A comprehensive population-based study, conducted by the BC Centre for Excellence in HIV/AIDS (BC-CfE) and presented at the 17th Conference on Retroviruses and Opportunistic Infections in San Francisco, shows that expanded highly active antiretroviral therapy (HAART) coverage was associated with a 50% decrease in new yearly HIV infections among injection drug users.
These results were temporally related to an outreach effort specifically targeting injection drug users. In addition, increased HAART coverage was associated with a decrease in the community HIV plasma viral load in British Columbia.
Providing HAART treatment to HIV-infected drug users has been strongly debated by researchers and clinicians. Some argue that social instability related to illicit drug use can compromise HAART-related benefits. As a result, on a global scale, drug users have been less likely to be prescribed HAART and are consequently more likely to have worse health outcomes, including higher rates of HIV disease progression to AIDS and death.
But the BC-CfE's study results point to the effectiveness of HAART in providing life-supporting benefits to all HIV-infected people, including those in marginalized communities such as injection drug users. A previous BC-CfE study showed that five-year mortality is similar between HIV-infected injection drug users and non-users infected with HIV and treated with HAART. Today's results show that HAART's secondary benefit of HIV prevention will also be realized among drug users.
"Our results clearly reveal the need to develop specific initiatives to increase HAART coverage among injection drug users," said Dr. Julio Montaner, Director, BC-CfE, and an early proponent of expanding HAART coverage as a way to decrease progression to AIDS and death in HIV-infected individuals and to prevent HIV infections among individuals at risk.
Based on HAART's proven efficacy and results from studies at the BC-CfE, the British Columbia government has announced a new C$48-million, four-year initiative to enhance HAART outreach to hard-to-reach populations in B.C., including injection drug users. This builds on the earlier developmental funding ($2.5 million over five years) provided by the National Institutes of Drug Abuse at the U.S. National Institutes of Health and the Knowledge Translation Award (C$100,000) from the Canadian Institutes of Health Research.
The project, known as Seek and Treat to Optimize Prevention of HIV and AIDS (STOP HIV & AIDS), is aimed at curbing the transmission of HIV and decreasing AIDS-related morbidity and mortality. These benefits will occur by expanding HIV treatment, care and support, as well as improving access to HIV drugs for hard-to-reach residents. The pilot project will focus on Prince George and Vancouver's Downtown Eastside, where access to services remains sub-optimal.
As part of this initiative, specific efforts will be made to identify and test individuals at risk (seek) and engage them in care and on HAART if medically appropriate (treat), all within a supportive environment that includes harm reduction strategies. Medical care, laboratory monitoring and HAART are all available free of charge as part of the universal health care system in B.C.
The results of the BC-CfE's study come at a key time, given concerns raised by a recent mathematical model based on the San Francisco experience published by Smith et al (Science, January 14, 2010). The study conducted in San Francisco suggested that the effectiveness of increased HAART coverage could be seriously undermined by the emergence of an epidemic of drug-resistant HIV.
"However, our population-based results collected over the last decade demonstrate that high levels of sustained viral suppression can be achieved and the emergence of drug-resistant HIV can be prevented through the appropriate use of modern antiretroviral regimens as currently recommended by the World Health Organization (WHO) coupled with adequate patient support. These lessons are keys to the roll out of HAART around the world," said Montaner, who is Professor of Medicine, Chair of AIDS Research and Head of the Division of AIDS at the University of British Columbia.
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