Molecular Epidemiology Reveals Long-Term Changes in HIV Type 1 Subtype B Transmission in Switzerland

作者:Kouyos Roger D*; von Wyl Viktor; Yerly Sabine; Boeni Juerg; Taffe Patrick; Shah Cyril; Buergisser Philippe; Klimkait Thomas; Weber Rainer; Hirschel Bernard; Cavassini Matthias; Furrer Hansjakob; Battegay Manuel; Vernazza Pietro L; Bernasconi Enos; Rickenbach Martin; Ledergerber Bruno; Bonhoeffer Sebastian; Guenthard Huldrych F
来源:Journal of Infectious Diseases, 2010, 201(10): 1488-1497.
DOI:10.1086/651951

摘要

Background. Sequence data from resistance testing offer unique opportunities to characterize the structure of human immunodeficiency virus (HIV) infection epidemics.
Methods. We analyzed a representative set of HIV type 1 (HIV-1) subtype B pol sequences from 5700 patients enrolled in the Swiss HIV Cohort Study. We pooled these sequences with the same number of sequences from foreign epidemics, inferred a phylogeny, and identified Swiss transmission clusters as clades having a minimal size of 10 and containing >= 80% Swiss sequences.
Results. More than one-half of Swiss patients were included within 60 transmission clusters. Most transmission clusters were significantly dominated by specific transmission routes, which were used to identify the following patient groups: men having sex with men (MSM) (38 transmission clusters; average cluster size, 29 patients) or patients acquiring HIV through heterosexual contact (HETs) and injection drug users (IDUs) (12 transmission clusters; average cluster size, 144 patients). Interestingly, there were no transmission clusters dominated by sequences from HETs only. Although 44% of all HETs who were infected between 1983 and 1986 clustered with injection drug users, this percentage decreased to 18% for 2003-2006 (P < .001), indicating a diminishing role of injection drug users in transmission among HETs over time.
Conclusions. Our analysis suggests (1) the absence of a self-sustaining epidemic of HIV-1 subtype B in HETs in Switzerland and (2) a temporally decreasing clustering of HIV infections in HETs and IDUs.