1. AIDS Research Program, Providence Health Care Institute, B518 1081 Burrard Street, Vancouver, BC, Canada V6Z 1Y6
2. Department of Family Practice, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
3. British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada V6Z 1Y6
4. Division of AIDS, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
5. Community Research Initiative of New England, Boston, MA 02111, USA