Objectives: To examine temporal trends in plasma viral load (pVL) suppression and antiretroviral resistance from 1997 to 2010 in British Columbia (BC), Canada, and determine characteristics, pVL ranges, and resistance profiles of HIV-positive individuals with unsuppressed pVL in 2010.
Methods: HIV-positive individuals ≥19 years old in the provincial database at the BC Centre for Excellence in HIV/AIDS were included. Virological suppression was defined as 2 consecutive pVL <500 copies per milliliter within each calendar year. Temporal trends were evaluated using the Cochran–Armitage test. Persons with suppressed vs. unsuppressed pVL in 2010 were compared using the Pearson χ2 or Fisher exact test (categorical variables) and the Wilcoxon rank-sum test (quantitative variables), including unsuppressed individuals only if they were on antiretroviral therapy (ART) in 2010 or their baseline CD4 count was <350 cells per cubic millimeter or <500 cells per cubic millimeter, in separate analyses.
Results: The proportion of individuals with suppressed pVL increased from 24% to 80% (P < 0.001). In comparative analyses, individuals with unsuppressed pVL (877 of 6142) were more likely to be female (30% vs. 16%), younger (median, 43 vs. 48 years), have injection drug use history (38% vs. 30%), report Aboriginal ancestry (30% vs. 16%), and have hepatitis C coinfection (57% vs. 34%) (all P < 0.001). Similar patterns were observed using the <500 cells per cubic millimeter CD4 cutoff. The median pVL of all unsuppressed individuals in 2010 was 12,896 copies per milliliter (interquartile range, 1495–47,763).
Conclusions: The proportion of individuals achieving pVL suppression in BC has increased markedly since 1997; however, further efforts are needed to maximize the individual and societal benefits of modern antiretroviral therapy.
*British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada;
†University of British Columbia, Vancouver, British Columbia, Canada; and
‡Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
Correspondence to: Julio S. G. Montaner, MD, British Columbia Centre for Excellence in HIV/AIDS, 667–1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada (e-mail: firstname.lastname@example.org).
C.J.B. is supported by a Vanier Canada Graduate Scholarship from the Canadian Institutes of Health Research (CIHR) [CGV-104812]. P.R.H. has received grants from, served as an ad hoc advisor to, or spoke at various events sponsored by Pfizer, Glaxo-Smith Kline, Abbott, Merck, Virco, and Monogram. He is supported by a CIHR/GSK Research Chair in Clinical Virology and has consulted and/or received grant funding from a variety of pharmaceutical diagnostic companies. M.H. has received grant support from the National Institute on Drug Abuse (NIDA R01DA031043-01) and has received honoraria for speaking engagements and/or consultancy meetings from the following: Bristol-Myers Squibb, Gilead Sciences, Merck, Ortho-Janssen, Pfizer, Vertex Pharmaceuticals, and ViiV. R.S.H. has held grant funding in the past 5 years from the National Institutes of Health (NIH), CIHR, Health Canada, Merck, and SSHRC. J.S.G.M. has received grants from Abbott, Biolytical, Boehringer Ingelheim, Bristol-Myers Squibb, Gilead Sciences, Janssen, Merck and ViiV Healthcare. He is also supported by the Ministry of Health Services and the Ministry of Healthy Living and Sport, from the Province of British Columbia; through a Knowledge Translation Award from CIHR; and through an Avant-Garde Award (No. 1DP1DA026182-01) from the NIDA, at the US NIH. He has also received support from the International AIDS Society, United Nations AIDS Program, World Health Organization, NIDA, NIH-Office of AIDS Research, National Institute of Allergy & Infectious Diseases, The United States President's Emergency Plan for AIDS Relief (PEPfAR), Bill & Melinda Gates Foundation, French National Agency for Research on AIDS & Viral Hepatitis (ANRS), and the Public Health Agency of Canada. He has academic partnerships with the University of British Columbia, Simon Fraser University, Providence Health Care, and Vancouver Coastal Health. B.N. is a CIHR Bisby Fellow and is also funded, in part, by the Michael Smith Foundation for Health Research. The remaining authors report no disclosures.
Presented at the 19th Conference on Retroviruses and Opportunistic Infections (CROI), March 5–8, 2012, Seattle, WA (Abstract #1116).
The study was conceived and designed by J.S.G.M., A.C., J.I.F., S.K., K.J.L., and M.H. Data were analyzed by S.K., C.J.B., and A.C. and interpreted by all authors. S.K. provided statistical expertise. The manuscript was drafted by A.C., J.S.G.M., and C.J.B. and was critically reviewed and subsequently approved by all authors.
Received March 06, 2013
Accepted August 08, 2013