Hepatitis D virus infection in persons with HIV and hepatitis B virus across Europe : A cross‐sectional analysis of the HDV‐Europe cohort

Abstract Introduction Infection with hepatitis D virus (HDV) is known to accelerate the progression of liver disease and is associated with mortality in individuals with HIV and hepatitis B virus (HBV). However, little is known about current HDV epidemiology, including HDV‐testing practices and prevalence, in this population in Europe. Methods We conducted a cross‐sectional study of clinical cohorts across Europe (Germany, Italy, the Netherlands, Poland, Spain, Switzerland and United Kingdom). Included individuals were those living with HIV, ever hepatitis B surface antigen positive, aged ≥18 years and actively in care on December 31, 2023. We calculated the percentage of individuals tested for HDV, prevalence of individuals who ever had anti‐HDV positive serology (i.e., past/current infection) and the prevalence of individuals whose last HDV RNA result was positive (i.e., active infection). Results A total of 2970 individuals were included. Anti‐HDV antibody results were available in 2189 (73.7%). Of them, 261 (12.0%) had past/current HDV infection, ranging between 3.8% in the United Kingdom and 27.3% in Poland. Among the 261 individuals with an anti‐HDV‐positive result, 162 (62.1%) had been tested for HDV RNA. Of them, 92 (56.8%) had active HDV infection. Of the overall population with available data, active HDV infection was observed in 4.4% ( n = 92/2077), ranging between 0.9% in the Netherlands and 11.0% in Italy. Conclusions In Europe, about one‐eighth of individuals with HIV/HBV in care have evidence of past/current HDV infection, in whom half have active HDV infection. Nevertheless, these results come from a setting where one‐quarter have yet to be tested for anti‐HDV antibodies.