Aritra Biswas

Current molecular methods for the detection of hepatitis C virus in high risk group population: A systematic review

Hepatitis C virus (HCV) is an emerging infection worldwide and the numbers of persons infected are increasing every year. Poor blood transfusion methods along with unsafe injection practices are potential sources for the rapid spread of infection. Early detection of HCV is the need of the hour especially in high risk group population as these individuals are severely immunocompromised. Enzyme Immunoassays are the most common detection techniques but they provide no evidence of active viremia or identification of infected individuals in the antibody-negative phase and their efficacy is limited in individuals within high risk group population. Molecular virological techniques have an important role in detecting active infection with utmost specificity and sensitivity. Technologies for assessment of HCV antibody and RNA levels have improved remarkably, as well as our understanding of how to best use these tests in patient management. This review aims to give an overview of the different serological and molecular methods employed in detecting HCV infection used nowadays. Additionally, the review gives an insight in the new molecular techniques that are being developed to improve the detection techniques particularly in High Risk Group population who are severely immunocompromised.

Changing pattern of dengue virus serotypes circulating during 2008–2012 and reappearance of dengue serotype 3 may cause outbreak in Kolkata, India

Dengue virus infection is a major cause of morbidity within the endemic tropical and subtropical regions of the world. Dengue virus has four distinct serotypes with specific clinical manifestations. In this study, we observed the changing pattern of dengue serotypes, age‐wise dengue infection and useful sero‐detection methods needed in a dengue endemic region. We identified dengue serotypes during a period of 5 years among patients with dengue symptoms visiting one of the largest tertiary care infectious disease hospitals of eastern India in Kolkata. A total of 433 dengue RNA positive samples were isolated from 712 acute dengue suspected cases. Age wise distribution highlighted the susceptible age group being >21 years (24.02%) followed by 11–15 years (21.71%) and 5–10 years (21.02%) of the total infected population. Higher numbers of infected cases were found within females as they are involved in more indoor works. The period of study experienced two dengue outbreaks one in 2008 and another in 2012. For early dengue detection, NS1 was found to be more confirmatory than IgM ELISA regarding sensitivity and specificity. DENV‐1, 2, and 4 serotypes were the common circulating strains from 2008 until 2010, after which DENV‐3 serotype infections rise and led to a massive dengue outbreak in Kolkata with increased numbers of DHF and DSS cases in 2012. The finding within our study emphasizes the public health importance of such prospective surveillance programs with respect to the changing dengue viral etiology and serotypes. J. Med. Virol. 88:1697–1702, 2016.

Impact of Host IL28B rs12979860, rs8099917 in Interferon Responsiveness and Advanced Liver Disease in Chronic Genotype 3 Hepatitis C Patients

Background and Aims Genetic polymorphisms near interleukin 28B gene are associated with spontaneous and treatment induced clearance of hepatitis C virus (HCV). Our objective was to evaluate the impact of interleukin 28B single nucleotide polymorphism (rs12979860, rs8099917) variability in HCV genotype 3 infected populations. Methods 400 hepatitis C seroreactive patients from different population groups in Eastern and North Eastern part of India were assessed for host and viral genotypic analysis. 83 HCV genotype 3 infected patients were administered pegylated interferon- ribavirin therapy. Viral genotyping was performed using nested reverse transcriptase-PCR followed by direct sequencing methods. Host interleukin 28B genotyping was performed using real-time PCR based single nucleotide polymorphism analysis. Results Out of 400 hepatitis C seroreactive individuals, 73.25% were found to be RNA positive. HCV genotype 3 (65.87%) was found to be the major circulating strain in this region followed by genotype 1 (32.08%). rs12979860 CC genotype was significantly associated with sustained virological response in HCV genotype 3 infected population. In patients achieving rapid virological response, favourable CC/TT allele at rs12979860, rs8099917 was found to be predominant at both the alleles at 77%, 73.2% respectively; whereas in case of patients with relapsed HCV infection CT, TG alleles were found to be predominant. Additionally, CC genotypes at rs12979860 were found to be associated with sustained virological response in patients with high viral load (OR = 6.75, 0.05<p). HCV unfavourable rs12979860 TT, rs8099917 GG alleles were present in 34%, 27.6% patients with relapsed HCV infection respectively. Also unfavourable CT, TG genotypes were found to be predominant in patients with advanced stages of liver disease. Conclusion CC, TT the two favourable markers at SNPs rs12979860 and rs8099917 are strongly associated with sustained virological response in genotype 3 infected populations. This information will aid clinicians to effectively design response based treatment regimen.

Modulation of TLR 3, 7 and 8 expressions in HCV genotype 3 infected individuals: potential correlations of pathogenesis and spontaneous clearance.

Background. Hepatitis C virus is the major cause of chronic hepatitis worldwide which finally leads to the development of hepatocellular carcinoma. Toll like receptors (TLRs) play an important role in the course of many viral infections, but the role of TLRs in HCV pathogenesis has not been well elucidated so far. Objective. The aim of this study was to analyse the mRNA expression of TLRs 3, 7, and 8 in different stages of HCV infection including chronic, cirrhosis, interferon treated resolved, and relapsed cases. Methodology. Total RNA from whole blood was extracted and mRNA expression of TLRs 3, 7, and 8 genes was analyzed by quantitative real-time RT-PCR using β-Actin gene as an internal control. Results. This study consisted of 100 HCV infected individuals and twenty healthy controls. TLR 3 expression was found to be significantly elevated in individuals who had spontaneously cleared the virus (p < 0.001), whereas TLR 7 was found to be 3.26 times more elevated in patients with cirrhosis of liver. In IFN induced individuals, TLR 8 expression levels were found to be 2.28-fold elevated as compared to control population. Conclusion. TLRs 3, 7, and 8 are prime biomarker candidates for HCV infection mRNA expression analysis which might improve current therapeutic approaches.

Interferon λ3 gene (IL28B) is associated with spontaneous or treatment-induced viral clearance in hepatitis C virus-infected multitransfused patients with thalassemia: ROLE OF IL28B IN HCV-INFECTED PATIENTS

Hepatitis C virus (HCV) is the major posttransfusion infection in multitransfused individuals in India with thalassemia major. To our knowledge, this study is the first conducted to correlate and comprehend the effects of the host interleukin (IL)28B gene polymorphism at loci rs12979860 and rs8099917 in spontaneous or interferon (IFN)‐induced treatment response in the HCV‐seroreactive individuals with thalassemia major.

Recombination in hepatitis C virus is not uncommon among people who inject drugs in Kolkata, India

Recombination in RNA virus is a rare event in the survival and evolution to evade host immune system. This is increasing within high risk group population (HRG) due to super infection that occurs by continuous sharing of common drug equipment by HCV infected or HIV-HCV co-infected recurrent drug users. Recombination causes impediment to vaccine development and therapeutic intervention as standard HCV treatment is still genotype specific. Blood samples of 194 people who inject drugs (PWID) were collected from an Opioid Substitution Therapy Centre in Kolkata, India. HCV sero-reactivity was checked by ELISA. Detection of HCV RNA by nested RT-PCR and genotyping by DNA sequencing were done. Phylogenetic analysis, Simplot, Bootscan plot, Recombination Detection Program were used for recombinant strain identification. Out of 80 HCV sero-reactive samples, 77 were RNA positive (96.25%). Out of 74 HIV mono-infected individuals, 12 HCV sero-nonreactive samples were HCV RNA positive. Out of total 89 RNA positive samples, 64 paired partial core and NS5B region (71.9%) were sequenced by Sangers method. Two major genotypes (1 and 3), four subtypes and an inter-genotype recombinant strain (3a/1a) with a novel breakpoint in the NS4B coding region were found.