title: Changes in the prevalence, incidence and residual risk for HIV and hepatitis C virus in Southern Brazilian blood donors since the implementation of NAT screening.
abstract: BACKGROUND
  Previous studies have shown high residual risk of transfusing a blood donation contaminated by human immunodeficiency virus (HIV) or hepatitis C virus (HCV) in Brazil and motivated the development of a Brazilian platform for simultaneous detection of both viruses by nucleic acid amplification test (NAT) denominated HIV/HCV Bio-Manguinhos/Fundação Oswaldo Cruz (FIOCRUZ). The objective of this study was to verify seroprevalence, incidence and residual risk for both viruses before and after the implementation of NAT.
  
  
  METHODS
  Over 700,000 blood samples from all blood banks in the southern Brazilian State of Santa Catarina were analyzed during the period between January 2007 and July 2013.
  
  
  RESULTS
  Compared with the period preceding the NAT screening, HIV prevalence increased from 1.38 to 1.58 per 1,000 donors, HIV incidence rate increased from 1.22 to 1.35 per 1,000 donor-years, and HIV residual risk dropped almost 2.5 times during the NAT period. For HCV, seroprevalence increased from 1.22 to 1.35 per 1,000 donors, incidence dropped from 0.12 to 0.06 per 1,000 donor-years, and residual risk decreased more than 3 times after the NAT implementation.
  
  
  CONCLUSIONS
  NAT reduced the duration of the immunologic window for HIV and HCV, thus corresponding to approximately 2.5- and 3-fold respective residual risk reductions.
authors.affiliation: Departamento de Saúde Pública, Universidade Federal de Santa Catarina, Florianópolis, SC.
authors.forename: Emil
authors.initials: E
authors.lastname: Kupek
authors.affiliation: Centro de Hematologia e Hemoterapia do Estado de Santa Catarina, Florianópolis, SC.
authors.forename: Andrea
authors.initials: A
authors.lastname: Petry
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001782:Blood Donors / Q000706:statistics & numerical data*; D001938:Brazil / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology*; D006526:Hepatitis C / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D015995:Prevalence; D012307:Risk Factors; D055815:Young Adult