[Molecular epidemiological study on HIV/AIDS under the follow-up program in Zhejiang province in 2009].

Objective: To analyze the molecular epidemiological characteristics on HIV infectors/AIDS patients (HIV/AIDS) under a follow-up program in Zhejiang province in 2009.

Methods: 303 cases were randomly sampled. Information on the cases was collected and followed by genomic DNA extraction. Gag gene fragments were amplified by nested PCR, followed by sequencing and bio-informatic analysis.

Results: The rate of success for sequence acquisition was 74.3% (225/303). Distributions of HIV subtypes were as follows: CRF01_AE (58.7%), CRF07_BC (13.8%), CRF08_BC (9.8%), B' (15.1%), C (1.8%), G (0.4%) and unassigned BC (unique recombinant form 0.4%).

Results: from the HIV BLAST analysis showed that the sources of strains with the highest homology involved in 10 provinces/municipalities (Liaoning, Guangxi, Yunnan, Henan, etc.) and five other countries (Thailand, Vietnam, India, South Africa and Libya). The CRF01_AE phylogenetic tree was divided into four clusters. The sequences of HIV/AIDS with homosexual transmission showed a gather in cluster 1, and mix with those infected through heterosexual contact.

Conclusion: Circulating recombinant forms of HIV seemed to play a dominant role in Zhejiang province. Unique recombinant form and new subtype of HIV were found. People living with HIV under homosexual transmission and heterosexual transmission had a trend of interwoven with each other. Increase of both the diversity and complexity of HIV strains were also noticed in Zhejiang province.