Background
To assess transmitted drug resistance (TDR) to tenofovir (TDF)/emtricitabine (FTC), using as pre-exposure prophylaxis, among newly diagnosed human immunodeficiency virus-1 (HIV-1)-infected residents in Shenyang city, northeast China.
Methods
Demographic and epidemiological information of all newly diagnosed HIV-1 infected residents in Shenyang city from 2016 to 2018 were anonymously collected from the local HIV epidemic database. HIV-1 pol sequences were amplified from RNA in cryopreserved plasma samples and sequenced directly. Viral subtypes were inferred with phylogenetic analysis and drug resistance mutations (DRMs) were determined according to the Stanford HIVdb algorithm. Recent HIV infection was determined with HIV Limiting Antigen avidity electro immunoassay.
Results
A total of 2176 sequences (92.4%, 2176/2354) were obtained; 70.9% (1536/2167) were CRF01_AE, followed by CRF07_BC (18.0%, 391/2167), subtype B (4.7%, 102/2167), other subtypes (2.6%, 56/2167), and unique recombinant forms (3.8%, 82/2167). The prevalence of TDR was 4.9% (107/2167), among which, only 0.6% (13/2167) was resistance to TDF/FTC. Most of these subjects had CRF01_AE strains (76.9%, 10/13), were unmarried (76.9%, 10/13), infected through homosexual contact (92.3%, 12/13), and over 30 years old (median age: 33). The TDF/FTC DRMs included K65R (8/13), M184I/V (5/13), and Y115F (2/13). Recent HIV infection accounted for only 23.1% (3/13). Most cases were sporadic in the phylogenetic tree, except two CRF01_AE sequences with K65R (Bootstrap value: 99%).
Conclusions
The prevalence of TDR to TDF/FTC is low among newly diagnosed HIV-infected cases in Shenyang, suggesting that TDR may have little impact on the protective effect of the ongoing CROPrEP project in Shenyang city.
