1. Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
2. Department of Public Health Sciences, Karolinska Institutet, Nobels väg 6, Solna and Alfred Nobels Allé 8, Huddinge, Stockholm, Sweden
3. Department of Reproductive Health and Research, World Health Organization, 20 Avenue Appia, 2011 Geneva, Switzerland
4. CEPED, IRD, Université de Paris, Equipe SAGESUD, ERL INSERM U 1244, 45 Rue des Saints Pères, Paris, France