title: Expansion of HAART coverage is associated with sustained decreases in HIV/AIDS morbidity, mortality and HIV transmission: the "HIV Treatment as Prevention" experience in a Canadian setting.
abstract: BACKGROUND
  There has been renewed call for the global expansion of highly active antiretroviral therapy (HAART) under the framework of HIV treatment as prevention (TasP). However, population-level sustainability of this strategy has not been characterized.
  
  
  METHODS
  We used population-level longitudinal data from province-wide registries including plasma viral load, CD4 count, drug resistance, HAART use, HIV diagnoses, AIDS incidence, and HIV-related mortality. We fitted two Poisson regression models over the study period, to relate estimated HIV incidence and the number of individuals on HAART and the percentage of virologically suppressed individuals.
  
  
  RESULTS
  HAART coverage, median pre-HAART CD4 count, and HAART adherence increased over time and were associated with increasing virological suppression and decreasing drug resistance. AIDS incidence decreased from 6.9 to 1.4 per 100,000 population (80% decrease, p = 0.0330) and HIV-related mortality decreased from 6.5 to 1.3 per 100,000 population (80% decrease, p = 0.0115). New HIV diagnoses declined from 702 to 238 cases (66% decrease; p = 0.0004) with a consequent estimated decline in HIV incident cases from 632 to 368 cases per year (42% decrease; p = 0.0003). Finally, our models suggested that for each increase of 100 individuals on HAART, the estimated HIV incidence decreased 1.2% and for every 1% increase in the number of individuals suppressed on HAART, the estimated HIV incidence also decreased by 1%.
  
  
  CONCLUSIONS
  Our results show that HAART expansion between 1996 and 2012 in BC was associated with a sustained and profound population-level decrease in morbidity, mortality and HIV transmission. Our findings support the long-term effectiveness and sustainability of HIV treatment as prevention within an adequately resourced environment with no financial barriers to diagnosis, medical care or antiretroviral drugs. The 2013 Consolidated World Health Organization Antiretroviral Therapy Guidelines offer a unique opportunity to further evaluate TasP in other settings, particularly within generalized epidemics, and resource-limited setting, as advocated by UNAIDS.
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Julio S G
authors.initials: JS
authors.lastname: Montaner
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Viviane D
authors.initials: VD
authors.lastname: Lima
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: P Richard
authors.initials: PR
authors.lastname: Harrigan
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada.
authors.forename: Lillian
authors.initials: L
authors.lastname: Lourenço
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada.
authors.forename: Benita
authors.initials: B
authors.lastname: Yip
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada.
authors.forename: Bohdan
authors.initials: B
authors.lastname: Nosyk
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Evan
authors.initials: E
authors.lastname: Wood
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerr
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kate
authors.initials: K
authors.lastname: Shannon
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Moore
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hogg
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Providence Health Care, Vancouver, British Columbia, Canada ; Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada.
authors.forename: Rolando
authors.initials: R
authors.lastname: Barrios
authors.affiliation: BC Centre for Disease Control, Vancouver, British Columbia, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Gilbert
authors.affiliation: BC Centre for Disease Control, Vancouver, British Columbia, Canada.
authors.forename: Mel
authors.initials: M
authors.lastname: Krajden
authors.affiliation: Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada.
authors.forename: Reka
authors.initials: R
authors.lastname: Gustafson
authors.affiliation: Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada.
authors.forename: Patricia
authors.initials: P
authors.lastname: Daly
authors.affiliation: Ministry of Health, Province of British Columbia, Victoria, British Columbia, Canada.
authors.forename: Perry
authors.initials: P
authors.lastname: Kendall
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy* / Q000401:mortality* / Q000517:prevention & control; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods* / Q000706:statistics & numerical data*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D002170:Canada; D003140:Communicable Disease Control; D018450:Disease Progression; D024882:Drug Resistance, Viral; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality* / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D016012:Poisson Distribution; D015995:Prevalence; D012042:Registries; D012044:Regression Analysis; D016896:Treatment Outcome; D019562:Viral Load