[The identification of recombinant HIV-1 strains in IDUs in southwest and northwest China].

OBJECTIVE: To search for possible recombination of HIV-1 strains in China.
METHODS: The blood samples were collected from the HIV infected individuals in areas where epidemic of more than two subtypes of HIV-1 were found. The HIV env and tat genes were amplified by nested PCR from PBMCs and directly sequenced and analyzed.
RESULTS: The sequence analysis were performed on 14 HIV-1 strains collected in the subtype B' and C epidemic areas of China. No evidence of recombination after sequencing of env was found. The recombnant HIV-1 strains of subtype B' and C were found in 10 of the 14 samples tested when the first exon of the tat gene was sequenced. In addition, three subtype B' and one subtype C non-recombinant HIV-1 strains were found among IDUs in Sichuan Province.
CONCLUSIONS: The recombinant HIV-1 strains of subtype B' and C were firstly identified in Sichuan Province of southwest China and Xinjiang Autonomous Region of western China. Their identical sequences and recombinant patterns indicated the same origin of the recombinant strains, it strongly indicates a close correlation between these two HIV epidemic regions. Since no other subtype of HIV-1 except the recombinant was found in Xinjiang, whereas both subtype B and C as well as B'/C recombinant were found in Sichuan, the recombination was most probably happened in Sichuan Province rather than in Xinjiang.