hosted by
publicationslist.org
    
Fuat Kurbanov
Department of Clinical Molecular Informative Medicine,
Nagoya City University Graduate School of Medical Sciences
Nagoya 467-8601
Japan
Phone: +81-52-853-8292
Fax: +81-52-842-0021
fuat@med.nagoya-cu.ac.jp

Journal articles

2008
 
DOI   
PMID 
Dildora Avazova, Fuat Kurbanov, Yasuhito Tanaka, Masaya Sugiyama, Ivan Radchenko, Dilmurod Ruziev, Erkin Musabaev, Masashi Mizokami (2008)  Hepatitis B virus transmission pattern and vaccination efficiency in Uzbekistan.   J Med Virol 80: 2. 217-224 Feb  
Abstract: A national program of universal vaccination for the prevention of chronic hepatitis B virus (HBV) infection was launched in Uzbekistan since 1998. To evaluate the 6 years' outcome of the program, 567 children were enrolled in the study. Among those enrolled, 333 had immunized with adw2 type based Engerix-B (Glaxo Smith Kline Beechem, Rixensart, Belgium) and 48 with adr type based Hepavax-Gene (Green Cross Vaccine Corporation, Korea). A cohort of 186 children born before the immunization program, was also included in the study. When 45 vaccinated children were compared to age/sex-matched 45 unvaccinated children, the sero-prevalence of HBsAg was 0 versus 11% (P = 0.56), and of anti-HBc was 0% versus 44% (P < 0.0001), respectively. Loss of anti-HBs was observed in 18.4% after 5 years. Among 13 HBsAg carriers found in this study, genotype HBV/D was found in 69%, HBV/A in 23% (all in unvaccinated group) and HBV/C in 8% (in vaccinated group). No significant differences were observed in this study between groups which received different vaccine formulation. Phylogenetic analysis of the HBV isolates obtained from family members of the HBsAg-positive children, revealed evidence suggesting that transmission in the vaccinated group was exclusively perinatal, whereas in the unvaccinated group horizontal transmission pattern predominated. In conclusion, HBV universal vaccination is efficient in Uzbekistan irrespective of the vaccine formulation used, because the horizontal transmission pattern predominates currently in this endemic region. J. Med. Virol. 80:217-224, 2008. (c) 2007 Wiley-Liss, Inc.
Notes:
 
DOI   
PMID 
Anis Khan, Fuat Kurbanov, Yasuhito Tanaka, Abeer Elkady, Masaya Sugiyama, Abdusamad Dustov, Masashi Mizokami (2008)  Epidemiological and clinical evaluation of hepatitis B, hepatitis C, and delta hepatitis viruses in Tajikistan.   J Med Virol 80: 2. 268-276 Feb  
Abstract: The implication of genotypes is recognized increasingly in the clinical course of hepatitis B virus (HBV) and in response to anti-viral drugs of hepatitis C virus (HCV). Genotypic prevalence of both etiological agents varies geographically and no data are available for Tajikistan. To investigate the epidemiology and clinical significance of HBV and HCV genotypes in chronic hepatitis (group 1) and liver cirrhosis/hepatocellular carcinoma (HCC) (group 2) patients in Tajikistan, 124 patients with chronic liver disease (group 1 = 84 and group 2 = 40) were enrolled. Genotypes of HBV, HCV, and delta hepatitis virus (HDV) were determined by sequencing. The overall prevalence of anti-HCV, HCV core antigen (HCVcAg) and HBsAg was 46% (57/124) and 41.1% (51/124), respectively. Coinfection of HCV/HBV, HBV/HDV, and HCV/HBV/HDV was found in 4.8% (6/124), 11.2% (12/124), and 0.8% (1/124) of cases, respectively. HDV genotype 1 was found in 19.6% (10/51) of HBsAg-positive patients. The HBV/HDV coinfection was relatively high in group 2 compared to group 1 (15% vs. 7.1%). HCV/1b detected in 84.6% (44/52) of HCV RNA-positive patients, followed by 3a (7.6%), 2a (5.7%), and 2c (1.9%). HBV/D was detected in 94.1% (48/51) of HBsAg-positive patients, followed by HBV/A [5.8% (3/51)]. T1762/A1764 double mutation was associated with liver cirrhosis/HCC in HBV-infected patients (P = 0.0004). This is the first study on the molecular epidemiology of hepatitis viruses among chronic liver diseases patients in Tajikistan. Among HBV-infected patients, the T1762/A1764 mutation was associated with liver cirrhosis/HCC. J. Med. Virol. 80:268-276, 2008. (c) 2007 Wiley-Liss, Inc.
Notes:
2007
 
DOI   
PMID 
Zhanhui Wang, Yasuhito Tanaka, Yuehua Huang, Fuat Kurbanov, Jinjun Chen, Guobing Zeng, Bin Zhou, Masashi Mizokami, Jinlin Hou (2007)  Clinical and virological characteristics of hepatitis B virus subgenotypes Ba, C1, and C2 in China.   J Clin Microbiol 45: 5. 1491-1496 May  
Abstract: Hepatitis B virus (HBV) subgenotypes Ba, C1 (Cs), and C2 (Ce) are the most prevalent HBV variants in China. To investigate the virological characteristics of these subgenotypes and their clinical implications, we enrolled a cohort of 211 patients in the Guangdong Province of China, including 132 with chronic hepatitis B virus infection (CH), 32 with liver cirrhosis (LC), and 47 with hepatocellular carcinoma (HCC) according to clinical examination, liver function test, and ultrasonograph results. Overall, HBV Ba was found in 51.2% (108/211), HBV C1 in 33.6% (71/211), and HBV C2 in 15.2% (32/211) of the cases. The distribution of HBV genotype C was greater among patients in the LC and HCC groups than among patients in the CH group, while the distribution of HBV genotype B was greater among the CH patients than among the LC and HCC patients. No significant differences in clinical features were found among patients with HBV Ba, C1, and C2. Virologically, HBV C1 had the strongest association with the A1762T G1764A double mutation, while the mutation at position 1896 resulting in A (1896A) was uncommon. In contrast, HBV Ba had the highest frequency of 1896A but the lowest of A1762T G1764A, and HBV C2 had intermediate frequencies of these mutations. Mutations of 1653T and 1753V were specifically associated with HBV C2 and C1, respectively. Multivariate analyses showed that the 1653T, 1753V, and A1762T G1764A mutations and patient age significantly increased the risk of HCC development. In conclusion, HBV Ba, C1, and C2 have different mutation patterns in the enhancer II/core promoter/precore region. Therefore, genotyping and detecting the 1653T and 1753V mutations, in addition to the A1762T G1764A double mutation, might have important clinical implications as predictive risk factors for hepatocarcinogenesis.
Notes:
 
DOI   
PMID 
Jing Yuan, Boping Zhou, Yasuhito Tanaka, Fuat Kurbanov, Etsuro Orito, Zuojiong Gong, Liumei Xu, Jian Lu, Xiaoling Jiang, Weizhen Lai, Masashi Mizokami (2007)  Hepatitis B virus (HBV) genotypes/subgenotypes in China: mutations in core promoter and precore/core and their clinical implications.   J Clin Virol 39: 2. 87-93 Jun  
Abstract: BACKGROUND: The association of hepatitis B virus (HBV) genotypes with clinical course of infection is increasingly recognized. OBJECTIVES: In order to investigate the genetic diversity of HBV and its clinical implications, 241 HBV-infected patients including 34 with hepatocellular carcinoma (HCC) were enrolled in this study. METHODS: HBV genotyping was performed with an ELISA assay. HBV subgenotypes were determined by PCR-RFLP. HBV core promoter/precore/core mutations were analyzed by direct sequencing. RESULTS: The overall prevalence of HBV/B and C was 65% and 33%, respectively. Among HBV/C, 42% were Cs/C1 and 58% were Ce/C2. The HBV/C1 was only found in the patients originating from Southern China (p=0.0001). Among HCC patients, HBV/C2 was only found in the elder age group (> or =51 years; p<0.05) and HBV/Ba was associated with young HCC patients (<35 years). Mutations associated with HCC were V1753 and T1762/A1764 (p<0.01). The prevalence of the V1753 was higher in HBV/C1 strains (p<0.04), A1898 was only found among HBV/C1 (p=0.056). T1762/A1764 was frequently demonstrated in both subgenotypes. The T1858 (90%) and A1896 (40%) mutations were most frequent in HBV/C2 (p<0.008). CONCLUSIONS: HBV/C1 and HBV/C2 have distinct geographic distributions in China. V1753 in addition to T1762/A1764 double mutation in the basal core promoter region seems to be associated with HCC development, especially in the patients with HBV/C1.
Notes:
 
DOI   
PMID 
Hong Zhao, Fuat Kurbanov, Mo-Bin Wan, You-Kuan Yin, Jun-Qi Niu, Jin-Lin Hou, Lai Wei, Gui-Qiang Wang, Yasuhito Tanaka, Masashi Mizokami, Chong-Wen Si (2007)  Genotype B and younger patient age associated with better response to low-dose therapy: a trial with pegylated/nonpegylated interferon-alpha-2b for hepatitis B e antigen-positive patients with chronic hepatitis B in China.   Clin Infect Dis 44: 4. 541-548 Feb  
Abstract: BACKGROUND: Cost and clinically significant adverse effects are the major limiting factors of interferon (IFN) use in therapy for chronic hepatitis B virus (HBV) infection. A clinical trial was conducted in China to study the efficiency and clinical relevance of low-dose regimen of IFN treatment for chronic HBV infection and to reveal factors predicting sustained combined response. METHODS: During a randomized, open-label control study, hepatitis B e antigen (HBeAg)-positive patients with chronic HBV infection (n=230) were assigned to receive pegylated IFN- alpha -2b (1.0 micro g/kg) (n=115) or IFN- alpha -2b (3 MIU; n=115) for a 24-week period. Sustained combined response was assessed 24 weeks after the completion of treatment. RESULTS: The greater rate of HBeAg loss in the pegylated IFN-group (23%) was the only statistically significant difference between the 2 treatment arms observed at the end of follow-up. The results of the multivariate statistical analysis revealed that HBV genotype B and patient age (< or =25 years) were 2 independent factors associated with sustained combined response. A total of 40% of patients with HBV genotype B aged < or =25-years achieved sustained combined response. Only 4 (1.7%) of 230 patients discontinued therapy because of clinically significant adverse effects. CONCLUSIONS: The choice of low-dose IFN regimen might be a relevant clinical option to reduce the cost and adverse effects of therapy for younger patients with chronic HBV infection and genotype B infection in countries where it is prevalent.
Notes:
 
DOI   
PMID 
H Kato, Y Maeno, Y Seko-Nakamura, J Monma-Ohtaki, S Sugiura, K Takahashi, L X Zhe, T Matsumoto, F Kurvanov, M Mizokami, M Nagao (2007)  Identification and phylogenetic analysis of hepatitis C virus in forensic blood samples obtained from injecting drug users.   Forensic Sci Int 168: 1. 27-33 May  
Abstract: Injecting drug users (IDUs) are a high-risk group for contracting hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections. In Japan, data on the prevalence of those blood-borne viruses among IDUs are very limited. Blood samples were obtained from 12 cadavers of IDUs sent to Nagoya City University for the purpose of judicious autopsy and two alive IDUs with hepatitis C referred to a local hospital at the same period. The viruses were detected by polymerase chain reaction and phylogenetic analysis was performed. Two (16.6%) of the 12 autopsy cases were positive for HCV, but no case was positive for either HBV or HIV. Phylogenetic analysis of the two HCV isolates revealed that one was classified into genotype 1b and another was genotype 2b. Furthermore, nucleotide sequences of two isolates recovered from IDUs with hepatitis C were identical, that indicated the transmission of HCV between them, and those HCV were phylogenetically classified into genotype 2a. The prevalence of HCV infection among IDUs in Japan, despite the case of judicious autopsy, seems to be high, but HIV infection seems to be rare. The transmission of HCV between IDUs was demonstrated, and this indicates that phylogenetic analysis would applicable to also forensic analysis. HCV isolates identified in this study did not phylogenetically segregate, thus multiple transmission route of HCV among IDUs seems be exist in Japan.
Notes:
 
DOI   
PMID 
Atsunori Kusakabe, Yasuhito Tanaka, Etsuro Orito, Fuminaka Sugauchi, Fuat Kurbanov, Tomoyuki Sakamoto, Noboru Shinkai, Noboru Hirashima, Izumi Hasegawa, Tomoyoshi Ohno, Ryuzo Ueda, Masashi Mizokami (2007)  A weak association between occult HBV infection and non-B non-C hepatocellular carcinoma in Japan.   J Gastroenterol 42: 4. 298-305 Apr  
Abstract: BACKGROUND: In Japan, approximately 10% of hepatocellular carcinoma (HCC) patients are negative for both hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV), i.e., they constitute the so-called category of non-B non-C (NBNC) HCC. Little is known about the characteristics of NBNC-HCC. METHODS: Potential risk factors for carcinogenesis (including occult HBV infection [HBsAg is negative but HBV DNA is positive by polymerase chain reaction (PCR)], obesity, and diabetes) were assessed in 233 HCC patients grouped according to hepatitis virus serological status (152 with HCV-HCC, 36 with HBV-HCC, and 45 with NBNC-HCC). RESULTS: The prevalence of patients with obesity or diabetes was significantly higher in the NBNC-HCC group than in the HBV-HCC group. The same trend was observed even when patients with massive alcohol intake were excluded from the analysis. Only 8 patients (18%) in the NBNC-HCC group had detectable serum HBV DNA, and this was at very low levels (HBV/Ce/C2 and HBV/D were determined in 7 and 1 patients, respectively). In the NBNC-HCC group, the determined nucleotide sequences of the enhancer II/core promoter/precore/core region did not contain any HCC-associated mutations, whereas 25 of 30 patients in the HBV-HCC group carried strains with C1653T, T1753V, and/or A1762T/G1764A mutations. CONCLUSIONS: A weak association between occult HBV infection and HCC development was observed in the NBNC patients. This study indicates that nonalcoholic steato-hepatitis should be further investigated to assess its contribution to HCC development in this category of patients.
Notes:
 
DOI   
PMID 
Kurbanov, Tanaka, Avazova, Khan, Sugauchi, Kan, Kurbanova-Khudayberganova, Khikmatullaeva, Musabaev, Mizokami (2007)  Detection of hepatitis C virus natural recombinant RF1_2k/1b strain among intravenous drug users in Uzbekistan.   Hepatol Res Nov  
Abstract: Aim: A series of recent studies have indicated the presence of natural intergenotypic recombinant hepatitis C virus (HCV) strains in distinct parts of the world. The majority of the current genotyping methods are based on analysis of either 5'UTR, structural (Core/E1/E2) or non-structural (NS5B) genomic regions of the virus. Methods: In the present study, based on both structural and non-structural regions, we determined the genotype of 55 anti-HCV-positive intravenous drug users (IDUs) in Uzbekistan. Results: HCV-3a (67.3%) was the most prevalent genotype in this cohort, followed by HCV-1b (27.3%). A discrepancy in results was observed between structural and non-structural regions in one case (1.8%). Phylogenetically this strain was related to the previously reported RF1_2k/1b variant. Based on accumulated sequences, specific primers were designed for polymerase chain reaction (PCR) spanning the tentative intergenotypic crossover point of RF1_2k/1b. The sensitivity and specificity of the method were assessed using generated template clones of HCV-1b, 2a, 2 k and RF1_2k/1b. The method was applied to 55 cases in the present study and only one case showed a positive result, indicating that in these individuals, the variant is not present as a minor quasispecies clone. Conclusion: In conclusion, the finding of RF1_2k/1b in Central Asia indicates that the variant has wide geographic distribution. The PCR-based screening method developed in this study should be useful in further epidemiological and clinical studies on the recombination phenomenon in HCV.
Notes:
 
DOI   
PMID 
Masaya Sugiyama, Yasuhito Tanaka, Fuat Kurbanov, Nobuaki Nakayama, Satoshi Mochida, Masashi Mizokami (2007)  Influences on hepatitis B virus replication by a naturally occurring mutation in the core gene.   Virology 365: 2. 285-291 Sep  
Abstract: Little is known about specific naturally occurring mutations of hepatitis B virus (HBV) and underlying mechanisms of their association with fulminant hepatitis. A HBV clone isolated from a patient with fulminant hepatitis was analyzed, and the features of the particular mutations observed around furin cleavage site in core region (A2339G/G2345A) were assessed using an in vitro replication model. The clone belonged to genotype B with precore stop codon mutation (G1896A). Replication efficiency of 1.24-fold HBV genome in Huh-7 cells was increased in the presence of A2339G. Further in vitro studies using furin inhibitor indicated that the effect of the mutation was probably associated with accumulation of the full-length core protein without cleavage by furin-like protease, suggesting that a processing of the core protein might play an important role in regulation of viral replication. In conclusion, the A2339G mutation was considered as one of the viral factors involved in high replication efficiency.
Notes:
 
DOI   
PMID 
Abeer Elkady, Yasuhito Tanaka, Fuat Kurbanov, Noboru Hirashima, Masaya Sugiyama, Anis Khan, Hideaki Kato, Akihiko Okumura, Masashi Mizokami (2007)  Evaluation of anti-hepatitis E virus (HEV) immunoglobulin A in a serological screening for HEV infection.   J Gastroenterol 42: 11. 911-917 Nov  
Abstract: BACKGROUND: Several formulations of serological diagnostic kits were developed recently in Japan for detecting hepatitis E virus (HEV) infection. The present study was conducted to evaluate a novel anti-HEV serological kit based on detection of class A immunoglobulin antibody (anti-HEV IgA). METHODS: Serum samples from 81 acute hepatitis (AH) and 112 chronic hepatitis (CH) patients were tested for anti-HEV IgG, anti-HEV IgM, and anti-HEV IgA by enzyme immunoassay, and HEV RNA was detected by reverse transcription-polymerase chain reaction. RESULTS: Eight of 81 (9.9%) AH patients were positive for anti-HEV IgG; 6/81 (7.4%) were positive for anti-HEV IgM; and 3/81 (3.7%) were positive for anti-HEV IgA. HEV RNA was detected only in two patients, and both were positive for anti-HEV IgA and negative for hepatitis A, B, and C virus markers. Of 112 CH patients, reactivity to anti-HEV IgM and anti-HEV IgG was found in two and four patients, respectively. None of these six patients was positive for anti-HEV IgA or HEV RNA. For these six CH patients, serial serum samples stored during the clinical follow-up (1994-2003) were further subjected to anti-HEV IgG, IgM, IgA, and HEV RNA examinations. None of the examined stored samples was reactive for anti-HEV IgA or HEV RNA despite reactivity to anti-HEV IgM and IgG. CONCLUSIONS: Serological examination for anti-HEV IgA together with IgM and IgG allows sensitive and specific determination of acute or past infection with HEV. Although its prevalence is low, HEV infection must be investigated in acute hepatitis patients even in nonendemic HEV countries.
Notes:
 
DOI   
PMID 
Tomoyuki Sakamoto, Yasuhito Tanaka, Josephine Simonetti, Carla Osiowy, Malene L Borresen, Anders Koch, Fuat Kurbanov, Masaya Sugiyama, Gerald Y Minuk, Brian J McMahon, Takashi Joh, Masashi Mizokami (2007)  Classification of hepatitis B virus genotype B into 2 major types based on characterization of a novel subgenotype in arctic indigenous populations.   J Infect Dis 196: 10. 1487-1492 Nov  
Abstract: Hepatitis B virus genotype B (HBV/B) has been classified into 5 subgenotypes. Except for Bj/B1 in Japan, the subgenotypes (Ba/B2-B5) have undergone recombination with HBV/C in the core promoter/precore/core genomic region. Phylogenetic analyses of complete sequences show that the Arctic strains belong to a novel subgenotype (HBV/B6) without the recombination, analogous to what is seen with Bj/B1. Comparison of 50 HBV/B6 carriers from the Arctic versus 50 Bj and 50 Ba age- and sex-matched carriers from Asia revealed that clinical characteristics of HBV/B6 carriers were similar to those of Bj/B1 carriers in Japan. The results suggest that HBV/B may be classified into nonrecombinant (Bj/B1 and B6) and recombinant (Ba/B2-B5) types.
Notes:
 
DOI   
PMID 
Yasuhito Tanaka, Kousuke Hanada, Hideji Hanabusa, Fuat Kurbanov, Takashi Gojobori, Masashi Mizokami (2007)  Increasing genetic diversity of hepatitis C virus in haemophiliacs with human immunodeficiency virus coinfection.   J Gen Virol 88: Pt 9. 2513-2519 Sep  
Abstract: Patients with inherited bleeding disorders who received clotting factor concentrates before 1987 have high rates of hepatitis C virus (HCV) or HCV/human immunodeficiency virus (HIV) infection. To determine whether the persistent nature of HIV affects the genetic diversity of HCV by less selective pressure through the immunosuppression of HIV/HCV-coinfected patients, both the change of genetic diversity and selective pressure were examined in the HCV envelope genes (E1 and E2) of 325 genotype 1a subclones from eight HIV-positive and five HIV-negative patients with two time points (more than 6 years apart). To infer the genetic diversity of HCV in each patient, we used two approaches. One method was to estimate the difference of total evolutionary distances in the phylogenetic tree between the two time points, and another was to estimate the changes of genetic diversity along the time based on the coalescence theory. The two results indicate that the HIV-positive group has significantly more diverse population structure than the HIV-negative group. A comparative analysis of the synonymous and non-synonymous substitutions found that the HIV-positive group was subject to less selective pressure than the HIV-negative group. In conclusion, HIV-positive patients would have a more diversified HCV population than HIV-negative patients due to less selective pressure from the immune system.
Notes:
 
DOI   
PMID 
F Kurbanov, Y Tanaka, A Elkady, T Oyunsuren, M Mizokami (2007)  Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia.   J Viral Hepat 14: 9. 667-674 Sep  
Abstract: An estimated incidence of hepatocellular carcinoma (HCC) in Mongolia is currently one of the highest in the world. According to previous reports, the sero-prevalence of hepatitis B (HBV) and hepatitis C (HCV) viruses in general population of the country is very high (HBV, 10% and HCV, 15%, respectively). Moreover, the majority (75-100%) of the HBV-infected individuals have co-infection with hepatitis Delta virus (HDV). Despite reported observations that HBV + HDV/HCV co-infection have significantly stronger association with HCC when compared with HCV-monoinfection, the later is still frequently observed among Mongolian HCC patients (39%). In this study, an approach based on principles of population genetics and mathematical epidemiology was used to trace an epidemic history of HCV and HDV. In agreement with the sero-epidemiological and social-historical background of the country, the results have demonstrated that the viruses had different epidemic dynamics in Mongolia; HCV was characterized by earlier epidemic expansion, whereas HDV spread with approximately 50 years lag. This may explain the comparable contribution of the HCV-monoinfection and HBV + HDV co-infection in current HCC rate despite different levels of risk of carcinogenesis. Used approach is useful in evaluation of current and prospective disease burden.
Notes:
 
DOI   
PMID 
Z Wang, J Hou, G Zeng, S Wen, Y Tanaka, J Cheng, F Kurbanov, L Wang, J Jiang, N V Naoumov, M Mizokami, Y Qi (2007)  Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China.   J Viral Hepat 14: 6. 426-434 Jun  
Abstract: Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies.
Notes:
 
DOI   
PMID 
Atsunori Kusakabe, Yasuhito Tanaka, Fuat Kurbanov, Kenji Goto, Hitoshi Tajiri, Jun Murakami, Chiaki Okuse, Hiroshi Yotsuyanagi, Takashi Joh, Masashi Mizokami (2007)  Virological features of hepatitis B virus-associated nephropathy in Japan.   J Med Virol 79: 9. 1305-1311 Sep  
Abstract: Hepatitis B virus (HBV)-associated nephropathy is considered as an immune-mediated disorder which is dependent on interactions between viral, host, and environmental factors. But there are few reports that investigated the relationship between the development of HBV-associated nephropathy and HBV genotypes and the mutations. To clarify the relationship between nephropathy and HBV genotype in Japan, six male patients with HBV-associated nephropathy were examined. The complete genome sequences of HBV were determined directly and the specific mutations associated with the development of HBV-associated nephropathy were examined by comparison of the alignments along with consensus sequences [HBV/A1 (Aa), A2 (Ae), B1 (Bj), B2 (Ba), C1 (Cs) and C2 (Ce)] retrieved from international database. The mean age of the six patients was 33.5 years. HBeAg was found in all patients and serum HBV-DNA levels were relatively high. Histological findings of renal tissues indicated five cases of membranous nephropathy and one membranoproliferative glomerulonephritis. HBV genotypes from the six patients were two HBV/A1, two A2 and two C2, suggesting HBV/A was predominant. G1862T mutation was observed in the two HBV/A1 patients, resulting in the pre-core amino acid substitution with a switch from valine (Val) to phenylalanine (Phe). Only one patient had core deletions. It is concluded that HBV/A may be associated with membranous nephropathy, but little relationship between HBV gene mutations and the development of HBV-associated nephropathy was observed.
Notes:
2006
 
DOI   
PMID 
Yasuhito Tanaka, Fuat Kurbanov, Shuhei Mano, Etsuro Orito, Victor Vargas, Juan I Esteban, Man-Fung Yuen, Ching-Lung Lai, Anna Kramvis, Michael C Kew, Heidi E Smuts, Sergey V Netesov, Harvey J Alter, Masashi Mizokami (2006)  Molecular tracing of the global hepatitis C virus epidemic predicts regional patterns of hepatocellular carcinoma mortality.   Gastroenterology 130: 3. 703-714 Mar  
Abstract: BACKGROUND & AIMS: Molecular evolutionary analysis based on coalescent theory can provide important insights into epidemiologic processes worldwide. This approach was combined with analyses of the hepatitis C virus (HCV) epidemiologic-historical background and HCV-related hepatocellular carcinoma (HCC) in different countries. METHODS: The HCV gene sequences of 131 genotype 1b (HCV-1b) strains from Japan, 38 HCV-1a strains from the United States, 33 HCV-1b strains from Spain, 27 HCV-3a strains from the former Soviet Union (FSU), 47 HCV-4a strains from Egypt, 25 HCV-5a strains from South Africa, and 24 HCV-6a strains from Hong Kong isolated in this study and previous studies were analyzed. RESULTS: The coalescent analysis indicated that a transition from constant size to rapid exponential growth (spread time) occurred in Japan in the 1920s (HCV-1b), but not until the 1940s for the same genotype in Spain and other European countries. The spread time of HCV-1a in the United States was estimated to be in the 1960s; HCV-3a in the FSU, HCV-5a in South Africa, and HCV-6a in Hong Kong in the 1960s, mid-1950s, and late 1970s, respectively. Three different linear progression curves were determined by analysis of the relationship between HCV seroprevalence and HCC mortality in different geographic regions; a steep ascent indicated the greatest progression to HCC in Japan, a near horizontal line indicated the least progression in the United States and the FSU, and an intermediate slope was observed in Europe. CONCLUSIONS: These findings strongly suggest that the initial spread time of HCV is associated with the progression dynamics of HCC in each area, irrespective of genotype.
Notes:
 
DOI   
PMID 
Arup Banerjee, Fuat Kurbanov, Sibnarayan Datta, Partha Kumar Chandra, Yasuhito Tanaka, Masashi Mizokami, Runu Chakravarty (2006)  Phylogenetic relatedness and genetic diversity of hepatitis B virus isolates in Eastern India.   J Med Virol 78: 9. 1164-1174 Sep  
Abstract: Hepatitis B virus (HBV) has been classified into eight genotypes, and several subgenotypes, distinctly distributed geographically. The genotypes A and D were previously reported to be predominant in India. Recent studies indicated evidence of circulation of genotype C in Eastern part of India. With the aim to confirm the phylogenetic relation and molecular genetic characteristics of the HBV circulating in Kolkata, the most populous city in Eastern India, 11 strains were isolated and the complete genome sequences were analyzed. Phylogenetic analysis determined; three genotype C (adr-serotype) isolates closely related with C1 (Cs) subgenotype references from South East Asia, and three genotype A (adw2-serotype) isolates, related to Asia-variant references of subgenotype A1 (Aa). Whereas, five genotype D (ayw2, ayw3 serotype) isolates were highly divergent; one was related to subgenotype D1, two to subgenotype D3, and the remaining two clustered with a single genotype D isolate from Japan belonging to an unclassified subgenotype. Together, these two isolates differed from HBV D1-D4 subgenotypes by nucleotide differences ranging from 5.0 to 5.49%, probably indicating a new subgenotype, which we designate as D5. All serotype ayw3 of genotype D isolates had specific amino acid substitution Threonine at codon 118 and Methionine at codon 125 in antigenic determinant of surface gene that has not been reported previously in isolates from other parts of India. In conclusion; using the complete genome analyses this study has confirmed circulation of the genotype C in Eastern part of India and demonstrated considerable genotypic heterogeneity of the Indian genotype D.
Notes:
 
DOI   
PMID 
Yasuhito Tanaka, Motokazu Mukaide, Etsuro Orito, Man-Fung Yuen, Kiyoaki Ito, Fuat Kurbanov, Fuminaka Sugauchi, Yasuhiro Asahina, Namiki Izumi, Michio Kato, Ching-Lung Lai, Ryuzo Ueda, Masashi Mizokami (2006)  Specific mutations in enhancer II/core promoter of hepatitis B virus subgenotypes C1/C2 increase the risk of hepatocellular carcinoma.   J Hepatol 45: 5. 646-653 Nov  
Abstract: BACKGROUND/AIMS: Hepatitis B virus genotype C (HBV/C) has been classified into two geographically distinct subgenotypes; HBV/C1/Cs (Southeast Asia) and HBV/C2/Ce (East Asia). METHODS: Viral differences in enhancer II/core promoter and precore regions between the subgenotypes and their association with hepatocellular carcinoma (HCC) were assessed in a matched cross-sectional control study of 118 carriers (from Hong Kong) with HBV/C1/Cs (48.0 years, 81% male, 40% HBeAg+, 44% HCC) and 210 HBV/C2/Ce (172 from Japan, 38 from Hong Kong) (50.2 years, 78% male, 30% HBeAg+, 46% HCC). RESULTS: Univariate analyses showed that mutation V1753 was predictive for HCC among HBeAg-positive-C1/Cs-carriers (P=0.0055), and T1653 among HBeAg-positive-C2/Ce-carriers (P=0.018), and T1653 or V1753 or T1762/A1764 among HBeAg-negative-C2/Ce-carriers (P<0.05). In the multivariate analysis on all HBV/C subjects, independent predictive factors for HCC were subgenotype C2/Ce (odds ratio, 4.21; 95% confidence interval, 1.07-16.23), T1653 (3.64; 1.93-6.86), V1753 (3.07; 1.66-5.65) and T1762/A1764 (2.58; 1.21-5.49) mutations, age (50 years), gender (male) and HBeAg (positive). CONCLUSIONS: Our data indicate that T1653 and/or V1753 mutations in addition to T1762/A1764 are differently associated with HCC in context of HBeAg status among HBV/C1/Cs and C2/Ce-carriers. HBV/C subgenotypes have specific mutation patterns, which is probably responsible for increased carcinogenesis of HBV/C2/Ce.
Notes:
 
DOI   
PMID 
Tsendsuren Oyunsuren, Fuat Kurbanov, Yasuhito Tanaka, Abeer Elkady, Ruvjir Sanduijav, Onkhoon Khajidsuren, Byambin Dagvadorj, Masashi Mizokami (2006)  High frequency of hepatocellular carcinoma in Mongolia; association with mono-, or co-infection with hepatitis C, B, and delta viruses.   J Med Virol 78: 12. 1688-1695 Dec  
Abstract: To investigate the association between viral infection pattern and hepatocellular carcinoma (HCC), 292 chronic hepatitis patients, including 108 with developed HCC were screened using serological and molecular genetics methods. Viral etiology was established in 267 (91.4%), anti-HCV detected in 198 (67.8%), and HBsAg in 124 (42.5%) including 93 (74.4%) cases with HDV co-infection. HCV mono-infection predominated in both, "non-HCC" and "HCC" groups (54% and 39%, respectively) with higher frequency in the first group (P = 0.011), whereas HBV in co-infection with HDV was more frequent in HCC group (14% vs 25%, P = 0.017). Patients with HCV mono-infection were older than those with co-infection (P<0.02), had higher frequency of HCV-viraemia (82% vs 7%, P < 0.0001), and yet had significantly lower prevalence of HCC (29.6% vs. 49.1%, P = 0.003). Alpha-fetoprotein (AFP) and protein induced by vitamin K antagonist-II (PIVKA-II) were specifically elevated in 71% of HCC patients. In conclusion, although HCV monoinfection pattern predominates in Mongolia, co-infection with HBV and HDV had stronger association with HCC development at younger age. Liver tumor markers; AFP and PIVKA-II are useful tools for complex HCC-screening and clinical follow-up for chronic hepatitis patients in Mongolia.
Notes:
 
DOI   
PMID 
Izumi Hasegawa, Yasuhito Tanaka, Fuat Kurbanov, Namiko Yoshihara, Ahmed El-Gohary, Eligius Lyamuya, Mecky Matee, Pius Magessa, Kei Fujiwara, Atsushi Ozasa, Fuminaka Sugauchi, Etsuro Orito, Ryuzo Ueda, Masashi Mizokami (2006)  Molecular epidemiology of hepatitis B virus in the United Republic of Tanzania.   J Med Virol 78: 8. 1035-1042 Aug  
Abstract: In the United Republic of Tanzania, 457 voluntary blood donors were enrolled in hepatitis B virus (HBV) serological screening; 4.8% (22/457) carried HBsAg, 13.6% (3/22) of whom were HBeAg-positive. The mean age among HBeAg-negative carriers was 31 years. HBV DNA was detectable in 81.8% (18/22), the mean level was 3.67 (+/-1.77) log copies/ml. Genotype A was determined in 90.9% (20/22) and 18/20 were classified into subgenotype Aa (Asia/Africa). The basal core promoter, precore and partial core nucleotide sequences were analyzed in the 18 strains; T1809/T1812 ("Kozak" sequence) and A/T1888 (encapsidation signal) variants were identified in 100% and 78%, respectively. The complete genome sequencing for one of the Tanzanian strains revealed no recombination. In conclusion, HBV seroprevalence is high among general population in Tanzania, and the HBV/Aa-infection is predominant. The indicated tendency to early HBeAg seroconversion and declining of the viral load should be confirmed further in case-control studies.
Notes:
2005
 
PMID 
Motokazu Mukaide, Yasuhito Tanaka, Hirokazu Kakuda, Kei Fujiwara, Fuat Kurbanov, Eturo Orito, Kentaro Yoshioka, Kiyotaka Fujise, Shoji Harada, Takazumi Kozaki, Kazuo Takemura, Kazumasa Hikiji, Masashi Mizokami (2005)  New combination test for hepatitis C virus genotype and viral load determination using Amplicor GT HCV MONITOR test v2.0.   World J Gastroenterol 11: 4. 469-475 Jan  
Abstract: AIM: To develop a new sensitive and inexpensive hepatitis C virus (HCV) combination test (HCV Guideline test) that enables the determination of HCV genotypes 1, 2 and 3, and simultaneous determination of HCV viral load using commercial Amplicor GT HCV MONITOR test v2.0 (microwell version). METHODS: The HCV Guideline test used the PCR product generated in commercial Amplicor GT HCV Monitor test v2.0 for viral load measurement using microwell plate version of Amplicor HCV Monitor and also captured on separate plates containing capture probes and competitive oligonucleotide probes specific for HCV genotypes 1, 2 and 3, The HCV genotype was subsequently determined using the biotin-labeled PCR product and five biotin-labeled HCV-specific probes. RESULTS: The sensitivity of the HCV Guideline test was 0.5 KIU/mL. Specificity of the HCV Guideline test was confirmed by direct sequencing of HCV core region and molecular evolutionary analyses based on a panel of 31 samples. The comparison of the HCV Guideline test and an in-house HCV core genotyping assay using 252 samples from chronic hepatitis C patients indicated concordant results for 97.2% of samples (59.5% genotype 1, 33.7% genotype 2, 6.0% genotype 3, and 0.8% mixed genotypes). Similarly, the HCV Guideline test showed concordance with a serological test, and the serological test failed to assign any serotype in 12.7% of the samples, indicating a better sensitivity of the HCV Guideline test. CONCLUSION: Clinically, both viral load and genotypes (1, 2 and 3) have been found to be major predictors of antiviral therapy outcome regarding chronic hepatitis C based on guidelines and they are, in normal circumstances, performed as separate stand-alone assays. The HCV Guideline test is a useful method for screening large cohorts in a routine clinical setting for determining the treatment regimen and for predicting the outcome of antiviral therapy of chronic hepatitis C.
Notes:
 
DOI   
PMID 
Fuat Kurbanov, Yasuhito Tanaka, Kei Fujiwara, Fuminaka Sugauchi, Dora Mbanya, Leopold Zekeng, Nicaise Ndembi, Charlotte Ngansop, Lazare Kaptue, Tomoyuki Miura, Eiji Ido, Masanori Hayami, Hiroshi Ichimura, Masashi Mizokami (2005)  A new subtype (subgenotype) Ac (A3) of hepatitis B virus and recombination between genotypes A and E in Cameroon.   J Gen Virol 86: Pt 7. 2047-2056 Jul  
Abstract: Blood samples (n=544) from two different populations (Pygmies and Bantus) in Cameroon, West Africa, were analysed. Serological tests indicated that the anti-hepatitis C virus (HCV) prevalence in Bantus (20.3 %) was higher than that in Pygmies (2.3 %, P<0.0001), whereas the distribution of hepatitis B virus (HBV) serological markers was equally high in both populations: in total, 9.4, 17.3 and 86.8 % for HBsAg, anti-HBs and anti-HBc, respectively. HBV genotype A (HBV/A) and HBV/E were predominant (43.5 % each) in both populations, and HBV/D was found in a minority (13 %). The preS/S region was sequenced in nine cases (five HBV/A and four HBV/E) and the complete genome in six cases (four HBV/A and two HBV/E). Subsequent phylogenetic analysis revealed that the HBV/A strains were distinct from the subtypes (subgenotypes) described previously, Ae (A2) and Aa (A1), and in the preS/S region they clustered with previously reported sequences from Cameroon. Based on the nucleotide difference from Aa (A1) and Ae (A2), more than 4 % in the complete genome, the Cameroonian strains were suggested to represent a new subtype (subgenotype), designated HBV/Ac (A3). A high (3.9 %) nucleotide divergence in HBV/Ac (A3) strains suggested that the subtype (subgenotype) has a long natural history in the population of Cameroon. One of the HBV/Ac (A3) strains was found to be a recombinant with an HBV/E-specific sequence in the polymerase reverse transcriptase domain. Further cohort studies will be required to assess detailed epidemiological, virological and clinical characteristics of HBV/Ac (A3), as well as its recombinant form.
Notes:
 
DOI   
PMID 
Yasuhito Tanaka, Etsuro Orito, Man-Fung Yuen, Motokazu Mukaide, Fuminaka Sugauchi, Kiyoaki Ito, Atsushi Ozasa, Tomoyuki Sakamoto, Fuat Kurbanov, Ching-Lung Lai, Masashi Mizokami (2005)  Two subtypes (subgenotypes) of hepatitis B virus genotype C: A novel subtyping assay based on restriction fragment length polymorphism.   Hepatol Res 33: 3. 216-224 Nov  
Abstract: Recently hepatitis B virus genotype C (HBV/C) has been classified into geographically typical two subtypes (subgenotypes); HBV/C1 in Southeast Asia (Cs) and HBV/C2 in East Asia (Ce). Our aim is to develop a rapid subtyping assay and to examine the virological features of these two subtypes. Based on 171 HBV/C strains retrieved from the database, 17 single nucleotides polymorphisms (SNPs) were found between two subtypes. Taking advantage of five SNPs in non-overlapping polymerase region, a restriction fragment length polymporphism method with three endonucleases was newly developed for distinguishing between HBV/Cs and HBV/Ce. The method was applied to 49 HBV/C carriers from Japan and Hong Kong. The 24 in Hong Kong were classified into HBV/Cs, and the 25 in Japan were HBV/Ce, confirmed by sequencing. Some specific mutations were detected in the encapsidation signal; precore stop mutation (A1896), accompanied by a C-to-T substitution at nt 1858, was found in HBV/Ce strains, and another precore mutation (A1898), accompanied by a C-to-T mutation at nt 1856, was found in HBV/Cs. Especially, two closely linked mutations (A1896 and A1899) in HBV/Ce could stabilize the epsilon loop structure more efficiently and influece viral replication. Hence, these virological differences between the two subtypes might influence clinical features.
Notes:
2004
 
DOI   
PMID 
Salah Agha, Yasuhito Tanaka, Niveen Saudy, Fuat Kurbanov, Mostafa Abo-Zeid, Mohamed El-Malky, Mohamed Khalaf, Nobuo Ohta, Hiroshi Yoshizawa, Masashi Mizokami (2004)  Reliability of hepatitis C virus core antigen assay for detection of viremia in HCV genotypes 1, 2, 3, and 4 infected blood donors: a collaborative study between Japan, Egypt, and Uzbekistan.   J Med Virol 73: 2. 216-222 Jun  
Abstract: Nucleic acid amplification-based methods are used for confirmation of viremia in antibody to hepatitis C virus (anti-HCV)-positive patients. However, this technology is labor intensive, time consuming, requires complex laboratory conditions, and expensive. The aim of this study was to evaluate the sensitivity and specificity of the HCV core antigen (HCVcAg) assay as an alternative approach for confirmation of viremia in HCV-infected subjects with HCV genotype 1-4. Two hundred forty-six asymptomatic HCV RNA- positive donors were enrolled in this study, consisting of 122 blood donors from Egypt (116 with genotype 4, 4 with genotype 1, and 2 with 1 + 4 genotypes), 109 from Japan (85 with genotype 1, and 24 with genotype 2), and 15 from Uzbekistan (all with genotype 3). A total of 234 (95.1%) of 246 RNA-positive specimens were detected by the HCVcAg assay; the sensitivity of HCVcAg assay consisted 93.4, 100, 100, and 94.8% for genotypes 1, 2, 3, and 4, respectively in comparison with RT-PCR assay. The specificity of the assay was confirmed in the absence of the false-positive results among 53 anti-HCV-negative, but anti-Schistosoma mansoni (anti-Sm) positive donors from Egypt. A positive correlation between HCVcAg and HCV RNA concentration levels (r = 0.671, P < 0.05) was observed among specimens with HCV genotype 4. The mean HCVcAg level was significantly lower in specimens with genotype 4 (2,935 fmol/L) comparing to genotypes 1, 2, and 3 (5,034, 4,962, and 4,740 fmol/L, respectively). No specific mutation was found in the core-encoding region of the studied specimens. In conclusion, HCVcAg is shown to be specific, sensitive, and informative qualitative index for HCV viremia in asymptomatic carriers.
Notes:
 
DOI   
PMID 
Yasuhito Tanaka, Salah Agha, Niveen Saudy, Fuat Kurbanov, Etsuro Orito, Takanobu Kato, Mostafa Abo-Zeid, Mohamed Khalaf, Yuzo Miyakawa, Masashi Mizokami (2004)  Exponential spread of hepatitis C virus genotype 4a in Egypt.   J Mol Evol 58: 2. 191-195 Feb  
Abstract: Hepatitis C virus (HCV) infects >10% of the general population in Egypt, in which intravenous injection with an antimony compound for endemic schistosomiasis in the past has been implicated. To simulate the epidemic history of HCV in Egypt, sera were obtained from 3608 blood donors at 13 governorates in or surrounding the Nile valley during 1999. The prevalence of antibody to HCV (anti-HCV) and genotypes was determined in them, and the molecular evolutionary analysis based on the neutral theory was applied to HCV isolates of genotype 4a, which is outstandingly prevalent in Egypt and indigenous there. Of 3608 sera, 317 (8.8%) were positive for anti-HCV. The molecular evolutionary analysis on 47 HCV genotype 4a isolates of carriers from various districts in Egypt indicated that the spread of HCV-4a would have increased exponentially during the 1940s through 1980 when oral medications became available. In conclusion, the estimated spread time is consistent with the duration of intravenous antimony campaigns in Egypt.
Notes:
2003
 
PMID 
Hideaki Kato, Etsuro Orito, Fuminaka Sugauchi, Ryuzo Ueda, Takuya Koshizaka, Shoko Yanaka, Robert G Gish, Fuat Kurbanov, Ruslan Ruzibakiev, Anna Kramvis, Michael C Kew, Nooruddin Ahmad, Mobin Khan, Sadakazu Usuda, Yuzo Miyakawa, Masashi Mizokami (2003)  Frequent coinfection with hepatitis B virus strains of distinct genotypes detected by hybridization with type-specific probes immobilized on a solid-phase support.   J Virol Methods 110: 1. 29-35 Jun  
Abstract: A genotype-specific probes assay (GSPA) was developed for distinguishing the seven genotypes (A-G) of hepatitis B virus (HBV). Nucleotide (nt) sequences corresponding to preS1 region were amplified by PCR with a primer labeled with biotin, and delivered to eight wells on which complementary sequences specific to one or other genotype had been immobilized. Thereafter, hybridization of HBV DNA sequences amplified from the test serum was detected by colorimetry. When 256 sera from HBV carriers in Bangladesh, Cameroon, Japan, South Africa, USA and Uzbekistan were subjected to GSPA, genotypes were concordant with those of ELISA with monoclonal antibodies to epitopes on preS2-region products in 242 (94.6%) of them; 8 sera (3.1%) were not genotypeable by either method. Cloning analysis confirmed the presence of two distinct HBV genotypes in the seven selected sera with coinfection. There were 7 (2.7%) sera with discordant genotyping results between GSPA and ELISA. When HBV DNA clones propagated from these sera were sequenced and analyzed phylogenetically, the genotypes determined by GSPA were verified. Coinfection with HBV strains of two distinct genotypes was identified by GSPA in 28 (10.9%) sera, while it was suggested by ELISA in only 2 (0.8%) sera. The GSPA method would be particularly useful for detecting the coinfection with distinct HBV genotypes of any clinical relevance, which seems to be more frequent than reported previously.
Notes:
 
DOI   
PMID 
Fuat Kurbanov, Makiko Kondo, Yasuhito Tanaka, Mariam Zalalieva, Guzal Giasova, Takako Shima, Nao Jounai, Nadira Yuldasheva, Ruslan Ruzibakiev, Masashi Mizokami, Mitsunobu Imai (2003)  Human immunodeficiency virus in Uzbekistan: epidemiological and genetic analyses.   AIDS Res Hum Retroviruses 19: 9. 731-738 Sep  
Abstract: This study investigates the molecular epidemiology of HIV in Uzbekistan--a former Soviet Union (FSU) country located in central Asia. A total of 18,910,370 subjects were involved in an HIV serological examination through a population survey conducted in 1987-2002. Rapid changes in epidemiological dynamics and transmission modes have been observed since 1999: incidence rose from 25 newly HIV-infected subjects per year to more than 100 new cases per month within the first half of 2002, and the rate of intravenous drug use (IVDU)-associated HIV infection increased to 75% per year during the same period. Thirty HIV-1 strains, isolated from specimens obtained in 1999-2000, were directly sequenced in the env region. Phylogenetic analysis revealed a relationship to genotype A in 56.7%, and to 03_CRFAB in 13.3%; both variants have been previously reported in the FSU. The majority (85.7%) of these strains were isolated from IVDUs. The demographic history of the most prevalent HIV strain in Uzbekistan was inferred from reconstructed molecular phylogenies; exponential growth of the viral population size was thus observed to occur after the mid-1990s. In summary, detectable HIV seroprevalence remains low in the general population of Uzbekistan. However, the current study demonstrates a substantially increasing number of new infections, in association with IVDU, and an exponentially growing effective population size of the IVDU-associated HIV strain.
Notes:
 
DOI   
PMID 
Fuat Kurbanov, Yasuhito Tanaka, Fuminaka Sugauchi, Hideaki Kato, Ruslan Ruzibakiev, Mariam Zalyalieva, Zulhumor Yunusova, Masashi Mizokami (2003)  Hepatitis C virus molecular epidemiology in Uzbekistan.   J Med Virol 69: 3. 367-375 Mar  
Abstract: The aim of this study was to identify hepatitis C virus (HCV) genotypes and to estimate their prevalence in various risk groups and the regional distribution in Uzbekistan. Preliminary serological screening of 1,269 subjects revealed 6.5% anti-HCV-positive in a general population, 27.1% in patient groups, and 51.7% among intravenous drug users. HCV genotypes of 104 anti-HCV-positive subjects were determined using a PCR-genotyping system in core region, and the results were supported by nucleotide sequencing of the NS5B region. Genotype 1b identified in total 64.2%, was the most prevalent. The genotype 3a identified in 25.0% was the second one distributed. HCV genotypes 2a, 1a, 2b, and 3b were identified in 3.8%, 2.9%, 2.9%, and 1.0% of cases, respectively. The intravenous drug users were distinguished from other groups by having the highest prevalence of genotype 3a, i.e., 50.0%, higher than the 33.3% for genotype 1b in this group. Geographically, genotype 1b was common; genotype 3a was also found frequently in all three regions. Uncommon HCV genotypes (1a, 2a, 2b, and 3b) were found in comparatively greater variability in the western region. Molecular evolutionary analysis based on the NS5B region did not reveal specific clustering or indigenous strains among Uzbekistan HCV isolates. In summary, two main mechanisms of HCV infection distribution were observed in Uzbekistan: HCV 1b genotype infection is widespread through blood products, and HCV 3a genotype infection is spreading through the growing number of intravenous drug users.
Notes:
2002
 
DOI   
PMID 
Hideaki Kato, Ruslan Ruzibakiev, Nodira Yuldasheva, Tatyana Hegay, Fuat Kurbanov, Bakhodir Achundjanov, Lazis Tuichiev, Sadakazu Usuda, Ryuzo Ueda, Masashi Mizokami (2002)  Hepatitis B virus genotypes in Uzbekistan and validity of two different systems for genotyping.   J Med Virol 67: 4. 477-483 Aug  
Abstract: Hepatitis B virus (HBV) has been classified into seven genotypes, designated A-G. The HBV genotype has a characteristic geographical distribution. The Republic of Uzbekistan is located in the heart of Asia and has been considered to be a region with high endemicity of hepatitis viruses. However, the present distribution of hepatitis virus infection in this region is unknown. The aim of this study was to investigate the distribution of HBV genotypes and to elucidate the validity of two genotyping systems in Uzbekistan. Fifty-four patients with hepatitis B surface antigen were investigated. HBV genotypes were determined by two methods: one based on restriction fragment length polymorphism (RFLP) targeting to S region, and another on enzyme-linked immunosorbent assay (ELISA), using monoclonal antibodies to pre-S2 region. Seven (13%) and 47 (87%) of the 54 subjects were classified into genotypes A and D, respectively. Dual infection of two viral populations of the same genotype was observed in one subject. No significant difference of ALT level (203.3 +/- 244.7 vs. 190.6 +/- 39.5) and HBeAg (42.9% vs. 42.6%) were found between genotypes A and D. In this study, the validity of the genotyping systems in this region was confirmed.
Notes:
2001
 
PMID 
R Ruzibakiev, H Kato, R Ueda, N Yuldasheva, T Hegay, D Avazova, F Kurbanov, M Zalalieva, L Tuichiev, B Achundjanov, M Mizokami (2001)  Risk factors and seroprevalence of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection in uzbekistan.   Intervirology 44: 6. 327-332  
Abstract: OBJECTIVES: The aim of this study was to elucidate the seroprevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection in Uzbekistan and to explore whether there is a correlation between those blood-borne agents and socioeconomic risk factors. METHODS: One thousand nine hundred and eighteen subjects were studied. The subjects were divided into a low-risk group, a high-risk group and a patient group. Sera were tested for HBV surface antigen (HBsAg), anti-HCV, and anti-HIV. RESULTS: The seroprevalence of HBsAg, anti-HCV, and anti-HIV in the general population was 13.3, 13.1 and 0%, respectively. The anti-HCV infection rate was significantly higher in intravenous drug users (62.7%) than in prostitutes (9.2%), homosexuals (11.1%), and medical laboratory employees (12.5%) (p < 0.01). In the low-risk group, positivity for anti-HCV increased with age from 2.2% in the 15- to 20-year-olds up to the highest rate of 17.6% in the 31- to 40-year-olds; the positivity then decreased to 0% in the group over 60 years of age. In the high-risk group, the positivity for anti-HCV in the age groups under 40 years was approximately 30% and significantly higher than in the low-risk group (p < 0.01). Risk factors for transmission of HCV were medical treatment in the low-risk group, drug abuse in the high-risk group, and both in the patient group. CONCLUSIONS: This study demonstrates that the seroprevalence of HBV and HCV infection is high, whereas HIV infection is yet uncommon in Uzbekistan.
Notes:
Powered by publicationslist.org.