Genetic diversity and drug resistance of human immunodeficiency virus type 1 (HIV-1) strains circulating in Shanghai.

The HIV-1 epidemic in Shanghai is rapidly increasing. To better understand the HIV-1 genetic diversity and the mutations associated with resistance to protease inhibitors (PIs) and reverse transcriptase inhibitors (RTIs), 95 antiretroviral (ARV)-treated and treatment-naive HIV-1-seropositive individuals living in Shanghai were investigated. The HIV-1 pol gene in 70 of the 95 plasma samples was successfully amplified and analyzed. The result showed that CRF01_AE predominated in Shanghai with 42.9%, followed by subtype B (10%), B' (12.9%), CRF07_BC (11.4%), CRF08_BC (10%), CRF02_AG (4.3%), G (2.9%), and K (1.4%). In addition, three new intersubtype and/or inter-CRF recombinants were detected including B'/CRF01_AE (1.4%), U/G (1.4%), and U/CRF01_AE (1.4%). The mutations conferring primary and secondary resistance to PIs were detected in 3 of 70 (4.3%) patients and the mutations conferring resistance to RTIs were identified in 12 of 70 (17.2%) patients, among whom 11 of 15 (73.3%) and 1 of 55 (1.8%) were ARV-treated and treatment-naive individuals, respectively (p < 0.01). This study reveals the emergence of genetic diversity of HIV-1 currently circulating in Shanghai. HIV-1 infection by heterosexual contact is still a major route for introduction of HIV-1 variants into this city in recent years. It is believed that this information may help to guide recommendations for diagnostic assays, vaccine design, and antiretroviral regimen strategies in China.