Prevalence of chronic HCV infection in EU/EEA countries in 2019 using multiparameter evidence synthesis

Background

Epidemiological data are crucial to monitoring progress towards the 2030 Hepatitis C Virus (HCV) elimination targets. Our aim was to estimate the prevalence of chronic HCV infection (cHCV) in the European Union (EU)/European Economic Area (EEA) countries in 2019.

Methods

Multi-parameter evidence synthesis (MPES) was used to produce national estimates of cHCV defined as: π = πrecρrec + πexρex + πnonρnon; πrec, πex, and πnon represent cHCV prevalence among recent people who inject drugs (PWID), ex-PWID, and non-PWID, respectively, while ρrec, ρex, and ρnon represent the proportions of these groups in the population. Information sources included the European Centre for Disease Prevention and Control (ECDC) national operational contact points (NCPs) and prevalence database, the European Monitoring Centre for Drugs and Drug Addiction databases, and the published literature.

Findings

The cHCV prevalence in 29 of 30 EU/EEA countries in 2019 was 0.50% [95% Credible Interval (CrI): 0.46%, 0.55%]. The highest cHCV prevalence was observed in the eastern EU/EEA (0.88%; 95% CrI: 0.81%, 0.94%). At least 35.76% (95% CrI: 33.07%, 38.60%) of the overall cHCV prevalence in EU/EEA countries was associated with injecting drugs.

Interpretation

Using MPES and collaborating with ECDC NCPs, we estimated the prevalence of cHCV in the EU/EEA to be low. Some areas experience higher cHCV prevalence while a third of prevalent cHCV infections was attributed to PWID. Further efforts are needed to scale up prevention measures and the diagnosis and treatment of infected individuals, especially in the east of the EU/EEA and among PWID.

Funding

ECDC.

Historical epidemiology of hepatitis C virus (HCV) in selected countries

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6,358,000 cases in 2008 and Brazil with 2,106,000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV-infected populations are critical for addressing HCV-related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

The present and future disease burden of hepatitis C virus (HCV) infection with today's treatment paradigm

The disease burden of hepatitis C virus (HCV) is expected to increase as the infected population ages. A modelling approach was used to estimate the total number of viremic infections, diagnosed, treated and new infections in 2013. In addition, the model was used to estimate the change in the total number of HCV infections, the disease progression and mortality in 2013-2030. Finally, expert panel consensus was used to capture current treatment practices in each country. Using today's treatment paradigm, the total number of HCV infections is projected to decline or remain flat in all countries studied. However, in the same time period, the number of individuals with late-stage liver disease is projected to increase. This study concluded that the current treatment rate and efficacy are not sufficient to manage the disease burden of HCV. Thus, alternative strategies are required to keep the number of HCV individuals with advanced liver disease and liver-related deaths from increasing.

Strategies to manage hepatitis C virus (HCV) disease burden

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV-related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3-5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

TTV and HPV co-infection in cervical smears of patients with cervical lesions

BACKGROUND

The female lower genital tract is a gateway for pathogens entering the host through the mucous membrane. One of the prevalent human viruses is Torque teno virus (TTV). The major reported routes of TTV transmission are fecal-oral and parenteral. Furthermore, other modes of transmission, e.g. sexual contact, are suggested. To investigate the sexual route of TTV transmission, cervical smears of healthy women and those with cervical lesions were screened for the presence of TTV DNA.

METHODS

TTV DNA was studied in cervical smears of 95 patients with cervical lesions and 55 healthy women. Paired serum samples were available from 55 and 42 women, respectively. All healthy women had normal cytology while 44 patients had histologically confirmed low-grade lesion (LGL) and 51 high-grade lesion (HGL). TTV DNA was detected with primers specific for the non-coding region. In 40 paired cervical smears and serum samples, the phylogenetic group of TTV isolates was determined. The presence of HPV DNA in cervical smears was detected by means of PCR with MY09/11 primers.

RESULTS

The prevalence of TTV DNA in cervical smears of healthy women was 52.7% and was comparable with that in paired serum samples (50%). Symptomatic women had significantly higher prevalence of TTV DNA in cervical smears (74.7%) than healthy controls. The TTV DNA prevalence in patient serum samples was 51%. The phylogenetic groups of TTV serum isolates were concordant with those of TTV from cervical smears of the same subjects. In cervical smears, a wider variety of TTV isolates was found. The viral loads in cervical smears were 10 to 1000 times as high as in sera. The HPV-positive study subjects had significantly higher TTV DNA prevalence than HPV negatives. The prevalence of TTV was not associated with disease severity.

CONCLUSION

High prevalence of TTV in cervical smears suggests that sexual transmission is another mode of expansion of TTV infection among the population. The higher viral load in cervical smears than in the respective serum samples might indicate active TTV replication in the female genital tract. Nevertheless, cooperation between TTV and HPV needs to be further investigated.

Prevalence of HBV genotypes in Central and Eastern Europe

The importance of hepatitis B virus (HBV) genotypes for disease progression and response to interferon-alpha-based treatment is well established. While almost all patients in the Mediterranean area are infected with HBV genotype D, HBV genotype A is dominant in Northern Europe. However, the distribution of HBV genotypes is unknown for several Central and Eastern European countries. Data are described of 1313 HBsAg-positive patients recruited at 14 referral centers in eight countries. There were only very few cases of HBV genotype B, C, E, F, and H infection while HBV genotypes A and D were found in 42% and 48% of patients, respectively. Eight percent of patients had positive bands for more than one genotype using the hybridization assay. The frequency of genotype A was higher in Poland (77%) and the Czech Republic (67%) as compared to Hungary (47%), Lithuania (41%), Croatia (8%), and Germany (32%). In contrast, HBV genotype D was most frequent in Croatian, Romanian, and Russian patients with 80%, 67%, and 93% of cases, respectively. In conclusion, HBV genotype A versus D showed significantly different distribution patterns in Central and Eastern Europe which deserves consideration for national guidelines and treatment decisions.

[Diagnosis and treatment of chronic hepatitis B. Recommendations of the Czech Hepatology Society of the J. E. Purkinje Medical Society and the Society of Infectious Medicine of the J.E. Purkinje Medical Society]

Chronic hepatitis B is one of the world's most common infectious diseases. In the Czech Republic it has a prevalence of 0.56%. Antiviral therapy for chronic hepatitis B demonstrably increases quality of life and where indication criteria are met and standard therapeutic procedures are followed, it is clearly cheaper than treatment for the complications of advanced cirrhosis of the liver or hepatocellular carcinoma. At the time of issuing of this recommendation, 4 medicines were classified for the treatment of chronic hepatitis B in the Czech Republic--pegylated interferon (IFN) alpha-2a, conventional IFN alpha, lamivudine (LAM) and adefovir dipivoxil (ADV). In a number of other developed states, entecavir (ETV) and telbivudine (LdT) have also been approved for treatment. The most effective treatment available at present is pegylated IFN alpha-2a, which should be the medication of first choice for initial treatment of hepatitis B, HBeAg positive and negative forms, provided that there are no contraindications for IFN alpha treatment. Conventional (standard, classical) IFN alpha can also be used, though clinical studies have shown it to be less effective than pegylated IFN alpha-2a. The main advantage of interferon compared to other commercially available medications is its relatively shorter and more clearly defined treatment period, the high probability of permanent suppression of virus replication and seroconversion of HBeAg/anti-HBe (in HBeAg positive forms of the illness) and the non-creation of mutant strains of HBV resistant to IFN in the course of treatment. If there are contraindications for IFN alpha (pegylated or conventional) or it is ineffective or poorly tolerated, ADV, ETV, LAM or LdT can be used. LAM and LdT treatments are often accompanied by the appearance of mutant strains of HBV, that are resistant to lamivudine or LdT and therefore they are not preferred.

The European Sero-Epidemiology Network 2: standardization of assay results for hepatitis B virus

The aim of the European Sero-Epidemiology Network 2 was to coordinate and standardize the serological surveillance of vaccine-preventable diseases in Europe. In this study, the standardization of hepatitis B virus (HBV) results is described. The 15 participating national laboratories tested a unique panel of 172 sera established by the Greek reference centre for HBV surface antigen (HBsAg), antibodies to HBsAg (anti-HBs) and/or to the HBV core antigen (anti-HBc) by assay methods of their choice. Country-specific quantitative measurements for anti-HBs and anti-HBc were transformed into common units using standardization equations derived by regressing each country's panel results against the reference centre's results, thus adjusting for interassay and interlaboratory variability. For HBsAg, a qualitative analysis (positive/negative) showed at least 99% agreement with the reference laboratory for all countries. By combining these standardized and qualitative results for the markers mentioned earlier, it was possible to achieve comparable estimates of the proportion of the population susceptible to HBV, vaccinated against HBV, with a past HBV infection, and with a current infection or chronic carrier state. Standardization is a very important tool that allows for international serological comparisons to assess the current vaccination policies and the progress of HBV control in Europe.

Long-term protective effect of post-exposure Havrix administration during viral hepatitis Type A outbreaks

Administration of human normal immunoglobulin (HNIG) post-exposure has been routinely used in Slovakia for outbreak control of hepatitis A, but requires deep intramuscular injection, provides only short-lived protection and is a human blood product. The protective effect of post-exposure administration of an inactivated hepatitis A vaccine was evaluated during 10 outbreaks in Slovakia. Direct contacts of confirmed hepatitis A cases received either: a single dose of hepatitis A vaccine (n = 2171) or immunoglobulin (HNIG, n = 3837). In the HNIG group the number of hepatitis A confirmed cases dropped within the first 7 weeks, however the decrease was not as rapid or as marked as that observed in the vaccinated group where the number of hepatitis A cases dropped within the first 4 weeks after vaccination. Among contacts, 67 cases of hepatitis A were detected during the maximum incubation period of 45 days: 16 cases (0.7%) in the vaccine group and 51 cases (1.3%) in the HNIG group (p < 0.05). After two and three years respectively, 50 and 39 volunteers who had previously received one dose of hepatitis A vaccine received a booster dose and anti-HAV antibodies were measured. Differences in anti-HAV antibody GMCs before and after the booster were statistically significant. The longer time interval (3 years instead of 2) between primary vaccination and booster administration did not seem to impact the magnitude of the booster response. The results of this study show that active post-exposure immunisation with only one dose of inactivated vaccine confers high and long-term protection and effectively controls viral hepatitis A outbreaks.

[HCV genotyping by combination of the Cobas Amplicor HCV 2.0 test and the reverse hybridization Versant HCV Genotype Assay]

Genotyping of hepatitis C virus (HCV) is of relevance to scheduling the treatment of patients with chronic hepatitis C (VHC), making their prognosis and monitoring the treatment efficacy. A set of 62 sera testing HCV RNA positive in Cobas Amplicor HCV 2.0 test (CA) were genotyped using Versant HCV Genotype Assay (LiPA) Bayer, i.e. the reverse hybridization method, with the CA amplified product being directly used in the assay. Fifty-six out of 57 samples reactive in reverse hybridization (92%) were genotyped. One sample showed a profile differing from any genotype, five samples were not reactive and one sample was not tested within this study design. Two out of five non-reactive sera and one non-tested serum could be genotyped by nested PCR based reverse hybridization. It can be concluded that the CA product resulting from one-step HCV RNA amplification is suitable for use in genotyping by reverse hybridization. The CA product based genotyping procedure is easier to perform, less time-consuming and less costly. The nested PCR based procedure could be used for typing of sera with lower HCV concentrations nontypeable with the combination of CA and Versant HCV Genotype Assay. Forty-eight selected samples were typed not only by reverse hybridization but also by a serological kit Murex HCV Serotyping 1-6 Assay (Abbot Murex). Thirty-seven (77%) of these sera, including all of three sera negative in reverse hybridization, appeared typeable by this kit. Although less sensitive, serotyping may be of relevance to typing of sera with low HCV levels or not containing detectable viral NA which are nontypeable by reverse hybridization. Thirty-three sera appeared genotypeable by both of the methods tested with the results being in good agreement. In two cases only the serotyping method revealed one more type of virus (mixed genotype) compared to the reverse hybridization.

Hepatitis D

Hepatitis D virus (HDV) is a small, RNA-containing virus that requires the concomitant presence of Hepatitis B virus (HBV) in an obligate manner for its survival and pathogenicity. HDV infection is very uncommon in Czech Republic. The results of antiviral therapy of hepatitis D patients are not satisfactory. Alpha-interferon (alpha-IFN) in high doses (9-10 MU three times a week for 12 months) is usually recommended.

The 2001 serological survey in the Czech Republic--viral hepatitis

Within serological surveys 2001, prevalence of markers of hepatitis viruses A (anti-HAV), B (anti-HBc, HBsAg, anti-HBs) and for the first time also C (anti-HCV) was investigated. Sera were collected in 2001 and tested by respective kits AxSYM, Abbott. HAV: 2,623 sera were tested for the presence of anti-HAV antibodies. Comparison with serological surveys of 1984 and 1996 revealed again shifts of the age prevalence curve for anti-HAV antibodies towards higher age groups corresponding to time intervals between epidemiological surveys. High prevalence rates of anti-HAV antibodies (more than 20%) were only found for the population age groups who lived in the period of high incidence of VHA, i.e. up to 1965. The prevalence of anti-HAV antibodies increased by about 5-10% in the population under 20 years of age, the increase being significant and assumingly attributable to vaccination against VHA, and remained the same as in 1996 in the age group 20-29 years. HBV: 2,568 sera were tested for the presence of anti-HBc antibodies and 76 reactive specimens were further tested for the presence of HBsAg and anti-HBs antibodies. The prevalence of anti-HBc antibodies continuously increases with age. The total prevalence of anti-HBc antibodies calculated for the Czech population is 5.59% compared to 6.95% recorded in 1996. The calculated prevalence rate of HBsAg is 0.56% and that of anti-HBs antibodies is 3.99% for the non-vaccinee population. HCV: The prevalence rate of anti-HCV antibodies was 0.2% with 6 out of 2,950 sera testing positive. Age dependence could not be assessed because of the small number of positive persons. HCV infection is known to afflict high-risk groups, likely to escape a general serological survey, rather than the normal population.

The serology of hepatitis C virus (HCV) infection: antibody crossreaction in the hypervariable region 1

We determined the NS1/E2 N-terminal sequence including the hypervariable region 1 (HVR1) from five individuals chronically infected with HCV: two from the Czech Republic and three from Germany. From each sequence, six 12-mer overlapping peptides were synthesized and used in a peptide scan to evaluate seroreactivity of each of those patients, as well as three anti-HCV positive blood donors to the different isolates. We could show the general presence of antibodies to multiple HVR1 specific sequences reflecting the existence of multiple variants in infected persons. Finally, we observed the persistance of HCV infections in all individuals despite an active humoral response directed against the virus.