High frequency of non-B subtypes in newly diagnosed HIV-1 infections in Switzerland

J Acquir Immune Defic Syndr. 1999 Oct 1;22(2):174-9. doi: 10.1097/00126334-199910010-00010.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Gene Products, env / analysis
  • HIV Infections / epidemiology
  • HIV Infections / virology*
  • HIV-1 / classification*
  • Heterosexuality
  • Homosexuality
  • Humans
  • Male
  • Prevalence
  • Risk Factors
  • Substance Abuse, Intravenous / complications
  • Switzerland / epidemiology

Substances

  • Gene Products, env