[1] NYU, Sch Med, New York, NY USA
[2] Univ Oxford, Oxford OX1 2JD, England
[3] Papua New Guinea Inst Med Res, Madang, Papua N Guinea
[4] Inst Rech Dev, Cotonou, Benin
[5] Harvard Sch Publ Hlth, Boston, MA USA
[6] Kilifi KEMRI Wellcome Trust Collaborat Programme, Klilfi, Kenya