Biomedical subjects

L Stuyver

Publications and source records attributed to L Stuyver.

At least 37 records · Page 2Linked to original sources

PubMed1998

[Update on hepatitis C virus: its variability and the implications].

Hepatitis C virus (HCV) is the main etiologic factor of post-transfusional and sporadic hepatitis, called non-A non-B in the past. These infections are characterized by a very high number of chronic carriers always with a persistent viral increase, but often at a slow pace. The seriousness of liver disease differs from one individual to another, varying from an asymptomatic form with minor or no liver injuries, to cirrhosis and hepatocellular carcinoma. Physiopathological mechanisms involved in liver injuries are still poorly understood. The direct role of immune response and of possible genetic factors is still under study. This review aims at summing up the discovery of HCV, its structure, and its variability in the various genome regions in the same individual and from one individual to another. The different methods and techniques to analyze this variability are also reviewed, as well as the various suggested ways of classifying the different types. The geographical distribution and both clinical and biological consequences of this variability are also discussed.

Antibody Specificity↗

PubMed1998

Antigenic diversity of hepatitis B virus strains of genotype F in Amerindians and other population groups from Venezuela.

The adw4 subtype of hepatitis B virus (HBV) belongs to a unique genomic group (genotype F) representing the original HBV strains from the New World. Data regarding the prevalence of this subtype among HBV carriers in South America are, however, scarce, and those concerning HBV genotype F are based on only a few samples from Latin America. In this study, serum samples were obtained from 141 hepatitis B surface antigen (HBsAg) carriers from Amerindians and urban populations from Venezuela. The HBsAg subtype was identified with monoclonal antibodies in 105 samples, and the HBV genotype was identified by reverse-phase hybridization with DNA fragments in 58 samples. The adw4 subtype was highly prevalent in the population studied (75%); among the Amerindians, the prevalence was 97%. The adw2 subtype was also present (10%), while other subtypes (ayw3 and ayw4) were only occasionally found. The HBV subtype was associated with the expected genotype in most cases (80%), and thus genotype F was highly prevalent. Sequencing of viral strains that gave genotypes unpredicted by the HBsAg subtyping confirmed seven of them as belonging to not previously described genotype-subtype associations: namely, adw2 and ayw4 within genotype F.

Amino Acid Substitution↗

PubMed1998

Evidence for high genetic diversity and long-term endemicity of hepatitis C virus genotypes 1 and 2 in West Africa.

During 1994 and 1995, the prevalence of hepatitis C virus (HCV) and its genotypes were studied in several rural and urban populations in three West African countries: Guinea, Burkina Faso, and Benin. The following groups were screened for antibodies to HCV (anti-HCV): 459 villagers in the forest region of Guinea; 965 individuals in urban, suburban, and rural populations of the Bobo Dioulasso area, Burkina Faso; and 582 blood donors in Cotonou, Benin. In Benin, 60 patients with sickle cell anemia (30 with and 30 without history of multiple transfusion) and 13 hospital patients with liver disease were also tested. RT-PCR detection of HCV-RNA was carried out on all anti-HCV positive samples, followed by genotyping and sequencing of unrecognized subtypes. The prevalence rates of anti-HCV were 1.1% in the Guinean population group, 1.4% among blood donors in Benin, and 4.9% in residents of Burkina Faso. In patients with sickle cell anemia, five of the 30 polytranfused patients (17%) had anti-HCV, whereas none of the patients without a history of blood transfusion had anti-HCV (P < 0.05). Among the 13 patients with liver disease, five had anti-HCV, of whom four had history of blood transfusion. HCV-RNA was detected in 41 anti-HCV positive sera. All belonged to genotypes 1 or 2, with a high genomic diversity; 18 different subtypes were identified, including 2c, 2d, and 16 new subtypes. Such genetic diversity poses a challenge for vaccine development and also implies that HCV infection is long-established in these West African regions.

Adolescent↗

PubMed1997

Presence of an inducible HIV-1 latent reservoir during highly active antiretroviral therapy.

Although highly active antiretroviral therapy (HAART) in the form of triple combinations of drugs including protease inhibitors can reduce the plasma viral load of some HIV-1-infected individuals to undetectable levels, it is unclear what the effects of these regimens are on latently infected CD4+ T cells and what role these cells play in the persistence of HIV-1 infection in individuals receiving such treatment. The present study demonstrates that highly purified CD4+ T cells from 13 of 13 patients receiving HAART with an average treatment time of 10 months and with undetectable (<500 copies HIV RNA/ml) plasma viremia by a commonly used bDNA assay carried integrated proviral DNA and were capable of producing infectious virus upon cellular activation in vitro. Phenotypic analysis of HIV-1 produced by activation of latently infected CD4+ T cells revealed the presence in some patients of syncytium-inducing virus. In addition, the presence of unintegrated HIV-1 DNA in infected resting CD4+ T cells from patients receiving HAART, even those with undetectable plasma viremia, suggests persistent active virus replication in vivo.

Anti-HIV Agents↗

PubMed1997

Serological and molecular analysis of hepatitis C virus envelope regions 1 and 2 during acute and chronic infections in chimpanzees.

Acute and chronic Hepatitis C virus infections were investigated retrospectively in chimpanzees that had been infected from a single source. Anti-E1 and anti-E2 were detected in two of three chimpanzees with a chronic infection, but were first detected 1 to 2 years after inoculation. Sequence evolution of the E1 region in three animals over a period of 9 to 11 years revealed a mutation rate of 1.02 to 2.23 x 10(-3) base substitutions per site per year. The acute phase viremia levels in acute infections which resolved appeared to be at least 10-fold higher than during the acute phase of chronic infections. During chronic infections, the viral load fell rapidly after the acute phase and remained at very low levels for several years. After 4 to 6 years, the viral load and liver enzymes increased again, suggesting reactivation of the infection. There was no clear temporal relationship between sequence evolution of the E1 region, changes in viral load, and the production of antibodies to the envelope proteins.

Acute Disease↗

PubMed1997

Mutations of hepatitis C virus 1b NS5A 2209-2248 amino acid sequence do not predict the response to recombinant interferon-alfa therapy in French patients.

BACKGROUND/AIMS: Studies of HCV quasispecies during interferon treatment have shown the selection of resistant clones. Enomoto et al. have defined the interferon sensitivity-determining region in an amino acid stretch of the HCV-1b NS5A region. Patients with a mutant strain before treatment were complete responders, whereas those with wild-type HCV-J strain were resistant to interferon. The same region was studied in HCV isolates of French patients. METHODS: Forty-three HCV-1b chronically infected patients, consisting of 26 non-responders and 17 complete responders to interferon-alfa treatment (3 MUI tiw for 6 months), were included retrospectively. We directly sequenced the NS5A(2209-2248) HCV region of these patients before treatment. The viral load could be obtained from six complete responders and 15 non-responders. RESULTS: We detected wild-type and intermediate strains, but only two mutant strains were present. One of them was found in a non-responder. In three complete responders, we found a wild-type strain. The distribution of the various strains was rather different from that found in Japan. Before treatment, the viral load was lower in complete responders (p=0.01). CONCLUSIONS: Only two mutant strains were detected in our study. This could partially explain the low response rate to interferon treatment of French HCV-1b-infected patients, although the dose regimen was lower than in Japanese studies. Also, wild-type strains were found in some complete responders, and no correlation was determined between the mutation number in the NS5A(2209-2248) region and response to alfa interferon therapy. This may be related to epidemiological differences between HCV-1b strains present in France and those in Japan. Searching for the mutant NS5A pattern before treatment does not appear to be useful in French patients as it is too uncommon.

Adult↗

PubMed1997

Line probe assay for rapid detection of drug-selected mutations in the human immunodeficiency virus type 1 reverse transcriptase gene.

Upon prolonged treatment with various antiretroviral nucleoside analogs such as 3'-azido-3'-deoxythymidine, 2',3'-dideoxyinosine, 2',3'-dideoxycytidine, (-)- beta-L-2', 3'dideoxy-3'thiacytidine and 2',3'-didehydro-3'-deoxythymidine, selection of human immunodeficiency virus type 1 (HIV-1) strains with mutations in the reverse transcriptase (RT) gene has been reported. We designed a reverse hybridization line probe assay (LiPA) for the rapid and simultaneous characterization of the following variations in the RT gene: M41 or L41; T69, N69, A69, or D69; K70 or R70; L74 or V74; V75 or T75; M184, I184, or V184; T215, Y215, or F215; and K219, Q219, or E219. Nucleotide polymorphisms for codon L41 (TTG or CTG), T69 (ACT or ACA), V75 (GTA or GTG), T215 (ACC or ACT), and Y215 (TAC or TAT) could be detected. In addition to the codons mentioned above, several third-letter polymorphisms in the direct vicinity of the target codons (E40, E42, K43, K73, D76, Q182, Y183, D185, G213, F214, and L214) were found, and specific probes were selected. In total, 48 probes were designed and applied to the LiPA test strips and optimized with a well-characterized and representative reference panel. Plasma samples from 358 HIV-infected patients were analyzed with all 48 probes. The amino acid profiles could be deduced by LiPA hybridization in an average of 92.7% of the samples for each individual codon. When combined with changes in viral load and CD4+ T-cell count, this LiPA approach proved to be useful in studying genetic resistance in follow-up samples from antiretroviral agent-treated HIV-1-infected individuals.

Acquired Immunodeficiency Syndrome↗

PubMed1996

Lymphoproliferative responses to hepatitis C virus core, E1, E2, and NS3 in patients with chronic hepatitis C infection treated with interferon alfa.

The quality of the hepatitis C virus (HCV)-specific T-cell response may greatly determine the course of an HCV infection. An adequate T-cell response may contribute to a successful clearance of the virus and a rapid recovery from the disease. An inadequate response may lead to viral persistence and may eventually contribute to the pathogenesis of hepatocellular damage in chronic disease. The effect of interferon alfa (IFN-alpha), presently the most popular therapeutic agent for chronic HCV infections, on HCV-specific T-cell responses is completely unknown. To demonstrate the presence of HCV-specific T lymphocytes during chronic HCV infections, to know their antigenic specificities, and to examine possible effects of IFN-alpha treatment on their presence and antigen recognition patterns, we have stimulated peripheral blood mononuclear cells (PBMC) from 35 chronic HCV patients with nine pools of synthetic peptides representing the HCV Core, E1, and E2 proteins as well as with a recombinant NS3 protein. The proliferative responses of PBMC from 16 healthy control subjects toward these antigens were measured for comparison. Lymphoproliferative responses of patients with chronic HCV infections were assayed either before (in 10 patients), during (in 13 patients), or after (in 21 patients) treatment with IFN-alpha. The analysis showed that PBMC from most HCV patients consistently recognized the COOH-terminal part of the core protein. E1, E2, and NS3 were recognized less frequently. This recognition pattern was not related to the therapy with IFN-alpha nor to the clinical response of the patient toward this therapy. The response to the Core protein could be fine-mapped to the COOH-terminal region encompassing amino acids (aa) 73 to 92, 121 to 140, 145 to 164, and 157 to 176.

Adult↗

PubMed1996

HCV viraemia is more important than genotype as a predictor of response to interferon in Sicily (southern Italy).

BACKGROUND/AIMS: To investigate host- and virus-related factors predictive of early and sustained alanine aminotransferase normalization after interferon therapy for HCV-related chronic liver disease, in an area where genotype 1 is highly prevalent. METHODS: We studied 100 patients with HCV-RNA positive chronic liver disease (73 chronic hepatitis and 27 cirrhosis) undergoing alpha-interferon treatment. Thirty-four patients had an early response but relapsed, 15 patients remained into sustained response for at least 12 months after therapy, and 51 patients did not respond. Serum HCV-RNA levels were assessed by bDNA (Chiron), and genotype by LiPA (Innogenetics) and by sequencing of the 5' non-coding region. RESULTS: Mean pre-treatment HCV-RNA level (x 10(3) genome equivalents/ml +/- SD) was lower in sustained responders (3854 +/- 7142) than in relapsers (9587 +/- 10163) or in non-responders (5709 +/- 6618). HCV subtype 1b was highly prevalent (82%), while types 1a, 2a, 3 and 4 were rare (about 5% each). However, the prevalence of 1b was much lower (31%) under 40 years of age. The prevalence of subtype 1b among sustained responders (74%) was similar to that observed among relapsers (82%) or non-responders (84%), but some nucleotide substitutions in the putative RNA loop of the 5' non-coding region were seen only among relapsers or non-responders. Multiple logistic regression model showed that early response to interferon was predicted by absence of cirrhosis and a pre-treatment HCV-RNA level below 350. Sustained response to interferon was predicted by pre-treatment HCV-RNA level below 350 and a low fibrosis score. CONCLUSIONS: Among patients with hepatitis C from an area where subtype 1b is highly prevalent, absence of cirrhosis and low pre-treatment serum HCV-RNA level are the most important predictors of response to IFN. Some nucleotide substitutions found in the 5' non-coding region of subtype 1b are associated with non-response or relapse.

Adult↗

PubMed1996

Hepatitis C virus in a hemodialysis unit: molecular evidence for nosocomial transmission.

Between February 1991 and January 1992, elevated alanine aminotransferase (ALT) levels were observed in several hemodialysis patients in a dialysis center in Dendermonde, Belgium. By the end of 1992, 25 out of 68 patients had seroconverted for HCV antibodies. The HCV strains from 23 of these seroconverters were genotyped and classified as genotype 1b. Sequence analysis of the HCV Core region was carried out in 12 patients, 9 of whom were infected with a strain bearing a unique sequence motif as compared with the currently known HCV 1b strains. A new 5' UR/Core line probe assay was designed to screen for such variations. Twenty patients tested positively for this special sequence motif, while the other 3 showed the regular subtype 1b sequence. Phylogenetic analysis of the Core sequences further revealed that the latter three were neither related to the main special strain of the infection, nor to each other. These three strains could be traced to two patients already infected at the time of residence in other dialysis units and to one patient who already showed ALT elevations in 1989. Epidemiological studies revealed no traceable source for this outbreak. In conclusion, molecular analysis demonstrates nosocomial transmissions by a peculiar genotype 1b strain in a dialysis center. Three other genotype 1b strains were also present in the unit, but were not responsible for the outbreak.

Alanine Transaminase↗

PubMed1996

Hepatitis C virus (HCV) genotype analysis in apparently healthy anti-HCV-positive Parisian blood donors.

BACKGROUND: As only a few studies have examined the prevalence of various hepatitis C virus (HCV) subtypes in blood donors, information about the variability and route of infection in apparently healthy persons is limited. STUDY DESIGN AND METHODS: Blood donations collected at a large Parisian hospital (52,441) were investigated for antibodies to HCV. Serum samples were screened with an enzyme immunoassay. All HCV-positive donations were retested with a second enzyme immunoassay and confirmed by immunoblot. The HCV genotype was determined for all polymerase chain reaction-positive subjects. Untypable genotypes were sequenced in the NS5B region. RESULTS: In total, 83 (0.26%) blood donors were anti-HCV positive. Men (0.34%) were significantly more likely to be infected (p < 0.001) than women (0.19%). Prevalence rates in men between 20 and 39 years of age were higher than those in similar women (p = 0.01), but greater in women aged from 50 to 65 years (p = 0.05). Fifty-five sera were viremic, of which 49 could be genotyped by a line probe assay. One new HCV type 1 subtype and three new HCV type 2 subtypes were discovered. In total, 28, 10, 11, 5, and 1 serum samples were grouped into HCV types 1 through 5, respectively, involving a total of 13 subtypes. The mean age of HCV type 2-infected donors was 42 +/- 11 years, but that for type 3-infected subjects was only 30 +/- 4 years (p = 0.0048). Forty-nine subjects showed elevated alanine aminotransferase levels; 39 (80%) of these subjects were viremic (p < 0.05). CONCLUSION: Among the sampled population, an HCV prevalence rate of 0.26 percent was found, with the five most common European genotypes causing the infections. Four new subtypes were discovered. Correlation between genotype and risk factors was not apparent, but links with age, sex, and ethnic origin emerged.

Adult↗

PubMed1996

Second-generation line probe assay for hepatitis C virus genotyping.

Because of the enormous variability of hepatitis C virus (HCV), the development of reliable genotyping assays is a formidable challenge. The optimal genotyping region appears to be the 5' untranslated region (UR) because of high conservation within, but considerable variability between, genotypes. In this study, 21 probes dispersed over seven variable 5' UR areas were applied to a line probe assay (LiPA) and used to analyze 506 HCV-infected sera from different geographical regions representing a multitude of subtypes. At least 31 different reactivity patterns emerged, with 404 (80%) of 506 distributed over 11 prototype patterns, in general corresponding to subtypes 1a, 1b, 2a/2c, 2b, 3a, 5a, and 6a and several type 4 subtypes. Subtyping specificity ranged from 97% in Hong Kong to 90% in Europe but was only 11% in West Africa, while typing specificity was always 100% when samples from Vietnam were excluded. In a second evaluation, the subtype prediction by LiPA of 448 GenBank 5' UR HCV sequences was scored. Of the 58 theoretically predicted patterns, 321 sequences (72%) were covered by the 11 prototype patterns. We concluded that (i) the selected probes detected the corresponding signature motifs in the seven variable regions with 100% reliability; (ii) these motifs allowed correct type interpretation of samples collected worldwide, with the exclusion of Vietnam, Thailand, or Vietnamese patients residing in European hospitals; and (iii) subtyping specificities vary according to geographical region, with 11 prototype subtyping patterns identifying the majority of samples from Europe and the Americas. These results indicate that the LiPA is a reliable assay applicable to routine typing and subtyping of HCV specimens.

Base Sequence↗

PubMed1995

Rapid genotyping of hepatitis C virus RNA-isolates obtained from patients residing in western Europe.

Two rapid genotyping methods for hepatitis C virus (HCV), the line probe assay (Inno-LiPA) and the subtype-specific core amplification system [Okamoto et al., (1992b) Journal of General Virology 73:673-679], were applied to 58 HCV isolates which were typed as type 1 (n = 37) and type 2 (n = 21) by sequence analysis of the 5' untranslated region (5'UTR). The line probe assay targets the 5'UTR and recognized 12 subtype 1a, 25 subtype 1b, 18 subtype 2a, 2 subtype 2b and 1 subtype 2d in accordance with sequence analysis of this region. Subtype-specific core amplification revealed 7 discrepancies among the 37 type 1 isolates when compared to LiPA. A different subtype was observed in 3 isolates (1a versus 1b), 2 isolates remained untyped and 2 isolates showed a coinfection of subtype 1a and 1b. The first 5 discrepancies were confirmed by sequence analysis of the core region whereas the coinfection could not be confirmed. Of the 21 type 2 isolates only one could be typed by subtype-specific core amplification. HCV RNA was detected in all 21 cases after the general first round of polymerase chain reaction (PCR). Direct sequencing of the core region indicated sequence variation as a source of failure. It is concluded that LiPA results are conclusive for typing of HCV. However, LiPA is hampered occasionally for subtyping by lack of subtype-specific sequence variation in 5'UTR. Subtyping results by subtype-specific core amplification were accurate. However, it seems that this assay is not suitable for the identification of genotype 2 isolates that circulate in patients living in Western Europe.

Adult↗

PubMed1995

Significance of anti-hepatitis C virus core IgM antibodies in patients with chronic hepatitis C.

Antihepatitis C virus (HCV) IgM antibodies were found in patients with both acute and chronic hepatitis C. The aims of the study were to determine the significance, in terms of liver disease and virological parameters, of anti-HCV core IgM antibodies in the serum of patients with chronic hepatitis C, and the possible relationship between the presence of these antibodies before treatment and biochemical and virological responses to interferon therapy. Sixty-one patients with chronic hepatitis C were studied. Tests for serum anti-HCV core IgM antibodies were carried out before treatment. The patients received 3 mega units of interferon alpha-2a subcutaneously thrice weekly for at least 3 months (6 months when alanine aminotransferase activity was normal at month 3). A biochemical response to interferon therapy was defined as normal alanine aminotransferase activity at the end of treatment (month 6: biochemical response) and 6 months later (month 12: sustained biochemical response). A sustained virological response was defined as serum HCV RNA negativity by a polymerase chain reaction-based detection method (PCR) in patients with normal alanine aminotransferase at month 12. Anti-HCV core IgM antibodies were detected in 28 of the 61 patients (46%). The prevalence of these antibodies was significantly higher in patients infected with HCV genotype 1 (including subtypes 1a and 1b) than in patients infected with other genotypes (including 2a and 3a) (57% vs. 17%; P < 0.01). No significant difference was found between IgM-positive and IgM-negative patients as regards the mean age, sex ratio, serum alanine aminotransferase and gamma-glutamyl transpeptidase activities, the prevalence of cirrhosis in liver biopsy specimens, detection of HCV RNA by PCR, and quantitation by branched DNA assay. At month 6 of interferon therapy, normal alanine aminotransferase activity was significantly more frequent in IgM-negative than in IgM-positive patients (52% vs. 21%, respectively; P < 0.02). At month 12, normal alanine aminotransferase activity and PCR negativity were significantly more frequent in IgM-negative than in IgM-positive patients (18% vs. 0%, P < 0.04). It is concluded that anti-HCV core IgM antibodies in serum are significantly more frequent in patients infected by HCV type 1 than by other types. This suggests that their overall prevalence in patients with chronic hepatitis C in industrialized countries, where HCV type 1 accounts for the majority of infections, would be of the order of 50%, that anti-HCV core IgM antibodies are not associated with characteristic features of liver disease, and that their presence before treatment is associated with a failure of interferon alpha therapy to clear the virus.

Adolescent↗

PubMed1995

HCV infection in a rural population of the Central African Republic (CAR): evidence for three additional subtypes of genotype 4.

The prevalence of hepatitis C virus (HCV) antibodies, HCV infection, and genotypes was studied in a rural population of the Central African Republic. In five villages, blood samples were taken from all the inhabitants present during the survey, belonging to Pygmies (299) and to Bantu and Banda ethnic groups (247). Using a second-generation ELISA screening and confirmation by immunoblot assay for the detection of HCV antibodies, all the Pygmies were negative, whereas seven Bantus/Bandas, aged > 35 years and with no familial relationship, were positive, giving a prevalence of 2.8% in this ethnic group. Five samples were also PCR positive; all belonged to genotype 4, but with three new subtypes identified by phylogenic analysis. These results indicate the co-existence of different HCV subtypes and raise questions about the natural transmission of HCV in this secluded population.

Adolescent↗

PubMed1995

Hepatitis C virus genotyping by means of 5'-UR/core line probe assays and molecular analysis of untypeable samples.

To test the theoretical possibility of 5'-UR mistyping between hepatitis C virus subtypes 1a and 1b, we combined a 5'-UR/Core line probe assay (LiPA) with a nested PCR system and retested 183 sera, previously genotyped as type 1a or 1b and originating mainly from Western Europe. Eight percent of these were found to be wrongly subtyped. Based on this method, 3 additional subtypes of type 1 were discovered (1d-1f). Randomly selected European type 2 sera (n = 18) were tested with a similar type 2 5'-UR/Core LiPA. They were unexpectedly found to belong to subtype 2c in the majority of cases. Among serum samples originating from South-East Asia, several additional genotypes (7a, 7c, 7d, and 9a) were detected which had 5'-UR sequence motifs indistinguishable from genotype 1. Based on 13,203 pairwise comparisons in the 340-bp NS5B region, classification into types, subtypes, and isolates was obtained in 99.8% of all cases by using the phylogenetic border value of 0.328 for subtypes/types and 0.127 for isolates/subtypes; and evidence for a 10th major type of HCV was provided. Combination of all available HCV sequence data from the 447-bp Core/E1 region and the NS5B 340-bp and 222-bp regions provided evidence for the existence of 10 types, including 50 subtypes. Previously, extensive studies involving genotypes 1a, 1b, 2a, and 2b indicated the importance of HCV subtyping in interferon treatment and progression of chronic liver disease. The herein described expansion in the number of HCV types and subtypes should help improve diagnosis, treatment and possibly prophylaxis of hepatitis C liver disease.

Base Sequence↗

PubMed1995

Relationship between hepatitis C virus genotypes and sources of infection in patients with chronic hepatitis C.

This study examined the relationships between hepatitis C virus (HCV) genotypes and the routes of HCV transmission in 101 patients with chronic hepatitis C. Patients who received blood transfusions (43%) and those with chronic hepatitis C of unknown cause (37%) had similar mean ages, age distribution, and HCV genotype distribution (1a, 19% vs. 14%; 1b, 52% vs. 54%; 3a, 10% vs. 9%; other, 19% vs. 23%). Intravenous drug users (IVDUs) were significantly younger and had a different genotype distribution (1a, 33%; 1b, 0; 3a, 63%; other, 5%; P < .001). Transmission of HCV 3a has been observed only over the past 20 years; other genotypes were transmitted up to 40 years ago. These results suggest that for 20 years there have been two independent ongoing hepatitis C epidemics. One affects persons who received blood transfusions or whose source of infection is unknown. These persons are older and are mainly infected by HCV 1b. The second type of infection occurs in IVDUs and infects younger persons, mainly with HCV 3a.

Adult↗

PubMed1995

Sequence analysis of hepatitis C virus genotypes 1 to 5 reveals multiple novel subtypes in the Benelux countries.

Hepatitis C virus (HCV) isolates from a cohort of 315 patients from the Benelux countries (Belgium, The Netherlands, Luxembourg) were genotyped by means of reverse hybridization Inno-LiPA (line probe assay). Genotypes 1a, 1b, 2a, 2b, 3a, 4a and 5a were detected. From the cohort, isolates representing all types and those showing an aberrant LiPA pattern were further analysed by sequencing parts of the 5' UTR, core (nt 1 to 326; aa residues 1 to 108) and core/E1 (nt 477 to 924; aa residues 159 to 308) regions. Molecular evolutionary analysis of the core and core/E1 regions allowed discrimination between known and additional subtypes, especially within types 2 and 4. The core region is not suitable for classification of new subtypes because of the relatively high level of conservation. The core/E1 region displays a higher level of sequence variation and allows much more distinct discrimination between subtypes. Genotypes 2 and 4 are particularly heterogeneous, with at least 7 and 10 subtypes, respectively. In contrast to previous reports from Europe, HCV isolates from the cohort constituted a highly heterogeneous population of virus variants, especially within genotypes 2 and 4.

Belgium↗