TY - JOUR VL - 102 TI - Genetic analysis reveals the complex structure of HIV-1 transmission within defined risk groups EP - 4429 A1 - Hué, S. A1 - Pillay, D. A1 - Clewley, J.P. A1 - Pybus, O.G. ID - discovery316 IS - 12 Y1 - 2005/03/22/ SN - 1091-6490 SP - 4425 N2 - We explored the epidemic history of HIV-1 subtype B in the United Kingdom using statistical methods that infer the population history of pathogens from sampled gene sequence data. Phylogenetic analysis of HIV-1 pol gene sequences from Britain showed at least six large transmission chains, indicating a genetically variable, but epidemiologically homogeneous, epidemic among men having sex with men. Through coalescent-based analysis we showed that these chains arose through separate introductions of subtype B strains into the United Kingdom in the early-to-mid 1980s. After an initial period of exponential growth, the rate of spread generally slowed in the early 1990s, which is more likely to correlate with behaviour change than with reduced infectiousness resulting from highly active antiretroviral therapy. Our results provide new insights into the complexity of HIV-1 epidemics that must be considered when developing HIV monitoring and prevention initiatives. UR - http://www.pnas.org/cgi/content/full/102/12/4425 AV - public JF - Proceedings of the National Academy of Sciences of the United States of America ER -