EPIDEMIOLOGY: PDF OnlyHigh Frequency of Non-B Subtypes in Newly Diagnosed HIV-1 Infections in SwitzerlandBöni, Jürg*; Pyra, Halina*; Gebhardt, Martin†; Perrin, Luc‡; Bürgisser, Philippe§; Matter, Lukas∥; Fierz, Walter¶; Erb, Peter#; Piffaretti, Jean-Claude**; Minder, Elisabeth††; Grob, Peter‡‡; Burckhardt, Johann J.§§; Zwahlen, Marcel†; Schüpbach, Jörg* Author Information *Swiss National Center for Retroviruses, University of Zurich, Zurich; †Swiss Federal Office of Public Health, Berne; ‡Central Virology Laboratory, Geneva University Hospital, Geneva; §Division of Immunology and Allergology, University Hospital Center, Lausanne; ∥Institute for Medical Microbiology, University of Berne, Berne; ¶Institute for Clinical Microbiology and Immunology, Kantonsspital, St. Gallen; #Institute for Medical Microbiology, University of Basel, Basel; **Istituto Cantonale Batteriosierologico, Lugano; ††Triemli City Hospital, Zurich; ‡‡Division of Clinical Immunology, Department of Medicine, Zurich University Hospital, Zurich; and §§Central Laboratory of the Swiss Red Cross, Berne, Switzerland Address correspondence and reprint requests to Jörg Schüpbach, Swiss National Center for Retroviruses, University of Zurich, Gloriastrasse 30, CH-8028 Zurich, Switzerland; email: [email protected] Manuscript received March 29, 1999; accepted July 13, 1999. JAIDS Journal of Acquired Immune Deficiency Syndromes 22(2):p 174-179, October 1, 1999. Free Abstract Summary: HIV-1 subtypes were determined in newly diagnosed residents of Switzerland. Blood was anonymously collected from patients with a first confirmed positive HIV-1 test result. Viral DNA from the env V3-V5 region was amplified by nested polymerase chain reaction (PCR) and screened for subtype B by heteroduplex mobility assay. All amplicons not identified as B were sequenced. From November 1996 to February 1998, 206 samples were analyzed. Main transmission risks were unprotected heterosexual (55.7%) or homosexual (27.1%) sexual contact or intravenous drug use (12.9%). Subtype B dominated in patients of Swiss, other European, American, or Asian citizenship; particularly high frequencies were found in homosexuals (97%) and drug users (94%). Non-B subtypes including A, C, D, E, F, G, H, a possible B/F recombinant, and a sequence related to J were present in 28.2% (95% confidence interval [CI], 22.9%-35.0%). Non-B were frequent in African citizens (95%), heterosexually infected individuals (44%), and women (43%). Heterosexually infected Swiss males harbored non-B strains in 18% and females in 33%. The results document a change in the epidemiology of newly diagnosed HIV-1 infections in Switzerland: predominance of heterosexual transmission and a high frequency of non-B subtypes. © 1999 Lippincott Williams & Wilkins, Inc.