[1] Martin Luther Univ Halle Wittenberg, Inst Med Epidemiol Biometr & Informat, D-06097 Halle, Saale, Germany
[2] Addis Ababa Univ, Sch Publ Hlth, Dept Prevent Med, Addis Ababa, Ethiopia
[3] Addis Ababa Univ, Dept Microbiol Immunol & Parasitol, Addis Ababa, Ethiopia
[4] Charite Univ Med Berlin, Clin Gynecol, Augustenburgerpl 1, D-13353 Berlin, Germany
[5] Free Univ Berlin, Augustenburgerpl 1, D-13353 Berlin, Germany
[6] Humboldt Univ, Augustenburgerpl 1, D-13353 Berlin, Germany
[7] Berlin Inst Hlth, Augustenburgerpl 1, D-13353 Berlin, Germany