one of 821 HIV-exposed infants tested had inconclusive HCV antibody results, none were HCV PCR positive.

Conclusions

This study suggests that HBV vertical transmission is likely to be occurring in HIV-exposed infants in South Africa.. A more robust strategy of HBV prevention, including birth dose vaccination, is required to eradicate HBV MTCT. HCV infection was not detected.

Estimating the proportion of people with chronic hepatitis B virus infection eligible for hepatitis B antiviral treatment worldwide: a systematic review and meta-analysis

BACKGROUND

In 2016, of the estimated 257 million people living with chronic hepatitis B virus (HBV) infection worldwide, only a small proportion was diagnosed and treated. The insufficiency of information on the proportion of people infected with HBV who are eligible for treatment limits the interpretation of global treatment coverage. We aimed to estimate the proportion of people with chronic HBV infection who were eligible for antiviral treatment worldwide, based on the WHO 2015 guidelines.

METHODS

In this systematic review and meta-analysis, we searched Medline, EMBASE, and the Cochrane databases from Jan 1, 2007, to Jan 31, 2018, for studies describing HBsAg-positive people in the population or health-care facilities. We extracted information from published studies using a standardised form to estimate the frequency of cirrhosis, abnormal alanine aminotransferase (ALT), HBV DNA exceeding 2000 IU/mL or 20 000 IU/mL, presence of HBeAg, and eligibility for treatment as per WHO and other guidelines as reported in the studies. We pooled proportions through meta-analysis with random effects. The study was registered with PROSPERO, CRD42020132345.

FINDINGS

Of the 13 497 studies, 162 were eligible and included in our analysis. These studies included 145 789 participants. The pooled estimate of the proportion of cirrhosis was 9% (95% CI 8-10), ranging from 6% (4-8) in community settings to 10% (9-11) in clinic settings. Examining the proportion of participants who had characteristics used to determine eligibility in the WHO guidelines, 1750 (10·1%) of 17 394 had HBV DNA exceeding 20 000 IU/mL, and 20 425 (30·8%) of 66 235 had ALT above the upper limit of normal. 32 studies reported eligibility for treatment according to WHO or any other guidelines, with a pooled estimate of eligibility at 19% (95% CI 18-20), ranging from 12% (6-18) for studies in community settings to 25% (19-30) in clinic settings.

INTERPRETATION

Many studies described people with HBV infection, but few reported information in a way that allowed assessment of eligibility for treatment. Although about one in ten of the 257 million people with HBV infection (26 million) might be in urgent need of treatment because of cirrhosis, a larger proportion (12-25%) is eligible for treatment in accordance with different guidelines. Future studies describing people with HBV infection should report on treatment eligibility, according to broadly agreed definitions.

FUNDING

WHO and US Centers for Disease Control and Prevention.

Hepatitis B virus drug resistance mutations in HIV/HBV co-infected children in Windhoek, Namibia

In patients who are HIV infected, hepatitis B virus (HBV) infection is an important co-morbidity. However, antiretroviral options for HIV/HBV co-infected children are limited and, at the time of this study, only included lamivudine. These children may remain on this regimen for many years until late adolescence. They are at high risk of developing HBV drug resistance and uncontrolled HBV disease. The aim of this study was to characterize HBV infection in HIV/HBV co-infected children. Known HIV-infected/HBsAg-positive children, previously exposed to lamivudine monotherapy against HBV, and their mothers were recruited at the Katutura Hospital paediatric HIV clinic in Windhoek, Namibia. Dried blood spot and serum samples were collected for HBV characterization and serological testing, respectively. Fifteen children and six mothers participated in the study. Eight of the 15 children (53.3%) tested HBV DNA positive; all eight children were on lamivudine-based ART. Lamivudine-associated resistance variants, together with immune escape mutants in the surface gene, were identified in all eight children. Resistance mutations included rtL80I, rtV173L, rtL180M, rtM204I/V and the overlapping sE164D, sW182*, sI195M and sW196LS variants. HBV strains belonged to genotypes E (6/8, 75%) and D3 (2/8, 25%). Further analysis of the HBV core promoter region revealed mutations associated with reduced expression of HBeAg protein and hepatocarcinogenesis. All six mothers, on HBV-active ART containing tenofovir and lamivudine, tested HBV DNA negative. This study confirms the importance of screening HIV-infected children for HBV and ensuring equity of drug access to effective HBV treatment if co-infected.

HBV genotypes circulation in pregnant women in Romania: a pilot study

Background: The risk of mother to child transmission of hepatitis B virus (HBV) is recognized worldwide, a reason for which the World Health Organization aims to reduce this public health issue of major concern in the next ten years. The aim of our study was to detect circulating HBV genotypes in a selected population of pregnant women, as scientific evidence to recommend personalized antiviral therapy and to obtain updated epidemiological information.

Methods: HBsAg positive pregnant women were selected by the National Institute of Public Health Romania. Blood samples were collected after signing the informed consent. The HBV genotypes were tested by INNO LiPA HBV genotyping method.

Results. The D genotype was detected in 9/18 (50%) patients, genotype A in 3/18 (16.7%), and genotype F in 3/18 (16.7%) patients. Three patients had double infection, 11 had unique infection, and 4 had no detectable genotype.

Conclusion. This study confirmed the results of previous studies regarding HBV genotype circulation in our country, with the mention that F genotype was a new one for our area. These data are useful from an epidemiological point of view and also for therapeutical reasons, as it is known that therapy should be genotype guided.

Molecular identification of hepatitis B virus genotypes/subgenotypes: revised classification hurdles and updated resolutions

The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term "recombino-subgenotype". Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term "immigro-subgenotype" to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.