[1] Lund Univ, Translat Med, Lund, Sweden
[2] Kenya Med Res Inst Wellcome Trust Res Programme, Nairobi, Kenya
[3] Nyanza Reprod Hlth Soc, Kisumu, Kenya
[4] Univ Nairobi, Nairobi, Kenya
[5] Univ Manitoba, Winnipeg, MB, Canada
[6] Kenya Govt Med Res Ctr, Ctr Dis & Control, Nairobi, Kenya
[7] Univ Washington, Seattle, WA 98195 USA
[8] Univ Oxford, Oxford, England