1. Department of Dermatology, Venereology and Allergology; Center for Sexual Health and Medicine; Ruhr-University Bochum; Bochum Germany
2. National Reference Center for Papilloma- and Polyomaviruses; Institute of Virology; Uniklinik Köln; University of Cologne; Koeln Germany
3. Competence Network for HIV/AIDS (KompNet HIV/AIDS); Ruhr-University Bochum; Bochum Germany
4. Institute of Cytology; Bonn Germany
5. Clinical Trial Centre (ZKS); University of Cologne; Cologne Germany