title: HIV-1 subtype C dissemination in southern Brazil.
abstract: OBJECTIVE
  To describe the molecular and epidemiological profile of HIV-1 in patients followed at the University Hospital of Rio Grande, Brazil.
  
  
  METHODS
  A cross-sectional study was conducted from September to December 2002. Plasma viral RNA of 85 patients was extracted and protease and reverse transcriptase genes were polymerase chain reaction-amplified and sequenced. Sequences were subtyped and examined to antiretroviral resistance mutations. Laboratory data and past history of antiretroviral treatment were also collected.
  
  
  RESULTS
  Most viruses were either subtype B (42%) or subtype C (45%). No risk behaviour, sexual orientation or laboratory parameter was associated with any specific subtype, but subtype C tended to be more frequently found in women (P = 0.06). The prevalence of subtype C has increased over the HIV/AIDS epidemic, accounting for almost 60% of cases diagnosed in 2002. Intra-subtype genetic distances were smaller in subtype C than in subtype B, suggesting a more recent introduction of the former in the epidemic. Of patients under treatment, 60% had at least one antiretroviral drug resistance mutation, but no mutation was specifically associated with any HIV-1 subtype. Only one resistance mutation each was found in drug-naive patients with subtypes B and C.
  
  
  CONCLUSIONS
  Despite the fact that subtype C appeared in southern Brazil more recently than subtype B, it is now the predominant strain in Rio Grande. The epidemic spread of subtype C could be taking place in Brazil, and possibly in south America, a phenomenon similar to that seen in other countries where this subtype is now totally dominant.
authors.affiliation: Laboratório de Virologia Molecular, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Esmeralda A J M
authors.initials: EA
authors.lastname: Soares
authors.forename: Ana M B
authors.initials: AM
authors.lastname: Martínez
authors.forename: Thatiana M
authors.initials: TM
authors.lastname: Souza
authors.forename: André F A
authors.initials: AF
authors.lastname: Santos
authors.forename: Vanusa
authors.initials: V
authors.lastname: Da Hora
authors.forename: Jussara
authors.initials: J
authors.lastname: Silveira
authors.forename: Francisco I
authors.initials: FI
authors.lastname: Bastos
authors.forename: Amilcar
authors.initials: A
authors.lastname: Tanuri
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Soares
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral; D054303:HIV Reverse Transcriptase; D016333:HIV Protease