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The Hepatitis C virus (HCV) infection is a public health problem. The high level of HCV replication and its lack of post-transcriptional correction mechanisms results in the emergence of viral variants and the difficulty in determining polymorphisms and variants that contain the substitutions associated with resistance towards new antivirals. The main focus of this study was to map the NS5A and NS5B polymorphisms and resistance mutations to new antiviral drugs in HCV strains genotype 1 from patients with chronic hepatitis C infection. Serum samples were collected from patients who underwent routine viral load tests at the Instituto Adolfo Lutz, Sao Paulo city, Brazil. A total of 698 and 853 samples were used for the characterization of NS5A and NS5B regions, respectively, which comprise the HCV genotypes 1a and 1b. The prevalence of resistance mutations found in the NS5A region was 6.4%, with Y93H, L31M, Q30R, and Y93N as the main resistance-associated substitutions (RAS). No NS5B-associated RAS was observed for any of the analyzed drugs. These findings support that the RAS test should be offered to individuals with poor response to double combination regimens prior to treatment initiation, thereby assisting strain vigilance and selection of effective treatment or retreatment options using DAA regimens.

Ana Paula de Torres Santos,1,2 Vanessa Cristina Martins Silva,1 Maria Cássia Mendes-Corrêa,3 Marcilio Figueiredo Lemos,1 Fernanda de Mello Malta,4 Rúbia Anita Ferraz Santana,5 Gregório Tadeu Fernando Dastoli,5 Vanessa Fusco Duarte de Castro,5 João Renato Rebello Pinho,2,4,5 Regina Célia Moreira1 1Laboratory of Viral Hepatitis, Virology Center, Instituto Adolfo Lutz, São Paulo, SP, Brazil; 2Divisão de Laboratório Central, Laboratório de Imunologia, Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil; 3LIM-52-Institute of Tropical Medicine, Department of Infectious Diseases, School of Medicine, University of São Paulo, São Paulo, SP, Brazil; 4Laboratory of Tropical Gastroenterology and Hepatology “João de Queiroz and Castorina Bettencourt Alves”‑LIM 07‑Institute of Tropical Medicine Department of Gastroenterology, School of Medicine, University of São Paulo, São Paulo, SP, Brazil; 5Albert Einstein Medicina Diagnóstica, Hospital Israelita Albert Einstein, São Paulo, SP, BrazilCorrespondence: Regina Célia MoreiraInstituto Adolfo Lutz, Centro de Virologia, Av: Dr Arnaldo, 355 Pacaembu, SP, Cep 01246-000, BrazilTel +55 11 30682911Email regina.moreira@ial.sp.gov.brPurpose: Globally, it is estimated that 71 million people are chronically infected with hepatitis C, and 10– 20% of these will develop cirrhosis and hepatocellular carcinoma. The development of new direct-acting antiviral (DAA) drugs has contributed to sustained virological response (SVR), eliminating the infection and achieving cure of chronic hepatitis C. However, treated patients can develop HCV resistance to DAAs, which can contribute to the failure of treatment. Here, we aimed to evaluate the prevalence and specific pattern of NS5A and NS5B resistance-associated substitutions (RAS) in samples from patients chronically infected with HCV genotype 3a at a public health laboratory, Instituto Adolfo Lutz, São Paulo, Brazil.Patients and Methods: Serum samples from the enrolled individuals were submitted to “in-house” polymerase chain reaction amplification of NS5A and NS5B non-structural protein genes, which were then sequenced by Sanger method.Results: A total of 170 and 190 samples were amplified and analyzed for NS5A and NS5B, respectively. For NS5A, 20 (12.0%) samples showed some important RAS; 16 (9.0%) showed some type of substitution and 134 (79.0%) showed no polymorphism. No sample showed any RAS for NS5B.Conclusion: This study found important RAS in samples from naïve chronic HCV patients in some areas from São Paulo. The most prevalent were A62S, A30K, and Y93H, which could indicate an increase in resistance to some DAAs used in HCV treatment.Keywords: HCV, nonstructural NS5A/NS5B, resistance, polymorphism, RAS

In Brazil, few studies on the molecular aspects of hepatitis B virus (HBV) infection have been conducted in the interior regions of Sao Paulo State. This study aimed to identify HBV genotypes and evaluate strains with resistance mutations for nucleoside analogues in the Administrative Region (AR) of the municipality of Sao Jose do Rio Preto. We performed nested PCRs of 127 samples from the Health Care Services of the AR to amplify, sequence and analyze fragments of the HBV DNA, in order to identify genotypes and resistance mutations. The HBV S/Pol regions of 126 samples were successfully amplified and sequenced. Five different genotypes were found, and the main ones were A, D and F; a greater number of samples contained the subgenotypes A1 (n = 51; 40.5%), D3 (n = 36; 28.6%), A2 (n = 14; 11.1%) and F2a (n = 9; 7.1%). Resistance mutations (rtM204V/I/S) associated or not with compensatory mutations (rtL180M, rtV173L) were identified in 13.9% (5/36) of patients undergoing viral treatment and 1.1% (1/90) of naïve patients. The diversity of genotypes/subgenotypes found is probably due to the intense migration occurring in the region. These data can complement epidemiological and clinical surveillance, and can be used for a more effective management of chronic HBV patients.

Hepatitis C virus (HCV) infection is a public health problem with an estimated 71 million infected people worldwide. The high level of HCV replication and its lack of post - transcriptional correction mechanisms result in the rapid emergence of viral variants, difficulty in determining polymorphisms, and variants that contain substitutions associated with resistance and/or reduction of susceptibility towards new antivirals. The aim of this study was to map the polymorphisms in NS5A and NS5B and resistance mutations to new antiviral drugs in HCV strains with genotype 1a and 1b derived from patients with chronic hepatitis C infection. Serum samples from patients who underwent routine viral load tests and monitoring at the laboratory of viral hepatitis at the Adolfo Lutz Institute, São Paulo, Brazil were collected. A total of 698 and 853 samples were used for the characterization of NS5A and NS5B regions respectively; comprising HCV genotypes 1a and 1b. The prevalence of resistance mutations in the NS5A region was found to be 6.4%, with Y93H, L31M, Q30R, and Y93N as the main resistance-associated substitutions (RAS). No NS5B- associated RAS was observed for any of the drugs analyzed. This study reveals the presence of significant RAS in the HCV serum samples. These findings support the RAS test should be offered to individuals with poor response to double combination regimens prior to treatment initiation, thereby assisting strain vigilance and selection of effective treatment or retreatment options using DAA regimens.

INTRODUCTION: Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) have identical transmission routes, explaining the high prevalence of coinfections. The main aim of this study was to detect fluctuations in serological HCV levels in HIV patients. METHODS: We analyzed samples of 147 patients who attended an outpatient service that supports HIV/AIDS patients in São Paulo city. We also recruited 22 HCV-monoinfected patients who attended the Instituto Adolfo Lutz Laboratory in São Paulo city, to compare the test results. Serological testing of the blood samples was performed for the detection of HCV antibodies. The samples were then analyzed using real-time PCR for RNA viral quantification and sequencing. RESULTS We found that 13.6% of the study population was coinfected with HIV and HCV. In 20% of coinfected patients, fluctuations in serology results were detected in samples collected during the follow-up. No changes in anti-HCV serological markers were observed in HCV-monoinfected patients. An HCV viral load was detected in 9,5% of the samples collected from HIV patients. CONCLUSIONS: Our findings provide important clinical data to public health professionals and highlight the importance of periodic monitoring of HCV/HIV coinfected patients.