1 Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; BC Centre for Excellence in HIV/AIDS, Vancouver, BC V6Z 1Y6, Canada.
2 Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; BC Centre for Excellence in HIV/AIDS, Vancouver, BC V6Z 1Y6, Canada. Electronic address: bobhogg@cfenet.ubc.ca.