Genetic and temporal dynamics of human immunodeficiency virus type 1 CRF07_BC in Xinjiang, China

Abstract

To explore the temporal genetic variation of human immunodeficiency virus type 1 CRF07_BC and reconstruct its epidemic in Xinjiang, China, we studied 216 C2–V4 fragments of env genes sampled from 1996 to 2008. Phylogenetic analysis indicates that the viruses prevailing in Xinjiang form a large monophyletic cluster and may have originated from a common ancestor. The epidemic in Xinjiang was probably established around 1995 (95 % confidence interval, 1994–1996). We noted an increased diversity of CRF07_BC over time, with a rapid evolutionary rate we estimated to be 8.3×10−3 substitutions per site per year in the env gene. After 5–6 years of the epidemic (1997–2002), the transmission rate of CRF07_BC in Xinjiang slowed down, although CRF07_BC infection remained at a high prevalence.