title: Multiple-infection and recombination in HIV-1 within a longitudinal cohort of women.
abstract: BACKGROUND
  Recombination between strains of HIV-1 only occurs in individuals with multiple infections, and the incidence of recombinant forms implies that multiple infection is common. Most direct studies indicate that multiple infection is rare. We determined the rate of multiple infection in a longitudinal study of 58 HIV-1 positive participants from The Women's Interagency HIV Study with a richer sampling design than previous direct studies, and we investigated the role of recombination and sampling design on estimating the multiple infection rate.
  
  
  RESULTS
  40% of our sample had multiple HIV-1 infections. This rate of multiple infection is statistically consistent with previous studies once differences in sampling design are taken into account. Injection drug use significantly increased the incidence of multiple infections. In general there was rapid elimination of secondary strains to undetectable levels, but in 3 cases a superinfecting strain displaced the initial infecting strain and in two cases the strains coexisted throughout the study. All but one secondary strain was detected as an inter- and/or intra-genic recombinant. Injection drug use significantly increased the rate of observed recombinants.
  
  
  CONCLUSIONS
  Our multiple infection rate is consistent with rates estimated from the frequency of recombinant forms of HIV-1. The fact that our results are also consistent with previous direct studies that had reported a much lower rate illustrates the critical role of sampling design in estimating this rate. Multiple infection and recombination significantly add to the genetic diversity of HIV-1 and its evolutionary potential, and injection drug use significantly increases both.
authors.affiliation: Department of Biology, Washington University, St Louis, Missouri, USA. temple_a@wustl.edu
authors.forename: Alan R
authors.initials: AR
authors.lastname: Templeton
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Kramer
authors.forename: Joseph
authors.initials: J
authors.lastname: Jarvis
authors.forename: Jeanne
authors.initials: J
authors.lastname: Kowalski
authors.forename: Stephen
authors.initials: S
authors.lastname: Gange
authors.forename: Michael F
authors.initials: MF
authors.lastname: Schneider
authors.forename: Qiujia
authors.initials: Q
authors.lastname: Shao
authors.forename: Guang Wen
authors.initials: GW
authors.lastname: Zhang
authors.forename: Mei-Fen
authors.initials: MF
authors.lastname: Yeh
authors.forename: Hua-Ling
authors.initials: HL
authors.lastname: Tsai
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Richard B
authors.initials: RB
authors.lastname: Markham
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D055030:Drug Users; D005260:Female; D014644:Genetic Variation; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D016865:Reassortant Viruses; D011995:Recombination, Genetic; D012307:Risk Factors; D015163:Superinfection / Q000453:epidemiology* / Q000209:etiology / Q000821:virology; D054299:env Gene Products, Human Immunodeficiency Virus / Q000032:analysis / Q000235:genetics; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000032:analysis / Q000235:genetics
chemical_list: D004279:DNA, Viral; D054299:env Gene Products, Human Immunodeficiency Virus; D054302:pol Gene Products, Human Immunodeficiency Virus