[1] Univ KwaZulu Natal, Dept Paediat & Child Hlth, Durban, South Africa
[2] Royal Childrens Hosp, Murdoch Childrens Res Inst, Melbourne, Vic, Australia
[3] Univ Melbourne, Melbourne, Vic, Australia
[4] WHO, Dept Child & Adolescent Hlth, CH-1211 Geneva, Switzerland
[5] WHO, Indonesia Off, Jakarta, Indonesia
[6] Boston Univ, Sch Publ Hlth, Ctr Int Hlth & Dev, Boston, MA USA
[7] Boston Univ, Sch Med, Infect Dis Sect, Boston, MA 02118 USA