Prevalence of hepatitis C genotypes among patients with chronic hepatitis C in Norway. Construct Group

A systematic review of hepatitis C virus epidemiology in Europe, Canada and Israel

BACKGROUND AND AIM

Decisions on public health issues are dependent on reliable epidemiological data. A comprehensive review of the literature was used to gather country-specific data on risk factors, prevalence, number of diagnosed individuals and genotype distribution of the hepatitis C virus (HCV) infection in selected European countries, Canada and Israel.

METHODOLOGY

Data references were identified through indexed journals and non-indexed sources. In this work, 13,000 articles were reviewed and 860 were selected based on their relevance.

RESULTS

Differences in prevalence were explained by local and regional variances in transmission routes or different public health measures. The lowest HCV prevalence (≤ 0.5%) estimates were from northern European countries and the highest (≥ 3%) were from Romania and rural areas in Greece, Italy and Russia. The main risk for HCV transmission in countries with well-established HCV screening programmes and lower HCV prevalence was injection drug use, which was associated with younger age at the time of infection and a higher infection rate among males. In other regions, contaminated glass syringes and nosocomial infections continue to play an important role in new infections. Immigration from endemic countries was another factor impacting the total number of infections and the genotype distribution. Approximately 70% of cases in Israel, 37% in Germany and 33% in Switzerland were not born in the country. In summary, HCV epidemiology shows a high variability across Europe, Canada and Israel.

CONCLUSION

Despite the eradication of transmission by blood products, HCV infection continues to be one of the leading blood-borne infections in the region.

Market uptake of new antiviral drugs for the treatment of hepatitis C

BACKGROUND/AIMS

Peginterferon plus ribavirin is the state-of-the-art antiviral therapy for prevention of serious complications of hepatitis C. Our aim was to compare market uptake of and access to these drugs across Europe.

METHODS

We collected launch and sales data for peginterferons for 21 countries in the WHO European region and compared country-specific sales rates. Additionally, we converted sales figures into patient numbers and related those to country-specific hepatitis C prevalence, taking into account genotype distribution, patient characteristics and practice patterns.

RESULTS

Peginterferon sales rates differed considerably across countries. The earliest, most rapid and highest adoption rates were in EU founder states, followed by EU members that joined after foundation, and EU non-member states. Most new member states showed a marked increase in sales. By the end of 2005, approximately 308,000 patients had been treated with peginterferons in the 21 countries evaluated. The number of patients ever treated ranged from 16% of prevalent cases in France to less than 1% of cases in Romania, Poland, Greece and Russia.

CONCLUSIONS

Peginterferon market uptake and access differed considerably across Europe, suggesting unequal access to optimised therapy. Besides budget restrictions, national surveillance and treatment policies should be considered as reasons for market access variation.

The changing epidemiology of hepatitis C virus infection in Europe

The epidemic of hepatitis C virus (HCV) infection in Europe is continuously evolving and epidemiological parameters (prevalence, incidence, disease transmission patterns and genotype distribution) have changed substantially during the last 15 years. Four main factors contribute to such changes: increased blood transfusion safety, improvement of healthcare conditions, continuous expansion of intravenous drug use and immigration to Europe from endemic areas. As a result, intravenous drug use has become the main risk factor for HCV transmission, prevalent infections have increased and genotype distribution has changed and diversified. Hence, prevalence data from studies conducted a decade ago may not be useful to estimate the current and future burden of HCV infection and additional epidemiological studies should be conducted, as well as new preventive strategies implemented to control the silent epidemic. This review summarizes recently published data on the epidemiology of HCV infection in Europe focusing on the factors currently shaping the epidemic.

Hepatitis C impairs survival following liver transplantation irrespective of concomitant hepatocellular carcinoma

BACKGROUND/AIMS

Liver transplantation (LTX) is the only curative treatment for end-stage liver disease caused by hepatitis C (HCV). Hepatocellular carcinoma (HCC) is common in patients with HCV cirrhosis.

METHODS

Two hundred and eighty-two HCV patients listed for LTX in the Nordic countries in a 17-year period were included. For comparison a group of patients with non-viral chronic liver disease (n=1552) was used.

RESULTS

Two hundred and fifty-three (90%) patients received a first liver allograft. HCC was found in 38% of the explanted livers. Survival at 1, 3 and 5years was 82%, 69% and 61% vs. 85%, 80% and 76% for the comparison group (p<0.0001), this survival difference was also evident when excluding patients with HCC (p=0.007). HCV patients with HCC had 1, 3 and 5year survival of 73%, 52% and 46% compared with 88%, 80% and 71% for the HCV patients without HCC (p=0.0005). In an intention-to-treat analysis (from time of acceptance to the waiting list) HCV was also associated with an impaired survival.

CONCLUSIONS

HCV cirrhosis, which is now also an important indication for LTX in the Nordic countries, and significantly impairs survival following LTX. Concomitant HCC and donor age are the two most important factors contributing to an impaired survival.

Genetic characterization of hepatitis C virus strains in Estonia: fluctuations in the predominating subtype with time

During the last decade, there has been a dramatic increase in intravenous drug use in young adults in Estonia with an increased incidence of both hepatitis B and C as a consequence. Since genetic data are limited regarding hepatitis C virus (HCV) strains in Estonia, the aim of the study was to characterize HCV strains in different risk groups to determine their relatedness to strains from other geographical regions. Three hundred fifty-three anti-HCV positive sera collected during 1994-2004 from hospitalized patients, blood donors and health care workers were used as source of HCV RNA. Two hundred nine (59%) of the sera were positive for HCV RNA by PCR directed to the 5'-UTR region. For 174 strains the HCV subtype was determined by analyses of the NS5B and/or the 5'UTR-core regions. 1b (71%) was the most common subtype followed by 3a (24%), 2c (2%), 1a (1%), and 2a (1%). The 1b and 3a strains were similar to strains from other regions of the former USSR. Within genotype 1b there were several HCV lineages. However, for 3a there seemed to be two separate introductions into Estonia. There was a relative shift from subtype 1b to 3a in 1999-2000 with a further replacement of 3a with 1b in intravenous drug users in 2001 and onwards (P < 0.05). However, both subtypes were found to co-circulate in the community independent of risk factors. One patient was infected with the 2k/1b recombinant presumed to originate from St. Petersburg being the first isolate of this recombinant recovered outside Russia.

Hepatitis C treatment of opioid dependants receiving maintenance treatment: results of a Norwegian pilot study

BACKGROUND

Many physicians are still skeptic to treat opioid dependants, with or without maintenance treatment, for hepatitis C (HCV) because of concerns about psychiatric comorbidity, stability and adherence. In Norway, there are about 3,500 patients participating in the restrictive medication-assisted rehabilitation (LAR) programs in which all patients are given methadone or buprenorphine maintenance therapy. This study was undertaken to determine whether HCV combination therapy with pegylated interferon alpha-2a plus ribavirin is feasible, efficient and safe in this patient group.

METHOD

Seventeen patients with HCV genotype 3a were treated for 24 weeks. To optimize compliance, the treatment was given from a department of infectious diseases in cooperation with an LAR center. All injections were given in the LAR center and the patients were given psychosocial support.

RESULTS

The compliance was 100%. All responded to the therapy and 16 (94%) were sustained responders.

DISCUSSION/CONCLUSION

This study indicates that compliance and treatment outcome of opioid dependants on methadone or buprenorphine maintenance after 24 weeks of HCV treatment corresponds to that for non-dependants if extra support is given. The treatment should be undertaken in collaboration with specialists in addiction medicine, hepatology and infectious diseases.

Liver TX for hepatitis C cirrhosis in a low prevalence population: risk factors and status at evaluation

OBJECTIVE

Hepatitis C virus (HCV) cirrhosis is the most common indication for liver transplantation (LTX) world-wide. The prevalence of HCV infections is much lower in Norway than in most other countries from which data on HCV infection and liver transplantation have been published.

MATERIAL AND METHODS

Patients with HCV infection referred for evaluation of a possible LTX between 1990 and 2005 were included in the study. Their clinical status, biochemical parameters and risk factors were recorded. All patients were followed until 1 January 2005 irrespective of transplantation status.

RESULTS

Fifty-one patients were included; 80% were males and 18% were non-Caucasians. Previous intravenous drug abuse (28%) and exposure to contaminated IgG products (15%) were the most common routes of infection. In 45/51 (88%) of the evaluated patients at least one risk factor for rapid progression of HCV disease was identified. Twenty-seven patients were accepted on the waiting list. The MELD (model for endstage liver disease) score for the accepted patients was significantly higher than that for the patients who were not listed because they were found to be too healthy (18.4 versus 12.1, p<0.01). Twenty-four patients (89% of those listed) received a liver allograft; their 1-, 3- and 5-year survival rates following LTX were 81%, 68% and 68%, respectively. Two patients needed a second transplantation.

CONCLUSIONS

A low number of HCV-infected patients have so far been evaluated for LTX in Norway. The present study demonstrates that almost all of the HCV patients progressing to cirrhosis and being evaluated for LTX in Norway have additional risk factors for development of cirrhosis.

A rapid real-time PCR assay for determination of hepatitis C virus genotypes 1, 2 and 3a

The genotypes of hepatitis C virus (HCV) in serum of patients have been described as independent predictors of success of antiviral therapy. Therefore, different antiviral regimens have been proposed depending on the infecting HCV genotype. HCV strain is usually determined by polymerase chain reaction (PCR) amplification of genome followed by sequencing or by line-probe assays. We report a new one step real-time PCR assay for genotyping of HCV strains that are prevalent in patients in Norway. HCV types 1, 2 and 3a were genotyped unambiguously in 37 patient serum samples with 100% correlation to genotyping by nucleotide sequence analysis and line-probe assays. Genotyping could also be confirmed against an HCV genotype panel from the National Institute for Biological Standards and Control. This assay does not require manipulation of amplified PCR products, it involves very little hands on and analysis time. This assay can be used for rapid genotyping of HCV-RNA in infected patients to aid physicians decide suitability of patients for treatment and subsequent length of treatment.

Genomic and phylogenetic analysis of hepatitis C virus isolates: a survey of 535 strains circulating in southern France

The present study examines the distribution of Hepatitis C virus (HCV) genotypes in Marseille, France in 2001-2002 and evaluates the efficiency of two in house direct sequence PCR protocols based on 5'NC analysis or NS5B analysis. By 5'NC sequencing, the distribution of 535 HCV strains derived from patients attending gastroenterology and AIDS referral centers, or dialysis units was as follows: 33% were infected by genotype 1a; 26% by 1b; 7% by 2; 22% by 3a; 10.7% by 4. In univariate analysis, HCV distribution was associated with age and source of infection, whereas in multivariate analysis only injecting drug use was an independent determinant for genotype distribution. Among the 535 specimens submitted to 5'NC direct sequencing, 18% could not be classified accurately into subtypes. A subset of 187 samples was amplified efficiently and sequenced by targeting the NS5B region of the viral genome. The two methods yielded concordant results in 70% of cases. Specimens unsubtypeable or misclassified most frequently by 5'NC analysis were type 1b and subtypes 2a/2c and 4a/4c. The data show that 5'NC direct sequence analysis is a sensitive method to identify genotypes in all cases, but that it can lead to subtyping misclassification (in particular, subtype 1b and 1a) or doubtful results (in particular subtypes 2a/2c and 4a/4c). Conversely, NS5B direct sequence assay, based on phylogenetic analysis, allowed better discrimination between subtypes. These two approaches are complementary and should be made available in clinical laboratories to ensure a reliable survey of HCV strains.

Changing molecular epidemiology of hepatitis C virus infection in Northeast Italy

To assess HCV genotype distribution and its determinants, 318 consecutive HCV RNA positive patients were examined. Subtype 1b infection was the most prevalent (35.5%), followed by subtype 1a (22%), 3a (21.4%) and 2 genotype (21.3%). Subtypes 1a, 1b and 3a had a comparable prevalence (30-35%) in the 0-15-, 16-30- and 31-45-year age groups. In subjects older than 45 years, genotype 2 prevalence increased, whereas subtype 1a and 3a infections decreased markedly. In this age group types 1b and 2 accounted for a prevalence of more than 90% in a comparable proportion. Genotype prevalence rates according to different risk factors were different statistically (P < 0.001): subtype 1a and 3a infections were predominant in injection drug users (42.9% and 37.7%, respectively), whereas community acquired infections and infections in patients with a history of transfusion were caused mainly by subtype 1b (38.5% and 66.6%, respectively). Logistic regression showed that age and injection drug use are independent determinants of genotype distribution.

Distribution of HCV genotypes among risk groups in Serbia

Blood samples from 190 patients that were anti-hepatitis C virus (HCV) positive were genotyped and 165 were found to contain HCV-RNA. Genotyping was performed by PCR based on type-specific primers (117 isolates) and LiPA test (48 isolates) and verifying by sequencing. In Serbia, the most frequent genotype was 1b (49.1%), followed by genotype 3 (21.2%) and genotype 1a (8.5%). The frequency of genotypes 2 and 4 was below 5% and mixed infections were encountered in 9.1% of cases. Distribution of genotypes was monitored in different risk groups: intravenous drug abusers, patients under blood transfusion, patients with previous history of surgery, patients undergoing hemodialysis and those with unknown risk factors. Genotype distribution is essentially the same in all the groups, except for the patients undergoing hemodialysis and those with previous history of surgery where significant difference exists compared with the group with unknown route of transmission (p < 0.001 and p < 0.05, respectively). There exists significant age-dependent genotype 3 distribution in Serbian population (p < 0.01).

Chronic hepatitis C in Sweden: genotype distribution over time in different epidemiological settings

Hepatitis C virus (HCV) strains are divided into 6 genotypes and several subtypes. Recent studies reported a change in the relative frequency of genotypes within certain regions. We studied the HCV genotype in 312 Swedish patients with chronic hepatitis C, using a core region primer-specific PCR, and grouped the patients according to parenteral risk factors. The date of infection could be estimated in 127 cases. Genotypes 1a (35%) and 3 (31%) were the most common genotypes, followed by genotype 2 (17%), while only 6% had genotype 1b. Genotype 3 was relatively more frequent among subjects infected sexually or by intravenous drug use. The genotype distribution was different from that in studies from other parts of the world, with a lower frequency of genotype 1 (especially 1b) and a higher frequency of genotype 3. The frequency of genotype 1b has decreased and genotype 3 increased over time. The reasons for a different distribution of genotypes in Sweden, compared with other countries, might be a relatively recent introduction of HCV into the population, or a different pattern of transmission.

Interferon-alpha 2b therapy in low-activity hepatitis C: a pilot study

BACKGROUND

Many patients with chronic hepatitis C have long periods of normal or near-normal liver enzyme levels, even though histologic alterations have been confirmed. The recommendation today is not to treat this patient group.

METHODS

In a pilot study 23 hepatitis C virus (HCV) RNA-positive patients with alanine aminotransferase (ALAT) levels less than 1.5 times upper normal limits for at least 6 months on more than three occasions and with histologic liver abnormalities compatible with chronic hepatitis C were treated with 3 MU of interferon-alpha 2b three times a week for 6 months.

RESULTS

Nine patients (39%) became HCV RNA-negative in serum during treatment, but only two (8.7%) remained so after 6 months' follow-up. Significantly more patients with genotype other than type 1 became HCV RNA-negative than patients with genotype 1 during treatment (P = 0.005).

CONCLUSIONS

Patients with low-activity chronic hepatitis C have a response to interferon-alpha treatment similar to that of patients with increased ALAT levels. Genotype seems to influence the rate of response.