[1] Univ Botswana, Dept Paediat & Adolescent Hlth, Fac Med, P Bag 00713, Gaborone, Botswana
[2] Botswana Harvard AIDS Inst Partnership, Gaborone, Botswana
[3] Harvard TH Chan Sch Publ Hlth, Dept Immunol & Infect Dis, Boston, MA USA
[4] Massachusetts Gen Hosp, Dept Internal Med, Boston, MA 02114 USA
[5] Massachusetts Gen Hosp, Dept Pediat, Boston, MA 02114 USA
[6] Ann & Robert H Lurie Childrens Hosp Chicago, Dept Pediat, Chicago, IL 60611 USA
[7] Northwestern Univ, Feinberg Sch Med, Dept Obstet & Gynecol, Chicago, IL 60611 USA
[8] Northwestern Univ, Dept Pediat, Feinberg Sch Med, Chicago, IL 60611 USA
[9] Northwestern Univ, Dept Med, Feinberg Sch Med, Chicago, IL 60611 USA