2 Pan American Health Organization, Washington, DC, USA.
3 Drugs for Neglected Diseases initiative, Geneva 1202, Switzerland.
4 Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; UK & Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana.
5 Médecins Sans Frontières Access Campaign, Geneva, Switzerland.