HIV subtypes in Scotland, 2000-2006.

The purpose of this study was to document the dynamics of HIV-1 subtypes in Scotland over a 6-year period. Viral RNA from all-new diagnoses was amplified by nested PCR and sequenced in the gag and/or env regions. Subtype was assigned by phylogenetic analysis, and aligned with demographic data including likely route and geographical origin of infection. We present data on 80% of all new diagnoses in Scotland between April 2000 and April 2006. Within the background of an expanding epidemic, subtype B predominates in men who have sex with men and intravenous drug users but there is a small but consistent number of UK-acquired infections in these risk groups caused by non-B subtypes. In heterosexuals, non-B subtypes acquired abroad, especially Africa, are still the largest group but again UK-acquired numbers are rising. The social and clinical significance of the spread of non-B subtypes in different ethnic and risk groups remains to be established.