title: HIV-1 co/super-infection in intravenous drug users.
abstract: BACKGROUND
  The frequency of HIV-1 co/super-infection is unknown despite their implications for public health and vaccine development. This issue was addressed during an epidemic of both CRF11 and B subtype among intravenous drug users (IVDUs).
  
  
  METHODS
  Bulk sequencing of reverse transcriptase, protease and C2V3 regions and subtype-specific nested polymerase chain reaction (PCR) in plasma and proviral DNA were performed using baseline and follow-up samples collected in recently infected IVDUs between 1998-2002 and in IVDUs with chronic infection living in the same area and presenting an unexpected rise of viremia (> 1 log10).
  
  
  RESULTS
  In 58 recently infected patients, three B/CRF-11 co-infections, 25 B, 28 CRF-11 and two other subtypes were detected at baseline. In the three co-infected patients, both CRF-11 and B were detected in plasma and proviral DNA and persisted during follow-up. B- and CFR-11-specific PCR performed on follow-up samples of 40 of 58 recently infected patients (median follow-up, 14.5 months) revealed a transient B super-infection in a patient initially infected by CRF-11. Five of 156 chronic IVDUs (total follow-up: 346 years) had an unexpected rise of viremia. In two of them, aviremic without treatment for years after an initial B infection, a symptomatic CRF-11 super-infection occurred and was associated with high viral load and a fall of CD4 cell count.
  
  
  CONCLUSIONS
  In recently infected IVDUs, co-infection B/CRF-11 is relatively frequent (5%). In chronically infected IVDUs super-infection may be transient and may occur in patients controlling efficiently HIV infection by the initial strain.
authors.forename: Sabine
authors.initials: S
authors.lastname: Yerly
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Jost
authors.forename: Martine
authors.initials: M
authors.lastname: Monnat
authors.forename: Amalio
authors.initials: A
authors.lastname: Telenti
authors.forename: Matthias
authors.initials: M
authors.lastname: Cavassini
authors.forename: Jean-Phillppe
authors.initials: JP
authors.lastname: Chave
authors.forename: Laurent
authors.initials: L
authors.lastname: Kaiser
authors.forename: Philippe
authors.initials: P
authors.lastname: Burgisser
authors.forename: Luc
authors.initials: L
authors.lastname: Perrin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D016415:Sequence Alignment; D015819:Substance Abuse, Intravenous / Q000150:complications*; D015163:Superinfection / Q000150:complications* / Q000235:genetics
chemical_list: D054303:HIV Reverse Transcriptase