title: HIV genotypes and primary drug resistance among HIV-seropositive blood donors in Brazil: role of infected blood donors as sentinel populations for molecular surveillance of HIV.
abstract: BACKGROUND
  There are few surveillance studies analyzing genotypes or primary (transmitted) drug resistance in HIV-infected blood donors in Brazil. The aim of this study was to characterize patterns of HIV genotypes and primary resistance among HIV-seropositive donors identified at 4 geographically dispersed blood centers in Brazil.
  
  
  METHODS
  All HIV-infected donors who returned for counseling at the 4 REDS-II Hemocenters in Brazil from January 2007 to March 2011 were invited to participate in a case-control study involving a questionnaire on risk factors. Viral sequencing was also offered to positive cases to assign genotypes and to detect and characterize primary resistance to reverse transcriptase and protease inhibitors according to World Health Organization guidelines.
  
  
  RESULTS
  Of the 341 HIV-seropositive donors who consented to participate in the risk factor and genetics study, pol sequences were obtained for 331 (97%). Clade B was predominant (76%) followed by F (15%) and C (5%). Primary resistance was present in 36 [12.2%, 95% confidence interval (CI) 8.2 to 15.5] of the 303 individuals not exposed to antiretroviral therapy, varying from 8.2% (95% CI: 2.7 to 13.6) in Recife to 19.4% in São Paulo (95% CI: 9.5 to 29.2); there were no significant correlations with other demographics or risk factors.
  
  
  CONCLUSIONS
  Although subtype B remains the most prevalent genotype in all 4 areas, increasing rates of subtype C in Sao Paulo and F in Recife were documented relative to earlier reports. Transmitted drug resistance was relatively frequent, particularly in the city of Sao Paulo which showed an increase compared with previous HIV-seropositive donor data from 10 years ago.
authors.affiliation: Department of Infectious Disease, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Cecília S
authors.initials: CS
authors.lastname: Alencar
authors.forename: Ester C
authors.initials: EC
authors.lastname: Sabino
authors.forename: Silvia M F
authors.initials: SM
authors.lastname: Carvalho
authors.forename: Silvana C
authors.initials: SC
authors.lastname: Leao
authors.forename: Anna B
authors.initials: AB
authors.lastname: Carneiro-Proietti
authors.forename: Ligia
authors.initials: L
authors.lastname: Capuani
authors.forename: Cláudia L
authors.initials: CL
authors.lastname: Oliveira
authors.forename: Danielle
authors.initials: D
authors.lastname: Carrick
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Birch
authors.forename: Thelma T
authors.initials: TT
authors.lastname: Gonçalez
authors.forename: Sheila
authors.initials: S
authors.lastname: Keating
authors.forename: Priscilla A
authors.initials: PA
authors.lastname: Swanson
authors.forename: John
authors.initials: J
authors.lastname: Hackett
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D001483:Base Sequence; D001782:Blood Donors; D001938:Brazil; D016022:Case-Control Studies; D024882:Drug Resistance, Viral / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D006679:HIV Seropositivity / Q000097:blood*; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D018571:Sentinel Surveillance; D017423:Sequence Analysis, RNA; D011795:Surveys and Questionnaires; D019562:Viral Load; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics*
chemical_list: D019380:Anti-HIV Agents; D054302:pol Gene Products, Human Immunodeficiency Virus