Dalton C Wamalwa1
, Carey Farquhar2,3
, Elizabeth M Obimbo1
, Sara Selig4
, Dorothy A Mbori-Ngacha1
, Barbra A Richardson5
, Julie Overbaugh6
, Thaddeus Egondi1
, Irene Inwani7
and Grace John-Stewart2,3 
1
Department of Paediatrics University of Nairobi, Nairobi, Kenya
2
Department of Epidemiology, University of Washington, Seattle, USA
3
Department of Medicine, University of Washington, Seattle, USA
4
University of Colorado School of Medicine, Denver, USA
5
Department of Biostatistics, University of Washington, Seattle, USA
6
Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, USA
7
Kenyatta National Hospital, Nairobi, Kenya