The incidence of hepatitis delta virus (HDV) infection has decreased during the last decades. However, an increasing trend has been reported recently.Patients and methods
We carried out a case–control study to analyze changes in its prevalence in 1215 chronic hepatitis B virus (HBV) patients, diagnosed consecutively in a tertiary center, between 1983 and 2012. According to the year of diagnosis, patients were distributed into two groups: A [1983–1997 (n=786)] and B [1998–2012 (n=429)].Results
The prevalence of anti-HDV was 8.2% (9.4% in group A and 6.1% in group B) (P=0.04). Multivariate regression revealed that intravenous drug use [odds ratio (OR) 261.0; 95% confidence interval (CI), 28.7–2368.5; P<0.001], blood transfusion (OR 28.0; 95% CI, 2.7–295.9; P=0.03), anti-HIV(+) (OR 4.8; 95% CI, 1.6–14.5; P=0.004), and high alanine aminotransferase (OR 14.4; 95% CI, 3.4–60.6; P<0.001) were associated independently with the presence of anti-HDV in group A, whereas in group B, it was associated with immigration (OR 20.0; 95% CI, 4.7–84.9; P<0.001), intravenous drug use (OR 683.5; 95% CI, 52.7–8855.7; P<0.001), promiscuous sexual activity (OR 22.6; 95% CI, 2.2–228.5; P=0.008), and high alanine aminotransferase (OR 3.4; 95% CI, 1.1–10.0; P=0.02).Conclusion
Although a significant decrease in the prevalence of HDV infection has been observed, it is still above 5%. Immigration and sexual transmission have emerged as new risk factors for HDV infection.