In the absence of a vaccine against the AIDS virus, the most effective treatment method is aggressive treatment of HIV infections with cocktails of antiretroviral drugs, an approach known as highly active antiretroviral therapy or HAART. A new study conducted in British Columbia has found that the infection rate in the province has been halved since 1996 by the widespread adoption of HAART, researchers reported online Sunday in the journal Lancet and at the International AIDS Conference in Vienna. For every 100 new patients treated, the infection rate went down 3%, Dr. Julio Montaner, director of the British Columbia Centre for Excellence in HIV/AIDS, reported.
"This study strengthens the evidence that maximizing HAART coverage within current medical guidelines will help to curb the spread of HIV," Dr. Nora D. Volkow, director of the U.S. National Institute on Drug Abuse, said in a statement. The agency funded the study. "These findings are especially important since new HIV cases have remained stubbornly steady in the United States at a rate of about 56,000 per year for the past 10 years."
British Columbia is a good place for such a study because it is relatively small — population about 4,420,00 — and everyone in the province receives free medical care. In 1996, the number of new HIV diagnoses was 702 per year, and only 837 people were receiving HAART. By 2009, Montaner said, 5,413 people were receiving HAART, and the number of new diagnoses had fallen to 338 per year. The largest decrease was among users of injection drugs, a finding that was somewhat surprising because of the belief among many clinicians that such drug abusers were unlikely to follow treatment regimens.
The number of new diagnoses was closely correlated to the prevalence of treatment. In the periods 1996 to 2000 and 2004 to 2009, HAART treatment rose sharply, and the number of new diagnoses dropped 30% and 17%, respectively. During the period 2001 to 2003, treatment guidelines were evolving, and fewer new HAART regimens were initiated. New diagnoses declined only 2% during the period.
In an editorial accompanying the report in the Lancet, Italian physicians wrote, "While waiting for an effective vaccine, experiences such as those reported today should be strongly considered by clinicians, national and international agencies, policymakers, 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."
More than 33-million people around the world are HIV-positive, and an estimated 2.7 million new infections occur each year, according to UNAIDS.