[1] Univ Zimbabwe, Coll Hlth Sci, Harare, Zimbabwe
[2] Univ Zimbabwe, Zimbabwe AIDS Prevent Project, Dept Community Med, Harare, Zimbabwe
[3] UZ UCSF Collaborat Program Womens Hlth, Harare, Zimbabwe
[4] Minist Hlth & Child Welf, Harare, Zimbabwe
[5] Wake Forest Univ Hlth Sci, Dept Pediat, Winston Salem, NC 27157 USA