HAART, or Highly Active Antiretroviral Therapy has halved the annual number of new HIV diagnoses since 1996, when the therapy was first introduced, say Canadian researchers in a study published in the peer-reviewed medical journal The Lancet. Study findings are being presented at the forthcoming AIDS Society conference in Vienna.
Professor Julio Montaner, Director, British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada, and team reported that for every 100 patients placed on HAART, new diagnoses of HIV dropped by 3%.
The researchers undertook a population-based study of HAART coverage and HIV transmission in British Columbia, Canada, where HIV care is free. They obtained data on total HIV tests and new HIV diagnoses from the the British Columbia Centre for Disease Control. Data for viral load, CD4 cell count, and HAART use were extracted from the British Columbia Centre for Excellence in HIV/AIDS population-based registries.
They found that between 1996 and 2009, the total number of people actively receiving HAART rose from 837 to 5,413, an increase of 547%. However, the number of new HIV diagnoses dropped from 702 to 338 per year, a fall of 52%. There was a strong link between the total number of patients on HAART and falling numbers of new diagnoses (3% drop for every 100 new patients on HAART). Mean HIV viral load concentrations also decreased markedly and were linked to a decrease in new HIV cases.
Between 1996 and 2000 new HIV diagnoses decreased by 30% and dropped by 3% during the 2001-2003 period. There was a 17% drop between 2004 and 2009.
HAART use increased considerably in 1996-2000 and 2004-09, and remained stable in 2001-03, driven by evolving contemporary treatment guidelines. The researchers showed that the drop in new HIV diagnoses per year was mainly driven by the subset of individuals with documented history of injecting drug use, in whom new HIV annual diagnoses per year decreased by nearly 50% during the study.
These findings cannot be accounted for by decreasing sexual HIV risk behaviour, because rates of sexually transmitted infections and hepatitis C infection increased during the last 15 years of the study.
The researchers said:
Our results show a strong and significant association between increased HAART coverage, reduced community viral load, and decreased number of new HIV diagnoses per year in the population of a Canadian province.
They concluded:
Our results support the proposed secondary benefit of HAART used within existing medical guidelines to reduce HIV transmission..[and] provide a strong rationale for re-examination of the HIV prevention and treatment dichotomy, as has been strongly advocated by the UN Joint Programme on HIV/AIDS (UNAIDS) as part of a comprehensive combination prevention strategy. Furthermore, our results should serve to reenergise the G8’s universal access pledge as a means to curb the effect of AIDS and the growth of the HIV pandemic.
Professor Montaner adds that this work and a previous paper on this subject that he and his team wrote have helped UNAIDS shape their strategy on the new Treatment 2.0 initiative, which calls for 15 million people globally to be treated with antiretroviral drugs that can slow down the progression of HIV-AIDS symptoms – up from the five million currently undergoing treatment. This strategy would cost some $26 billion per year. Such a plan would require innovations such as simpler, safer, and more resilient treatment regimens as well as minimal laboratory monitoring.
In an accompanying Lancet Comment, Dr Franco Maggiolo and Dr Sebastiano Leone, Division of Infectious Diseases, Ospedali Riuniti, Bergamo, Italy, wrote:
HAART might prove effective within other risk populations provided that the source individuals are thoroughly identified and correctly treated. Therefore we must couple the use of antiretrovirals with risk-reduction strategies, and identify infected individuals through information or education interventions that favour individual access to screening programmes. Integrated experiences that provide voluntary routine HIV testing and rapid entry into care, such as those recently implemented in Washington, DC, would tell us whether HAART can succeed as an epidemic control measure.
(conclusion) While waiting for an effective vaccine, experiences such as those reported today should be strongly considered by clinicians, national and international agencies, policy makers, and all parties involved in the development of treatment guidelines, because the population-based dimension of HAART might play an important part in the future control of the HIV epidemic.
Prof Julio SG Montaner MD, Viviane D Lima PhD, Rolando Barrios MD, Benita Yip, Evan Wood MD, Thomas Kerr PhD, Kate Shannon PhD, P Richard Harrigan PhD, Robert S Hogg PhD, Patricia Daly MD, Perry Kendall MD
The Lancet, Early Online Publication, 18 July 2010
doi:10.1016/S0140-6736(10)60936-1
Written by Christian Nordqvist