Prospective study of hepatitis B and D epidemiology and risk factors in Romania:A 10-year update

BACKGROUND The global burden of hepatitis D virus(HDV)infection represents a major medical challenge and a public health crisis worldwide.However,there is a lack of accurate data on the epidemiology and risk factors for HDV.Hepatitis B virus(HBV)and HDV coinfection causes the most severe form of viral hepatitis,leading to a higher cumulative incidence of liver-related events compared with HBV monoinfection,including the need for liver transplantation and death.AIM To investigate the epidemiology,natural history,risk factors and clinical management of HBV and HDV coinfection in Romanian patients.METHODS This prospective study was conducted between January and July 2022 in six tertiary gastroenterology and hepatology referral centres in Romania.All consecutive adults admitted for any gastroenterology diagnosis who were HBV-positive were enrolled.Patients with acute hepatitis or incomplete data were excluded.Of the 25390 individuals who presented with any type of gastroenterology diagnosis during the study period,963 met the inclusion criteria.Testing for anti-HDV antibodies and HDV RNA was performed for all participants.Demographic and risk factor data were collected by investigators using medical charts and patient questionnaires.All data were stored in an anonymized online database during the study.RESULTS The prevalence of HBV was 3.8%;among these patients,the prevalence of HBV/HDV coinfection was 33.1%.The median age of the study population was 54.0 years,and it consisted of 55.1%men.A higher prevalence of HBV/HDV coinfection was observed in patients 50–69 years old.Patients with HBV/HDV coinfection were significantly older than those with HBV monoinfection(P=0.03).Multivariate multiple regression analysis identified female gender(P=0.0006),imprisonment(P<0.0001),older age at diagnosis(P=0.01)and sexual contact with persons with known viral hepatitis(P=0.0003)as significant risk factors for HDV.CONCLUSION This study shows that HDV infection among those with HBV remains endemic in Romania and updates our understanding of HDV epidemiology and associated risk factors.It emphasizes the need for systematic screening for HDV infection and collaborative initiatives for controlling and preventing HBV and HDV infection.

Molecular epidemiology of hepatitis B virus in Asia

Although safe and effective vaccines against hepatitis B virus(HBV) have been available for three decades, HBV infection remains the leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma(HCC) worldwide, especially in Asian countries. HBV has been classified into at least 9 genotypes according to the molecular evolutionary analysis of the genomic DNA sequence and shown to have a distinct geographical distribution. Novel HBV genotypes/subgenotypes have been reported, especially from Southeast Asian countries. The clinical characteristics and therapeutic effectiveness of interferon(IFN) and nucleos(t)ide analogues vary among different HBV genotypes. Mutations at T1653 C in subgenotype C2 from Japan and South Korea, C/A1753 T and C1858 T in subgenotype C1 from Vietnam, and C1638 T and T1753 V in subgenotype B3 from Indonesia were reported to be associated with advanced liver diseases including HCC. Genotype distribution in Japan has been changed by an increasing ratio of subgenotype A2 in chronic hepatitis B. While a large number of epidemiological and clinical studies have been reported from Asian countries, most of the studies were conducted in developed countries such as Taiwan, China, South Korea and Japan. In this review, the most recent publications on the geographical distribution of genetic variants of HBV and related issues such as disease progression and therapy in Asia are updated and summarized.

Clinical epidemiology of chronic viral hepatitis B:A Tuscany real-world large-scale cohort study

AIM To build a regional database of chronic patients to define the clinical epidemiology of hepatitis B virus(HBV)-infected patients in the Tuscan public health care system.METHODS This study used a cross-sectional cohort design. We evaluated chronic viral hepatitis patients with HBV referred to the outpatient services of 16 hospital units. Information in the case report forms included main demographic data, blood chemistry data, viral hepatitis markers, instrumental evaluations, and eligibility for treatment or ongoing therapy and liver transplantation. RESULTS Of 4015 chronic viral hepatitis patients, 1096(27.3%) were HBV infected. The case report form was correctly completed for only 833 patients(64% males, 36% females; mean age 50.1 ± 15.4). Of these HBV-infected patients, 73% were Caucasian, 21% Asian, 4% Central African, 1% North African and 1% American. Stratifying patients by age and nationality, we found that 21.7% of HBV-infected patients were aged < 34 years(only 2.8% were Italian). The most represented routes of transmission were nosocomial/dental procedures(23%), mother-to-child(17%) and sexual transmission(12%). The most represented HBV genotypes were D(72%) and A(14%). Of the patients, 24.7% of patients were HBe Ag positive, and 75.3% were HBe Ag negative. Of the HBV patients 7% were anti-HDV positive. In the whole cohort, 26.9% were cirrhotic(35.8% aged < 45 years), and 47% were eligible for or currently undergoing treatment, of whom 41.9 % were cirrhotic. CONCLUSION Only 27.3% of chronic viral hepatitis patients were HBV infected. Our results provide evidence of HBV infection in people aged < 34 years, especially in the foreign population not protected by vaccination. In our cohort of patients, liver cirrhosis was also found in young adults.

Hepatitis B virus/hepatitis D virus epidemiology: Changes over time and possible future influence of the SARS-CoV-2 pandemic

Hepatitis D virus(HDV)is a defective liver-tropic virus that needs the helper function of hepatitis B virus(HBV)to infect humans and replicate.HDV is transmitted sexually or by a parenteral route,in co-infection with HBV or by super-infection in HBV chronic carriers.HDV infection causes acute hepatitis that may progress to a fulminant form(7%-14%by super-infection and 2%-3%by HBV/HDV co-infection)or to chronic hepatitis(90%by HDV super-infection and 2%-5%by HBV/HDV co-infection),frequently and rapidly progressing to cirrhosis or hepatocellular carcinoma(HCC).Peg-interferon alfa the only recommended therapy,clears HDV in only 10%-20%of cases and,consequently,new treatment strategies are being explored.HDV endemicity progressively decreased over the 50 years from the identification of the virus,due to improved population lifestyles and economic levels,to the use of HBV nuclei(t)side analogues to suppress HBV replication and to the application of universal HBV vaccination programs.Further changes are expected during the severe acute respiratory syndrome coronavirus-2 pandemic,unfortunately towards increased endemicity due to the focus of healthcare towards coronavirus disease 2019 and the consequently lower possibility of screening and access to treatments,lower care for patients with severe liver diseases and a reduced impulse to the HBV vaccination policy.

Hepatitis D virus dual-infection among Chinese hepatitis B patient related to hepatitis B surface antigen,hepatitis B virus DNA and age

The screening practices for hepatitis D virus(HDV)are diverse and nonstandardized worldwide,and the exact prevalence of HDV is uncertain.AIM To estimate HDV prevalence and investigate viral marker quantity trends in patients with hepatitis D.METHODS We collected 5594 serum samples from patients with hepatitis B in Jilin Province,China(3293 males and 2301 females,age range of 2 to 89 years).We then conducted tests for hepatitis B surface antigen(HBsAg),hepatitis B Virus(HBV)DNA,anti-hepatitis D antigen(HDAg),and HDV RNA.RESULTS We found that the prevalence of anti-HDAg and HDV RNA among hepatitis B patient were 3.6%(3.2-4.2%)and 1.2%(0.9-1.5%),respectively,87.69%of hepatitis D patients were 51-70 years old.HDV infection screening positive rate of patients with HBV DNA levels below 2000 IU/mL(2.0%)was higher than those above 2000 IU/mL(0.2%).Among anti-HDAg positive patients,the HDV RNA positive rate was positively correlated with the HBsAg level and anti-HDAg level.There was a weak correlation between HBsAg and anti-HDAg levels among hepatitis D patients.CONCLUSION Our study highlights the importance of considering multiple factors when assessing the severity of HDV infection,comprehensive evaluation of patients’clinical and laboratory parameters is necessary for proper diagnosis and treatment.

Seroepidemiology of hepatitis B virus infection and impact of vaccination

AIM: To investigate hepatitis B virus(HBV) prevalence in the general population in China.METHODS: A total of 148931 individuals were investigated by multistage random sampling in Eastern China. Data were collected on demographics and hepatitis B vaccination history, and serum was tested for hepatitis B surface antigen(HBs Ag) by ELISA. RESULTS: A total of 11469 participants(7.70%, 95%CI: 7.57%-7.84%) were positive for HBs Ag. HBs Ag prevalence was 0.77% among children < 5 years old but increased progressively from adolescents(1.40%-2.55%) to adults(5.69%-11.22%). A decrease in HBs Ag prevalence was strongly associated with vaccination and familial history of HBV among both children and adult groups. Meanwhile, HBs Ag risk in adults was associated with invasive testing and sharing needles. The HBV immunization rate among participants aged < 20 years was 93.30%(95%CI: 93.01%-93.58%). Significant difference in HBs Ag prevalence appeared between vaccinated and unvaccinated participants(3.59% vs 10.22%). CONCLUSION: Although the national goal of HBs Ag prevalence < 1% among children < 5 years old has been reached, immunization programs should be maintained to prevent resurgence.

Epidemiology of Hepatitis B and Associated Liver Diseases in China

Hepatitis B virus (HBV) infection has long been a critical public health challenge in China. National surveys revealed a prevalence of approximate 10% for chronic HBV infection in general population. HBV has been the leading cause of chronic hepatitis, cirrhosis, and liver cancers in Chinese population and a common pathogen of acute viral hepatitis. Meanwhile, the epidemic provided important opportunities to research the natural history, public health impact, and therapeutic and preventive interventions for HBV in China. In this review, we summarized the selected key epidemiological studies since 1970s regarding HBV infection and its associated liver diseases in China, and provided considerations for future research, prevention and treatment of HBV.

Epidemiology of acute and chronic hepatitis B and delta over the last 5 decades in Italy

The spread of hepatitis B virus(HBV)infection has gradually decreased in Italy in the last 5 decades as shown by the steady reduction in the incidence rates of acute hepatitis B,from 10/100000 inhabitants in1984 to 0.85/100000 in 2012,and by the reduced prevalence of hepatitis B surface antigen(HBsAg)-positive cases among chronic hepatitis patients with different etiologies,from 60%in 1975 to about 10%in 2001.The prevalence of HBsAg chronic carriers in the general population also decreased from nearly 3%in the 1980s to 1%in 2010.Linked to HBV by its characteristics of defective virus,the hepatitis delta virus(HDV)has shown a similar epidemiological impact on the Italian population over time.The incidence of acute HDV infection decreased from 3.2/100000 inhabitants in 1987 to 0.8/100000 in 2010 and the prevalence of HDV infection in HBsAg chronic carriers decreased from24%in 1990 to 8.5%in 2006.Before the beneficial effects of HBV mass vaccination introduced in 1991,the decreased endemicity of HBV and HDV infection in Italy paralleled the improvement in screening blood donations,the higher standard of living and impressive reduction in the birth rate associated with a marked reduction in the family size.A further contribution to the decline in HBV and HDV infections most probably came from the media campaigns to prevent the spread of human immunodeficiency virus infection by focusing the attention of the general population on the same routes of transmission of viral infections such as unsafe sexual intercourse and parenteral exposures of different kinds.

Epidemiological and clinical aspects of hepatitis B virus infection in Italy over the last 50 years

A relevant gradual reduction of both the incidence rate of acute hepatitis B(AHB)and prevalence of chronic hepatitis B has occurred in Italy in the last 50 years,due to substantial epidemiological changes:Improvement in socioeconomic and hygienic conditions,reduction of the family unit,accurate screening of blood donations,abolition of re-usable glass syringes,hepatitis B virus(HBV)-universal vaccination started in 1991,use of effective well tolerated nucleo(t)side analogues able to suppress HBV replication available from 1998,and educational mediatic campaigns against human immunodeficiency virus infection focusing on the prevention of sexual and parenteral transmission of infections.As an example,AHB incidence has gradually decreased from 10/100000 inhabitants in 1985 to 0.21 in 2020.Unfortunately,the coronavirus disease 2019(COVID-19)pandemic has interrupted the trend towards HBV eradication.In fact,several HBV chronic carriers living in the countryside have become unable to access healthcare facilities for screening,diagnosis,clinical management,and nucleo(t)side analogue therapy in the COVID-19 pandemic,mainly for anxiety of becoming infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),movement restrictions,and reduced gains from job loss.In addition,one-third of healthcare facilities and personnel for HBV patients have been devolved to the COVID-19 assistance.

Epidemiology and prevention of hepatitis B virus in China

Hepatitis B virus (HBV) infection is prevalent in China. Approximately 600 million people have ever been infected by HBV. About 130 million are HBV chronic carriers and 30 million HB patients. Among them, 50% of HBV carriers are caused by carrier mothers to born infants. Around 300 000 people died of liver disease including liver cirrhosis and primary hepatocellular carcinoma each year and 50% of them died of primary hepatocellular carcinoma. HBV infection is not only the health problem but also becoming a social problem. HBV chronic carriers and patients have endured the great pressure from disease burden and social discrimination. According to the report of the national screening program of HBV released by the ministry of health in 2008, China has taken many effective measures to control the HBV infection, including vaccine immunization program, strengthening the management of blood sources and blood productions, prevention of nosocomial HBV infection, strengthening health education on HBV infection and safe injection techniques. The implementation of HB vaccine immunization program, which China officially introduced into the national immunization program since 1992, has dramatically reduced the incidence of HBV infection among infants and children. Integrated with other interventions, the rate of HBV infection decreased gradually. According to the survey of the national screening program of HBV in 2006, compared with the incidence of HBV in 1992, the incidence rate of HBsAg positive has decreased 26.36% , the number of children who have ever been infected by HBV decreased 80 million since 1992. However some problems are still existing. The solutions of low rate of vaccination in rural areas and migration population, lacking of practical measures on management of hepatitis B patients, the occurrence of health care acquired HBV infection, and low rate of vaccination among high risk groups have also been recommended.

Epidemiology and transmission of hepatitis B and C viruses in Kazakhstan

AIM: To investigate the epidemiology of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in the two major ethnic groups in Kazakhstan. METHODS: A cross-sectional prospective study of HBV and HCV seroprevalence was performed among individuals born in Kazakhstan with no history of chronic hepatitis or liver disease. RESULTS: There were 290 volunteers (140 Russians and 150 Kazakhs) aged 10 to 64 years, males accounted for 46%. Active HBV infection (HBsAg positive) was present in 3.8%, anti-HBc in 30%. The prevalence was similar in females and males (33% vs 25%) (P = 0.18). The prevalence of anti-HBc increased from 19% in 10-29 years old volunteers to 53% in 50-years and older volunteers. The prevalence of HBV infection was higher in married than in single adults (38% vs 26%, respectively) (P = 0.2) and more common in Kazakhs (35%) than in Russians (24%) (P = 0.07). HCV infection was present in 9 subjects (3.2%), 5 of them also were positive for anti-HBc in the absence of HBsAg. CONCLUSION: The frequency of active HBV infection (3.8%) coupled with a high prevalence of HBV exposure in those > 50 years of age increases with age, which suggests that horizontal transmission likely relates tothe use of contaminated needles. The low prevalence of HCV infection suggests that HBV and HCV are acquired differently in this group of subjects.

Epidemiological, Clinical and Biological Characteristics of Patients with Chronic Hepatitis B Infection Followed-Up at the University Hospital of Conakry, Guinea

Introduction: Very little information is available in Guinea on chronic hepatitis B infections. The objective of this study was to describe the epidemiological, clinical and biological features of patients who are chronic carriers of the hepatitis B virus. Patients and Methods: This is a retrospective study carried out from January 2017 to May 2020, based on the medical records of patients seen via consultation or hospitalized with a record of positive HBs antigen for more than 6 months. Clinical and paraclinical data were collected and analyzed. Results: Seven hundred and sixteen patients with a mean age of 35.6 ± 12.2 (sex ratio 2.05), were included. The HBs antigen was discovered incidentally in 36% of cases (n = 258). A history of dental care and surgical procedures was found in 46.3% (n = 290) and 21.1% (n = 138) of cases, respectively. The median value of ALAT enzymes was 34 (21 - 47) IU/L. HBeAg was positive in 20.8% (n = 55/265) of cases. The median B viral load was 458.5 (87 - 3827) IU/ml and 29% (n = 94) of patients had a viral load over 2000 IU/ml. Anti-HCV antibody was present in 10.4 % of cases (n = 39/374). HIV serology was positive in 2.7% (n = 8/298). A total of 19.4% (n = 139) of the patients had cirrhosis and 4.5% (n = 32) had hepatocellular carcinoma. Conclusion: The discovery of chronic HBs antigen was mostly fortuitous in young sexually active men, some of whom were already at the stage of cirrhosis and hepatocellular carcinoma. The best prevention strategy against this infection remains early detection and vaccination.

A comparative study on serologic profiles of virus hepatitis B

INTRODUCTIONHepatitis B viral infection, one of the most-prevalent liver disorders in China and Korea, is aserious infectious disease as it has the potential ofprogressing into liver cirrhosis and primary hepaticcarcinoma. China and Korea both belong to high-risk endemic regions of viral hepatitis[1]. TheHBsAg positive rates in China ranged from 6.9% -17.9% by age, race and test methods[2-5].

Epidemiological and clinical features of hepatitis B virus related liver failure in China

AIM:To examine the epidemiologic and clinical characteristics of hepatitis B virus (HBV) related liver failure in patients in China.METHODS:This study was conducted with a retrospective design to examine 1066 patients with HBVrelated liver failure in the southwest of China.RESULTS:There were more male than female patients.Young and middle-aged people comprised most of the patients.Farmers and laborers comprised the largest proportion (63.09%).Han Chinese accounted for 98.12%,while minority ethnic groups only accounted for 0.88% of patients.A total of 43.47% patients had a family history of HBV-related liver failure and 56.66% patients had a history of drinking alcohol.A total of 42.59% patients with HBV-related liver failure had definite causes.With regard to the clinical manifestation of HBV-related liver failure,the symptoms were:hypodynamia,anorexia and abdominal distension.Total bilirubin (TBIL) and alanine aminotransferase (ALT) levels were altered in 46.23% of patients with evident damage of the liver.Univariate logistic regression analysis showed that the patients' prognoses were correlated with ALT,aspartate aminotransferase,albumin,TBIL,prothrombin activity (PTA),and alpha-fetoprotein levels,and drinking alcohol,ascites,hepatorenal syndrome,infection and ≥ 2 complications.Multifactor logistic regression analysis showed that the activity of thrombinogen and the number of complications were related to the prognosis.CONCLUSION:Alcohol influences the patients' prognosis and condition.PTA and complications are independent factors that can be used for estimating the prognosis of HBV-related liver failure.

Different natural courses of chronic hepatitis B with genotypes B and C after the fourth decade of life

AIM: To investigate the different impact of genotypes B and C on the development of liver cirrhosis (LC) among different age groups of patients with chronic hepatitis B (CH-B). METHODS: We examined the outcome of 121 patients with CH-B, divided by age and genotype. Univariate analyses were used to compare different groups. The Cox proportional hazard model was employed to evaluate factors affecting the development of LC. RESULTS: In patients < 30 years old, there were no significant predictors for development of LC. However, in patients ≥ 30 years old, genotype C was the only significant predictor. In the genotype C group, 8 of 12 patients who progressed to LC were 30-49 years old at initial diagnosis of chronic hepatitis (7 patients were positive for HBeAg). In the genotype B group, 4 of 8 patients who developed LC were ≥ 50 years old at initial diagnosis and were HBeAg-negative. CONCLUSION: The rate of development of LC was comparable in patients infected with genotypes B and C when CH-B occurred at < 30 years old. However, CH-B patients infected with genotype C showed poor prognosis if they were 30-49 years old and were positive for HBeAg. Age-specific natural course of CH-B should be considered when patients with CH-B are treated with antiviral drugs.

Epidemiologic and socioeconomic factors impacting hepatitis B virus and related hepatocellular carcinoma

Chronic Hepatitis B is a highly prevalent disease worldwide and is estimated to cause more than 800000 annual deaths from complications such as cirrhosis and hepatocellular carcinoma(HCC).Although universal hepatitis B vaccination programs may have reduced the incidence and prevalence of chronic hepatitis B and related HCC,the disease still imposes a significant healthcare burden in many endemic regions such as Africa and the Asia-Pacific region.This is especially concerning given the global underdiagnosis of hepatitis B and the limited availability of vaccination,screening,and treatment in low-resource regions.Demographics including male gender,older age,ethnicity,and geographic location as well as low socioeconomic status are more heavily impacted by chronic hepatitis B and related HCC.Methods to mitigate this impact include increasing screening in high-risk groups according to national guidelines,increasing awareness and health literacy in vulnerable populations,and developing more robust vaccination programs in under-served regions.

Molecular analysis of hepatitis B virus isolates in Mexico:Predominant circulation of hepatitis B virus genotype H

AIM: To determine the genotypes in Mexican hepatitis Bvirus (HBV) isolates and characterize their precore andcore promoter mutations.METHODS: Forty-nine HBV isolates of Mexico obtainedfrom sera of 15 hepatitis patients, 6 hemodialysis pa-tients, 20 men seeking HIV testing, and 8 AIDS patientswere analyzed. HBV isolates were amplified by PCR,and genotyped by line probe assay (INNO-LiPA HBVGenotyping; INNOGENETICS N V, Ghent, Belgium).HBV genotype confirmation was performed by DNAsequencing part of the sAg region. Precore and core pro-moter mutation characterization was performed by lineprobe assay (INNO-LiPA HBV PreCore; INNOGENETICS NV, Ghent, Belgium).RESULTS: Overall, HBV genotype H was found in 37(75.5%) out of the 49 isolates studied. HBV genotypesG, A, and D were found in 5 (10.2%), 4 (8.2%), and 3(6.1%) isolates, respectively. HBV genotype H was pre-dominant in isolates from hemodialysis patients (100%),hepatitis patients (80%), and men seeking HIV test-ing (75%), and accounted for half of infections in AIDSpatients (50%). Six (12.2%) out of the 49 HBV isolatesshowed both wild type and mutant populations at pre-core codon 28. These mixed wild type and precore mu-tant populations were observed in one HBV genotype Aisolate and in all HBV genotype G isolates. A dual variantcore promoter mutation was observed in 1 (2%) of theisolates, which was genotype H.CONCLUSION: HBV genotype H is highly predominantin HBV isolates of Mexico followed by genotypes G, Aand D. A low frequency of precore and core promotermutations is observed in HBV Mexican isolates.

Enigmatic origin of hepatitis B virus:An ancient travelling companion or a recent encounter?

Hepatitis B virus(HBV)is the leading cause of liver disease and infects an estimated 240 million people worldwide.It is characterised by a high degree of genetic heterogeneity because of the use of a reverse transcriptase during viral replication.The ten genotypes(A-J)that have been described so far further segregate into a number of subgenotypes which have distinct ethno-geographic distribution.Genotypes A and D are ubiquitous and the most prevalent genotypes in Europe(mainly represented by subgenotypes D1-3 and A2);genotypes B and C are restricted to eastern Asia and Oceania;genotype E to central and western Africa;and genotypes H and F(classified into 4 subgenotypes)to Latin America and Alaska.This review summarises the data obtained by studying the global phylodynamics and phylogeography of HBV genotypes,particularly those concerning the origin and dispersion histories of genotypes A,D,E and F and their subgenotypes.The lack of any consensus concerning the HBV substitution rate and the conflicting data obtained using different calibration approaches make the time of origin and divergence of the various genotypes and subgenotypes largely uncertain.It is hypothesised that HBV evolutionary rates are time dependent,and that the changes depend on the main transmission routes of the genotypes and the dynamics of the infected populations.

Molecular epidemiology and putative origin of hepatitis C virus in random volunteers from Argentina

AIM:To study the subtype prevalence and the phylogenetic relatedness of hepatitis C virus(HCV)sequences obtained from the Argentine general population,a large cohort of individuals was analyzed.METHODS:Healthy Argentinian volunteers(n=6251)from 12 provinces representing all geographical regions of the country were studied.All parents or legal guardians of individuals younger than 18 years provided informed written consent for participation.The corresponding written permission from all municipal authorities was obtained from each city or town where subjects were to be included.HCV RNA reverse transcription-polymerase chain reaction products were sequenced and phylogenetically analyzed.The 5’untranslated region(5’UTR)was used for RNA detection and initial genotype classification.The NS5B polymerase region,encompassing nt 8262-8610,was used for subtyping.RESULTS:An unexpectedly low prevalence of HCV infection in the general population(0.32%)was observed.Our data contrasted with previous studies that reported rates ranging from 1.5%to 2.5%,mainly performed in selected populations of blood donors or vulnerable groups.The latter values are in keeping with the prevalence reported by the 2007 Argentinian HCV Consensus(approximately 2%).HCV subtypes weredistributed as follows:1a(25%),1b(25%),2c(25%),3a(5%),and 2j(5%).Two isolates ascribed either to genotype 1(5%)or to genotype 3(5%)by 5’UTR phylogenetic analysis could not be subtyped.Subtype 1a sequences comprised a highly homogeneous population and clustered with United States sequences.Genotype1b sequences represented a heterogeneous population,suggesting that this genotype might have been introduced from different sources.Most subtype 2c sequences clustered close to the 2c reported from Italy and Southern France.CONCLUSION:HCV has a low prevalence of 0.32%in the studied general population of Argentina.The pattern of HCV introduction and transmission in Argentina appears to be a consequence of multiple events and different for each subtype.

Molecular epidemiological study on pre-X region of hepatitis B virus and identification of hepatocyte proteins interacting with whole-X protein by yeast two-hybrid

AIM: To identify the pre-X region in hepatitis B virus (HBV)genome and to study the relationship between the genotype and the pre-X region. To investigate the biological function of whole-X (pre-X plus X) protein, we performed yeast two-hybrid to screen proteins in liver interacting with whole-X protein.METHODS: The pre-X region of HBV was amplified by polymerase chain reaction (PCR) method, and was cloned to pGEM Teasy vector. After the target region was sequenced, Vector 8.0 software was used to analyze the sequences. The whole-X bait plasmid was constructed by using yeast two-hybrid system 3. Yeast strain AH109 was transformed. After expression of the whole-X protein in AH109 yeast strains was proved, yeast two-hybrid screening was performed by mating AH109 with Y187 containing liver cDNA library plasmid. The mated yeast was plated on quadruple dropout medium and assayed for α-gal activity. The interaction between whole-X protein and the protein obtained from positive colonies was further confirmed by repeating yeast two-hybrid. After extracting and sequencing of plasmid from blue colonies, we carried out analysis by bioinformatics. RESULTS: After sequencing, 27 of 45 clones (60%) were found encoding the pre-X peptide. Eighteen of twenty-seven clones (66.7%) of pre-X coding sequences were found from genotype C. Five positive colonies that interacted with whole-X protein were obtained and sequenced; namely, fetuin B, UDP glycosyltransferase 1 family-polypeptide A9, mannose-P-dolichol utilization defect 1, fibrinogen-B beta polypeptide, transmembrane 4 superfamily member 4CD81 (TM4SF4).CONCLUSION: The pre-X gene exists in HBV genome.Genes of proteins interacting with whole-X protein in hepatocytes were successfully cloned. These results brought some new clues for studying the biological functions of whole-X protein.