RESUMO
Objective To analyze the subtypes and characteristics of HIV-1 among men who have sex with men (MSM) in Zhejiang province from the year 2004 to 2011.Methods Blood DNA/RNA was extracted from the MSM HIV -1 infected individuals and then HIV-1 gag and pol fragments were amplified by nested polymerase chain reaction (nested-PCR)or RT-PCR.The positive PCR products were sequenced and the obtained sequences were analyzed by phylogenetic inference.Results A total of 117 HIV-1 infected MSMindividuals were analyzed,covering 21 provinces according to their household registry.Totally,three major strains were identified including CRF01_AE (84.62%,n =99 ),B (5.98%,n=7)and CRF07_BC (5.13%,n=6). Moreover,3 novel 01B recombinant stains,1 CRF59_01B and 1 CRF08_BC were found.According to the neighbor-joining tree by pol fragments,there were more than 30 sub clusters with bootstrap value higher than 70% among the 84 CRF01_AE sequences.Conclusion CRF01_AE is the major HIV-1 infection strain among MSMin Zhejiang province.CRF59_01B and other novel 01B recombinant stains are first reported among MSM individuals in Zhejiang province.