title: Prevalence and epidemiology of hepatitis D among patients with chronic hepatitis B virus infection: a report from Northern Spain.
abstract: BACKGROUND
  The incidence of hepatitis delta virus (HDV) infection has decreased during the last decades. However, an increasing trend has been reported recently.
  
  
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: aLiver Unit, Division of Gastroenterology and Hepatology bVirology Unit, Department of Microbiology, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Ordieres
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Navascués
authors.forename: María L
authors.initials: ML
authors.lastname: González-Diéguez
authors.forename: Mercedes
authors.initials: M
authors.lastname: Rodríguez
authors.forename: Valle
authors.initials: V
authors.lastname: Cadahía
authors.forename: María
authors.initials: M
authors.lastname: Varela
authors.forename: Luis
authors.initials: L
authors.lastname: Rodrigo
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodríguez
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D060085:Coinfection; D054242:Emigrants and Immigrants; D004641:Emigration and Immigration; D005260:Female; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D003699:Hepatitis D / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D015229:Sexually Transmitted Diseases, Viral / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D013030:Spain / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000453:epidemiology; D062606:Tertiary Care Centers; D013997:Time Factors