Four weeks of off-treatment follow-up is sufficient to determine virologic responses at off-treatment week 12 in patients with hepatitis C virus infection receiving fixed-dose pangenotypic direct-acting antivirals.

Early confirmation of sustained virologic response (SVR) or viral relapse after direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection is essential based on public health perspectives, particularly for patients with high risk of nonadherence to posttreatment follow-ups. A total of 1011 patients who achieved end-of-treatment virologic response, including 526 receiving fixed-dose pangenotypic DAAs, and 485 receiving other types of DAAs, who had available off-treatment weeks 4 and 12 serum HCV RNA data to confirm SVR at off-treatment week 12 (SVR12) or viral relapse were included. The positive predictive value (PPV) and negative predictive value (NPV) of SVR4 to predict patients with SVR12 or viral relapse were reported. Furthermore, we analyzed the proportion of concordance between SVR12 and SVR24 in 943 patients with available SVR24 data. The PPV and NPV of SVR4 to predict SVR12 were 98.5% (95% confidence interval [CI]: 98.0-98.9) and 100% (95% CI: 66.4-100) in the entire population. The PPV of SVR4 to predict SVR12 in patients receiving fixed-dose pangenotypic DAAs was higher than those receiving other types of DAAs (99.8% [95% CI: 98.9-100] vs. 97.1% [95% CI: 96.2-97.8], p < 0.001). The NPVs of SVR4 to predict viral relapse were 100%, regardless of the type of DAAs. Moreover, the concordance between SVR12 and SVR24 was 100%. In conclusion, an off-treatment week 4 serum HCV RNA testing is sufficient to provide an excellent prediction power of SVR or viral relapse at off-treatment week 12 among patients with HCV who are treated with fixed-dose pangenotypic DAAs.

Immortalized hepatocyte-like cells: A competent hepatocyte model for studying clinical HCV isolate infection.

More than 58 million individuals worldwide are inflicted with chronic HCV. The disease carries a high risk of end stage liver disease, i.e., cirrhosis and hepatocellular carcinoma. Although direct-acting antiviral agents (DAAs) have revolutionized therapy, the emergence of drug-resistant strains has become a growing concern. Conventional cellular models, Huh7 and its derivatives were very permissive to only HCVcc (JFH-1), but not HCV clinical isolates. The lack of suitable host cells had hindered comprehensive research on patient-derived HCV. Here, we established a novel hepatocyte model for HCV culture to host clinically pan-genotype HCV strains. The immortalized hepatocyte-like cell line (imHC) derived from human mesenchymal stem cell carries HCV receptors and essential host factors. The imHC outperformed Huh7 as a host for HCV (JFH-1) and sustained the entire HCV life cycle of pan-genotypic clinical isolates. We analyzed the alteration of host markers (i.e., hepatic markers, cellular innate immune response, and cell apoptosis) in response to HCV infection. The imHC model uncovered the underlying mechanisms governing the action of IFN-α and the activation of sofosbuvir. The insights from HCV-cell culture model hold promise for understanding disease pathogenesis and novel anti-HCV development.

The clinical significance of long non-coding RNAs MALAT1 and CASC2 in the diagnosis of HCV-related hepatocellular carcinoma.

BACKGROUND: Globally, hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death due to a lack of early predictive and/or diagnostic tools. Thus, research for a new biomarker is important. LncRNAs play a functional role in target gene regulation and their deregulation is associated with several pathological conditions including HCC. OBJECTIVE: This study aimed to explore the diagnostic potential of two LncRNAs MALAT1 and CASC2 in HCC compared to the routinely used diagnostic biomarker. MATERIALS AND METHODS: The current study is a case-control study carried out at Fayoum University Hospital and conducted on 89 individuals. The study included three groups of 36 HCC patients on top of HCV(HCC/HCV), 33 HCV patients, and 20 healthy volunteers as a control group. All study subjects were subjected to radiological examinations. The determination of CBC was performed by the automated counter and liver function tests by the enzymatic method were performed. In addition, HCV RNA quantification and the expression level of two LncRNAs (MALAT1 and CASC2) were performed by qRT-PCR. RESULTS: The results revealed a statistically significant difference between study groups regarding liver function tests with a higher mean in HCC/HCV group. Also, serum MALAT1 significantly up-regulated in HCV (11.2±2.8) and HCC/HCV (4.56±1.4) compared to the control group. Besides, serum CASC2 levels in the HCV group were significantly upregulated (14.9±3.6), while, downregulated in the HCC group (0.16± 0.03). Furthermore, The ROC analysis for diagnostic efficacy parameters indicated that CASC2 has higher accuracy (94.6%) and sensitivity (97.2%) for HCC diagnosis than AFP with an accuracy of (90.9%), sensitivity (69.4%), and MALAT1 showed an accuracy of (56.9%), sensitivity (72.2%). CONCLUSION: Our study results indicated that CASC2 is a promising biomarker and is considered better and could help in HCC diagnosis on top of HCV than MALAT1 and the routine biomarker AFP.

Comparison of diagnostic performance among Abbott RealTime HCV Genotyping II, Abbott HCV Genotype plus RUO, and Roche Cobas HCV Genotyping assays for hepatitis C virus genotyping.

Comparison of diagnostic accuracy for commercial hepatitis C virus (HCV) genotyping (Abbott RealTime HCV Genotyping II, Roche Cobas Genotyping) and investigational Abbott HCV Genotype plus RUO assays designed to discriminate genotype (GT)-1a, 1b or 6 in cases of ambiguous GT from the Abbott commercial assay remains limited. 743 HCV-viremic samples were subjected to analysis using Abbott and Roche commercial as well as Abbott HCV Genotype plus RUO assays. Next-generation sequencing (NGS) targeting core region was employed as the reference standard. Diagnostic accuracy was reported as the number of participants (percentages) along with 95% confidence intervals (CIs). Using NGS, 741 samples (99.7%) yielded valid genotyping results. The diagnostic accuracies were 97.6% (95% CI: 96.1%-98.5%) and 95.3% (95% CI: 93.4%-96.6%) using Abbott and Roche commercial assays (p = 0.0174). Abbott commercial assay accurately diagnosed HCV GT-6a and 6w, whereas Roche commercial assay accurately diagnosed HCV GT-6a. Both assays demonstrated low accuracies for HCV GT-6b, 6e, 6g, and 6n. Abbott HCV Genotype plus RUO assay discriminated 13 of the 14 samples (92.9%; 95% CI: 64.2%-99.6%) that yielded ambiguous GT. Both assays were capable of diagnosing mixed HCV infections when the minor genotype comprised >8.4% of the viral load. The diagnostic performance of commercial HCV genotyping assays is commendable. Abbott assay demonstrated superior performance compared to Roche assay in diagnosing HCV GT-6. Abbott HCV Genotype plus RUO assay aids in discriminating ambiguous GT. Both commercial assays are proficient in diagnosing mixed HCV infections at a cut-off viral load of 8.4% in minor genotype.

Seroprevalence and molecular characterization of viral hepatitis and HIV co-infection in the Central African Republic.

BACKGROUND: The Central African Republic (CAR) is one of the countries with the highest prevalence of viral hepatitis infection in the world. Coinfection with HIV increases the morbidity and mortality beyond that of mono-infection with either hepatitis or HIV. The present study describes the geographic distribution of viral hepatitis infections and molecular characterization of these viruses in the CAR. METHODOLOGY: Out of 12,599 persons enrolled during the fourth Multiple Indicator Cluster Survey of 2010 in the CAR, 10,621 Dried Blood Spot (DBS) samples were obtained and stored at -20°C. Of these DBS, 4,317 samples were randomly selected to represent all regions of the CAR. Serological tests for hepatitis B, D, and C viruses were performed using the ELISA technique. Molecular characterization was performed to identify strains. RESULTS: Of the 4,317 samples included, 53.2% were from men and 46.8% from women. The HBsAg prevalence among participants was 12.9% and that HBc-Ab was 19.7%. The overall prevalence of HCV was 0.6%. Co-infection of HIV/HBV was 1.1% and that of HBV/HDV was 16.6%. A total of 77 HBV, 6 HIV, and 6 HDV strains were successfully sequenced, with 72 HBV (93.5%) strains belonging to genotype E and 5 (6.5%) strains belonging to genotype D. The 6 HDV strains all belonged to clade 1, while 4 recombinants subtype were identified among the 6 strains of HIV. CONCLUSION: Our study found a high prevalence of HBV, HBV/HDV and HBV/HIV co-infection, but a low prevalence of HCV. CAR remains an area of high HBV endemicity. This study's data and analyses would be useful for establishing an integrated viral hepatitis and HIV surveillance program in the CAR.

Determination of hepatitis C virus subtype prevalent in Sindh, Pakistan: a phylogenetic analysis.

Hepatitis is a major public health issue, affecting 10-17 million people worldwide, with its prevalence continuously increasing. The Hepatitis C virus (HCV) is responsible for liver related diseases, which include liver cirrhosis, hepatocellular carcinoma, and chronic hepatitis. Pakistan is experiencing a serious rise in HCV cases. This study aimed to assess the prevalence and distribution of HCV genotypes in Sindh, Pakistan. Serum samples from HCV-positive patients were collected from various local hospitals in Sindh. These samples were first screened for HCV antibodies using ELISA. Samples that tested positive for HCV RNA underwent further genotyping through sequencing using the standard Sanger method. The genotypes were identified by comparing the sequences with those available in the National Center for Biotechnology Information (NCBI) database, and a phylogenetic tree was constructed. The phylogenetic analysis showed that all isolates in this study were clustered with genotypes 3a and 3b, except for one sequence that was clustered with genotype 1a. No isolates were found to be clustered with reference genomes of genotypes 2, 4, 5, 6, and 7 suggesting that genotype 3a is endemic in this region. The analyzed sequences demonstrated a 98% similarity with reference and isolated sequences. In summary, sequencing of the HCV 5' UTR essential for identifying the predominant genotype of HCV RNA in the Sindh region Further research on the distribution of HCV genotypes in other regions of Pakistan could aid in improving screening processes, identifying more effective treatment options, and developing suitable prevention strategies.

Hepatitis B and C viral coinfection and associated factors among HIV-positive patients attending ART clinics of Afar regional state, northeast Ethiopia.

BACKGROUND: Hepatitis B (HBV) and C virus (HCV) coinfection are the major causes of liver-related morbidity and mortality among people living with Human Immunodeficiency Virus (HIV). The burden of hepatitis among HIV-positive individuals has not been studied in the Afar region. Therefore, this study aimed to determine the prevalence of HBV and HCV coinfection and associated factors among HIV-positive patients in Afar Regional State, northeast Ethiopia. METHODS: A cross-sectional study was conducted on 477 HIV-positive patients between February 2019 and May 2019. A structured and pretested questionnaire was used to collect socio-demographic data and associated factors. Five milliliters of blood was collected, and Hepatitis B surface antigen (HBsAg) and HCV antibodies were detected using rapid test kits. Positive samples were confirmed using enzyme-linked immunosorbent assay (ELISA). Binary and multivariable logistic regression analyses were performed to identify associated factors. Statistical significance was set at P <0.05. RESULTS: Among the 477 study participants, 320/477(67.1%) of them were females and 157(32.9%) males. The overall prevalence of HIV-HBV and HIV-HCV coinfection was 25(5.2%) and 7(1.5%), respectively. Multi-sexual practice was significantly associated with HIV-HBV coinfection (AOR = 5.3; 95% CI: 1.2-24.4, P = 0.032). CONCLUSION: The prevalence of both HIV-HBV and HIV-HCV coinfection was intermediate. Multi-sexual practice was significantly associated with HIV-HBV coinfection. Screening of all HIV-positive patients for HBV and HCV and health education regarding the transmission modes should be considered.

Hepatitis C viremic lung transplantation to aviremic recipients: Comprehensive outcomes and post-transplant viremia.

BACKGROUND/AIMS: Direct-acting antiviral (DAA) therapy has revolutionized solid organ transplantation by providing an opportunity to utilize organs from HCV-viremic donors. Though transplantation of HCV-viremic donor organs into aviremic recipients is safe in the short term, midterm data on survival and post-transplant complications is lacking. We provide a midterm assessment of complications of lung transplantation (LT) up to 2 years post-transplant, including patient and graft survival between HCV-viremic transplantation (D+) and HCV-aviremic transplantation (D-). METHODS: This is a retrospective cohort study including 500 patients from 2018 to 2022 who underwent LT at our quaternary care institution. Outcomes of patients receiving D+ grafts were compared to those receiving D- grafts. Recipients of HCV antibody+ but PCR- grafts were treated as D- recipients. RESULTS: We identified 470 D- and 30 D+ patients meeting inclusion criteria. Crude mortality did not differ between groups (p = .43). Patient survival at years 1 and 2 did not differ between D+ and D- patients (p = .89, p = .87, respectively), and graft survival at years 1 and 2 did not differ between the two groups (p = .90, p = .88, respectively). No extrahepatic manifestations or fibrosing cholestatic hepatitis (FCH) occurred among D+ recipients. D+ and D- patients had similar rates of post-transplant chronic lung allograft rejection (CLAD) (p = 6.7% vs. 12.8%, p = .3), acute cellular rejection (60.0% vs. 58.0%, p = .8) and antibody-mediated rejection (16.7% vs. 14.2%, p = .7). CONCLUSION: There is no difference in midterm patient or graft survival between D+ and D-LT. No extrahepatic manifestations of HCV occurred. No differences in any type of rejection including CLAD were observed, though follow-up for CLAD was limited. These results provide additional support for the use of HCV-viremic organs in selected recipients in LT.

Bystander Effects and Profibrotic Interactions in Hepatic Stellate Cells during HIV and HCV Coinfection.

This study aims to explore the influence of coinfection with HCV and HIV on hepatic fibrosis. A coculture system was set up to actively replicate both viruses, incorporating CD4 T lymphocytes (Jurkat), hepatic stellate cells (LX-2), and hepatocytes (Huh7.5). LX-2 cells' susceptibility to HIV infection was assessed through measurements of HIV receptor expression, exposure to cell-free virus, and cell-to-cell contact with HIV-infected Jurkat cells. The study evaluated profibrotic parameters, including programed cell death, ROS imbalance, cytokines (IL-6, TGF-ß, and TNF-α), and extracellular matrix components (collagen, α-SMA, and MMP-9). The impact of HCV infection on LX-2/HIV-Jurkat was examined using soluble factors released from HCV-infected hepatocytes. Despite LX-2 cells being nonsusceptible to direct HIV infection, bystander effects were observed, leading to increased oxidative stress and dysregulated profibrotic cytokine release. Coculture with HIV-infected Jurkat cells intensified hepatic fibrosis, redox imbalance, expression of profibrotic cytokines, and extracellular matrix production. Conversely, HCV-infected Huh7.5 cells exhibited elevated profibrotic gene transcriptions but without measurable effects on the LX-2/HIV-Jurkat coculture. This study highlights how HIV-infected lymphocytes worsen hepatic fibrosis during HCV/HIV coinfection. They increase oxidative stress, profibrotic cytokine levels, and extracellular matrix production in hepatic stellate cells through direct contact and soluble factors. These insights offer valuable potential therapies for coinfected individuals.

A Comparative Study of Human Pluripotent Stem Cell-Derived Macrophages in Modeling Viral Infections.

Macrophages play multiple roles in innate immunity including phagocytosing pathogens, modulating the inflammatory response, presenting antigens, and recruiting other immune cells. Tissue-resident macrophages (TRMs) adapt to the local microenvironment and can exhibit different immune responses upon encountering distinct pathogens. In this study, we generated induced macrophages (iMACs) derived from human pluripotent stem cells (hPSCs) to investigate the interactions between the macrophages and various human pathogens, including the hepatitis C virus (HCV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and Streptococcus pneumoniae. iMACs can engulf all three pathogens. A comparison of the RNA-seq data of the iMACs encountering these pathogens revealed that the pathogens activated distinct gene networks related to viral response and inflammation in iMACs. Interestingly, in the presence of both HCV and host cells, iMACs upregulated different sets of genes involved in immune cell migration and chemotaxis. Finally, we constructed an image-based high-content analysis system consisting of iMACs, recombinant GFP-HCV, and hepatic cells to evaluate the effect of a chemical inhibitor on HCV infection. In summary, we developed a human cell-based in vitro model to study the macrophage response to human viral and bacterial infections; the results of the transcriptome analysis indicated that the iMACs were a useful resource for modeling pathogen-macrophage-tissue microenvironment interactions.

Mixed Infections Unravel Novel HCV Inter-Genotypic Recombinant Forms within the Conserved IRES Region.

Hepatitis C virus (HCV) remains a significant global health challenge, affecting millions of people worldwide, with chronic infection a persistent threat. Despite the advent of direct-acting antivirals (DAAs), challenges in diagnosis and treatment remain, compounded by the lack of an effective vaccine. The HCV genome, characterized by high genetic variability, consists of eight distinct genotypes and over ninety subtypes, underscoring the complex dynamics of the virus within infected individuals. This study delves into the intriguing realm of HCV genetic diversity, specifically exploring the phenomenon of mixed infections and the subsequent detection of recombinant forms within the conserved internal ribosome entry site (IRES) region. Previous studies have identified recombination as a rare event in HCV. However, our findings challenge this notion by providing the first evidence of 1a/3a (and vice versa) inter-genotypic recombination within the conserved IRES region. Utilizing advanced sequencing methods, such as deep sequencing and molecular cloning, our study reveals mixed infections involving genotypes 1a and 3a. This comprehensive approach not only confirmed the presence of mixed infections, but also identified the existence of recombinant forms not previously seen in the IRES region. The recombinant sequences, although present as low-frequency variants, open new avenues for understanding HCV evolution and adaptation.

Investigation of the effectiveness of a classification method based on improved DAE feature extraction for hepatitis C prediction.

Hepatitis C, a particularly dangerous form of viral hepatitis caused by hepatitis C virus (HCV) infection, is a major socio-economic and public health problem. Due to the rapid development of deep learning, it has become a common practice to apply deep learning to the healthcare industry to improve the effectiveness and accuracy of disease identification. In order to improve the effectiveness and accuracy of hepatitis C detection, this study proposes an improved denoising autoencoder (IDAE) and applies it to hepatitis C disease detection. Conventional denoising autoencoder introduces random noise at the input layer of the encoder. However, due to the presence of these features, encoders that directly add random noise may mask certain intrinsic properties of the data, making it challenging to learn deeper features. In this study, the problem of data information loss in traditional denoising autoencoding is addressed by incorporating the concept of residual neural networks into an enhanced denoising autoencoder. In our experimental study, we applied this enhanced denoising autoencoder to the open-source Hepatitis C dataset and the results showed significant results in feature extraction. While existing baseline machine learning methods have less than 90% accuracy and integrated algorithms and traditional autoencoders have only 95% correctness, the improved IDAE achieves 99% accuracy in the downstream hepatitis C classification task, which is a 9% improvement over a single algorithm, and a nearly 4% improvement over integrated algorithms and other autoencoders. The above results demonstrate that IDAE can effectively capture key disease features and improve the accuracy of disease prediction in hepatitis C data. This indicates that IDAE has the potential to be widely used in the detection and management of hepatitis C and similar diseases, especially in the development of early warning systems, progression prediction and personalised treatment strategies.

Clinical Utility of Cytokeratins for Accurate Diagnosis of Hepatocellular Carcinoma Among Hepatitis C Virus High-Risk Patients.

OBJECTIVES: Hepatocellular carcinoma (HCC) is a primary malignancy of the liver and a global health problem. It is often diagnosed at advanced stage where hopeless for effective therapies. Identification of more reliable biomarkers for early detection of HCC is urgently needed. Cytokeratins are a marker of hepatic progenitor cells and act as a key player in tumor invasion. Herein, we sought to develop a novel score based on the combination of cytokeratin 18 (CK18) and cytokeratin 19 (CK19) with routine laboratory tests for accurate detection of HCC. MATERIAL & METHODS: Serum CK18, CK 19, α-fetoprotein, albumin and platelets count were assayed in HCC patients (75), liver cirrhosis patients (55) and healthy control (20). Areas under receiving operating curve (AUCs) were calculated and used for construction on novel score. A novel score named CK-HCC = CK 19 (ng/ml)×0.001+ CK18 (ng/ml)×0.004 + AFP (U/L)×5.4 - Platelets count (×109)/L×0.003 - Albumin (g/L)×0.27-36 was developed. CK-HCC score produces AUC of 0.919 for differentiating patients with HCC from those with liver cirrhosis with sensitivity and specificity of a cut-off 1.3 (i.e., less than 1.3 the case is considered cirrhotic, whereas above 1.3 it is considered HCC. CONCLUSION: CK-HCC score could replace AFP during screening of HCV patients and early detection of HCC.

Development of an effective single-chain variable fragment recognizing a novel epitope in the hepatitis C virus E2 protein that restricts virus entry into hepatocytes.

Previously, we reported a neutralizing monoclonal antibody, A8A11, raised against a novel conserved epitope within the hepatitis C virus (HCV) E2 protein, that could significantly reduce HCV replication. Here, we report the nucleotide sequence of A8A11 and demonstrate the efficacy of a single-chain variable fragment (scFv) protein that mimics the antibody, inhibits the binding of an HCV virus-like particle to hepatocytes, and reduces viral RNA replication in a cell culture system. More importantly, scFv A8A11 was found to effectively restrict the increase of viral RNA levels in the serum of HCV-infected chimeric mice harbouring human hepatocytes. These results suggest a promising approach to neutralizing-antibody-based therapeutic interventions against HCV infection.

HBCVTr: an end-to-end transformer with a deep neural network hybrid model for anti-HBV and HCV activity predictor from SMILES.

Hepatitis B and C viruses (HBV and HCV) are significant causes of chronic liver diseases, with approximately 350 million infections globally. To accelerate the finding of effective treatment options, we introduce HBCVTr, a novel ligand-based drug design (LBDD) method for predicting the inhibitory activity of small molecules against HBV and HCV. HBCVTr employs a hybrid model consisting of double encoders of transformers and a deep neural network to learn the relationship between small molecules' simplified molecular-input line-entry system (SMILES) and their antiviral activity against HBV or HCV. The prediction accuracy of HBCVTr has surpassed baseline machine learning models and existing methods, with R-squared values of 0.641 and 0.721 for the HBV and HCV test sets, respectively. The trained models were successfully applied to virtual screening against 10 million compounds within 240 h, leading to the discovery of the top novel inhibitor candidates, including IJN04 for HBV and IJN12 and IJN19 for HCV. Molecular docking and dynamics simulations identified IJN04, IJN12, and IJN19 target proteins as the HBV core antigen, HCV NS5B RNA-dependent RNA polymerase, and HCV NS3/4A serine protease, respectively. Overall, HBCVTr offers a new and rapid drug discovery and development screening method targeting HBV and HCV.

Hepatitis C virus subtype diversity and transmission clusters characteristics among drug users in Zhuhai, South China.

BACKGROUND: Hepatitis C virus (HCV) infection poses a major public health challenge globally, especially among injecting drug users. China has the world's largest burden of HCV infections. However, little is known about the characteristics of transmission networks among drug user populations. This study aims to investigate the molecular epidemiology and transmission characteristics of HCV infections among drug users in Zhuhai, a bustling port city connecting Mainland China and its Special Administrative Regions. METHODS: Participants enrolled in this study were drug users incarcerated at Zhuhai's drug rehabilitation center in 2015. Their sociodemographic and behavioral information, including gender, promiscuity, drug use method, and so forth, was collected using a standardized questionnaire. Plasmas separated from venous blood were analyzed for HCV infection through ELISA and RT-PCR methods to detect anti-HCV antibodies and HCV RNA. The 5'UTR fragment of the HCV genome was amplified and further sequenced for subtype identifications and phylogenetic analysis. The phylogenetic tree was inferred using the Maximum Likelihood method based on the Tamura-Nei model, and the transmission cluster network was constructed using Cytoscape3.8.0 software with a threshold of 0.015. Binary logistic regression models were employed to assess the factors associated with HCV infection. RESULTS: The overall prevalence of HCV infection among drug users was 44.37%, with approximately 19.69% appearing to clear the HCV virus successfully. Binary logistic regression analysis revealed that those aged over 40, engaging in injecting drug use, and being native residents were at heightened risk for HCV infection among drug user cohorts. The predominant HCV subtypes circulating among those drug users were 6a (60.26%), followed by 3b (16.7%), 3a (12.8%), 1b (6.41%) and 1a (3.85%), respectively. Molecular transmission network analysis unveiled the presence of six transmission clusters, with the largest propagation cluster consisting of 41 individuals infected with HCV subtype 6a. Furthermore, distinct transmission clusters involved eight individuals infected with subtype 3b and seven with subtype 3a were also observed. CONCLUSION: The genetic transmission networks revealed a complex transmission pattern among drug users in Zhuhai, emphasizing the imperative for a targeted and effective intervention strategy to mitigate HCV dissemination. These insights are pivotal for shaping future national policies on HCV screening, treatment, and prevention in port cities.

First National Prevalence in Italian Horse Population and Phylogenesis Highlight a Fourth Sub-Type Candidate of Equine Hepacivirus.

Equine hepacivirus (EqHV, Flaviviridae, hepacivirus) is a small, enveloped RNA virus generally causing sub-clinical hepatitis with occasional fatalities. EqHV is reported in equids worldwide, but for Italy data are limited. To address this, a survey study was set up to estimate prevalence at a national level and among different production categories (equestrian; competition; work and meat; reproduction) and national macro-regions (North, Central, South, and Islands). Data obtained testing 1801 horse serum samples by Real-Time RT PCR were compared within the categories and regions. The NS3 fragment of the PCR-positive samples was sequenced by Sanger protocol for phylogenetic and mutational analysis. The tertiary structure of the NS3 protein was also assessed. The estimated national prevalence was 4.27% [1.97-6.59, 95% CI] and no statistical differences were detected among production categories and macro-regions. The phylogenesis confirmed the distribution in Italy of the three known EqHV subtypes, also suggesting a possible fourth sub-type that, however, requires further confirmation. Mutational profiles that could also affect the NS3 binding affinity to the viral RNA were detected. The present paper demonstrates that EqHV should be included in diagnostic protocols when investigating causes of hepatitis, and in quality control protocols for blood derived products due to its parental transmission.

Influence of Hepatitis C virus genotype and other factors on the viral load.

Anti-HCV reactive subjects were selected and relevant data was collected. Viral load and genotype were determined for all patients and were divided into low (<800,000 IU/mL) and high viral load (>800,000 IU/mL). Correlation of viral load with parameters like age, gender, risk factors and genotype etc. was determined by binomial regression. Higher viral load was noted with genotype 4, males and high risk groups like People Who Inject Drugs (PWIDs), blood transfusion before routine testing or frequent transfusion, Intravenous drug therapy and MTP by unregistered medical practitioners (P ≤ 0.5). Prevention and treatment strategies for HCV should be tailored around these areas.

Unraveling the dynamics of hepatitis C virus adaptive mutations and their impact on antiviral responses in primary human hepatocytes.

Hepatitis C virus (HCV) infection progresses to chronicity in the majority of infected individuals. Its high intra-host genetic variability enables HCV to evade the continuous selection pressure exerted by the host, contributing to persistent infection. Utilizing a cell culture-adapted HCV population (p100pop) which exhibits increased replicative capacity in various liver cell lines, this study investigated virus and host determinants that underlie enhanced viral fitness. Characterization of a panel of molecular p100 clones revealed that cell culture adaptive mutations optimize a range of virus-host interactions, resulting in expanded cell tropism, altered dependence on the cellular co-factor micro-RNA 122 and increased rates of virus spread. On the host side, comparative transcriptional profiling of hepatoma cells infected either with p100pop or its progenitor virus revealed that enhanced replicative fitness correlated with activation of endoplasmic reticulum stress signaling and the unfolded protein response. In contrast, infection of primary human hepatocytes with p100pop led to a mild attenuation of virion production which correlated with a greater induction of cell-intrinsic antiviral defense responses. In summary, long-term passage experiments in cells where selective pressure from innate immunity is lacking improves multiple virus-host interactions, enhancing HCV replicative fitness. However, this study further indicates that HCV has evolved to replicate at low levels in primary human hepatocytes to minimize innate immune activation, highlighting that an optimal balance between replicative fitness and innate immune induction is key to establish persistence. IMPORTANCE: Hepatitis C virus (HCV) infection remains a global health burden with 58 million people currently chronically infected. However, the detailed molecular mechanisms that underly persistence are incompletely defined. We utilized a long-term cell culture-adapted HCV, exhibiting enhanced replicative fitness in different human liver cell lines, in order to identify molecular principles by which HCV optimizes its replication fitness. Our experimental data revealed that cell culture adaptive mutations confer changes in the host response and usage of various host factors. The latter allows functional flexibility at different stages of the viral replication cycle. However, increased replicative fitness resulted in an increased activation of the innate immune system, which likely poses boundary for functional variation in authentic hepatocytes, explaining the observed attenuation of the adapted virus population in primary hepatocytes.