title: Acute hepatitis B 14 years after the implementation of universal vaccination in Italy: areas of improvement and emerging challenges.
abstract: BACKGROUND
  Italy had intermediate-level endemicity for hepatitis B virus (HBV) infection in the 1970s and 1980s. In 1991, vaccination of infants and adolescents became mandatory. We report the impact of universal vaccination 14 years after its beginning.
  
  
  METHODS
  We performed a case-control study within a population-based surveillance for acute viral hepatitis. The incidence of acute hepatitis B (AHB) was estimated for the time since 1991, and the association between AHB and the considered risk factors was analyzed for the period 2001-2005.
  
  
  RESULTS
  The incidence of AHB progressively decreased from 1991 to 2005, mainly for persons in the age groups targeted by the universal vaccination campaign: there was a 24-fold and 50-fold decrease in the 15-24-year and 0-14-year age groups, respectively; for the > or =25-year age group, the incidence halved. Owing to the persons' ages, approximately 3% of total AHB cases should have been the target of vaccination campaign. In 2004-2005, foreigners accounted for 14% of total cases and for 57% of persons who should have been targets for vaccination. Missed opportunities for immunization were documented for approximately 50% of patients with AHB who reported cohabitation with HBV carriers and for 70% of those who reported injection drug use. The strongest associations with AHB were found for blood transfusion (adjusted odds ratio [OR(adj)], 8.4; 95% confidence interval [CI], 2.7-26), cohabitation with HBV carriers (OR(adj), 5.3; 95% CI, 3.6-7.7), injection drug use (OR(adj), 3.8; 95% CI, 2.5-5.8), and unsafe sexual practices (OR(adj), 2.8; 95% CI, 1.9-4.2).
  
  
  CONCLUSIONS
  Universal vaccination has contributed to a decreasing AHB incidence in Italy, especially by reducing the risk of infection among persons aged 15-24 years. Most infections occur in persons aged > or =25 years in association with injection drug use, unsafe sexual activity, percutaneous treatment, and iatrogenic exposure. Improvement of vaccine coverage in high-risk groups and adherence to infection control measures during surgery and percutaneous treatment are needed. The high risk still associated with blood transfusion needs to be further investigated, with consideration of occult HBV infection in blood donors. The potential spread of HBV infection from the immigrant population deserves adequate health policy prevention programs.
authors.affiliation: National Centre of Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mele
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Tosti
authors.forename: Andrea
authors.initials: A
authors.lastname: Mariano
authors.forename: Renato
authors.initials: R
authors.lastname: Pizzuti
authors.forename: Antonio
authors.initials: A
authors.lastname: Ferro
authors.forename: Bianca
authors.initials: B
authors.lastname: Borrini
authors.forename: Carla
authors.initials: C
authors.lastname: Zotti
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Lopalco
authors.forename: Filippo
authors.initials: F
authors.lastname: Curtale
authors.forename: Emanuela
authors.initials: E
authors.lastname: Balocchini
authors.forename: Enea
authors.initials: E
authors.lastname: Spada
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000517:prevention & control*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage*; D006515:Hepatitis B virus / Q000276:immunology; D006801:Humans; D017589:Immunization Programs / Q000639:trends*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D008297:Male; D009313:National Health Programs / Q000639:trends*; D011159:Population Surveillance / Q000379:methods*; D012307:Risk Factors; D014611:Vaccination
chemical_list: D017325:Hepatitis B Vaccines