[1] Ruhr Univ Bochum, Dept Dermatol Venereol & Allergol, Interdisciplinary Immunol Outpatient Clin, Bochum, Germany
[2] Ctr Sexual Hlth & Med, WIR Walk Ruhr, Grosse Beckstr 12, D-44787 Bochum, Germany
[3] London Sch Hyg & Trop Med, Dept Publ Hlth Environm & Soc, Sigma Res, London, England
[4] Cantonal Hosp St Gallen, Div Infect Dis, St Gallen, Switzerland
[5] Ruhr Univ Bochum, Inst Educ Res, Bochum, Germany
[6] Aids Serv Org Bochum eV, Bochum, Germany
[7] Local Hlth Author Bochum, Bochum, Germany