Purpose To review the incidence and characteristics of acute hepatitis B (AHB) in a large cohort of HIV infected persons from a low prevalence region during the last two decades. Methods Retrospective review of an HIV Cohort from a single reference centre in Madrid, Spain, between 2000 and 2018. AHB was diagnosed in persons with newly acquired HBAgS and acute hepatitis with positive IgM anti-HBc. Results Out of 5443 HIV+ patients in our cohort (3098 anti-HBc negative), 18 developed AHB from 2000 to 2018. The global incidence was 0.02 (0.01–0.04) per 100 patient-year in the entire population and 0.06 (0.01–0.1) per 100 patient-year in the anti-HBc negative population. A statistically significant decrease in AHB incidence was observed during these years (β = −0.006; p = 0.047). All 18 patients diagnosed with AHB were men, the majority (16) occurred in men who have sex with men. AHB was observed in 4 persons previously unresponsive to vaccination. Regarding antiretroviral treatment (ART), 15 were not receiving ART, two persons were on ART with any HBV active drugs and one person had lamivudine in the regimen. Two persons (11%) developed chronic hepatitis B. There were no cases of fulminant hepatitis. Conclusion The incidence of AHB in HIV positive persons in our cohort was low and shows a progressive decline in the last 20 years. Cases occurred in persons not protected against VHB: not vaccinated or non-responders to vaccine that were not receiving tenofovir.
