OBJECTIVETo study the prevalent status of CRF01_AE strains of recombinant HIV-1 in Shenzhen and their source of infection in order to predict the epidemic trend and evolution.

METHODSA total of 489 samples of HIV-1 positive plasma were collected from 1992 to 2008 in Shenzhen. HIV-1 Env genes were amplified by nested-PCR from RNA. Subtype analysis were performed on the nucleotide sequence data. CRF01_AE sequences were analyzed by phylogenetic methods and characterized by calculating the genetic distance.

RESULTSA total of 300 CRF01_AE strain sequences were amplified, accounting for 64.5% of all genotyped samples of all the 465 samples. The CRF01_AE strains of recombinant in 1992 - 1999, 2000 - 2005 and 2006 - 2008 accounted for 56.8% (21/37), 68.4% (78/114) and 64.0% (201/314) of genotyped samples, respectively. And in these three periods of times, 52.4% (11/21), 43.6% (34/78) and 45.8% (92/201) were heterosexually acquired adults; 4.8% (1/21), 0.0% (0/78) and 22.4% (45/201) were homosexually acquired adults; 19.0% (4/21), 51.3% (40/78), 30.8% (62/210) were intravenous drug users, respectively.Phylogenetic tree analysis revealed that HIV samples from different period of time showed distinct aggregation in time and transmission as well as cross infection. The gene divergence rate of CRF01_AE strains in the three different periods of time were (8.783 ± 4.717)%, (11.054 ± 7.141)%, and (13.218 ± 4.080)%, respectively.

CONCLUSIONCRF01_AE is the major epidemic strains in Shenzhen, which is transmitted through heterosexual contact, MSM and intravenous drug users. The gene variation increased gradually as time goes by.