Distribution of HIV-1 subtypes in Guangxi Zhuang Autonomous Region, 2008-2009

Abstract

To understand the distribution of HIV-1 subtypes in Guangxi Zhuang Autonomous Region. 294 participants who were infected by HIV-1 in 2008 - 2009 and residing in 13 cities in Guangxi were enrolled into this study. Epidemiological information showed that heterosexual transmission was the main transmitting route. 1584 bp full length gag gene, 3147 bp full length pol gene and 558 bp env (C2V3) fragments were amplified by using RT-PCR and then directly sequenced. NCBI genotyping tool and Mega 5.03 software were used to determine the HIV subtypes. Simplot and Recombinant HIV-1 Drawing Tool were used for the analysis of recombination. A total of 739 sequences, including 270 gag, 246 pol and 223 env (C2V3), were successfully obtained from 294 plasma specimens. Genotypes of HIV from 272 participants were determined. CRF01_AE was found the dominant (77.6%), followed by CRF08_BC (10.7%) and CRF07_BC (7.4%). 7 unique recombinant forms, 4 subtype B (B') and 1 subtype G were also identified. No significant difference on the distribution of subtypes among different regions and ethnics was found. Among the 7 unknown recombinant forms, 6 strains were mosaic B and/or C fragments with CRF01_AE genome as the backbone, while one strain originated from CRF07_BC and CRF08_BC. Currently, CRF01_AE was found the major subtype of HIV epidemic in Guangxi. New recombinant forms with CRF01_AE as backbones had been emerging, which called for serious attention.