Epidemiological trends of HBV and HDV coinfection among Viennese HIV+ patients

Background and aims: Despite vaccination recommendations, hepatitis B (HBV) and D (HDV) coinfections are common in HIV+individuals.
Methods: HBV immunization status (anti-HBs) as well as HBV (HBsAg/HBV-DNA) and HDV (anti-HDV) coinfection rates were assessed in 1870 HIV+individuals at HIV diagnosis (baseline, BL) and last follow-up (FU).
Results: Sixty-eight (3.6%) HIV patients were never tested for HBV. At BL, 89/1802 (4.9%) HIV patients were HBV coinfected. Four hundred and fifteen (23.0%) showed virological HBV clearance [HBsAg(-)/anti-HBc(+)/anti-HBs(+)] and 210 (11.7%) presented with anti-HBc(+) only. Seven hundred and ten (39.4%) were HBV naïve [HBsAg(-)/anti-HBs(-)/anti-HBc(-)/HBV-DNA(-)], but only 378 (21.0%) received vaccinations with detectable anti-HBs(+) titres. Among the 89 HBV/HIV-coinfected patients, only 52 (58.4%) were tested for HDV: 11/49 (22.4%) had anti-HDV(+) and 3/12 (25.0%) showed HDV-RNA viraemia. During a median FU of 6.5 (IQR 7.2) years, 44 (4.6%) of the 953 retested BL HBV-negative patients acquired new HBV infection (including 15/304, 4.9% of vaccinated patients). Of the 89 patients, 22 (24.7%) patients cleared their HBsAg, resulting in 60/1625 (3.7%) HIV/HBV individuals at FU: 34 (56.7%) showed HBV-DNA suppression and 15 (25.0%) were HBV viraemic, while 12/89 (13.5%) remained without a FU test. Vaccinations induced anti-HBs(+) in 137 of the retested 649 (21.1%) BL HBV-naïve patients.
Conclusion: HBV testing is well established among Viennese HIV+patients with HBV coinfection rates around 4%-5%. HBV vaccinations are insufficiently implemented since anti-HBs titres were detected in only 21.1% of HBV-naive HIV(+) patients and new HBV infections occurred in previously vaccinated patients. HDV testing is not systematically performed despite up to 25% of HIV/HBV patients may show HDV coinfection.