title: Emerging genetic diversity of HIV-1 in South America.
abstract: OBJECTIVE
  Genotype determination and risk group analysis of HIV-1 infected individuals in selected regions of South America.
  
  
  METHODS
  Cross-sectional convenience sampling of HIV-1-positive individuals in Peru, Ecuador, Uruguay and Paraguay from March, 1994 through September, 1998.
  
  
  METHODS
  HIV-1-positive subjects were identified through the national AIDS surveillance program in each country. A standardized questionnaire was used to obtain demographic, clinical and risk factor data on each study subject. Viral DNA was extracted from participants' peripheral blood mononuclear cells either directly or after co-cultivation. A nested PCR was used to obtain selected fragments of the envelope genes for genotyping by the heteroduplex mobility assay (HMA). A 600 bp sequence encompassing the V3 loop was sequenced from a selection of 23 of these samples for phylogenetic analysis and confirmation of HMA genotype.
  
  
  RESULTS
  Among the 257 successfully genotyped HIV-1-positive samples, genotype B was found in 98.3% (228/232) of those obtained from subjects in Peru, Ecuador, and Paraguay. In contrast, 56% (14/25) of the samples from Uruguay were genotype F, and the remainder were genotype B. Genotype F was detected for the first time in Peru (2/224) and Paraguay (1/4), and genotype A for the first time in Peru (1/224). Phylogenetic analysis confirmed the genotype identified by HMA in the 23 samples sequenced. There was no detectable genetic clustering of HIV-1 within the different high-risk groups or geographic locations.
  
  
  CONCLUSIONS
  These findings verify and extend the presence of several different HIV-1 genotypes in South America.
authors.affiliation: Naval Medical Research Center Detachment, Lima, Peru.
authors.forename: K L
authors.initials: KL
authors.lastname: Russell
authors.forename: C
authors.initials: C
authors.lastname: Carcamo
authors.forename: D M
authors.initials: DM
authors.lastname: Watts
authors.forename: J
authors.initials: J
authors.lastname: Sanchez
authors.forename: E
authors.initials: E
authors.lastname: Gotuzzo
authors.forename: A
authors.initials: A
authors.lastname: Euler
authors.forename: J C
authors.initials: JC
authors.lastname: Blanco
authors.forename: A
authors.initials: A
authors.lastname: Galeano
authors.forename: A
authors.initials: A
authors.lastname: Alava
authors.forename: J I
authors.initials: JI
authors.lastname: Mullins
authors.forename: K K
authors.initials: KK
authors.lastname: Holmes
authors.forename: J K
authors.initials: JK
authors.lastname: Carr
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000737:chemistry; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000276:immunology; D020180:Heteroduplex Analysis; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D012725:Sexual Behavior; D013020:South America / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D004279:DNA, Viral; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments