1 Cancer Epidemiology Research Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain; Centro de Investigación Biomédica en Red: Epidemiología y Salud Pública (CIBERESP CB06/02/0073), Madrid, Spain. Electronic address: [email protected].
2 Cancer Epidemiology Research Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain; Centro de Investigación Biomédica en Red: Epidemiología y Salud Pública (CIBERESP CB06/02/0073), Madrid, Spain.
3 Department of Global HIV, Hepatitis and Sexually Transmitted Infections Programmes, World Health Organization, Geneva, Switzerland.
4 Department of Global HIV, Hepatitis and Sexually Transmitted Infections Programmes, World Health Organization, Geneva, Switzerland; Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA.
5 Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland.