title: Genetic diversity and HIV-1 incidence estimation among cocaine users in São Paulo, Brazil.
abstract: We describe HIV-1 incidence and the prevalence of genetic subtypes among cocaine users in São Paulo, Brazil. A cross-sectional HIV-1 survey was carried out among 839 current cocaine users attending seven drug treatment units in the São Paulo metropolitan area from 1997 to 1998. HIV-1 subtyping was performed among 41 positive individuals using the heteroduplex mobility assay and DNA sequencing. Participants were mainly male (95.7%) with a history of previous imprisonment (54%), and the mean age was 26.9 years (SD = 7.2). The majority (64.4%) were current crack cocaine users, and 82.1% of the total participants were noninjectors. HIV-1 seroprevalence was 4.9% (95% confidence interval [CI], 3.6%-6.6%), and the incidence (estimated by the sensitive/less-sensitive immunoassay testing strategy) was 0.71% per year (95% CI, 0.07-3.03). HIV-1 subtype B was predominant (90.3%), followed by subtype F. There was no statistically significant association between HIV-1 subtype and specific route of drug administration. Our incidence data show evidence of recent HIV-1 transmission among cocaine users, mainly among noninjectors. Detection of recently infected HIV-1 cases linked to genetic diversity analysis may provide baseline information for public health interventions in this sentinel group.
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Federal University of Goiás, Goiás, Brazil. mturchi@cultura.com.br
authors.forename: Marília Dalva
authors.initials: MD
authors.lastname: Turchi
authors.forename: Ricardo Sobhie
authors.initials: RS
authors.lastname: Diaz
authors.forename: Celina Maria Turchi
authors.initials: CM
authors.lastname: Martelli
authors.forename: Ester Cerdeiro
authors.initials: EC
authors.lastname: Sabino
authors.forename: Wilson Pereira
authors.initials: WP
authors.lastname: Da Silva
authors.forename: Olavo Ferreira
authors.initials: OF
authors.lastname: Filho
authors.forename: Ronaldo Ramos
authors.initials: RR
authors.lastname: Laranjeira
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
authors.forename: Adauto
authors.initials: A
authors.lastname: Castelo
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D019970:Cocaine-Related Disorders / Q000150:complications*; D016578:Crack Cocaine; D005260:Female; D014644:Genetic Variation; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D006801:Humans; D015994:Incidence; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D017422:Sequence Analysis, DNA
chemical_list: D016578:Crack Cocaine