1. World Health Organization (WHO) (2017) Global hepatitis report 2017. Geneva. Available from: https://apps.who.int/iris/bitstream/handle/10665/255016/9789241565455-eng.pdf. Accessed 15 march 2021.
2. Borgia SM, Hedskog C, Parhy B, et al. (2018) Identification of a novel hepatitis C virus genotype from Punjab, India: expanding classification of hepatitis C virus into 8 genotypes. J Infect Dis 218(11):1722–1729. doi: 10.1093/infdis/jiy401.
3. Campiotto S, Pinho JRR, Carrilho FJ, et al. (2005) Geographic distribution of hepatitis C virus genotypes in Brazil. Braz J Med Biol Res 38(1):41-49. doi: https://dx.doi.org/10.1590/S0100-879X2005000100007.
4. Liu Z, Mao X, Yu K, et al. (2020) Prevalence of HCV resistance-associated substitutions among treatment-failure patients receiving direct-acting antiviral agents. J Viral Hepat. 27(6):585-592. doi: 10.1111/jvh.13270.
5. Kim CW, Chang KM (2013) Hepatitis C virus: virology and life cycle. Clin Mol Hepatol 19(1):17-25. doi: 10.3350/cmh.2013.19.1.17.
6. Scheel TKD, Rice CM (2013) Understanding the hepatitis C virus life cycle paves the way for highly effective therapies. Nat Med 19(7):837–849. doi: 10.1038/nm.3248.
7. Ministry of Health (MS). (2019) Clinical Protocol and Therapeutic Guidelines for Hepatitis C and Co-infections. Brasília–DF, 72p. Available from: http://www.aids.gov.br/pt-br/pub/2017/protocolo-clinico-e-diretrizes-terapeuticas-para-hepatite-c-e-coinfeccoes. Accessed 21 march 2021.
8. Foster GR, Irving WL, Cheung MC, et al. (2016) Impact of direct acting antiviral therapy in patients with chronic hepatitis C and decompensated cirrhosis. J Hepatol 64(6):1224-1231. doi: 10.1016/j.jhep.2016.01.029.
9. Paolucci S, Fiorina L, Mariani B, Gulminetti R, Novati S, Barbarini G et al. (2012) Naturally occurring mutations to HCV protease inhibitors in treatment-naïve patients. Virol j (9):245. doi: https://doi.org/10.1186/1743-422X-9-245.
10. Hedskog C, Dvory-Sobol H, Gontcharova V, Martin R, Ouyang W, Han B et al. (2015) Evolution of the HCV viral population from a patient with S282T detected at relapse after sofosbuvir monotherapy. J Viral Hepat 22:871-881. doi: 10.1111/jvh.12405.
11. Jiménez-Pérez M, González-Grande R, Contreras PE, Martínez IP, Lombardo JC, Martín RO (2016) Treatment of chronic hepatitis C with direct-acting antivirals: The role of resistance. World J Gastroenterol 22(29):6573-6581. doi: 10.3748/wjg.v22.i29.6573.
12. Andre-Garnier E, Besse B, Rodallec A, et al. (2017) An NS5A single optimized method to determine genotype, subtype and resistance profiles of Hepatitis C strains. PLOS ONE 12(7): e0179562. doi: https://doi.org/10.1371/journal.pone.0179562.
13. Santos APT, Silva VCM, Mendes-Corrêa MCJ, et al. (2021) Prevalence and Pattern of Resistance in NS5A/NS5B in Hepatitis C Chronic Patients Genotype 3 Examined at a Public Health Laboratory in the State of São Paulo, Brazil. Infect Drug Resist 14:723-730. doi:10.2147/IDR.S247071.
14. Sandres-Sauné K, Deny P, Pasquier C, Thibaut V, Duverlie G, Izopet J (2003) Determining hepatitis C genotype by analyzing the sequence of the NS5b region. J Virol Methods 109(2):187-193. doi:10.1016/s0166-0934(03)00070-3.
15. Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74(12):5463–5467.
16. Sharafi H, Alavian SM (2018) Hepatitis C resistance to NS5A inhibitors: Is it going to be a problem? World J Hepatol 10(9):543-548. doi: 10.4254/wjh.v10.i9.543.
17. Sarrazin C (2016) The importance of resistance to direct antiviral drugs in HCV infection in clinical practice. J Hepatol 64(2):486-504. doi.10.1016/j.jhep.2015.09.011.
18. Gower E, Estes C, Blach S, Razavi-Shearer K, Razavi H (2014) Global epidemiology and genotype distribution of the hepatitis C virus infection. J Hepatol 61(1suppl):S45–S57. doi:10.1016/j. jhep.2014.07.027.
19. Sorbo MC, Cento V, Di Maio VC, et al. (2018) Hepatitis C virus drug resistance associated substitutions and their clinical relevance. Drug Resist Updat 37:17–39. doi:10.1016/j.drup.2018.01.004.
20. Simmonds P, Bukh J, Combet C, et al. (2005) Consensus proposals for a unified system of nomenclature of hepatitis C virus genotypes. Hepatology 42:962–973. doi: 10.1002/hep.20819.
21. Lavanchy D (2011) Evolving epidemiology of hepatitis C virus. Clin Microbiol Infect 17(2):107-115. doi: 10.1111/j.1469-0691.2010.03432.x.
22. Suzuki F, Sezaki H, Akuta N, et al. (2012) Prevalence of hepatitis C virus variants resistant to NS3 protease inhibitors or the NS5A inhibitor (BMS-790052) in hepatitis patients with genotype 1b. J Clin Virol 54(4):352–354. doi: 10.1016/j.jcv.2012.04.024.
23. Sarrazin C, Berg T, Buggisch P, et al. (2014) Current recommendations for the treatment of chronic hepatitis C. Z Gastroenterol 52(10):1185–1197.
24. Rao H, Yang X, Tan Y, et al. (2020) Efficacy and Safety of All-oral Emitasvir and Sofosbuvir in Patients with Genotype 1b HCV Infections without Cirrhosis. J Clin Transl Hepatol 8(3):255-261. doi:10.14218/JCTH.2020.00031
25. Sulkowski MS, Gardiner DF, Rodriguez-Torres M, et al. (2014) Daclatasvir plus sofosbuvir for previously treated or untreated chronic HCV infection. N Engl J Med 370(3):211–221. doi: 10.1056/nejmoa1306218.
26. Cheng G, Tian Y, Doehle B, et al. (2016) In vitro antiviral activity and resistance profile characterization of the hepatitis C virus NS5A inhibitor ledipasvir. Antimicrob Agents Chemother 60:1847–1853. doi: 10.1128/AAC.02524-15.
27. Cuypers L, Ceccherini-Silberstein F, Van Laethem K, Li G, Vandamme AM, Rockstroh JK (2016) Impact of HCV genotype on treatment regimens and drug resistance: a snapshot in time. Rev Med Virol 26(6):408-434. doi: 10.1002/rmv.1895.
28. Gottwein JM, Pham LV, Mikkelsen LS, et al. (2018) Efficacy of NS5A Inhibitors Against Hepatitis C Virus Genotypes 1-7 and Escape Variants. Gastroenterology 154(5):1435-1448. doi: 10.1053/j.gastro.2017.12.015.
29. Wyles DL, Luetkemeyer AF (2017) Understanding Hepatitis C Virus Drug Resistance: Clinical Implications for Current and Future Regimens. Top antivi med 25(3):103–109.
30. Costa VD, Brandão-Mello CE, Nunes EP, et al. (2019) Treatment of chronic HCV infection with DAAs in Rio de Janeiro/Brazil: SVR rates and baseline resistance analyses in NS5A and NS5B genes. PLoS One 14(5):e0216327. doi: https://doi.org/10.1371/journal.pone.0216327.
31. Sagnelli E, Starace M, Minichini C, et al. (2018) Resistance detection and re-treatment options in hepatitis C virus-related chronic liver diseases after DAA-treatment failure. Infection 46(6):761–783. doi: 10.1007/s15010-018-1188-3.
32. Eltahla AA, Leung P, Pirozyan MR, et al. (2017) Dynamic evolution of hepatitis C virus resistance-associated substitutions in the absence of antiviral treatment. Sci Rep 7:41719. doi: https://doi.org/10.1038/srep41719.
33. Yoshimi S, Imamura M, Murakami E, et al. (2015) Long term persistence of NS5A inhibitor-resistant hepatitis C virus in patients who failed daclatasvir and asunaprevir therapy. J Med Virol 87:1913e20. doi: 10.1002/jmv.24255.
34. Chen CY, Huang CF, Cheng PN, et al. (2021) Factors associated with treatment failure of direct-acting antivirals for chronic hepatitis C: A real-world nationwide hepatitis C virus registry programme in Taiwan. Liver Int Online ahead of print. epub.PMID: 33655714. doi: 10.1111/liv.14849.