Intended for healthcare professionals

  1. Research
  2. Longitudinal community...
  3. Longitudinal community plasma HIV-1 RNA concentrations and incidence of HIV-1 among injecting drug users: prospective cohort study
Research

Longitudinal community plasma HIV-1 RNA concentrations and incidence of HIV-1 among injecting drug users: prospective cohort study

BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b1649 (Published 30 April 2009) Cite this as: BMJ 2009;338:b1649
  1. Evan Wood, research scientist1,
  2. Thomas Kerr, research scientist1,
  3. Brandon D L Marshall, PhD candidate2,
  4. Kathy Li, senior statistician1,
  5. Ruth Zhang, statistician1,
  6. Robert S Hogg, director, HIV/AIDS drug treatment program1,
  7. P Richard Harrigan, director, research laboratories1,
  8. Julio S G Montaner, head3
  1. 1British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada
  2. 2School of Population and Public Health, University of British Columbia, Vancouver
  3. 3Division of AIDS, Department of Medicine, University of British Columbia, Vancouver
  1. Correspondence to: E Wood uhri-ew{at}cfenet.ubc.ca
  • Accepted 12 January 2009

Abstract

Objective To examine the relation between plasma HIV-1 RNA concentrations in the community and HIV incidence among injecting drug users.

Design Prospective cohort study.

Setting Inner city community in Vancouver, Canada.

Participants Injecting drug users, with and without HIV, followed up every six months between 1 May 1996 and 30 June 2007.

Main outcome measures Estimated community plasma HIV-1 RNA in the six months before each HIV negative participant’s follow-up visit. Associated HIV incidence.

Results Among 622 injecting drug users with HIV, 12 435 measurements of plasma HIV-1 RNA were obtained. Among 1429 injecting drug users without HIV, there were 155 HIV seroconversions, resulting in an incidence density of 2.49 (95% confidence interval 2.09 to 2.88) per 100 person years. In a Cox model that adjusted for unsafe sexual behaviours and sharing used syringes, the estimated community plasma HIV-1 RNA concentration remained independently associated with the time to HIV seroconversion (hazard ratio 3.32 (1.82 to 6.08, P<0.001), per log10 increase). When the follow-up period was limited to observations after 1 January 1988 (when the median plasma HIV RNA concentration was <20 000 copies/ml), the median viral load was no longer statistically associated with HIV incidence (1.70 (0.79 to 3.67, P=0.175), per log10 increase).

Conclusions A longitudinal measure of community plasma HIV-1 RNA concentration was correlated with the community HIV incidence rate and predicted HIV incidence independent of unsafe sexual behaviours and sharing used syringes. If these findings are confirmed, they could help to inform both HIV prevention and treatment interventions.

Footnotes

  • We thank the VIDUS and BART participants, and Deborah Graham, Tricia Collingham, and Kelly Hsu for their research and administrative assistance.

  • Contributors: EW designed the study, wrote the initial draft of the manuscript, and is guarantor. RZ and KL conducted the statistical analyses. All authors contributed to the design of the study and the drafting of the manuscript.

  • Funding: The VIDUS and BART studies are supported by US National Institutes of Health grants R01DA011591 and R01DA021525 and by Canadian Institutes of Health Research grant MOP-79297. TK is supported by a Canadian Institutes of Health Research (CIHR) new investigator award and a Michael Smith Foundation for Health Research (MSFHR) scholar award. BDLM is supported by a doctoral research award from CIHR and a MSFHR senior trainee award. JSGM has received an Avant-Garde award (DP1 DA026182) from the National Institute of Drug Abuse, National Institutes of Health. The authors affirm the independence of the researchers from the funders.

  • Competing interests: RSH has received funding for research and continuing medical education programmes from pharmaceutical companies, including Abbott, Boehringer Ingelheim, and GlaxoSmithKline. JSGM has received educational grants from, served as an ad hoc adviser to, or spoken at various events sponsored by Abbott Laboratories, Agouron Pharmaceuticals, Boehringer Ingelheim Pharmaceuticals, Borean Pharma AS, Bristol-Myers Squibb, DuPont Pharma, Gilead Sciences, GlaxoSmithKline, Hoffmann-La Roche, Immune Response Corporation, Incyte, Janssen-Ortho, Kucera Pharmaceutical Company, Merck Frosst Laboratories, Pfizer Canada, Sanofi Pasteur, Shire Biochem, Tibotec Pharmaceuticals, and Trimeris.

  • Ethical approval: The research was approved by the University of British Columbia’s research ethics board at St Paul’s Hospital.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

View Full Text
Back to top