1 United Nations Children's Fund (UNICEF), New York, NY 10016, USA. Electronic address: adetjen@unicef.org.
2 Treatment Action Group (TAG), New York, NY, USA.
3 Centre for International Child Health, University of Melbourne Department of Paediatrics and Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; International Union Against Tuberculosis and Lung Disease, Paris, France.
4 The Children's Hospital at Westmead and The University of Sydney, Sydney, NSW, Australia.