HIV-1 Genetic Diversity and High Prevalence of Pretreatment Drug Resistance in Tianjin, China.

Diversity of genotypes and prevalence of pretreatment drug resistance (PDR) are challenges for the epidemic control and vaccine development of HIV-1. However, little is known about the situation in Tianjin. Blood samples were collected from newly diagnosed, antiretroviral treatment (ART)-naive HIV/AIDS patients from January 2016 to November 2019. The target fragment in the pol gene was sequenced after RNA extraction and gene amplification. The HIV-1 genotype was identified by phylogenetic analysis. Drug resistance was carried out using the Stanford University HIVdb algorithm. A total of 305 pol sequences from 279 non-PDR individuals and 35 PDR individuals were successfully amplified. The most prevalent genotype was CRF01_AE (65.6%, 200/305), followed by CRF07_BC (22.0%, 67/305) and B (3.0%, 9/305). A variety of circulating recombinant forms (CRFs) and unique recombinant forms were found. The overall incidence of PDR was 11.5% (35/305), with 9.8% (30/305) to non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs). The most frequent mutation pattern against NNRTIs was V179D/E/T (6.9%, 21/305), with M184V (1.0%, 3/305) and K65R (1.0%, 3/305) against nucleoside RT inhibitors (NRTIs). M64L (0.1%, 1/305) was the sole mutation found against protease inhibitors (PIs). Eight variants generated at least low-level resistance to NNRTIs (2.6%, 8/305), which was much higher than that to NRTIs (1.6%, 5/305) and PIs (0/305) (p < .05). Genotypic drug resistance testing before initiating ART in newly diagnosed HIV/AIDS patients may be necessary in Tianjin, China. The non-NNRTI-based regimen may be preferred as initial therapy in Tianjin.