title: High frequency of non-B subtypes in newly diagnosed HIV-1 infections in Switzerland.
abstract: 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.
authors.affiliation: Swiss National Center for Retroviruses, University of Zurich.
authors.forename: J
authors.initials: J
authors.lastname: Böni
authors.forename: H
authors.initials: H
authors.lastname: Pyra
authors.forename: M
authors.initials: M
authors.lastname: Gebhardt
authors.forename: L
authors.initials: L
authors.lastname: Perrin
authors.forename: P
authors.initials: P
authors.lastname: Bürgisser
authors.forename: L
authors.initials: L
authors.lastname: Matter
authors.forename: W
authors.initials: W
authors.lastname: Fierz
authors.forename: P
authors.initials: P
authors.lastname: Erb
authors.forename: J C
authors.initials: JC
authors.lastname: Piffaretti
authors.forename: E
authors.initials: E
authors.lastname: Minder
authors.forename: P
authors.initials: P
authors.lastname: Grob
authors.forename: J J
authors.initials: JJ
authors.lastname: Burckhardt
authors.forename: M
authors.initials: M
authors.lastname: Zwahlen
authors.forename: J
authors.initials: J
authors.lastname: Schüpbach
mesh_terms: D000328:Adult; D005260:Female; D015686:Gene Products, env / Q000032:analysis; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification*; D020010:Heterosexuality; D006716:Homosexuality; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000150:complications; D013557:Switzerland / Q000453:epidemiology
chemical_list: D015686:Gene Products, env