The distribution of hepatitis B virus genotypes in Thailand

Phylogenetic analysis was performed on hepatitis B virus (HBV) strains obtained from 86 hepatitis B surface antigen (HBsAg) positive donors from Thailand originating throughout the country. Based on the S gene, 87.5% of strains were of genotype C while 10.5% were of genotype B, with all genotype B strains obtained from patients originating from the central or the south Thailand. No genotype B strains were found in the north of Thailand. Surprisingly, one patient was infected with a genotype H strain while another patient was infected with a genotype G strain. Complete genome sequencing and recombination analysis identified the latter as being a genotype G and C2 recombinant with the breakpoint around nucleotide position 700. The origin of the genotype G fragment was not identifiable while the genotype C2 fragment most likely came from strains circulating in Laos or Malaysia. The performance of different HBsAg diagnostic kits and HBV nucleic acid amplification technology (NAT) was evaluated. The genotype H and G/C2 recombination did not interfere with HBV detection. J. Med. Virol. 84:1541–1547, 2012. © 2012 Wiley Periodicals, Inc.     

Clinical significance of hepatitis C virus genotypes

On the basis of phylogenetic analysis of nucleotide sequences, multiple genotypes and subtypes of hepatitis C virus (HCV) have been identified. Characterization of these genetic groups is likely to facilitate and contribute to the development of an effective vaccine against infection with HCV. Differences among HCV genotypes in geographic distributions have provided investigators with an epidemiologic marker that can be used to trace the source of HCV infection in a given population. HCV genotype 1 may represent a more aggressive strain and one that is less likely to respond to interferon treatment than HCV genotype 2 or 3. However, these observations require confirmation before HCV genotyping can be used in clinical settings.     

Geographical distribution of hepatitis C virus genotypes in India

HCV isolates from around the world show substantial nucleotide sequence variability throughout the viral genome. Based on the identification of these genome differences various genotypes and subtypes have been described from different geographical regions. They have been tentatively classified into six major genotypes and more than 30 subtypes, but new subtypes are continually being discovered. In recent years, substantial evidence has emerged indicating that typing and subtyping for HCV is clinically important. The present study aims at determining and comparing the prevalence of different genotypes from different parts of India (North, South, East and West). A total of 153 samples representing different regions have been genotyped in our lab. Our studies document a high prevalence of genotype 3 (> 76%) and very low prevalence of genotype 2 (< 2%), as a whole. However, genotype 3a has been found to be the highest (50%) with a decreased frequency of approximately 25% in the case of 3b, approximately 14% in 1b and approximately 10% in 1a, whereas a minimal number (approximately 4%) of genotype 4 has been found only in Southern and Western India.     

Turnover of hepatitis C virus genotypes in hemodialysis patients

Summary.  Hepatitis C virus (HCV) genotypes were determined in hemodialysis patients with a high prevalence and incidence of infection. A change of HCV genotype was observed in 6/14 follow-up samples analyzed 13 and 21 months later. The appearance and disappearance of HCV genotypes may be due to either genotype-specific intermittent viremic status or viral interference. Accepted October 14, 1997 Received June 20, 1997     

Immunoglobulin GM and KM genotypes in hepatitis C virus infection

Hepatitis C virus (HCV) is a major health problem, affecting over 170 million people worldwide. HCV causes a wide spectrum of liver disease, varying from persistent to asymptomatic infection. To evaluate the role of immunoglobulin (Ig) GM and KM genes in HCV infection, 191 HCV-infected Thai subjects were studied. These included 43 individuals with transient HCV infection and 148 individuals with persistent chronic HCV infection. The controls consisted of 134 healthy individuals. Several GM and KM alleles were determined by polymerase chain reaction-based methods. The frequency of G1M(f) homozygotes was lower (52.4% vs. 64.2%, P = 0.03) and the frequency of G1M(z) homozygotes was higher (10.5% vs. 3.7%, P = 0.02) in patients than the respective frequencies in controls. These results suggest that GM genotypes make a significant contribution to the risk of acquiring HCV infection.     

Hepatitis C genotypes in patients with dual hepatitis B and C virus infection

In patients with chronic hepatitis B and C virus (HBV, HCV) infection, an inverse relationship in the replicative activity of the two viruses has been reported. In the present study the genotype of HCV was evaluated in 34 consecutive cases found with hepatitis B surface antigen (HBsAg) and anti-HCV in the serum, in order to identify its possible influence in determining the pattern of HBV/HCV interaction. Nineteen patients were HCV-RNA positive and could be genotyped: 8 were infected by HCV-1 (3 by HCV-1a and 5 by HCV-1b), 10 by HCV-2, and only 1 by HCV-3. Among these, 3 were HBV-DNA positive, compared to 10 of 15 HCV-RNA-negative patients (P = 0.003), and all 3 were coinfected with HCV-2. Mean alanine aminotransferase (ALT) levels were similar between patients infected with HCV-1 and HCV-2. Among 7 patients with cirrhosis 5 were infected by HCV-2, while 6 of 12 of those without cirrhosis had HCV-1 infection. In conclusion, HBV replication was inhibited more efficiently by HCV-1 than by HCV-2. Cirrhosis was frequently found in patients with dual HBV and HCV-2 infection. © 1996 Wiley-Liss, Inc.     

Serological reactivity and viral genotypes in hepatitis C virus infection.

Patients infected with hepatitis C virus (HCV) were examined with four commercial HCV immunoblotting assays and for anti-GOR antibody to ascertain whether serological findings varied with the genotype of the infecting virus. The results indicate that patients infected with different HCV genotypes tend to show different immunoblotting profiles, mainly due to a low prevalence of antibodies to the viral region NS4 in patients infected with genotypes III and IV. Differences were more evident with second- than with third-generation assays. Patients infected with genotype IV exhibited a lower prevalence of anti-GOR antibody than patients infected with other genotypes.     

The prevalence of autoantibody and its relationship with genotypes of hepatitis C virus in patients with chronic hepatitis C virus infection

The prevalence of autoantibody in the patients with chronic hepatitis C infection, and the relationship between the autoantibodies and HCV genotypes were investigated in this study. One hundred and eight anti‐HCV positive and 86 anti‐HCV negative patients were included in the study. Anti‐HCV were studied by enzyme immunassay (EIA). HCV RNA was determined by real time polymerase chain reaction (PCR) and HCV genotypes were determined by a reverse‐line blot hybridization. Anti‐nuclear antibodies (ANA), anti‐smooth muscle antibodies (ASMA), Anti‐mitochondrial antibodies (AMA), liver kidney microsomal antibodies (LKM) were detected by indirect immunofluorescence assay. Among patients, 13 (12.03%) of 108 were positive for at least one autoantibody. The positivity was not observed in control group. The most prevalent autoantibody in anti‐HCV positive group was ANA. ANA was positive in six HCV patients with genotype 1. In HCV patients with genotype 1, the frequencies of ANA, ASMA, AMA and LKM1 were six, two, three and one, respectively. In HCV patients with genotype 2, ANA was positive one patient and ASMA, AMA and LKM1 were not detected in HCV patients with genotype 2. In conclusion, the autoantibodies in patients with chronic hepatitis C in the study were low as compared to those reported in previous studies.     

Hepatitis C virus genotypes in Hungarian and Austrian patients with chronic hepatitis C.

Hepatitis C virus (HCV) genotypes are relevant to epidemiological questions, vaccine development, and clinical management of chronic HCV infection. The aim of this study was to determine HCV genotypes of South Hungarian and Southeast Austrian patients with chronic hepatitis C. Results were obtained by the largely automated TruGene HCV 5'NC Genotyping Kit (Visible Genetics, Toronto, Ontario) and by phylogenetic analysis. All of the 20 Hungarian patients and 15 out of 20 Austrian patients were infected with genotype 1. The remaining Austrian patients were infected with genotypes 3 or 2. With the commercially available assay, it was not possible to determine the HCV subtype in a total of three patients. The TruGene HCV 5'NC Genotyping assay for the determination of HCV genotypes proved to be useful for a high-throughput routine diagnostic laboratory.     

Clinical characteristics and antibody profiles of chronic hepatitis C patients: Relation to hepatitis C virus genotypes

Genotyping of 179 consecutive Japanese chronic hepatitis C patients was carried out based on the variation in the hepatitis C virus (HCV) core gene. The results were correlated with clinical features and antibody responses toward specific HCV proteins deduced from the nucleotide sequence of genotype I/1 a. Genotypes II/1 b, III/2a, and IV/2b were identified in 138 (77%), 24 (13%), and 12 (7%) patients, respectively. Five patients had double infections. Genotype dependence was observed only for antibody response toward the NS4 (5–1–1) protein, which was infrequent in genotype III/2a patients (33%) compared with genotype II/1 b (81%; P < 0.01) and genotype IV/2b (75%; P < 0.05). Following interferon-α therapy, sustained aminotransferase normalisation was achieved by 89% (eight of nine) patients without antibody to the 5–1–1 protein and 33% (17 of 51) with it (P < 0.01). These findings indicate that absence of antibody response to the 5–1–1 protein is frequent in genotype III/2a HCV carriers and may serve to predict responses to interferon therapy. © 1995 Wiley-Liss, Inc.     

Prevalence of hepatitis C virus and distribution of its genotypes in Northern Eurasia

Summary We tested hepatitis C virus (HCV) antibody in 4 216 sera collected from healthy people living in European part of Russia (including Northern, North-Western, Central, Central-Blacksoil, Volga-Vyatka, Volga, and North-Caucasian regions), non-European part of Russia (the Urals, East-Siberia, and the Far-East regions) and Mongolia. Prevalence of HCV antibody varied significantly by regions, ranging from 0.7% in Central region of European part of Russia to 10.7% in Mongolia. Genotyping of HCV (into 1a, 1b, 2a, 2b, and 3a) was performed on 469 sera from blood donors and patients (in Russia, Moldova, Turkmenistan, and Mongolia) who were positive for both HCV antibody and RNA. Genotype 1b was the most dominant genotype irrespective of regions (68.9%), with the highest rate in Moldova (96%). HCV unclassificable into genotypes 1a-to-3a was found in 28 (6.0%) samples: particularly 4 of 10 samples from Lipetzk were untypable. Overall, HCV genotypes in European part of Russia were more similar to those in European countries, while those in Eastern part of Russia more similar to China or Japan. Genotype distribution was not associated with the clinical expression of HCV disease: acute hepatitis, chronic hepatitis or liver cirrhosis.     

The nationwide distribution and trends of hepatitis C virus genotypes in mainland China

Comprehensive data on hepatitis C virus (HCV) genotypes distribution is critical for treatment regimen selection, vaccine design, and drug development. This study aimed to understand the dynamic distribution of HCV genotypes in Mainland China. Three hundred sixty-two studies published from January 1993 to December 2017 involving 64 891 samples (5133 injecting drug users, 2748 volunteer blood donors, 1509 former paid plasma donors, 160 sexually encounters, and 1992 human immunodeficiency virus (HIV)/HCV coinfection patients) were eligible for the quantitative synthesis estimation. Pooled proportion of HCV genotypes (and 95% confidence intervals [CIs]) was estimated through the Freeman-Tukey double arcsine transformation by period, region, and risk group. A sharp decline of the subtype 1b was observed in all regions except in northwestern and central regions. The genotypes 3 and 6 showed an obvious increase in southern and southwestern regions and have already spread nationwide. After 2010, subtype 1b was the most dominant variant in all regions and risk groups, accounting for 54.0% (95% CI, 51.9-56.1) of all national infections. Subtype 2a was the second most prevalent strain in all regions except in the south and southwest, with 15.4% (95% CI, 13.1-17.8) national infections. The subtype 6a in southern region and 3b and 3a in southwestern region had a higher proportion of infections than that in other regions. In addition, the genotypes 3 and 6 are already prevalent in almost all risk groups. The distribution of HCV genotypes were sharply shifting in China in the past three decades. The HCV subtype 1b posed a sharp decline, whereas genotypes 3 and 6 played an increasing role in the regional and populational HCV pandemic.     

Identification of numerous hepatitis C virus genotypes in Montreal, Canada.

Hepatitis C virus genotypes were determined for 358 viremic individuals in Montreal, Canada, by restriction endonuclease analysis of PCR products and phylogenetic analysis of core gene sequences. Types 1, 2, and 3 occurred in 62.8, 14.2, and 13.7%, respectively; types 4 and 5 were found in 3.9 and 4.5%, respectively; and genotypes 6a and 7c and a novel genotype each occurred in 0.3%. Types 4, 6, and 7 and the novel genotype were mostly from persons who had immigrated to Canada.     

Seroepidemiology of hepatitis A virus infection among schoolchildren in Taiwan

Taiwan was a hyperendemic area for hepatitis A virus (HAV) infection before 1980. The aim of this study was to examine the association between seropositivity of antibodies against HAV (anti-HAV) by a community-based survey. School children from 10 elementary and 3 junior high schools, as well as staff members who worked at the above schools in central Taiwan were selected at random in this study. Anti-HAV was tested in sera of 1,954 healthy schoolchildren (aged 7-15 years old) and 254 teachers by enzyme-linked immunosorbent assay. Schoolchildren had a low prevalence of anti-HAV (2.3%) in contrast to the high seroprevalence in their teachers (52%). The seropositive rates of HAV antibody among the study subjects were increasing with age. No significant differences of anti-HAV seroprevalence among the study subjects were observed when they were stratified by gender, geographical area, household members, and parental education. Whereas, the anti-HAV seroprevalence was significantly higher in schoolchildren who were either aboriginal or living in areas without a supply of drinking tap-water. The seroprevalence of HAV data among the healthy pediatric population would be helpful to evaluate the need for mass vaccination policies.     

山东烟台地区HCV感染的基因分型研究

目的 了解山东烟台地区丙型肝炎病毒的基因分型,结合受试者的肝功能指标观察基因型别与肝损情况是否相关.方法 采用特异性PCR引物对HCV RNA5'UTR区和(或)NS5B区进行扩增,PCR产物进行序列分析,通过与GenBank中参考序列的比对,联合遗传进化树对标本予以分型.结果 9例无偿献血员中检出1b和3a两种基因亚型,分别为8例和1例.33例丙肝患者中,检出1b、2a和6a三种基因亚型,分别为22(66.7％)、10(30.3％)和1(3.03％)例.1b亚型是烟台地区HCV携带者的优势流行基因亚型,在不同人群中分布差异无统计学意义(x2=0.796,P=0.373);不同基因分型的受试者其肝损指标的差异有统计学意义(P＜0.05),2a型携带者的ALT、AST均值明显高于1b型.结论 山东烟台地区HCV基因型呈现多样性,以1b为主,并首次检出3a和6a亚型.HCV基因型与肝损指标具有相关性,2a型HCV感染可能在肝细胞的病变过程中起着重要作用.