[1] Open Soc Fdn, New York, NY 10019 USA
[2] Medecins Monde, F-75018 Paris, France
[3] Univ London London Sch Hyg & Trop Med, London WC1E 7HT, England
[4] Int Network People who Use Drugs, Unit 2CO5, London SE1 6LN, England
[5] Australian Injecting & Illicit Drug Users League, Canberra, ACT 2601, Australia
[6] Treatment Act Grp, New York, NY 10016 USA