Characterising Hepatitis D Virus in the UK From 2011 to 2021

Little is known about hepatitis B virus (HBV) and Hepatitis D virus (HDV) coinfection in the UK. HDV screening is recommended among all individuals with HBV, with coinfection associated with increased disease progression. Using data on HDV testing, shared by 11 laboratories in the UK who reported undertaking HDV testing, and national testing data for HBV we established a cohort of individuals tested for HDV, investigating testing pathways, describing characteristics and outcomes of those HDV-RNA positive to inform targeted interventions for testing, diagnosis and linkage to care. Demographic information, clinical assessments, treatment and recent laboratory results from NHS trusts, and through linkage to national healthcare datasets was collected for HDV-RNA positive individuals. Between 2011 and 2021, 42% of individuals newly diagnosed with HBV in England were linked to an HDV test. Anti-HDV positivity was 5.0%, 55.8% were HDV-RNA tested and 45.7% were ever HDV-RNA positive. HDV-RNA positivity in the absence of an anti-HDV result was 6.4%. Among individuals who were HDV-RNA positive, 94.3% were non-UK born, with 24 different primary languages reported, 49% had evidence of treatment, and 48% had evidence of cirrhosis. 10% had died of which 58.4% died of liver disease. In conclusion, our findings indicate that HDV testing in HBV positive individuals in the UK is sub-optimal against testing guidelines, including RNA testing among those who are anti-HDV positive. Considerable work is needed to improve the patient care pathway, to ensure patients are appropriately diagnosed, linked and retained in care, with adequate access to treatment.