Hepatitis C virus (HCV) genotypes in the Caribbean island of Martinique: evidence for a large radiation of HCV-2 and for a recent introduction from Europe of HCV-4

Identification of two novel hepatitis C virus subtype 2 from Tunisia (2v and 2w)

Background

Hepatitis C virus (HCV) has a high genetic diversity. Eight genotypes and 90 subtypes are currently described. Genotypes are clinically significant for therapeutic management and their determination is necessary for epidemiological studies.

Methods

Tunisian patients plasma samples (n = 6) with unassigned HCV-2 subtype using partial sequencing in the NS5B and Core/E1 regions were analyzed by realizing whole-genome sequencing analysis. Phylogenetic analyses were performed to assign subtypes.

Results

Phylogenetic analysis of the full genome sequences of Tunisian strains shows two subtypes within HCV-2. These later were genetically distinct from all previously established HCV-2 subtypes with nucleotide divergence greater than 15% (20% -31%). These two subtypes are proposed as new subtypes 2v and 2w.

Conclusions

The discovery of two new HCV-2 subtypes circulating in the Tunisian population confirms the great diversity of HCV-2 viruses and increases the total number of HCV-2 subtypes from 21 to 23.

Variation in Hepatitis C Virus Subtype Distribution during 20 Years in Venezuela

OBJECTIVE

Hepatitis C virus (HCV) infection is a public health problem and a major cause of chronic hepatitis. This virus exhibits a great genetic variability, with 8 genotypes and numerous subtypes. The aim of this study was to evaluate the fluctuations of HCV subtypes during 2 decades in Venezuela.

METHODS

HCV genotypes were determined by direct sequencing of the 5'-noncoding region in 392 isolates circulating in patients attended during the years 2014-2015. HCV subtype assignment was confirmed in a subset of samples (n = 24) by partial sequencing of the NS5B region. The genotype distribution was compared with the one observed in a previous study of patients followed up during the years 1994-1996 and 2005-2006.

RESULTS

Some variation was observed in the HCV genotype distribution over these 20 years. HCV genotype 1b prevalence was reduced significantly from 1994-1995 to 2004-2005, as previously described, and then remained constant. During the last 10 years, a significant decrease of HCV subtype 2b (36/237 in 2005-2006 vs. 24/392 in 2014-2015, p < 0.001) was observed. Patients infected with HCV G2acj were significantly older than the ones infected with G1 (53 vs. 47 years, p = 0.004), and male sex was significantly more prevalent among G3a-infected patients compared to the other ones (71 vs. 47%, p = 0.047).

CONCLUSIONS

Fluctuations in HCV subtype distribution have been observed over 2 decades in Venezuela. Different major mode of transmission and susceptibility to the available HCV treatment during each period might be playing a role in the observed fluctuations in HCV subtype distribution.

Genetic diversity of hepatitis viruses in West-African countries from 1996 to 2018

The severity of hepatic pathology and the response to treatment depend on the hepatitis virus genotype in the infected host. The objective of this review was to determine the distribution of hepatitis virus genotypes in West African countries. A systematic review of the literature in PubMed, Google Scholar and Science Direct was performed to identify 52 relevant articles reporting hepatitis A, B, C, D, E and G viruses genotypes. Hepatitis B virus (HBV) genotype E with a prevalence of 90.6% (95%CI: 0.891-0.920) found in this review, is characterized by low genetic diversity. Hepatitis C virus (HCV) genotypes 1 and 2 represented 96.4% of HCV infections in West African countries, while hepatitis delta virus, hepatitis A virus, hepatitis G virus genotypes 1 and HEV genotype 3 were reported in some studies in Ghana and Nigeria. HBV genotype E is characterized by high prevalence, low genetic diversity and wide geographical distribution. Further studies on the clinical implications of HBV genotype E and HCV genotypes 1 and 2 are needed for the development of an effective treatment against this viral hepatitis in West African countries. Surveillance of the distribution of different genotypes is also needed to reduce recombination rates and prevent the emergence of more virulent viral strains.

Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia

Chronic hepatitis C virus (HCV) infection and its progression are major health problems that many countries including Saudi Arabia are facing. Determination of HCV genotypes and subgenotypes is critical for epidemiological and clinical analysis and aids in the determination of the ideal treatment strategy that needs to be followed and the expected therapy response. Although HCV infection has been identified as the second most predominant type of hepatitis in Saudi Arabia, little is known about the molecular epidemiology and genetic variability of HCV circulating in the Jeddah province of Saudi Arabia. The aim of this study was to determine the dominance of various HCV genotypes and subgenotypes circulating in Jeddah using partial sequencing of the NS5B region. To the best of our knowledge, this is the first study of its kind in Saudi Arabia. To characterize HCV genotypes and subgenotypes, serum samples from 56 patients with chronic HCV infection were collected and subjected to partial NS5B gene amplification and sequence analysis. Phylogenetic analysis of the NS5B partial sequences revealed that HCV/1 was the predominant genotype (73%), followed by HCV/4 (24.49%) and HCV/3 (2.04%). Moreover, pairwise analysis also confirmed these results based on the average specific nucleotide distance identity: ±0.112, ±0.112, and ±0.179 for HCV/1, HCV/4, and HCV/3, respectively, without any interference between genotypes. Notably, the phylogenetic tree of the HCV/1 subgenotypes revealed that all the isolates (100%) from the present study belonged to the HCV/1a subgenotype. Our findings also revealed similarities in the nucleotide sequences between HCV circulating in Saudi Arabia and those circulating in countries such as Morocco, Egypt, Canada, India, Pakistan, and France. These results indicated that determination of HCV genotypes and subgenotypes based on partial sequence analysis of the NS5B region is accurate and reliable for HCV subtype determination.

Prevalence, determinants and genetic diversity of hepatitis C virus in the multi-ethnic population living in Suriname

Little is known about the epidemiology of HCV in Suriname, a former Dutch colony in South America. To study the prevalence, determinants and genetic diversity of HCV, a one-month survey was conducted at the only Emergency Department in the capital Paramaribo. Participants (≥18 years) completed an interviewer-led standardized HCV risk-factor questionnaire, were tested for HCV-antibodies, and if positive also for HCV RNA. The overall HCV prevalence was 1.0% (22/2128 participants; 95%CI 0.7-1.5). Male sex (OR=4.11; 95%CI 1.30-13.01), older age (OR=1.06 per year increase; 95%CI 1.04-1.09), Javanese ethnicity (OR=7.84; 95%CI 3.25-18.89) and cosmetic tattooing (OR=31.7; 95%CI 3.25-323.87) were independently associated with HCV-infection. Phylogenetic analysis revealed six distinct HCV subtypes, all HCV-genotype 2 (HCV-2): subtype 2f (also circulating in Indonesia) plus five yet unassigned HCV-2 subtypes exclusively linked to Suriname.

Phylogenetic Analysis and Epidemic History of Hepatitis C Virus Genotype 2 in Tunisia, North Africa

HCV genotype 2 (HCV-2) has a worldwide distribution with prevalence rates that vary from country to country. High genetic diversity and long-term endemicity were suggested in West African countries. A global dispersal of HCV-2 would have occurred during the 20th century, especially in European countries. In Tunisia, genotype 2 was the second prevalent genotype after genotype 1 and most isolates belong to subtypes 2c and 2k. In this study, phylogenetic analyses based on the NS5B genomic sequences of 113 Tunisian HCV isolates from subtypes 2c and 2k were carried out. A Bayesian coalescent-based framework was used to estimate the origin and the spread of these subtypes circulating in Tunisia. Phylogenetic analyses of HCV-2c sequences suggest the absence of country-specific or time-specific variants. In contrast, the phylogenetic grouping of HCV-2k sequences shows the existence of two major genetic clusters that may represent two distinct circulating variants. Coalescent analysis indicated a most recent common ancestor (tMRCA) of Tunisian HCV-2c around 1886 (1869-1902) before the introduction of HCV-2k in 1901 (1867-1931). Our findings suggest that the introduction of HCV-2c in Tunisia is possibly a result of population movements between Tunisia and European population following the French colonization.

Evaluation of the Abbott Real Time HCV genotype II assay for Hepatitis C virus genotyping

Objective:

The determination of HCV genotypes and subtypes is very important for the selection of antiviral therapy and epidemiological studies. The aim of this study was to evaluate the performance of Abbott Real Time HCV Genotype II assay in HCV genotyping of HCV infected patients in Kayseri, Turkey.

Methods:

One hundred patients with chronic hepatitis C admitted to our hospital were evaluated between June 2012 and December 2012, HCV RNA levels were determined by the COBAS® AmpliPrep/COBAS® TaqMan® 48 HCV test. HCV genotyping was investigated by the Abbott Real Time HCV Genotype II assay. With the exception of genotype 1, subtypes of HCV genotypes could not be determined by Abbott assay. Sequencing analysis was used as the reference method.

Results:

Genotypes 1, 2, 3 and 4 were observed in 70, 4, 2 and 24 of the 100 patients, respectively, by two methods. The concordance between the two systems to determine HCV major genotypes was 100%. Of 70 patients with genotype 1, 66 showed infection with subtype 1b and 4 with subtype 1a by Abbott Real Time HCV Genotype II assay. Using sequence analysis, 61 showed infection with subtype 1b and 9 with subtype 1a. In determining of HCV genotype 1 subtypes, the difference between the two methods was not statistically significant (P>0.05). HCV genotype 4 and 3 samples were found to be subtype 4d and 3a, respectively, by sequence analysis. There were four patients with genotype 2. Sequence analysis revealed that two of these patients had type 2a and the other two had type 2b.

Conclusion:

The Abbott Real Time HCV Genotype II assay yielded results consistent with sequence analysis. However, further optimization of the Abbott Real Time HCV Genotype II assay for subtype identification of HCV is required.

Seroepidemiology of chronic hepatitis B and C in the French Caribbean Island of Guadeloupe

BACKGROUND

The prevalence of chronic hepatitis B and C was evaluated some twenty years ago among specific populations in Guadeloupe. The present study was designed to update these data and determine epidemiological features of chronic hepatitis B and C infections in the French Caribbean island of Guadeloupe.

FINDINGS

The present study was carried out at the Sainte Genevieve Health and Prevention Center (Guadeloupe), between May 2006 and July 2007. This is a medical center where patients can attend a free medical check-up paid for by the Social Security system. Data on hepatitis B (HBV) and C (HCV) status and epidemiological factors were collected for this study.A total of 2,200 patients were included in the study. The prevalence of HBV surface antigen was 1.41% (95% CI: 1.0-2.0), and 0.55% (95% CI: 0.28-0.96) for HCV. The vaccination rate against HBV was 42.0%. HBV transmission was associated with piercing (12.9%, p = 0.014) and familial exposure (6.4%, p < 0.001) and HCV transmission with gynecological surgery (50.0%, p = 0.01). The HBV profile was generally hepatitis B e antigen-negative (94.5%). No hepatitis delta was found. For HCV, genotype 1 was predominant (80%).

CONCLUSIONS

This is the first study on the prevalence of HBV and HCV among a general clinic based population in Guadeloupe and the Caribbean islands. This study reveals that Guadeloupe is an area of low endemicity for HBV and low HCV prevalence. The reasons for these low prevalence rates are mainly related to the vaccination campaigns carried out during the past twenty years for HBV and the decrease of nosocomial transmission for HCV.

Review article: the epidemiology and therapy of chronic hepatitis C genotypes 4, 5 and 6

BACKGROUND

The global burden of hepatitis C (HCV) infection is mostly found in Africa, the Middle East and Asia, where HCV genotypes 4, 5 and 6 are common. The literature on these genotypes is sparse and this synopsis will review characteristics of patients infected with these genotypes.

AIM

To review characteristics of patients infected with HCV genotypes 4, 5 and 6.

METHODS

PubMed search for 'hepatitis C' AND 'genotype 4', 'hepatitis C' AND 'genotype 5', and 'hepatitis C' AND 'genotype 6' was conducted and relevant articles were reviewed.

RESULTS

Intravenous drug use is generally responsible for HCV genotype 4 infection in developed countries, but unsafe medical practices cause most cases of HCV genotypes 4, 5 and 6 in endemic countries. The sustained virological response (SVR) rate for patients with HCV genotype 4 who receive pegylated interferon and ribavirin for 48 weeks ranges from 40% to 70% in various small studies. The SVR rate is in the 60-70% range for HCV genotype 5 and 70-80% range for HCV genotype 6 following 48 weeks with pegylated interferon and ribavirin. Preliminary data suggest that a shorter course of 24 weeks of pegylated interferon and ribavirin may be acceptable for HCV genotype 6, with an SVR rate of approximately 70%.

CONCLUSIONS

The current standard-of-care therapy for HCV genotypes 4, 5 and 6 is pegylated interferon and ribavirin for 48 weeks. A shorter course with 24 weeks of therapy may be considered for patients with genotype 6. Newer and much more effective therapies may be forthcoming in the next few years.

Subtyping genotype 2 hepatitis C viruses from Tunisia: identification of two putative new subtypes

HCV variants were classified into six genotypes (1-6) subdivided into several subtypes with different geographic distribution worldwide. Previous studies conducted in Tunisia showed that genotype 1 counts for more than 80 % of circulating HCV genotypes and most of the isolates belong to subtype 1b. Genotype 2 comes in the second position, however, few sequences have been analyzed and published. In the present study, 89 isolates from Tunisian patients, typed as genotype 2 by the InnoLIPA commercial probe hybridization test, were sequenced in the NS5B and Core/E1 regions. All the isolates, clustered with the genotype 2 reference sequences, in the NS5B and in the Core/E1 region and the phylogenetic analyses in the two genomic regions were perfectly concordant: subtype 2c was the most frequent (58 out of 89, 65.1 %) and few isolates belonged to subtypes 2k(n = 10), 2i(n = 5), and 2b(n = 1). Fifteen isolates did not match with any of the reference sequences representing the genotype 2 subtypes, identified up-to-date. They divided into 2 separate clusters with high bootstrap values in both genomic regions. This study shows perfect concordance between the NS5B and the Core/E1 region suggesting that any of the two regions can be used for genotyping and that intergenotypic and intragenotypic recombinants are not very frequent, at least for HCV isolates from genotype 2. The present study also shows a predominance of subtype 2c among genotype 2 HCV isolates circulating in Tunisia, the co-circulation of minor subtypes (2k, 2i, and 2b) and proposes the possible existence of two other new subtypes.

The origin of hepatitis C virus

The origin of hepatitis C virus (HCV) can be conceptualised at several levels. Firstly, origins might refer to its dramatic spread throughout the Western world and developing countries throughout the twentieth century. As a blood-borne virus, this epidemic was fuelled by new parenteral transmission routes associated with medical treatments, immunisation, blood transfusion and more recently injecting drug use. At another level, however, origins might refer to the immediate sources of HCV associated with its pandemic spread, now identified as areas in Central and West sub-Saharan Africa and South and South East Asia where genetically diverse variants of HCV appear to have circulated for hundreds of years. Going back a final step to the actual source of HCV infection in these endemic areas, non-human primates have been long suspected as harbouring viruses related to HCV with potential cross-species transmission of variants corresponding to the 7 main genotypes into humans. Although there is tempting analogy between this and the clearly zoonotic origin of HIV-1 from chimpanzees in Central Africa, no published evidence to date has been obtained for infection of HCV-like viruses in either apes or Old World monkey species. Indeed, a radical re-think of both the host range and host-specificity of hepaciviruses is now required following the very recent findings of a non-primate hepacivirus (NPHV) in horses and potentially in dogs. Further research on a much wider range of mammals is needed to better understand the true genetic diversity of HCV-like viruses and their host ranges in the search for the ultimate origin of HCV in humans.

HCV genotype determination in monoinfected and HIV co-infected patients in Cuba

With the aim to characterize the HCV genotype distribution in Cuba, sera were collected from two subgroups: HCV-monoinfected and HCV/HIV co-infected patients. A combination of reverse transcription-PCR using genotype-specific primers, restriction fragment length polymorphism and sequencing was used to determine the genotype of 84 samples. Seventy-nine (94%) showed single infections (10 [12%] were genotype 1a and 69 [82%] genotype 1b) and 5 (6%) samples corresponded to mixed infections (2 [2%] with genotypes 1a/3a and 1 sample [1%] each with 1b/3a, 1b/4a and 1a/1b/3a). HCV/HIV co-infected subjects had a higher frequency of mixed infections (p=0.08), infection with genotype 3a (p=0.18) and for the first time genotype 4a was found. There was no association of any demographic characteristics with any specific genotype although HCV/HIV co-infected patients showed a tendency to have mixed genotypes in those older than 45 years of age (p=0.11). Phylogenetic analysis showed that HCV isolates clustered with subtypes 1b (n=15, maximal genetic distance 2.51%) and 1a (n=2, maximal genetic distance 0.35%). This report presents the prevalence of HCV genotypes in monoinfected and HIV co-infected patients, mixed HCV infections in HCV/HIV co-infected men who have sex with men with high-risk sexual practices and for the first time identifies that the uncommon genotype 4a can be present in a patient co-infected with HIV.

Distribution and molecular characterization of hepatitis C virus (HCV) genotypes in patients with chronic infection from Pernambuco State, Brazil

Hepatitis C virus (HCV) is a public health problem throughout the world and 3% of the world population is infected with this virus. It is estimated that 3-4 millions individuals are being infected every year. It has been estimated that around 1.5% of Brazilian population is anti-HCV positive and the Northeast region showed the highest prevalence in Brazil. The aim of this study was to characterize HCV genotypes circulating in Pernambuco State (PE), Brazil, located in the Northeast region of the country. This study included 85 anti-HCV positive patients followed up between 2004 and 2011. For genotyping, a 380bp fragment of HCV RNA in the NS5B region was amplified by nested PCR. Phylogenetic analysis was conducted using Bayesian Markov chain Monte Carlo simulation (MCMC) using BEAST v.1.5.3. From 85 samples, 63 (74.1%) positive to NS5B fragment were successfully sequenced. Subtype 1b was the most prevalent in this population (42-66.7%), followed by 3a (16-25.4%), 1a (4-6.3%) and 2b (1-1.6%). Twelve (63.1%) and seven (36.9%) patients with HCV and schistosomiasis were infected with subtypes 1b and 3a, respectively. Brazil is a large country with many different population backgrounds; a large variation in the frequencies of HCV genotypes is predictable throughout its territory. This study reports HCV genotypes from Pernambuco State where subtype 1b was found to be the most prevalent. Phylogenetic analysis suggests the presence of the different HCV strains circulating within this population.

Colonial history and contemporary transmission shape the genetic diversity of hepatitis C virus genotype 2 in Amsterdam

Evolutionary analysis of hepatitis C virus (HCV) genome sequences has provided insights into the epidemic history and transmission of this widespread human pathogen. Here we report an exceptionally diverse set of 178 HCV genotype 2 (HCV-2) isolates from 189 patients in Amsterdam, comprising 8 distinct HCV subtypes and 10 previously not recognized, unclassified lineages. By combining study subjects' demographic information with phylogeographic and molecular clock analyses, we demonstrate for the first time that the trans-Atlantic slave trade and colonial history were the driving forces behind the global dissemination of HCV-2. We detect multiple HCV-2 movements from present-day Ghana/Benin to the Caribbean during the peak years of the slave trade (1700 to 1850) and extensive transfer of HCV-2 among the Netherlands and its former colonies Indonesia and Surinam over the last 150 years. The latter coincides with the bidirectional migration of Javanese workers between Indonesia and Surinam and subsequent immigration to the Netherlands. In addition, our study sheds light on contemporary trends in HCV transmission within the Netherlands. We observe multiple lineages of the epidemic subtypes 2a, 2b, and 2c (together 67% of HCV-2 infections in Amsterdam), which cluster according to their suspected routes of transmission, specifically, injecting drug use (IDU) and contaminated blood/blood products. Understanding the epidemiological processes that generated the global pattern of HCV diversity seen today is critical for exposing associations between populations, risk factors, and specific HCV subtypes and might help HCV screening and prevention campaigns to minimize the future burden of HCV-related liver disease.

Full-length sequences of 11 hepatitis C virus genotype 2 isolates representing five subtypes and six unclassified lineages with unique geographical distributions and genetic variation patterns

In this study, we characterized full-length hepatitis C virus (HCV) genome sequences for 11 genotype 2 isolates. They were isolated from the sera of 11 patients residing in Canada, of whom four had an African origin. Full-length genomes, each with 18-25 overlapping fragments, were obtained by PCR amplification. Five isolates represent the first complete genomes of subtypes 2d, 2e, 2j, 2m and 2r, while the other six correspond to variants that do not group within any assigned subtypes. These sequences had lengths of 9508-9825 nt and each contained a single ORF encoding 3012-3106 aa. Predicted amino acids were carefully inspected and unique variation patterns were recognized, especially for a 2e isolate, QC64. Phylogenetic analysis of complete genome sequences provides evidence that there are a total of 16 subtypes, of which 11 have been described here. Co-analysis with 68 partial NS5B sequences also differentiated 18 assigned subtypes, 2a-2r, and eight additional lineages within genotype 2, which is consistent with the analysis of complete genome sequences. The data from this study will now allow 10 assigned subtypes and six additional lineages of HCV genotype 2 to have their full-length genomes defined. Further analysis with 2021 genotype 2 sequences available in the HCV database indicated that the geographical distribution of these subtypes is consistent with an African origin, with particular subtypes having spread to Asia and the Americas.

Hepatitis C virus sequences from different patients confirm the existence and transmissibility of subtype 2q, a rare subtype circulating in the metropolitan area of Barcelona, Spain

The hepatitis C virus (HCV) has been classified into six genotypes and more than 70 subtypes with distinct geographical and epidemiological distributions. While 18 genotype 2 subtypes have been proposed, only 5 have had their complete sequence determined. The aim of this study was to characterize HCV isolates from three patients from the Barcelona metropolitan area of Spain for whom commercial genotyping methods provided discordant results. Full-length genome sequencing was carried out for 2 of the 3 patients; for the third patient only partial NS5B sequences could be obtained. The generated sequences were subjected to phylogenetic, recombination, and identity analyses. Sequences covering most of the HCV genome (9398 and 9566  nt in length) were obtained and showed a 90.3% identity to each other at the nucleotide level, while both sequences differed by 17.5-22.6% from the other fully sequenced genotype 2 subtypes. No evidence of recombination was found. The NS5B phylogenetic tree showed that sequences from the three patients cluster together with the only representative sequence of the provisionally designed 2q subtype, which also corresponds to a patient from Barcelona. Phylogenetic analysis of the full coding sequence showed that subtype 2q was more closely related to subtype 2k. The results obtained in this study suggest that subtype 2q now meets the requirements for confirmed designation status according to consensus criteria for HCV classification and nomenclature, and its epidemiological value is ensured as it has spread among several patients in the Barcelona metropolitan area.

Evaluation of three different hepatitis C virus typing methods for detection of mixed-genotype infections

OBJECTIVE

To evaluate the clinical applicability of an eligible assay for the true prevalence of hepatitis C virus (HCV) mixed-genotype infections.

METHODS

A newly developed HCV genotyping method targeting all six major HCV genotypes and 12 subtypes, restriction fragment length polymorphism (RFLP) and a serotyping assay were utilized for the detection of HCV mixed-genotype infections using known HCV genotypes and unknown samples.

RESULTS

In a defined mix of HCV genotypes, a genotype present at levels as low as 8.3% was detected by our newly developed assay, showing a threefold increase in sensitivity over that of direct deoxyribonucleic (DNA) sequencing. A comparative study of the accuracy among the three genotyping methods was carried out on samples obtained from 50 thalassemic patients who received multiple blood transfusions. The results showed that viruses in approximately 42% of the samples from this group were determined to be infected with mixed genotypes by our newly developed method. A serotyping assay and RFLP analysis, performed with poor results, could identify only 18% and 10% of mixed-genotype infections, respectively.

CONCLUSION

The newly developed assay may be the method of choice when detection of genotypes present at low levels in mixed-genotype infections due to its higher level of sensitivity.

Genetic history of hepatitis C virus in Venezuela: high diversity and long time of evolution of HCV genotype 2

BACKGROUND

The subtype diversity of the hepatitis C virus (HCV) genotypes is unknown in Venezuela.

METHODOLOGY/PRINCIPAL FINDINGS

Partial sequencing of the NS5B region was performed in 310 isolates circulating in patients from 1995 to 2007. In the samples collected between 2005 and 2007, HCV genotype 1 (G1) was the most common genotype (63%), composed as expected of mainly G1a and G1b. G2 was the second most common genotype (33%), being G2a almost absent and G2j the most frequent subtype. Sequence analysis of the core region confirmed the subtype assignment performed within the NS5b region in 63 isolates. The complete genome sequence of G2j was obtained. G2j has been described in France, Canada and Burkina Fasso, but it was not found in Martinique, where several subtypes of G2 circulate in the general population. Bayesian coalescence analysis indicated a most recent common ancestor (MRCA) of G2j around 1785, before the introduction of G1b (1869) and G1a (1922). While HCV G1a and G1b experienced a growth reduction since 1990, coincident with the time when blood testing was implemented in Venezuela, HCV G2j did not seem to reach growth equilibrium during this period.

CONCLUSIONS/SIGNIFICANCE

Assuming the introduction of G2j from Africa during the slave trade, the high frequency of G2j found in Venezuela could suggest: 1- the introduction of African ethnic groups different from the ones introduced to Martinique or 2- the occurrence of a founder effect. This study represents an in-depth analysis of the subtype diversity of HCV in Venezuela, which is still unexplored in the Americas and deserves further studies.

Molecular and contextual markers of hepatitis C virus and drug abuse

The spread of hepatitis C virus (HCV) infection involves a complex interplay of social risks, and molecular factors of both virus and host. Injection drug abuse is the most powerful risk factor for HCV infection, followed by sexual transmission and additional non-injection drug abuse factors such as co-infection with other viruses and barriers to treatment. It is clearly important to understand the wider context in which the factors related to HCV infection occur. This understanding is required for a comprehensive approach leading to the successful prevention, diagnosis, and treatment of HCV. An additional consideration is that current treatments and advanced molecular methods are generally unavailable to socially disadvantaged patients. Thus, the recognition of behavioral/social, viral, and host factors as components of an integrated approach to HCV is important to help this vulnerable group. Equally important, this approach is key to the development of personalized patient treatment - a significant goal in global healthcare. In this review, we discuss recent findings concerning the impact of drug abuse, epidemiology, social behavior, virology, immunopathology, and genetics on HCV infection and the course of disease.

Molecular characterization of genotype 2 and 4 hepatitis C virus isolates in French blood donors

The subtype distribution of 142 genotype 2 and 97 genotype 4 hepatitis C virus (HCV) isolates from the sera of 1,319 volunteer blood donors in France was determined by gene sequencing and by phylogenetic analysis of the NS5B region and E1 envelope. Findings underlined a wide range of subtypes in both genotypes, that is, 20 in HCV-2 and 11 in HCV-4. Eighteen of these 31 subtypes had not been defined previously. Some subtypes, that is, 2a, 2b, 2c, 2i, 2k, 4a, and 4d, showed numerous strains while subtypes in donors from West Africa or Central Africa showed an endemic profile with only a few strains. A Bayesian coalescence approach was used to estimate the demographic history of each HCV subtype. The estimated mean dates of the most recent common ancestors (MRCA) were 1,889 (confidence interval (CI), 1,842-1,930) for HCV-2a, 1,886 (CI, 1,843-1,921) for HCV-2b, 1,791 (CI, 1,699-1,848) for HCV-2c, 1,846 (CI, 1,803-1,878) for HCV-2i, 1,911 (CI, 1,879-1,937) for HCV-4a, and 1,957 (CI, 1,943-1,967) for HCV-4d. The period of spread for subtype 2b, 2c, and 2i was between 1900 and 1960 whereas rapid exponential spread for subtype 2a, 4a, and 4d occurred in the 1960s. The inferred histories of population growth indicated that transmission rates differed according to HCV subtype. These results may help to predict the future burden of HCV in France.

Development and evaluation of a sensitive enzyme-linked oligonucleotide-sorbent assay for detection of polymerase chain reaction-amplified hepatitis C virus of genotypes 1-6

A high-throughput polymerase chain reaction (PCR)-based enzyme-linked oligonucleotide-sorbent assay (ELOSA) was developed for use in the diagnostic testing of serum from patients who may be infected with different hepatitis C virus (HCV) genotypes. Twelve genotype-specific 5'-aminated DNA-coated probes were designed based on the variable 5'-untranslated region sequences of the HCV genotypes 1-6. Using 100 clinical serum samples, the performance of the PCR-ELOSA method was compared with Roche's COBAS Amplicor HCV Monitor V2.0 assay and the VERSANT HCV genotype assay (LiPA), and the overall agreement was 99% at the level of HCV genotypes with a detection range of 2.0 x 10(2) to 1.0 x 10(7)IU/ml for PCR-ELOSA. The PCR-ELOSA was more comprehensive as demonstrated by the fact that approximately 20% of the samples with different subtypes could be discriminated by this method but not by LiPA. In addition, the PCR-ELOSA system showed high accuracy (CV<or=6.36%) and even higher reproducibility (CV<or=5.55%). Thus, this novel PCR-ELOSA system provides a sensitive and versatile alternative to current HCV detection assays.

Development of an improved genotyping assay for the detection of hepatitis C virus genotypes and subtypes in Pakistan

A new genotyping system was established for the specific detection of HCV genotypes 1a, 1b, 1c, 2a, 2b, 2c, 3a, 3b, 3c, 4a-h, 5a and 6a during the course of this study. The system is based on entire core region and a part of 5' noncoding region (5'NCR) with genotype-specific primers. Genotype-specific primers were designed on the basis of 114 HCV isolates. Serum samples with known genotypes were used as positive controls to validate the assay developed and to generate PCR band patterns. Band patterns generated from the clinical serum samples from HCV patients were compared to the patterns produced from these control samples. In addition, the type-specific bands were sequenced from the test patients and control clinical samples to validate further the test results. To determine sensitivity and specificity of the assay, a total 260 samples were analyzed simultaneously by this HCV genotyping method and that developed by Ohno and Murex HCV Serotyping 1-6 Assay. The system showed 79.2% concordance with Ohno's system and 65.38% with serotyping system. Samples with discordant results were sequenced and their genotypes were determined by molecular evolutionary analysis. The data indicate that the method described in this study may offer better sensitivity and specificity for the detection directly of HCV genotypes present at low levels in HCV patient samples.

Hepatitis C virus infection in Guinea-Bissau: a sexually transmitted genotype 2 with parenteral amplification?

Background

Sub-Saharan Africa is the continent with the highest prevalence of Hepatitis C virus (HCV) infection. Genotype 2 HCV is thought to have originated from West Africa several hundred years ago. Mechanisms of transmission remain poorly understood.

Methodology/Principal Findings

To delineate mechanisms for HCV transmission in West Africa, we conducted a cross-sectional survey of individuals aged ≥50 years in Bissau, Guinea-Bissau. Dried blood spots were obtained for HCV serology and PCR amplification. Prevalence of HCV was 4.4% (47/1066) among women and 5.0% (27/544) among men. In multivariate analysis, the independent risk factors for HCV infection were age (baseline: 50–59 y; 60–69 y, adjusted odds ratio [AOR]: 1.67, 95% CI: 0.91–3.06; ≥70 y, AOR: 3.47, 95% CI: 1.89–6.39), belonging to the Papel, Mancanha, Balanta or Mandjako ethnic groups (AOR: 2.45, 95% CI:1.32–4.53), originating from the Biombo, Cacheu or Oio regions north of Bissau (AOR: 4.16, 95% CI: 1.18–14.73) and having bought or sold sexual services (AOR: 3.60, 95% CI: 1.88–6.89). Of 57 isolates that could be genotyped, 56 were genotype 2.

Conclusions

Our results suggest that transmission of HCV genotype 2 in West Africa occurs through sexual intercourse. In specific locations and subpopulations, medical interventions may have amplified transmission parenterally.

Improvement of hepatitis C virus (HCV) genotype determination with the new version of the INNO-LiPA HCV assay

Hepatitis C virus (HCV) isolates have been classified into six main genotypes. Genotyping methods, and especially the widely used line probe assay (LiPA), are frequently based on the 5'-untranslated region (5'UTR). However, this region is not appropriate for discriminating HCV strains at the subtype level and for distinguishing many genotype 6 samples from genotype 1. We investigated the capacity of a novel LiPA (Versant HCV Genotype 2.0 assay) based on the simultaneous detection of 5'UTR and Core regions for genotypes 1 and 6 to provide correct HCV genotypes (characterized with a phylogenetic analysis) in a set of HCV strains mainly encountered in Western countries. The improvement was assessed by comparing the results to those obtained with the previous version of the assay. Of the 135 tested samples, 64.7% were concordant for genotype group and subtype with sequencing reference results using the Versant HCV Genotype 2.0 assay versus 37.5% with the previous version. The yield was mainly related to a better characterization of genotype 1, since the accuracy, tested in 62 genotype 1 samples, increased from 45.2% with the first version to 96.8% with the new one. However, this new version necessitates a specific PCR and could no longer be used after 5'UTR PCR used for current HCV infection diagnosis. Moreover, the information provided by 5'UTR hybridization is not reliable for correctly identifying the diversity within genotypes 2 and 4. Thus, the Versant HCV Genotype 2.0 assay remains a useful tool for clinical practice when only the discrimination between major HCV genotypes is necessary.

Analysis of the 5' noncoding region versus the NS5b region in genotyping hepatitis C virus isolates from blood donors in France

The 5' noncoding region (5' NCR) of the hepatitis C virus (HCV) has become the standard for genotyping even though several reports show that its use can result in classification errors. The purpose of this study was to perform genotyping based on sequence analysis of the NS5b region in a set of 357 HCV strains isolated from blood donors in France in 2002 and 2003. Results were compared with those previously obtained using 5' NCR analysis, and HCV subtype distribution was reevaluated. Twenty-six of 120 strains (approximately 22%) initially identified as genotype 1b by 5' NCR region sequence analysis were reclassified as genotype 1a by NS5b region sequence analysis. Similarly, 14 of 23 strains (approximately 61%) initially identified as 2a/2c were reclassified as non-2a and non-2c subtypes, and 12 of 22 strains (approximately 45%) initially identified as 4c/4d subtypes were reclassified as non-4c and non-4d subtypes. Sequence analysis of the NS5b region also revealed 5 putative new subtype 2 variants and 2 putative new subtype 4 variants. Although these findings demonstrated full agreement between 5' NCR and NS5b sequence analysis with regard to type classification, genotyping based on phylogenetic analysis of the NS5b region is more accurate for subtype determination than genotyping based on analysis of the 5' NCR. Sequence analysis of the NS5b region is mandatory for epidemiologic studies.

Investigating the origin and spread of hepatitis C virus genotype 5a

Epidemiological and phylogenetic studies of hepatitis C virus (HCV) have identified six major HCV genotypes and have attempted to characterize their origin and spread worldwide. Putative regions of endemic infection have been identified for all HCV genotypes except HCV genotype 5a. Although HCV genotype 5a was previously thought to be largely restricted to the northern part of South Africa, this study reports an unexpected cluster of the genotype in West Flanders Province in Belgium. To investigate the molecular epidemiology of this cluster and of HCV genotype 5a in general, a rigorous phylogenetic analysis of Belgian and South African HCV genotype 5a samples was performed. Remarkably, the Belgian and South African strains form two distinct clusters of similar diversity. We used a Bayesian coalescent method to estimate the rate of virus spread through time for HCV genotype 5a in both regions. Our results indicate that HCV genotype 5a strains have been spreading independently in Belgium and South Africa for more than 100 years, with a rate of spread characteristic of an epidemic genotype. These findings have major implications for tracing the origin of HCV genotype 5a. Here, we speculate about the possible origins of these clusters.

Genetic diversity and evolution of hepatitis C virus in the Latin American region

Hepatitis C virus (HCV) has been the subject of intense research and clinical investigations, as a consequence of the recognition of its major role in human disease. HCV evolution is a highly dynamic process. HCV exploits all known mechanisms of genetic variation, such as recombination and mutation, to ensure its survival. Like most RNA viruses, HCV circulates in vivo as a complex population of different but closely related variants, commonly referred to as a quasi species. This work describes the genetic variability of HCV in Latin America, with special emphasis on its diversification and recombination in this area of the world, and discusses how our knowledge of these issues can contribute to its control.

Genetic diversity of HCV genotype 2 strains in South Western France

Hepatitis C virus (HCV) is a major cause of chronic hepatitis and liver disease worldwide. The genetic heterogeneity of HCV and its spread among infected patients can be examined accurately by nucleotide sequencing. The diversity of HCV genotype 2 strains (HCV-2) was studied in a large cohort of patients in the Midi Pyrénées area of southern France. Phylogenetic analysis was performed on 344 NS5B sequences from patients infected with HCV-2. These included 145 strains whose E2 region was also analyzed, and epidemiological data were collected for the corresponding patients. HCV-2 accounts for 11.3% of HCV infections in this area. Phylogenetic analysis of NS5B sequences revealed eight subtypes, while that of the E2 region provided congruent results for 100% of strains. The most frequent subtypes were 2i (24.7%), 2k (22.4%) 2c (17.4%), and 2a (10.8%). The mean age of HCV-2-infected patients was 55.5 years. Epidemiological data showed that blood transfusion is the major route of infection, but it was not associated with any particular subtype. By contrast, intravenous drug users were infected predominantly with genotype 2a. HCV-2a-infected patients were younger than patients infected with other subtypes (48 vs. 56.5 years, P < 0.01). This study shows substantial genetic diversity of HCV-2 subtypes in the south of France and the spread of 2a strains via intravenous drug users.

Pegylated interferon and ribavirin therapy for chronic hepatitis C virus genotype 4 infection

Hepatitis C Virus (HCV) is classified into six genotypes. Genotype 4 is now spreading in Europe, especially among drug users, who are often infected with both HCV and the human immunodeficiency virus (HIV). Previous studies have shown that HCV-4 responds poorly to interferon. Pegylated interferon (peg-IFN) associated with ribavirin is now the most effective treatment for eradicating the virus. We have now studied the response of HCV-4 to peg-IFN and ribavirin and investigated the influence of HIV infection on anti-HCV therapy. Twenty-eight patients infected with HCV-4 were given peg-IFN plus ribavirin for 48 weeks. Patients infected with HCV alone tended to have a better initial response (66%) than patients infected with both HCV and HIV (30%, P = 0.06) and eradication was better (50%) than in doubly infected patients (15%, P = 0.06). After controlling for major factors influencing virus response, the virus response 12 weeks after the beginning of treatment in patients infected with HCV-4 (50%) was similar to that of patients infected with genotype 1 (53%) and lower than that of patients infected with genotypes 2 or 3 (82%, P < 0.05). The response 24 weeks after the end of therapy in patients infected with HCV-4 (32%) was similar to that of patients infected with HCV-1 (28%) and lower than that of patients with HCV-2 or HCV-3 (62% P < 0.05). These results indicate that HCV-4 patients should be considered to be difficult-to-treat.

Chronic hepatitis C: genotypes 4 to 9

Infection with hepatitis C virus (HCV) genotypes 1, 2, or 3 is widely distributed throughout the world and has been the focus of the majority of studies on the epidemiology and treatment of chronic hepatitis C. Infection with HCV genotypes 4 through 9 is prevalent in some geographic areas where the disease burden of chronic hepatitis C approaches endemic levels (eg, HCV genotype 4 in Egypt where there is an HCV infection prevalence of approximately 18%). This article reviews the existing literature, which suggests that chronic hepatitis C with genotypes 4 through 9 may exhibit epidemiologic, clinical, and treatment outcome differences from infection with genotypes 1, 2, or 3.

Comparison of hepatitis C virus NS5b and 5' noncoding gene sequencing methods in a multicenter study

A national evaluation study was performed in 11 specialized laboratories with the objective of assessing their capacities to genotype hepatitis C virus (HCV) and define the applicability of a given genotyping method. The panel consisted of 14 samples positive for HCV RNA of different genotypes (including 3 samples with two different artificially mixed genotypes) and 1 HCV-negative sample. Seventeen sets of data were gathered from the 11 participating laboratories. The sensitivities ranged from 64.3 to 100% and from 42.7 to 85.7% for the methods that used sequencing of the NS5b region and the 5' noncoding (5' NC) region, respectively. When the data for the artificially mixed samples were excluded, NS5b genotyping gave correct results for 80% of the samples, 1.7% of the samples were misclassified, and 18.3% of the samples had false-negative results. By 5' NC-region genotyping methods, 58.3% of the results were correct, 29.7% were incomplete, 8.3% were misclassifications, 1.2% were false positive, and 2.4% were false negative. Only two procedures based on NS5b sequencing correctly identified one of the three samples with mixtures of genotypes; the other methods identified the genotype corresponding to the strain with the highest viral load in the sample. Our results suggest that HCV 5' NC-region genotyping methods give sufficient information for clinical purposes, in which the determination of the subtype is not essential, and that NS5b genotyping methods are more reliable for subtype determination, which is required in epidemiological studies.

Heterogeneity of hepatitis C virus genotype 4 strains circulating in south-western France

Hepatitis C virus (HCV) is a major cause of liver disease. Knowledge of HCV variability is crucial for clinical and epidemiological analysis. HCV genotype 4 (HCV-4) has become increasingly prevalent in European countries, including France, in recent years. The present study investigates the heterogeneity of HCV-4 in south-western France by phylogenetic analysis of NS5B sequences from 166 patients. The E2 region of 90 strains was also analysed. Genotype 4 accounts for 7·4 % of HCV infections in this area. Analysis of the NS5B region revealed 12 subtypes and the NS5B and E2 phylogeny data were congruent, except for one strain. The epidemiological data indicated two main groups of patients. One included intravenous drug users (IVDUs) of French origin, who were infected by homogeneous strains of subtypes 4a or 4d. The second group comprised non-IVDU patients who were infected with heterogeneous strains. This group was subdivided into patients of French origin, who were infected with eight subtypes, and patients from non-European countries (Central Africa or the Middle East), who were mainly infected with 4f, 4k, 4r and other subtypes; they showed the greatest genetic heterogeneity. This study of a large cohort of patients shows the great diversity of HCV-4 strains, and that these subtypes have spread differently.

Response to Interferon-Based Therapies in HIV-Infected Patients with Chronic Hepatitis C Due to Genotype 4

Background

The hepatitis C virus (HCV) genotype is the main predictor of response to interferon (IFN)-based therapies. HCV genotype 4 is spreading among European intravenous drug users, who are frequently coinfected with HIV. Information about treatment response in this subset of patients is scarce and conflicting results have been reported.

Methods

All HIV-infected patients treated for chronic hepatitis C at our institution with a minimum follow-up of 6 months after discontinuing therapy were retrospectively analysed. They had received one of three HCV treatment modalities: IFN monotherapy, IFN plus ribavirin (RBV) or pegylated interferon (PEG-IFN) plus RBV. Treatment responses were stratified according to HCV genotype.

Results

A total of 390 patients were analysed. Sustained virological response (SVR) to HCV therapy had been reached by 90 (23.1%): 22/119 (18.5%) with IFN monotherapy; 17/106 (16%) with IFN plus RBV; and 51/165 (30.9%) with PEG-IFN plus RBV. SVR was significantly higher among those with HCV genotypes 2 or 3 (40.4%; 61/151) than in patients with either HCV genotype 1 (11.2%; 22/197) or HCV genotype 4 (16.7%; 7/42) ( P<0.0001). In contrast, there were no significant differences in the response rate comparing HCV genotypes 1 and 4 ( P=0.53).

Conclusions

Response to IFN-based therapies in HIV-positive patients with hepatitis C due to HCV genotype 4 is poor, similar to that obtained for HCV genotype 1 and much lower than for HCV genotypes 2 and 3. Therefore, HIV-infected patients with hepatitis C due to genotype 4 should be considered as a particular subset of difficult-to-treat patients. New treatment strategies and drugs for these patients are eagerly awaited.