[1] PATH, Seattle, WA 98117 USA
[2] Columbia Univ, Dept Pathol, New York, NY 10027 USA
[3] Univ Cape Town, Dept Obstet & Gynaecol, ZA-7700 Rondebosch, South Africa
[4] Agcy Res Canc Screening Grp, Lyon, France
[5] Columbia Univ, Mailman Sch Publ Hlth, New York, NY 10027 USA
[6] JHPIEGO, Baltimore, MD USA