[1] Columbia Univ Coll Phys & Surg, New York, NY 10032 USA
[2] Univ Calif San Francisco, Dept Med, San Francisco, CA USA
[3] Makerere Univ, Sch Med, Kampala, Uganda
[4] Blood Syst Res Inst, San Francisco, CA USA
[5] Blood Syst Labs, Tempe, AZ USA
[6] Gen Probe Inc, San Diego, CA USA
[7] Bio Rad, Redmond, WA USA
[8] Univ Calif San Francisco, Ctr AIDS Prevent Studies, San Francisco, CA 94143 USA