Molecular epidemiology of HIV-1 infection among married couples

Objective To understand the immune status of HIV-1 infected couples and the distribution of subtype strains of HIV-1 in Ningbo. Methods The whole blood samples were taken from 7 couples with confirmed HIV-1 infection to count the absolute numbers of CD4+ T lymphocyte. The partial HIV-1 env gene and gag gene were amplified and sequenced from clinical samples by nested-PCR. To determine the virus subtype, the sequences of clinical strains and reference strains ware compared and analyzed by using DNASTAR software. Results Eleven env gend and 13 gag gene sequences were obtained and the sequence analysis results showed that 6 were B subtype; 2 were CRF01_AE subtype, 2 were CRF07_BC subtype and 4 were CRF08_BC subtype. The absolute number of CD4+ T lymphocyte in clinical blood samples ranged from 7/l to 654/l (the mean value: 288/l). Conclusion Multiple HIV-1 subtypes are prevalent in the infected couples in Ningbo, and most of them need antivirus therapy because of poor immune status. It is necessary to strengthen the surveillance of immune status of this population and variation of HIV-1 subtypes among them to control the serious epidemic of AIDS.