1. Department of Preventive Medicine, School of Public Health, Addis Ababa University, Addis Ababa 366, Ethiopia
2. Global Health Working Group, Institute for Medical Epidemiology, Biometrics and Informatics (IMEBI), Martin-Luther-University Halle, 06112 Halle, Germany
3. Department of Gynecology, Martin-Luther-University Halle, 06120 Halle, Germany