Decreasing seroprevalence of anti‐hepatitis D virus antibodies in the antiviral era with inverse association with hepatitis B virus DNA, Taiwan, 2006 to 2019.

We examined the seroprevalence change of anti‐hepatitis D virus (HDV) antibodies in Taiwan from 2006 to 2019. A total of 1147 patients who had chronic hepatitis B virus (HBV) infection were assessed. Of them, 51 (4.4%) were positive for anti‐HDV antibodies. Comparison between anti‐HDV‐positive and negative groups was performed to examine clinical and virological factors related to anti‐HDV positivity. It was found that the median HBV‐DNA concentration was 1.6 × 105 IU/mL (range, <20‐4.5 × 1010 IU/mL) and <20 IU/mL (range, <20‐2.0 × 109 IU/mL) for patients with negative and positive anti‐HDV antibodies, respectively (P < .001). In addition, a progressive year‐to‐year decrease of anti‐HDV seroprevalence was unveiled. For patients who had HBV‐DNA >15 000 IU/mL, the year‐to‐year (calculated every 2 years) seropositive rates of anti‐HDV were 10.0%, 7.9%, 0.7%, 0.3%, 0%, 0%, and 0% (P < .001). For patients who had HBV‐DNA <15 000 IU/mL, the year‐to‐year seropositive rates were 18.6%, 12.8%, 7.8%, 5.0%, 7.3%, 8.0%, and 3.7% (P < .001). In conclusion, seropositive of anti‐HDV was inversely associated with HBV‐DNA levels. A progressive decrease of anti‐HDV seroprevalence was found with no anti‐HDV‐positive cases detected in high HBV‐DNA patient group after 2014. Highlight: Seroprevalence of anti‐HDV is decreasing in Taiwan.From 2006‐2019, 4.4% of chronic hepatitis B patients were anti‐HDV positive.Seroprevalence of anti‐HDV is inversely correlated with HBV‐DNA levels.No anti‐HDV‐positive cases were found after 2014 in high HBV DNA patients. [ABSTRACT FROM AUTHOR]