Update on epidemiology of hepatitis B in a low-endemic European country: There is still much to do.

The latest epidemiological data in Spain were obtained a decade ago and revealed a prevalence of hepatitis B surface antigen (HBsAg) of 0.7%; hence, updated epidemiological data are necessary. Our aim was to determine the prevalence of hepatitis B virus (HBV) infection, and to analyse associated factors and characterize chronic infection. A population-based, cross-sectional study was performed in Spain between July 2015 and April 2017. Participants from three regions were selected using two-stage conglomerate sampling and stratified by age. Anthropometric and demographic data were collected, and blood samples were taken to detect serological markers of HBV infection and to quantify HBV-DNA. The characterization of chronic HBV infection was based on ALT (alanine aminotransferase) values, HBV-DNA levels, and results of transient elastography. The overall prevalence rates of HBsAg and antibody to hepatitis B core antigen (anti-HBc) among 12 246 participants aged 20-74 years (58.4% females) were 0.6% (95% CI [0.4-0.7]) and 8.2% (7.7-8.7), respectively. The risk factors for HBV infection identified in the multivariate analysis were age, nosocomial risk, and non-Spanish nationality. Moreover, most patients HBsAg positive (76.6%) presented as hepatitis B e antigen (HBeAg)-negative chronic infection (formerly 'inactive carriers') and only 6 (9.4%) HBsAg carriers fulfilled current criteria for treatment. The current HBV burden in Spain remains low but virtually unchanged over the past 15 years. Increased efforts are still needed to reach the goal set forth by the World Health Organization (WHO) for HBV elimination by 2030.