London School of Hygiene & Tropical Medicine - Faculty of Epidemiology and Population Health, Government of the United States of America - HPV Serology Laboratory, Government of the United States of America - Division of Cancer Epidemiology and Genetics, World Health Organization (WHO) - Early Detection, Prevention and Infections Branch, Mwanza Intervention Trials Unit, Government of the United States of America - Division of Cancer Epidemiology and Genetics, Mwanza Intervention Trials Unit, Mwanza Intervention Trials Unit, Fundacion INCIENSA - Agencia Costarricense de Investigaciones Biomedicas (ACIB), University of York - York Biomedical Research Institute, Government of the United States of America - Division of Cancer Epidemiology and Genetics, World Health Organization (WHO) - Early Detection, Prevention and Infections Branch, Mwanza Intervention Trials Unit, Karolinska Institutet - Department of Laboratory Medicine, Mwanza Intervention Trials Unit, World Health Organization (WHO) - Early Detection, Prevention and Infections Branch, London School of Hygiene & Tropical Medicine - MRC International Statistics & Epidemiology Group, Government of the United States of America - HPV Serology Laboratory and Mwanza Intervention Trials Unit