BackgroundHBV is the leading global cause of cirrhosis and primary liver cancer. The virus’s attributable disease burden in the UK is concentrated in vulnerable populatons including ethinic minorities, people experiencing homelessness and people born in high-prevalence countries. Despite this the UK HBV population has not been well characterised, and estimates of UK HBV prevalence and/or positivity rate vary widely across sources. We summarised datasets that are available to represent UK CHB epidemiology, consider differences between sources, and discuss deficiencies in current estimates.MethodsWe searched for estimates of CHB case numbers in the UK (incorporating incidence and/or prevalence-like data) across a range of available sources, including UK-wide reports from government bodies, publications from independent bodies (including medical charities and non-governmental organisations) and articles in peer-reviewed scientific journals. We present positivity rates from each respective data source but caution that estimates may not be representative of the true UK-wide population prevalence.Results and DiscussionSix CHB case number estimates were identified, with three estimates reporting information concerning population subgroups, including number of infected individuals across age, sex and ethnicity categories., Estimates among sources reporting prevalence varied from 0.27% to 0.73%. An alterantive proxy for population prevalence (obtained via the UK antenatal screening programme which achieves over 95% coverage of every pregnant woman) estimated a CHB prevalence of <0.5%. Estimates varied by sources of error, bias and missingness, data linkage, and substantial “blind spots” in consistent testing and registration of HBV diagnoses. Multi-parameter evidence synthesis and back-calculation model methods similar to those used to generate estimates of HCV ad HIV population-wide prevalence may be applicable to HBV.

Background: HBV is the leading global cause of cirrhosis and primary liver cancer. However, the UK HBV population has not been well characterised, and estimates of UK HBV prevalence and/or incidence vary widely between sources. We summarised datasets that are available to represent UK CHB epidemiology, considering differences between sources, and discussing deficiencies in current estimates. Methods: We searched for estimates of CHB case numbers in the UK (incorporating incidence and/or prevalence-like data) across a range of available sources, including UK-wide reports from government bodies, publications from independent bodies (including medical charities and non-governmental organisations) and articles in peer-reviewed scientific journals to collate estimated positivity rates. An alternative proxy for population prevalence was obtained via the UK antenatal screening programme which achieves over 95% coverage of pregnant women. Results: We identified six CHB case number estimates, of which three reported information concerning population subgroups, including number of infected individuals across age, sex and ethnicity categories. Estimates among sources reporting prevalence varied from 0.27% to 0.73%, congruent with an estimated antenatal CHB prevalence of <0.5%.  Discussion: Estimates varied by sources of error, bias and missingness, data linkage, and substantial “blind spots” in consistent testing and registration of HBV diagnoses. The HBV burden in the UK is likely to be concentrated in vulnerable populations who may not be well represented in existing datasets including those experiencing socioeconomic deprivation, ethnic minorities, people experiencing homelessness and people born in high-prevalence countries. Together, these factors could lead to either under- or over-estimation of overall prevalence, and additional efforts are required to provide estimates that best reflect the whole population.  Multi-parameter evidence synthesis and back-calculation model methods similar to those used to generate estimates of HCV ad HIV population-wide prevalence may be applicable to HBV.

Background: HBV is the leading global cause of cirrhosis and primary liver cancer. However, the UK HBV population has not been well characterised, and estimates of UK HBV prevalence and/or incidence vary widely between sources. We aimed to i) extract and summarise existing national HBV prevalence estimates, ii) add a new estimate based on primary care data, and; iii) critique data sources from which estimates were derived. Methods: We undertook a narrative review, searching for national estimates of CHB case numbers in the UK (incorporating incidence, prevalence and/or test positivity data) across a range of overlapping sources, including governmental body reports, publications from independent bodies (including medical charities and non-governmental organisations) and articles in peer-reviewed scientific journals.  An alternative proxy for population prevalence was obtained via the UK antenatal screening programme which achieves over 95% coverage of pregnant women. We also searched for diagnoses of HBV in the QResearch primary care database based on laboratory tests and standardised coding. Results: We identified six CHB case number estimates, of which three reported information concerning population subgroups, including number of infected individuals across age, sex and ethnicity categories. Estimates among sources reporting prevalence varied from 0.27% to 0.73%, congruent with an estimated antenatal CHB prevalence of <0.5%. Our estimate, based on QResearch data, suggests a population prevalence of ~0.05%, reflecting a substantial underestimation based on primary care records. Discussion: Estimates varied by sources of error, bias and missingness, data linkage, and “blind spots” in HBV diagnoses testing/registration. The UK HBV burden is likely to be concentrated in vulnerable populations who may not be well represented in existing datasets including those experiencing socioeconomic deprivation and/or homelessness, ethnic minorities and people born in high-prevalence countries. This could lead to under- or over-estimation of population prevalence estimation. Multi-agency collaboration is required to fill evidence gaps.