Trend of HIV Transmitted Drug Resistance After the Introduction of Single-Tablet Regimens in Southern Taiwan

Hung-Chin Tsai,1– 5 I-Tzu Chen,1 Hui-Min Chang,6– 8 Susan Shin-Jung Lee,1,2 Yao-Shen Chen1,2 1Division of Infectious Diseases, Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; 2Faculty of Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan; 3Department of Parasitology, Kaohsiung Medical University, Kaohsiung, Taiwan; 4Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan; 5Shu-Zen Junior College of Medicine and Management, Kaohsiung, Taiwan; 6Department of Pharmacy, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; 7Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan; 8Department of Pharmacy and Graduate Institute of Pharmaceutical Technology, Tajen University, Pingtung, TaiwanCorrespondence: Hung-Chin Tsai, Section of Infectious Diseases, Department of Medicine, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung, 813, Taiwan, Tel +886 7 3422121 ext. 2029, Fax +886 7 346 8292, Email hctsai1011@yahoo.com.tw; tsaihungchin@gmail.comBackground: The prevalence of transmitted drug resistance (TDR) after the universal implementation of STRs is unknown in Taiwan.Objective: This study aimed to investigate the prevalence of TDR in patients with HIV-1 infection, clarify the risk factors for pol resistance, and compare differences in HIV drug resistance before and after the implementation of STRs in Taiwan.Methods: Adult patients infected with HIV-1 were enrolled in this study from 2013 to 2021. Mutations associated with drug resistance were identified using the 2019 International Antiviral Society-USA list of drug resistant mutations in HIV, and drug susceptibility was assessed according to the Stanford HIV Drug Resistance Database edition 9. A logistic regression model was used to analyze the risk factors for pol resistance, and the differences in the prevalence of drug resistance from 2013– 2016 to 2017– 2021 were compared using the Mann–Whitney U-test. General linear regression was used to analyze temporal changes in the annual proportion of TDR overall and by type of antiretroviral drugs.Results: A total of 369 patients were included. The prevalence rate of pol resistance was 9.8% (36/369). The resistance rates to nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs) were 3.3%, 6.9%, 0% and 1.8%, respectively. The patients with hepatitis C infection were more likely to have pol resistance (aHR 5.767, CI 1.232– 26.991, p=0.026). The prevalence rate of pol resistance did not decrease after the implementation of STRs as first-line therapy in 2017 (11.2% vs 8.7%, aHR 1.329, CI 0.667– 2.645, p=0.480), and no significant temporal changes were shown in the annual proportion of TDR overall or by type of antiretroviral drug.Conclusion: Our findings showed a stable prevalence rate of transmitted drug resistance despite the implementation of STRs as the first-line therapy in June 2016.Keywords: HIV, transmitted drug resistance, single-tablet regimen