Comparison of second- and third-generation enzyme immunoassays for detecting antibodies to hepatitis C virus

Prevalence of hepatitis C virus exposure and infection among Indigenous and tribal populations: a global systematic review and meta-analysis

OBJECTIVES

The objective of this study was to estimate prevalence of hepatitis C virus (HCV) exposure and infection among Indigenous and tribal populations globally.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We systematically searched bibliographic databases and grey literature (1/01/2000-16/06/2022). Prevalence estimates were synthesised overall, by World Health Organization region and HCV-risk group. For studies with comparator populations, prevalence ratios were estimated and pooled.

RESULTS

Ninety-two studies were included. Globally, among general Indigenous and tribal populations, the median prevalence of HCV antibody (HCV Ab) was 1.3% (interquartile range [IQR]: 0.3-3.8%, I2 = 98.5%) and HCV RNA was 0.4% (IQR: 0-1.3%, I2 = 96.1%). The Western Pacific Region had the highest prevalence (HCV Ab: median: 3.0% [IQR: 0.4-11.9%], HCV RNA: median 5.6% [IQR: 2.0-8.8%]). Prevalence was highest in people who injected drugs (HCV Ab: median: 59.5%, IQR: 51.5-67.6%, I2 = 96.6%; and HCV RNA: median: 29.4%, IQR: 21.8-35.2%, I2 = 97.2%). There was no association between HCV Ab prevalence and Indigenous/tribal status for general populations (prevalence ratio = 0.91; 95% CI: 0.56, 1.49) or key risk groups.

CONCLUSIONS

Indigenous and tribal peoples from the Western Pacific Region and recognised at-risk sub-populations had higher HCV prevalence. HCV prevalence showed no association with Indigenous/tribal status. However, this review was limited by heterogeneity and poor quality of constituent studies, varying definitions of Indigenous/tribal status, regional data gaps, and limited studies on chronic infection (HCV RNA). Comprehensive quality evidence on HCV epidemiology in Indigenous and tribal peoples is needed to tailor preventive and treatment interventions so these populations are not left behind in elimination efforts.

Advancing Diagnosis of Current Hepatitis C Virus Infection: A Key to Hepatitis C Elimination in the United States

More than 2 million adults have hepatitis C virus (HCV) infection in the United States, and new infections continue to increase. Without treatment, HCV infection can lead to advanced liver disease and death. Treatment is recommended for nearly everyone with hepatitis C, resulting in a cure in >95% of people treated and raising the possibility of hepatitis C elimination. Testing is the first step to accessing life-saving treatment. The Centers for Disease Control and Prevention recommends hepatitis C screening for all adults, all pregnant persons, and anyone with risk; yet about one-third of people with hepatitis C remain unaware of their infection. Testing begins with a hepatitis C antibody test, followed, when reactive, by a nucleic acid test to detect HCV RNA. This antibody-first, 2-step testing strategy misses early infections and can result in incomplete diagnoses. Advancements in hepatitis C diagnostics and the US regulatory landscape have created an opportunity to include viral-first testing strategies and improve hepatitis C diagnosis. This journal supplement features 8 articles detailing challenges and opportunities for improving hepatitis C diagnostics in support of advancing hepatitis C elimination in the United States.

Clinical performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of hepatitis C virus antibodies

BACKGROUND

Hepatitis C virus (HCV) infection screening and diagnosis are critical to control the hepatitis C epidemic. Testing for anti-HCV antibodies (Ab) in blood samples is the first step to screen people who have been infected with the virus.

OBJECTIVES

To evaluate the performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of HCV antibodies.

STUDY DESIGN

To assess the diagnostic specificity, serum samples from 5053 unselected donors and 205 blood specimens from hospitalized patients were collected. To evaluate the diagnostic sensitivity, 400 positive HCV Ab samples were collected and 30 seroconversion panels were tested. All samples that met the test criteria were tested with the MAGLUMI Anti-HCV (CLIA) Test according to manufacturer's instruction. Results of the MAGLUMI Anti-HCV (CLIA) Test were compared with the Abbott ARCHITECT anti-HCV reference test.

RESULTS

The specificity of the MAGLUMI Anti-HCV (CLIA) Test was 99.75% and 100.00% in blood donor and hospitalized patient samples, respectively. The sensitivity of the Test in HCV Ab positive samples was 100.00%. Seroconversion sensitivity was comparable between the MAGLUMI Anti-HCV (CLIA) Test and the reference assay.

CONCLUSIONS

The performance of the MAGLUMI Anti-HCV (CLIA) Test makes it suited for HCV infection diagnosis.

Cost-Effectiveness of Strategies to Identify Children with Perinatally Acquired Hepatitis C Infection

OBJECTIVE

To determine the optimal testing strategy to identify children with perinatally acquired hepatitis C virus (HCV) infection.

STUDY DESIGN

We used a decision-tree framework with a Markov disease progression model to conduct an economic analysis of 4 strategies, based on combinations of type and timing of test: anti-HCV with reflex to HCV RNA at 18 months among children known to be perinatally exposed (ie, baseline comparison strategy); HCV RNA testing at 2-6 months among infants known to be perinatally exposed (test strategy 1); universal anti-HCV with reflex to HCV RNA at 18 months among all children (test strategy 2); and universal HCV RNA testing at 2-6 months among all infants (test strategy 3). We estimated total cost, quality-adjusted life years, and disease sequalae for each strategy.

RESULTS

Each of the 3 alternative testing strategies resulted in an increased number of children tested and improved health outcomes. HCV RNA testing at 2-6 months (test strategy 1) was cost-saving and resulted in a population-level difference in cost of $469 671. The 2 universal testing strategies resulted in an increase in quality-adjusted life years and an increase in total costs.

CONCLUSIONS

Testing of perinatally exposed infants at age 2-6 months with a single HCV RNA test will reduce costs and improve health outcomes, preventing morbidity and mortality associated with complications from perinatal HCV infections.

A cost-effectiveness study of universal screening for hepatitis C virus infection in South Korea: A societal perspective

BACKGROUND/AIMS

This study aimed to evaluate the cost-effectiveness of hepatitis C virus (HCV) screening compared to no screening in the Korean population from societal and healthcare system perspectives.

METHODS

A published decision-tree plus Markov model was used to compare the expected costs and quality-adjusted life years (QALY) between one-time universal HCV screening and no screening in the population aged 40-65 years using the National Health Examination (NHE) program. Input parameters were obtained from analyses of the National Health Insurance claims data, Korean HCV cohort data, or from the literature review. The population aged 40-65 years was simulated in a model spanning a lifetime from both the healthcare system and societal perspectives, which included the cost of productivity loss due to HCV-related deaths. The incremental cost-effectiveness ratio (ICER) between universal screening and no screening was estimated.

RESULTS

The HCV screening strategy had an ICER of $2,666/QALY and $431/QALY from the healthcare system and societal perspectives, respectively. Both ICERs were far less than the willingness-to-pay threshold of $25,000/QALY, showing that universal screening was highly cost-effective compared to no screening. In various sensitivity analyses, the most influential parameters on cost-effectiveness were the antibodies to HCV (anti-HCV) prevalence, screening costs, and treatment acceptance; however, all ICERs were consistently less than the threshold. If the anti-HCV prevalence was over 0.18%, screening could be cost-effective.

CONCLUSION

One-time universal HCV screening in the Korean population aged 40-65 years using NHE program would be highly cost-effective from both healthcare system and societal perspectives.

A cost-effectiveness analysis of universal hepatitis C screening in all United States pregnancies

OBJECTIVE

To evaluate the cost-effectiveness of universal screening for HCV among all pregnant women in the United States.

METHODS

We designed a decision-analytic model to evaluate the cost-effectiveness and outcomes associated with universal HCV screening in pregnancy compared to no screening. A theoretical cohort of 3.9 million women, the approximate number of annual live births in the United States was used. Outcomes included hepatocellular carcinoma, decompensated cirrhosis, liver transplant and death, in addition to cost and quality-adjusted life years (QALYs). Model inputs were derived from the literature and the willingness-to-pay threshold was $100,000 per QALY. Sensitivity analysis were conducted to evaluate the robustness of the results.

RESULTS

In a theoretical cohort of 3.9 million women, universal HCV screening resulted in 3003 fewer cases of hepatocellular carcinoma, 1484 fewer decompensated cirrhosis, 46 fewer liver transplants and 2665 fewer deaths from HCV when compared to no screening. Universal HCV screening was found to be the dominant strategy, meaning it resulted in lower costs and higher QALYs. Sensitivity analyses showed our model was robust over a wide range of assumptions.

CONCLUSION

Among pregnant women in the United States, universal HCV screening is cost effective compared with no screening.

A study based on four immunoassays: Hepatitis C virus antibody against different antigens may have unequal contributions to detection

Background

All commercial Hepatitis C virus antibody (anti-HCV) assays use a combination of recombinant antigens to detect antibody response. Antibody responses to individual antigenic regions (core, NS3/4 and NS5) used in assays have not been investigated.

Methods

In this study, we quantified HCV viral load, tested anti-HCV with four commercial assays (Ortho-ELISA, Murex-ELISA, Architect-CMIA and Elecsys-ECLIA) in 682 plasma specimens. In antigenic region ELISA platform, microwells were coated with three antigens: core (c22-3), NS3/4 (c200) and NS5 individually. The signal-to-cutoff (S/Co) values of different assays, and antibody responses to individual antigens were compared. The specimens were divided into HCV RNA positive group, anti-HCV consistent group, and anti-HCV discrepant group.

Results

Anti-core and anti-NS3/4 were simultaneously detected in 99.2% of HCV RNA positive specimens and showed great consistency with total anti-HCV signals. Responses to the core region were more robust than those to the NS3/4 region in anti-HCV consistent group (p < 0.001). Anti-NS5 only occurred in companying with responses to the core and NS3/4 antigens, and failed to affect the final anti-HCV positive signals. In anti-HCV discrepant group, 39.0% of positive signals could not be traced back to any single antigenic region.

Conclusion

Antibody responses to the core and NS3/4 antigens were stronger, whereas responses to the NS5 antigen were the weakest, indicating that individual antigenic regions played different roles in total anti-HCV signals. This study provides an impetus for optimizing commercial anti-HCV assays.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01608-x.

Current Trends in Diagnostics of Viral Infections of Unknown Etiology

Viruses are evolving at an alarming rate, spreading and inconspicuously adapting to cutting-edge therapies. Therefore, the search for rapid, informative and reliable diagnostic methods is becoming urgent as ever. Conventional clinical tests (PCR, serology, etc.) are being continually optimized, yet provide very limited data. Could high throughput sequencing (HTS) become the future gold standard in molecular diagnostics of viral infections? Compared to conventional clinical tests, HTS is universal and more precise at profiling pathogens. Nevertheless, it has not yet been widely accepted as a diagnostic tool, owing primarily to its high cost and the complexity of sample preparation and data analysis. Those obstacles must be tackled to integrate HTS into daily clinical practice. For this, three objectives are to be achieved: (1) designing and assessing universal protocols for library preparation, (2) assembling purpose-specific pipelines, and (3) building computational infrastructure to suit the needs and financial abilities of modern healthcare centers. Data harvested with HTS could not only augment diagnostics and help to choose the correct therapy, but also facilitate research in epidemiology, genetics and virology. This information, in turn, could significantly aid clinicians in battling viral infections.

Cost-effectiveness and health-related outcomes of screening for hepatitis C in Korean population

BACKGROUND/AIM

In the era of direct-acting antivirals (DAA), active screening for hidden hepatitis C virus (HCV) infection is important for HCV elimination. This study estimated the cost-effectiveness and health-related outcomes of HCV screening and DAA treatment of a targeted population in Korea, where anti-HCV prevalence was 0.6% in 2015.

METHODS

A Markov model simulating the natural history of HCV infection was used to examine the cost-effectiveness of two strategies: no screening vs screening and DAA treatment. Screening was performed by integration of the anti-HCV test into the National Health Examination Program. From a healthcare system's perspective, the cost-utility and the impact on HCV-related health events of one-time anti-HCV screening and DAA treatment in Korean population aged 40-65 years was analysed with a lifetime horizon.

RESULTS

The HCV screening and DAA treatment strategy increased quality-adjusted life years (QALY) by 0.0015 at a cost of $11.27 resulting in an incremental cost-effectiveness ratio (ICER) of $7435 per QALY gained compared with no screening. The probability of the screening strategy to be cost-effective was 98.8% at a willingness-to-pay of $27 205. Deterministic sensitivity analyses revealed the ICERs were from $4602 to $12 588 and sensitive to screening costs, discount rates and treatment acceptability. Moreover, it can prevent 32 HCV-related deaths, 19 hepatocellular carcinomas and 15 decompensated cirrhosis per 100 000 screened persons.

CONCLUSIONS

A one-time HCV screening and DAA treatment of a Korean population aged 40-65 years would be highly cost-effective, and significantly reduce the HCV-related morbidity and mortality compared with no screening.

Global epidemiology of hepatitis C virus infection: An up-date of the distribution and circulation of hepatitis C virus genotypes

AIM

To review Hepatitis C virus (HCV) prevalence and genotypes distribution worldwide.

METHODS

We conducted a systematic study which represents one of the most comprehensive effort to quantify global HCV epidemiology, using the best available published data between 2000 and 2015 from 138 countries (about 90% of the global population), grouped in 20 geographical areas (with the exclusion of Oceania), as defined by the Global Burden of Diseases project (GBD). Countries for which we were unable to obtain HCV genotype prevalence data were excluded from calculations of regional proportions, although their populations were included in the total population size of each region when generating regional genotype prevalence estimates.

RESULTS

Total global HCV prevalence is estimated at 2.5% (177.5 million of HCV infected adults), ranging from 2.9% in Africa and 1.3% in Americas, with a global viraemic rate of 67% (118.9 million of HCV RNA positive cases), varying from 64.4% in Asia to 74.8% in Australasia. HCV genotype 1 is the most prevalent worldwide (49.1%), followed by genotype 3 (17.9%), 4 (16.8%) and 2 (11.0%). Genotypes 5 and 6 are responsible for the remaining < 5%. While genotypes 1 and 3 are common worldwide, the largest proportion of genotypes 4 and 5 is in lower-income countries. Although HCV genotypes 1 and 3 infections are the most prevalent globally (67.0% if considered together), other genotypes are found more commonly in lower-income countries where still account for a significant proportion of HCV cases.

CONCLUSION

A more precise knowledge of HCV genotype distribution will be helpful to best inform national healthcare models to improve access to new treatments.

Costs and consequences: Hepatitis C seroprevalence in the military and its impact on potential screening strategies

Knowledge of the contemporary epidemiology of hepatitis C viral (HCV) infection among military personnel can inform potential Department of Defense screening policy. HCV infection status at the time of accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period 2007-2010. A cost model was developed from the perspective of the Department of Defense for a military applicant screening program. Return on investment was based on comparison between screening program costs and potential treatment costs avoided. The prevalence of HCV antibody-positive and chronic HCV infection at accession among younger recently deployed military personnel born after 1965 was 0.98/1000 (95% confidence interval 0.45-1.85) and 0.43/1000 (95% confidence interval 0.12-1.11), respectively. Among these, service-related incidence was low; 64% of infections were present at the time of accession. With no screening, the cost to the Department of Defense of treating the estimated 93 cases of chronic HCV cases from a single year's accession cohort was $9.3 million. Screening with the HCV antibody test followed by the nucleic acid test for confirmation yielded a net annual savings and a $3.1 million dollar advantage over not screening.

CONCLUSIONS

Applicant screening will reduce chronic HCV infection in the force, result in a small system costs savings, and decrease the threat of transfusion-transmitted HCV infection in the battlefield blood supply and may lead to earlier diagnosis and linkage to care; initiation of an applicant screening program will require ongoing evaluation that considers changes in the treatment cost and practice landscape, screening options, and the epidemiology of HCV in the applicant/accession and overall force populations.

Biomarkers in HCV Infection

Liver-related biomarkers have been developed and validated mainly in patients with chronic hepatitis C for the prediction of liver fibrosis or cirrhosis, which is a final pathway of chronic liver injury. They are noninvasive, traceable, and easy-to-use. Biomarkers provide implications related to screening, diagnosis, treatment, and prognosis of chronic hepatitis. For the improvement of performance and coverage, biomarker panels, imaging biomarkers, and even genetic biomarkers have been developed. With the advancement of genomics and proteomics, earlier and more precise prediction is expected in the near future. In this review, multiple biomarker panels for the estimation of the degree of fibrosis in chronic hepatitis C, biomarkers for the screening and diagnosis of hepatitis C, biomarkers for the treatment of hepatitis C, biomarkers for the prediction of complications related to the chronic hepatitis C, and future perspectives will be summarized.

Plasma levels of adiponectin and primary liver cancer risk in middle-aged Japanese adults with hepatitis virus infection: a nested case-control study

BACKGROUND

Excess body weight is an independent risk factor for primary liver cancer, and the role of adiponectin in the pathogenesis of obesity-related malignancies is a focus of research interest. Few prospective studies have examined the association between circulating adiponectin and liver cancer risk, so we investigated this association in a nested case-control study of a population-based prospective cohort in Japan.

METHODS

From 18,628 target participants of ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or C virus infection at baseline (n = 1,544). Among these, 90 were newly diagnosed with primary liver cancer from 1993 through 2006, and matched to 177 controls. The ORs of liver cancer development based on plasma levels of adiponectin were estimated with a conditional logistic regression model.

RESULTS

Median values of total and high-molecular-weight (HMW) adiponectin tended to be higher in the patients with liver cancer, and plasma levels of adiponectin were positively associated with liver cancer risk. Body mass index- and diabetes-adjusted ORs for the highest tertile of total and HMW adiponectin levels versus the lowest were 3.30 [95% confidence interval (CI), 1.45-7.53; Ptrend < 0.01] and 3.41 (95% CI, 1.50-7.73; Ptrend < 0.01), respectively. There was no effect modification by body mass index and diabetes.

CONCLUSIONS

Higher plasma adiponectin levels were associated with an increased risk of primary liver cancer in middle-aged Japanese adults with hepatitis virus infection.

IMPACT

Circulating adiponectin levels may be a risk marker for primary liver cancer.

Development of a prediction model for 10-year risk of hepatocellular carcinoma in middle-aged Japanese: the Japan Public Health Center-based Prospective Study Cohort II

OBJECTIVE

The purpose of the present study was to develop a risk estimation model for the 10-year risk of hepatocellular carcinoma (HCC) that could be easily used in a general population to aid in the prevention of HCC.

METHODS

Our prediction model was derived from data obtained on 17,654 Japanese aged 40 to 69 years who participated in health checkups (follow-up: 1993-2006). Cox proportional hazards regression was applied to obtain coefficients for each predictor.

RESULTS

During follow-up, a total of 104 cases of HCC were newly diagnosed. After checking the model fit, we incorporated age, sex, alcohol consumption, body mass index, diabetes, coffee consumption, and hepatitis B and C virus infection into the prediction model. The model showed satisfactory discrimination (Harrell's c-index=0.94) and was well calibrated (the overall observed/expected ratio=1.03, 95% confidence interval=0.83-1.29). We also developed a simple risk scoring system. Those subjects with total scores of 17 or more under this system (score range: -1 to 19) had an estimated 10-year HCC risk of over 90%; those with 4 points or less had an estimated risk of less than 0.1%.

CONCLUSION

We developed a simple 10-year risk prediction model for HCC in the Japanese general population as a public education tool.

Consumption of n-3 fatty acids and fish reduces risk of hepatocellular carcinoma

BACKGROUND & AIMS

Fish is a rich source of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). Although consumption of fish and n-3 PUFA has been reported to protect against the development of some types of cancer, little is known about its association with hepatocellular carcinoma (HCC).

METHODS

We investigated the association between fish and n-3 PUFA consumption and HCC incidence (n = 398) in a population-based prospective cohort study of 90,296 Japanese subjects (aged, 45-74 y). Hazard ratios and 95% confidence intervals (CIs) for the highest vs the lowest quintile were estimated from multivariable adjusted Cox proportional hazards regression models. We also conducted subanalyses of subjects with known hepatitis B virus (HBV) or hepatitis C virus (HCV) status, and of subjects who were anti-HCV and/or hepatitis B surface antigen positive. All tests of statistical significance were 2-sided.

RESULTS

Among all subjects, consumption of n-3 PUFA-rich fish and individual n-3 PUFAs was associated inversely with HCC, in a dose-dependent manner. Hazard ratios for the highest vs lowest quintiles were 0.64 (95% CI, 0.42-0.96) for n-3 PUFA-rich fish, 0.56 (95% CI, 0.36-0.85) for EPA, 0.64 (95% CI, 0.41-0.98) for DPA, and 0.56 (95% CI, 0.35-0.87) for DHA. These inverse associations were similar irrespective of HCV or HBV status.

CONCLUSIONS

Consumption of n-3 PUFA-rich fish or n-3 PUFAs, particularly EPA, DPA, and DHA, appears to protect against the development of HCC, even among subjects with HBV and/or HCV infection.

Cost-effectiveness and population outcomes of general population screening for hepatitis C

BACKGROUND

Current US guidelines recommend limiting hepatitis C virus (HCV) screening to high-risk individuals, and 50%-75% of infected persons remain unaware of their status.

METHODS

To estimate the cost-effectiveness and population-level impact of adding one-time HCV screening of US population aged 20-69 years to current guidelines, we developed a decision analytic model for the screening intervention and Markov model with annual transitions to estimate natural history. Subanalyses included protease inhibitor therapy and screening those at highest risk of infection (birth year 1945-1965). We relied on published literature and took a lifetime, societal perspective.

RESULTS

Compared to current guidelines, incremental cost per quality-adjusted life year gained (ICER) was $7900 for general population screening and $4200 for screening by birth year, which dominated general population screening if cost, clinician uptake, and median age of diagnoses were assumed equivalent. General population screening remained cost-effective in all one-way sensitivity analyses, 30 000 Monte Carlo simulations, and scenarios in which background mortality was doubled, all genotype 1 patients were treated with protease inhibitors, and most parameters were set unfavorable to increased screening. ICER was lowest if screening was applied to a population with liver fibrosis similar to 2010 estimates. Approximately 1% of liver-related deaths would be averted per 15% of the general population screened; the impact would be greater with improved referral, treatment uptake, and cure.

CONCLUSIONS

Broader screening for HCV would likely be cost-effective, but significantly reducing HCV-related morbidity and mortality would also require improved rates of referral, treatment, and cure.

Estimating incidence rates with misclassified disease status: a likelihood-based approach, with application to hepatitis C virus

BACKGROUND

In epidemiologic research, incidence is often estimated from data arising from an imperfect diagnostic test performed at unequally spaced intervals over time.

METHODS

We developed a likelihood-based method to estimate incidence when disease status is measured imperfectly and assays are performed at multiple unequally spaced visits. We assumed conditional independence, no remission, known constant levels of sensitivity and specificity, and constant incidence rates over time. The method performance was evaluated by examining its bias, accuracy (i.e., mean squared error (MSE)), and coverage probability in a simulation study of 4000 datasets, and then we applied the proposed method to a study of hepatitis C virus (HCV) infection in a cohort of pregnant women in the period 1997-2006.

RESULTS

The simulation revealed that our method has minimal bias and low MSE, as well as good coverage probability of the resulting confidence intervals. In the application to HCV study, the standard incidence rate estimate which ignores the imperfections of the diagnostic test (number of events/person-years), was 13.7 new HCV cases per 1000 person-years (95% confidence interval 10.1, 17.4). The adjusted incidence estimates (obtained using our proposed method) ranged from 0.4 cases per 1000 person-years (when sensitivity and specificity were assumed to both be 95%) to 13.7 cases per 1000 person-years (when sensitivity and specificity were both 100%). The magnitude of difference between standard and adjusted estimates varied depending on specificity and sensitivity assumptions. Specificity had the greatest impact on the magnitude of bias.

CONCLUSIONS

Scientists should be aware of the impact of misclassification on incidence estimates. Appropriate study design, proper selection of the diagnostic test, and adjustment for misclassification probabilities in the analysis is necessary to obtain the most accurate incidence estimates.

Risk factors for hepatitis C virus acquisition and predictors of persistence among Egyptian children

BACKGROUND

Hepatitis C virus (HCV) has a lower prevalence in children and knowledge is limited regarding the natural outcome of HCV infection in children.

AIM

To study the risk factors of HCV acquisition and predictors of persistence in Egyptian children.

METHODS

Children, 1-9 years of age, were evaluated for acquisition of HCV (anti-HCV positive regardless of viraemia) and persistence of HCV (anti-HCV and HCV-RNA positive) at two paediatric hepatology clinics in Cairo at enrollment and at 3 monthly intervals. Spontaneous clearance of HCV was defined as ≥ two positive anti-HCV antibody tests with negative HCV-RNA at least 6 months apart.

RESULTS

Over a 33-month-period a total of 226 children <9 years of age were screened for HCV antibodies. Of those, 146 (65%) were anti-HCV positive of which 87 (60%) were HCV-RNA positive. The HCV acquisition was more likely to occur in older children (P = 0.003) with comorbid conditions (P < 0.01) compared to anti-HCV negative children. In a multivariate logistic regression analysis, the highest risk factors for HCV acquisition were surgical interventions [odds ratio (OR): 4.7] and blood transfusions (OR: 2.3). The highest risk factor for HCV persistence was dental treatment (OR: 16.9) and male gender (OR: 7.5). HCV persistence was also strongly associated with elevated baseline alanine aminotransaminase (ALT) levels (OR: 4.9) and fluctuating aspartate aminotransferase (AST) levels (OR: 8.1).

CONCLUSION

Although surgical interventions and blood transfusion are significant risk factors for HCV acquisition in Egyptian children, dental treatment remains the highest risk factor for HCV chronic persistence in children.

Risk Factors and Seroprevalence of Hepatitis C among Patients Hospitalized at Mulago Hospital, Uganda

The emergence of hepatitis C virus (HCV) and its associated sequelae in Africa is a cause for significant concern. Human immunodeficiency virus (HIV) positive patients are at an increased risk of contracting HCV infection due to similar risk factors and modes of transmission. We investigated the seroprevalence of hepatitis C in hospitalized HIV-positive and HIV-negative patients in Mulago Hospital, an academic hospital in Uganda. Blood samples were first tested for HCV antibodies, and positive tests were confirmed with HCV RNA PCR. We enrolled five hundred patients, half HIV-positive and half HIV negative. Overall, 13/500 patients (2.6%) tested positive for HCV antibodies. There was no difference in HCV antibody detection among HIV-positive and HIV-negative patients. Out of all risk factors examined, only an age greater than 50 years was associated with HCV infection. Traditional risk factors for concurrent HIV and HCV transmission, such as intravenous drug use, were exceedingly rare in Uganda. Only 3 of 13 patients with detectable HCV antibodies were confirmed by HCV RNA detection. This result concurs with recent studies noting poor performance of HCV antibody testing when using African sera. These tests should be validated in the local population before implementation.

A systematic review of hepatitis C virus epidemiology in Asia, Australia and Egypt

BACKGROUND

The hepatitis C pandemic has been systematically studied and characterized in North America and Europe, but this important public health problem has not received equivalent attention in other regions.

AIM

The objective of this systematic review was to characterize hepatitis C virus (HCV) epidemiology in selected countries of Asia, Australia and Egypt, i.e. in a geographical area inhabited by over 40% of the global population.

METHODOLOGY

Data references were identified through indexed journals and non-indexed sources. In this work, 7770 articles were reviewed and 690 were selected based on their relevance.

RESULTS

We estimated that 49.3-64.0 million adults in Asia, Australia and Egypt are anti-HCV positive. China alone has more HCV infections than all of Europe or the Americas. While most countries had prevalence rates from 1 to 2% we documented several with relatively high prevalence rates, including Egypt (15%), Pakistan (4.7%) and Taiwan (4.4%). Nosocomial infection, blood transfusion (before screening) and injection drug use were identified as common risk factors in the region. Genotype 1 was common in Australia, China, Taiwan and other countries in North Asia, while genotype 6 was found in Vietnam and other Southeast Asian countries. In India and Pakistan genotype 3 was predominant, while genotype 4 was found in Middle Eastern countries such as Egypt, Saudi Arabia and Syria.

CONCLUSION

We recommend implementation of surveillance systems to guide effective public health policy that may lead to the eventual curtailment of the spread of this pandemic infection.

Trends and projections of hepatitis C virus epidemiology in Latin America

BACKGROUND AND AIM

The purpose of the present investigation is to provide an analysis of previous works on the epidemiology of the hepatitis C virus (HCV) infection from six countries throughout Latin America, to forecast the future HCV prevalence trends in Argentina, Brazil, Mexico and Puerto Rico, and to outline deficiencies in available data, highlighting the need for further research.

METHODS

Data references were identified through indexed journals and non-indexed sources. Overall, 1080 articles were reviewed and 150 were selected based on their relevance to this work. When multiple data sources were available for a key assumption, a systematic process using multi-objective decision analysis (MODA) was used to select the most appropriate sources. When data were missing, analogues were used. Data from other countries with similar risk factors and/or population compositions were used as a proxy to help predict the future trends in prevalence.

RESULTS

The review indicates that the dominant genotype is type 1. HCV prevalence in the analysed countries ranges from 1 to 2.3%. The Latin American countries have been very proactive in screening their blood supplies, thus minimizing the risk of transmission through transfusion. This suggests that other risk factors are set to play a major role in continued new infections. The number of diagnosed and treated patients is low, thereby increasing the burden of complications such as liver cirrhosis or hepatocellular carcinoma. The HCV prevalence, according to our modelling is steady or increasing and the number of infected individuals will increase.

CONCLUSIONS

The results herein reported should provide a foundation for informed planning efforts to tackle hepatitis.

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.

Novel evolved immunoglobulin (Ig)-binding molecules enhance the detection of IgM against hepatitis C virus

Detection of specific antibodies against hepatitis C virus (HCV) is the most widely available test for viral diagnosis and monitoring of HCV infections. However, narrowing the serologic window of anti-HCV detection by enhancing anti-HCV IgM detection has remained to be a problem. Herein, we used LD5, a novel evolved immunoglobulin-binding molecule (NEIBM) with a high affinity for IgM, to develop a new anti-HCV enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase-labeled LD5 (HRP-LD5) as the conjugated enzyme complex. The HRP-LD5 assay showed detection efficacy that is comparable with two kinds of domestic diagnostic kits and the Abbott 3.0 kit when tested against the national reference panel. Moreover, the HRP-LD5 assay showed a higher detection rate (55.9%, 95% confidence intervals (95% CI) 0.489, 0.629) than that of a domestic diagnostic ELISA kit (Chang Zheng) (53.3%, 95% CI 0.463, 0.603) in 195 hemodialysis patient serum samples. Five serum samples that were positive using the HRP-LD5 assay and negative with the conventional anti-HCV diagnostic ELISA kits were all positive for HCV RNA, and 4 of them had detectable antibodies when tested with the established anti-HCV IgM assay. An IgM confirmation study revealed the IgM reaction nature of these five serum samples. These results demonstrate that HRP-LD5 improved anti-HCV detection by enhancing the detection of anti-HCV IgM, which may have potential value for the early diagnosis and screening of hepatitis C and other infectious diseases.

Development of a multiplex bead-based assay for detection of hepatitis C virus

Hepatitis C virus (HCV) infection is a major burden to public health worldwide, affecting approximately 3% of the human population. Although HCV detection is currently based on reliable tests, the field of medical diagnostics has a growing need for inexpensive, accurate, and quick high-throughput assays. By using the recombinant HCV antigens NS3, NS4, NS5, and Combined, we describe a new bead-based multiplex test capable of detecting HCV infection in human serum samples. The first analysis, made in a singleplex format, showed that each antigen coupled to an individual bead set presented high-level responses for anti-HCV-positive reference serum pools and lower-level responses for the HCV-negative pools. Our next approach was to determine the sensitivity and specificity of each antigen by testing 93 HCV-positive and 93 HCV-negative sera. When assayed in the singleplex format, the NS3, NS4, and NS5 antigens presented lower sensitivity values (50.5%, 51.6%, and 55.9%, respectively) than did the Combined antigen, which presented a sensitivity of 93.5%. All antigens presented 100% specificity. These antigens were then multiplexed in a 4-plex assay, which resulted in increased sensitivity and specificity values, performing with 100% sensitivity and 100% specificity. The positive and negative predictive values for the 4-plex assay were 100%. Although preliminary, this 4-plex assay showed robust results that, aligned with its small-sample-volume requirements and also its cost- and time-effectiveness, make it a reasonable alternative to tests currently used for HCV screening of potentially infected individuals.

European guideline for the management of hepatitis B and C virus infections, 2010

These are the guidelines on hepatitis B and C management for IUSTI/WHO in Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of hepatitis B and C with particular reference to sexual health clinical practice.

Evidence of intense ongoing endemic transmission of hepatitis C virus in Egypt

Egypt has the highest prevalence of antibodies to hepatitis C virus (HCV) in the world, estimated nationally at 14.7%. An estimated 9.8% are chronically infected. Numerous HCV prevalence studies in Egypt have published various estimates from different Egyptian communities, suggesting that Egypt, relative to the other nations of the world, might be experiencing intense ongoing HCV transmission. More importantly, a new national study provided an opportunity to apply established epidemiologic models to estimate incidence. Validated mathematical models for estimating incidence from age-specific prevalence were used. All previous prevalence studies of HCV in Egypt were reviewed and used to estimate incidence provided that there was sufficient age-specific data required by the models. All reports of anti-HCV antibody prevalence were much higher than any single other national estimate. Age was the strongest and most consistently associated factor to HCV prevalence and HCV RNA positivity. It was not possible to establish a prior reference point for HCV prevalence or incidence to compare with the 2009 incidence estimates. The modeled incidence from the national study and collectively from the modeled incidence from the previous community studies was 6.9/1,000 [95% confidence interval (CI), 5.5-7.4] per person per year and 6.6/1,000 (95% CI, 5.1-7.0) per person per year, respectively. Projected to the age structure of the Egyptian population, more than 500,000 new HCV infections per year were estimated. Iatrogenic transmission is the most likely, underlining exposure to the ongoing transmission. The study demonstrates the urgency to reduce HCV transmission in Egypt.

Decline of viral hepatitis prevalence among asymptomatic Egyptian blood donors: a glimmer of hope

BACKGROUND

Viral hepatitis is an important etiological agent of chronic hepatitis and liver disease and is a major cause of morbidity and mortality especially in Egypt since it has the highest prevalence of hepatitis C virus (HCV) infection. We aimed to assess if there is any change in the annual seroprevalence of both HCV and hepatitis B virus (HBV) infection in Egypt in the current era.

METHODS

Our study included 55,922 potentially healthy asymptomatic blood donors; 52,280 males and 3642 females with mean age of 30.98+/-8.6 years. All of them were volunteers for the first time and 70% were from rural areas. We applied our own questionnaire that included past medical history, surgical history, and history of blood donation. We screened their sera for the presence or absence of anti-HCV antibodies with the 3rd generation enzyme-linked immunosorbent assay (ELISA) and the presence or absence of hepatitis B surface antigen (HBsAg) with ELISA.

RESULTS

The cumulative seroprevalence of HCV and HBV infection was 11.95% and 1.3% respectively. The annual seroprevalence of both viruses showed a declining pattern throughout the study period from 17.7% to 7.4% regarding HCV and HBV infection from 2.3% to 0.9%. The decline trends for both viral infections were observed for both genders.

CONCLUSION

This study carries a glimmer of hope because of a decline in seroprevalence of viral hepatitis in Egypt. However stringent implementation of infection control programs in Egypt is mandatory to face this furious health problem.

Isoflavone consumption and subsequent risk of hepatocellular carcinoma in a population-based prospective cohort of Japanese men and women

The incidence of hepatocellular carcinoma (HCC) is much higher in men than in women. Several experiment and epidemiological studies have suggested that estrogen might play an inhibitory role in the development of HCC. Because isoflavones have a similar structure as 17beta-estradiol and appear to have an anti-estrogenic effect in women and estrogenic effect in men, we hypothesized that the effect of isoflavones on HCC differs by sex. We investigated the association between isoflavones (genistein and daidzein) and soy products and HCC in Japan in a population-based prospective study in 19,998 Japanese (7,215 men and 12,783 women) aged 40-69 years. During 11.8 years of follow-up, 101 subjects (69 men and 32 women) were newly diagnosed with HCC. Case patients were grouped according to consumption of isoflavones and soy products and stratified by hepatitis virus infection. Hazard ratios (HRs) and 95% confidence intervals (CIs) for HCC were calculated by Cox proportional-hazards modeling. In women, genistein and daidzein were dose-dependently associated with an increased risk of HCC, with multivariable HRs for the highest versus lowest tertile of 3.19 (95%CI = 1.13-9.00, p(trend) = 0.03) and 3.90 (95% CI = 1.30-11.69, p(trend) = 0.01), respectively. No association between isoflavones and HCC was observed in men. These results persisted when analysis was restricted to subjects positive for either or both hepatitis C and B virus. In conclusion, isoflavone consumption may be associated with an increased risk of HCC in women. Women with hepatitis virus infection may be advised to abstain from isoflavone consumption. Further studies are warranted to confirm these findings.

Serum aminotransferase level and the risk of hepatocellular carcinoma: a population-based cohort study in Japan

Aminotransferase level is presumed to be a marker of hepatic inflammation, but uncertainty remains whether elevated aminotransferase levels are associated with an increased risk of hepatocellular carcinoma (HCC). We evaluated the incidence of HCC by aminotransferase level in 19 812 middle-aged and older individuals with and without hepatitis virus infection from a large-scale population-based cohort study (JPHC Study cohort II) in Japan. Hepatitis virus infection was identified at baseline in 1236 participants, namely 737 (3.7%) with hepatitis C virus, 479 (2.4%) with hepatitis B virus, and 20 (0.1%) with both. By the end of follow-up, a total of 109 newly arising HCC cases were diagnosed (71 men, 38 women), of which 87 (79.8%) had evidence of viral etiology. Alanine aminotransferase (ALT) was concentration-dependently associated with an increased risk of HCC in both virus-positive and virus-negative participants. Compared with virus-negative participants with ALT levels of less than 30 IU/l, a significant increase in the risk of HCC was observed in virus-negative participants with an ALT level greater than 30 IU/l, and in virus-positive participants with an ALT less than 30 IU/l, 30-69 IU/l, and > or =70 IU/l [Hazard ratio (95% confidence interval): 9.4 (3.9-22.3), 15.2 (6.1-37.6), 180.5 (89.4-364.2), 454.2 (221.5-931.2), respectively; P for trend <0.001]. In conclusion, our findings suggest that elevated ALT levels are strongly associated with the incidence of HCC regardless of hepatitis virus positivity. This finding indicates that ALT level is a good independent determinant of the need for intervention. Clinical application of these findings may help decrease HCC-associated mortality in hepatitis virus-endemic regions.

Metabolic factors and subsequent risk of hepatocellular carcinoma by hepatitis virus infection status: a large-scale population-based cohort study of Japanese men and women (JPHC Study Cohort II)

OBJECTIVE

The association between metabolic factors and hepatocellular carcinoma (HCC) has not been well clarified. We prospectively examined whether metabolic factors predicts the subsequent risk of HCC in the Japan Public Health Center-based Prospective Study Cohort II, in consideration of hepatitis virus infection status.

METHODS

A total of 17,590 subjects aged 40-69 participating in a questionnaire and health checkup survey during 1993-1994 were followed for incidence of HCC through 2006. A total of 102 cases of HCC were newly documented. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for metabolic factors controlling for potential confounding factors.

RESULTS

The presence of metabolic factors in the aggregate was associated with a significantly increased risk of HCC, especially with hepatitis virus infection. HCC was positively associated particularly with high glucose (HR = 1.75, CI = 1.11-2.74) and overweight (HR = 2.22, CI = 1.42-3.48). Results were similar when analyses were limited to subjects with HCV infection.

CONCLUSIONS

Although metabolic factors in the aggregate may be associated with an increased risk of HCC, the main contributors to this association under HCV infection appear to be overweight and high glucose. Improvement of these factors may be a crucial target in preventing progression to HCC in those with HCV infection.

Clinical performance evaluation of four automated chemiluminescence immunoassays for hepatitis C virus antibody detection

Various automated chemiluminescence immunoassay (CLIA) analyzers for the detection of antibodies to hepatitis C virus (HCV) are now commercially available in clinical laboratories and are replacing conventional enzyme immunoassays. We investigated the performance of four anti-HCV CLIAs (the Architect Anti-HCV assay on the Architect i2000 system, the Vitros Anti-HCV assay on the Vitros ECiQ Immunodiagnostic System, the Access HCV Ab PLUS assay on the UniCel DxI 800 analyzer, and the newly developed Elecsys Anti-HCV assay on the Cobas e 411 analyzer). The total percent coefficient of variation values of imprecision were 3.5 to 5.7% with positive control materials and 7.2 to 10.2% with negative control materials. The agreement between the results of the Elecsys, Architect, Vitros, and Access CLIAs ranged from 94.5 to 98.1%. The clinical sensitivity of all CLIAs was 100%. Each CLIA showed excellent reproducibility and clinical sensitivity. The Elecsys, Architect, Vitros, and Access CLIAs showed clinical specificities of 98.2, 98.8, 96.5, and 98.2%.

Prospective study of the meaning of indeterminate results of the recombinant immunoblot assay for hepatitis C virus in blood donors

BACKGROUND

The interpretation of "indeterminate" results of the recombinant immunoblot assay (RIBA) is a particularly sensitive issue for Transfusion Services, and donors with such a serological condition require long-term follow-up.

MATERIALS AND METHODS

In the Immunohaematology and Transfusion Medicine Division of Umberto I University Hospital (Rome, Italy), 102,979 donor blood units were screened for hepatitis C virus (HCV) antibodies by enzyme-linked immunosorbent assay (ELISA) over a 5-year period (01.01.2000 - 31.12.2004). Since 24.10.2001, HCV-RNA testing was added. All samples repeatedly reactive by ELISA were then submitted to a HCV confirmatory assay (RIBA).

RESULTS

Among the 102,979 donors we found 271 positive to HCV ELISA testing. The results of the RIBA assay for these donors were negative in 178 (65.7%) cases, positive in 28 (10.3%) and indeterminate in 65 (24.0%). Of the 65 subjects with an indeterminate pattern, 24 completed a sufficient follow-up (median 25 months; range, 6 - 52), during which some (n = 8; 33%) converted to a negative status, some (n = 16; 67%) maintained their reactivity pattern, but none became seropositive for HCV.

CONCLUSIONS

The HCV-RIBA indeterminate status may indicate either a non-specific reaction (false positive) or a real pre-existing or initial infection and does not, therefore, enable a prediction of outcome. The use of HCV genomic assays (nucleic acid amplification testing), which are more specific than antibody-based assays (ELISA, RIBA), therefore improves HCV blood donor testing by allowing an accurate interpretation of such primary assays.

Double-antigen sandwich time-resolved immunofluorometric assay for the detection of anti-hepatitis C virus total antibodies with improved specificity and sensitivity

Current anti-hepatitis C virus (HCV) antibody screening immunoassays are routinely based on an indirect format. Although their use for anti-HCV antibody detection has achieved a very high specificity and sensitivity, false-positive results are still a problem especially among populations with a low prevalence of HCV infection. One strategy to obviate this problem is to adapt the assay from an indirect format to a double-antigen sandwich one to further improve its specificity. In this study, a double-antigen sandwich time-resolved immunofluorometric assay (DAS-TRIFMA) has been developed to detect total anti-HCV antibodies based on biotin-streptavidin interaction. For comparison, 1025 samples were analysed by the DAS-TRIFMA and three indirect anti-HCV antibody detection methods. For samples with discordant results, PCR-ELISA and Inno-LIA were employed as supplementary assays to analyse the presence of HCV antibodies. With regard to the 1025 clinical samples, the overall concordance between the DAS-TRIFMA and the three indirect methods was 99.41, 98.93 and 98.93 % for Ortho ELISA 3.0, WAT ELISA and I-TRIFMA, respectively. The specificity/sensitivity of the DAS-TRIFMA, Ortho HCV ELISA 3.0, WAT HCV ELISA and I-TRIFMA were 100/99.09, 99.34/98.18, 99.23/97.27 and 99.01 %/98.18 %, respectively. The DAS-TRIFMA was able to detect HCV antibodies at a concentration about 1/10 of that detectable by indirect methods. From the obtained results and their comparison, it is concluded that the DAS-TRIFMA is a more specific and reliable method for screening anti-HCV antibodies, and weakly positive S/Co values by the DAS-TRIFMA were more predictive of HCV infection than those by indirect methods.

A cost-identification analysis of screening and surveillance of hepatitis C infection in a prospective cohort of dialysis patients

The Center for Disease Control and Prevention (CDC) recommends screening and surveillance of dialysis patients for hepatitis C virus (HCV), but there are limited data on the real life performance of confirmatory tests. We performed a cost-identification analysis of CDC recommendations using a large database of dialysis subjects. Screening and surveillance were performed according to CDC guidelines: enzyme immunoassay (EIA) testing upon entry then biannual surveillance. All positive EIA tests were confirmed by either polymerase chain reaction (PCR) or radioimmunoblot assay (RIBA). A total of 12,563 patients were tested from 1997 to 2004. By EIA, the prevalence of HCV was 8.4% and annual incidence was 0.96%. The prevalence after confirmation by RIBA and PCR was 5.8% and 4.8%, respectively. The annual incidence of hepatitis C confirmed by RIBA and PCR was 0.13% and 0.084%, respectively. Using Medicare reimbursement, the cost to screen and confirm one case of hepatitis C by RIBA was $372 versus $503 by PCR. However, the cost to identify an incident infection increased to $30,594 by RIBA and $48,622 by PCR. In the sensitivity analysis, the cost of identifying incident HCV infection dropped by 50% when the surveillance interval was extended to 1 year or when seroconversion rates for EIA occurred at 2%. Due to high surveillance cost, further studies are necessary to determine optimal intervals and settings.

[Development of a Web-based Program to Calculate Sample Size for Evaluating the Performance of In Vitro Diagnostic Kits.]

BACKGROUND

Many studies evaluating the performance of in vitro diagnostic kits have been criticized for the lack of reliability. To attain reliability those evaluation studies should be preceded by sample size calculation ensuring statistical power. This study was intended to develop a web-based system to estimate the sample size, which was often neglected because it would require expert knowledge in statistics.

METHODS

For sample size calculation, we extracted essential parameters from the performance studies on the 3rd generation anti-hepatitis C virus (HCV) kits reported in the literature. We developed a system with PHP web-script language and MySQL. The statistical models used in this system were as follows; one sample without power consideration (model 1), one sample with power consideration (model 2), and two samples with power consideration (model 3).

RESULTS

Among the articles published between 1989 and 2005, 13 articles that evaluated the performance of anti-HCV kits were identified by searching with Medical Subject Headings (MeSH). The diagnostic sensitivity was 83-100% with a median of 145 samples (range; 12-1,091) and the specificity was 97-100% with a median of 1,025 samples (range; 33-4,381). The estimated sample size would be 280 in the model 1, 817 in the model 2, and 1,510 in the model 3, when we set 2% prevalence of HCV infection, 95% sensitivity of a conventional kit, 97% sensitivity of a new kit , 95% significance level (two-sided test), 2% allowable error, and 80% power.

CONCLUSIONS

Our study indicates that an insufficient sample size is still a problem in performance evaluation. Our system should be helpful in increasing the reliability of performance evaluation by providing an appropriate sample size.

[Hepatitis C virus screening: performances characteristics of a commercial automated chemiluminescent microparticle immunoassay (CMIA-ARCHITECT anti-HCV)]

OBJECTIVES

In spite of improvement of the third-generation enzyme immunoassay (EIA) for screening HCV antibodies, some non-specific reactions persist. With commercialisation of a new chemiluminescence microparticle immunoassay (CMIA), we assessed the specificity of 2 assays providing by Abbott Diagnostics: CMIA-ARCHITECT anti-HCV and MEIA-AxSYM HCV 3.0 for qualitative detection of HCV antibodies in serum sample of patients collected in CHU of Caen.

PATIENTS AND METHODS

Anti-HCV results of 9753 serum samples tested by MEIA-AxSYM V.3 (2004), 6135 tested by CMIA-ARCHITECT1 (April to December 2005) and 5598 tested by CMIA-ARCHITECT2 (February to August 2006) were retrospectively analysed. Prevalences were calculated according to S/C ratio. The serum samples with an average S/C ratio from 1 to 2 for CMIA-ARCHITECT2 were confirmed with an immunoblot assay (Chiron RIBA HCV 3.0 SIA).

RESULTS

The CMIA-ARCHITECT assays showed a strong discrimination between negative and positive samples. We observed a tiny distribution of negative results. The percentage of "low positive" was respectively 1.26% for the MEIA-AxSYM, 0.68% for the CMIA-ARCHITECT1 and 0.36% for the CMIA-ARCHITECT2. Thirty-three of 54 (61%) samples yielding S/C ratio between 1 and 2 in the initial screening analysis with the CMIA-ARCHITECT1 were tested negative with CMIA-ARCHITECT2. Among the 21 remaining, 62% of RIBA results were interpretable.

CONCLUSION

CMIA-ARCHITECT assays improve the anti-HCV screening with a decrease of low-positive reactivity. However, low-positive results persist for which it is difficult to distinguish false-positive from low titer of antibodies. Supplemental assays such as immunoblot can be recommended in particularly context to more improve specificity and HCV-RNA detection should exclude a seroconversion.

Metabolic and cardiovascular risk profiles and hepatitis C virus infection in rural Egypt

BACKGROUND AND AIMS

To investigate the relationship between lipid profiles and diabetes with past and chronic hepatitis C virus (HCV) infection among village residents of Egypt.

PATIENTS AND METHODS

Fasting lipids and glucose profiles were compared among adults never infected with HCV (negative HCV antibodies), infected in the past (positive HCV antibodies and negative HCV RNA) and chronically infected (positive HCV antibodies and HCV RNA).

RESULTS

Of the 765 participants, 456 (59.6%) were female, and median age was 40 (range 25-88) years. Chronic HCV infection was present in 113 (14.8%) and past infection in 67 (8.8%). After adjustment for age and sex, participants with chronic HCV infection had lower plasma low density lipoproteins (LDL) cholesterol and triglyceride levels compared with those never infected (age and sex adjusted differences (95% CI) were -19.0 (-26.3 to -11.7) mg/dl and -26.2 (-39.0 to -13.3) mg/dl, respectively). In contrast, participants with cleared HCV infection had higher triglyceride levels compared with those never infected (age and sex adjusted difference (95% CI) was +16.0 (0.03 to 31.9) mg/dl). In multivariate analysis, participants with chronic HCV infection were more likely to have diabetes (OR 3.05, 95% CI 1.19 to 7.81) compared with those never infected, independent of LDL cholesterol levels.

CONCLUSION

In conclusion, this community based study has shown that in a single population, chronic HCV infection is associated with glucose intolerance and, despite that, a favourable lipid pattern. An intriguing finding was the high triglyceride levels observed among participants with past infection, suggesting that elevated triglycerides at the time of acute infection may facilitate viral clearance.

Low prevalence of anti-hepatitis C virus antibodies in Mexico: A systematic review

BACKGROUND

The prevalence of reactive tests to anti-hepatitis C virus (HCV) antibodies in Mexico is unknown, though estimated to be 1%. There is no single nation-wide study or comprehensive literature review addressing the epidemiology of HCV infection in Mexico.

METHODS

We did a systematic review of English- and Spanish-language literature reporting on the frequency of anti-HCV antibodies in asymptomatic persons at low risk, of studies performed in Mexico. An exhaustive search in MEDLINE, IMBIOMED, MedicLatina, ARTEMISA and MEDIGRAPHIC databases was undertaken. Weighted mean prevalence (WMP) was calculated after combining the results of each study.

RESULTS

22 studies involving 825,377 persons at low risk, mainly blood donors, were identified. Crude seroprevalence reported in each study ranged from 0.1 to 2%, with 16 (73%) studies reporting below 1%. Overall, WMP of anti-HCV antibodies (tested by enzyme immunoassay) was 0.37% (95% CI, 0.36-0.38%), differing by country region and immunoassay generation (p < 0.01). The most frequent risk factor reported was blood transfusion. Confirmation of specific anti-HCV antibodies by recombinant immunoblot assay ranged from 30 to 100%, whereas confirmation of viremia by PCR ranged from 16 to 80%. In 3 studies on HCV genotype frequency, genotype 1 had crude prevalence ranging from 63 to 70%, subtype 1b being the most prevalent (21-47%).

CONCLUSIONS

The prevalence of anti-HCV antibodies in Mexico might be lower than previously estimated. Transfusion of blood products is the main risk factor. HCV subtype 1b is the most prevalent among persons with confirmed viremia. Information of a nation-wide survey is mandatory.

Hepatitis C inflection in dialysis patients: a link to poor clinical outcome?

Among the 350,000 maintenance dialysis patients in the USA, the mortality rate is high (20-23% per year) as is the prevalence of hepatitis C virus (HCV) infection (5-15%). An additional same number of dialysis patients in the USA may be infected with HCV but have undetectable HCV antibodies. Almost half of all deaths in dialysis patients, including HCV-infected patients, are due to cardiovascular disease. Since over two-thirds of dialysis patients die within 5 years of initiating dialysis and because markers of malnutrition-inflammation complex syndrome (MICS), rather than traditional cardiovascular risk factors, are among the strongest predictors of early death in these patients, the impact of HCV infection on nutritional status and inflammation may be a main cause of poor survival in this population. Based on data from our cross-sectional and limited longitudinal studies, we hypothesize that HCV infection confounds the association between MICS and clinical outcomes in dialysis patients and, by doing so, leads to higher short-term cardiovascular events and death. Understanding the natural history of HCV and its association with inflammation, nutrition and outcomes in dialysis patients may lead to testing more effective anti-HCV management strategies in this and other similar patient populations, providing benefits not only for HCV infection but the detrimental consequences associated with this infection. In this article, we review the link between the HCV infection and mortality in dialysis patients and compare HCV antibody to molecular methods to detect HCV infection in these individuals.

HCV-related morbidity in a rural community of Egypt

The origin of the hepatitis C virus (HCV) epidemic in Egypt has been attributed to intravenous schistosomiasis treatment in rural areas in the 1960s to 70s. The objective of this study was to estimate the HCV-related morbidity in a rural area where mass schistosomiasis treatment campaigns took place 20-40 years before. The study sample included 2,425 village residents aged 18-65 years recruited through home-based visits. Overall, HCV antibody prevalence was 448/2,425 = 18.5% (95% CI = 16.9-20.1%), reaching 45% in males over 40 years, and 30% in females over 50 years. Of those with HCV antibodies, 284/448 (63.4%, 95% CI = 58.7-67.9%) had chronic HCV infection, among which 107/266 (40.2%, 95% CI = 34.3-46.4%) had elevated alanine aminotransferase (ALT). As part of pre-treatment screening, 26 consenting patients had a liver biopsy: 13 (50.0%) had a treatment indication. Thus, of all patients with HCV antibodies, 13 (2.9%) were eligible for treatment and willing to be treated. The relatively low level of morbidity observed in this study is discussed in view of co-factors of HCV infection progression, such as young age at infection, absence of alcohol intake, the prevalence of Schistosoma mansoni infection, and the prevalence of chronic hepatitis B.

Higher clearance of hepatitis C virus infection in females compared with males

BACKGROUND AND AIMS

According to the literature, 14-46% of subjects clear hepatitis C virus (HCV) from blood after infection. Controversy exists about sex differences in HCV clearance rates.

PATIENTS AND METHODS

We compared HCV clearance in males and females using data from a large population based study on HCV infection in Egypt. Definitions used in the paper were: cleared HCV infection (positive HCV antibody and negative HCV RNA test results) and chronic HCV infection (positive HCV antibody and positive HCV RNA test results). The study sample included 4720 village residents aged 18-65 years recruited through home based visits (n = 2425) or voluntary screening (n = 2295).

RESULTS

Overall, HCV antibody prevalence was 910/4720 (19.3% (95% confidence interval 18.2-20.4)). Of those with HCV antibodies (n = 910), 61.5% had chronic HCV infection. Compared with males, females were more likely to have cleared the virus (44.6% v 33.7%, respectively; p = 0.001). Control for age, schistosomiasis history, iatrogenic exposures, and sexual exposure to HCV did not alter the positive association between female sex and viral clearance.

CONCLUSION

This study provides strong evidence in favour of a higher HCV clearance rate in females compared with males.

Active surveillance for acute viral hepatitis in rural villages in the Nile Delta

BACKGROUND

Acute viral hepatitis is less frequent in Egypt than serum antibody levels suggest. Because acute viral hepatitis has a wide clinical spectrum, we tested the hypothesis that many cases are undetected because of mild illness caused by initial, early-childhood exposure to hepatitis viruses.

METHODS

During active case detection among 20,000 inhabitants of rural villages in Egypt, we screened 1715 symptomatic patients for serum alanine aminotransferase (ALT) levels. Viral hepatitis markers were tested in 47 subjects who had ALT levels that were least twice the normal level.

RESULTS

Of the 47 individuals tested, 4 children aged 3-5 years had immunoglobulin M (IgM) antibodies to hepatitis A virus (anti-HAV IgM). One also had a possible false-positive result to a test for IgM antibodies to hepatitis E virus. None had serological evidence of acute hepatitis B virus (HBV) infection or hepatitis C virus (HCV) infection. However, 33 of the remaining 43 had active HCV infection, having both antibodies to HCV (anti-HCV) and HCV RNA. Four others anti-HCV without HCV RNA, and 2 others had seroconversion to anti-HCV during follow-up. Two patients who were positive for hepatitis B surface antigen had chronic HBV infection. Only 3 with elevated ALT levels had no evidence of acute or chronic infections with known hepatitis viruses. Immunoglobulin G antibodies to hepatitis E virus was detected in 40 patients.

CONCLUSION

Active surveillance covering approximately 50,000 person-years detected only 4 cases of acute HAV infection. Almost all persons with mild symptoms and elevated ALT levels had serological evidence of chronic viral hepatitis, most often associated with HCV. Many of these cases were probably "flare-ups" of HCV infection or incidental illness in patients with chronic HCV infection, but some could have been caused by difficult-to-confirm initial HCV infections. Although serological evidence for exposures was highly prevalent, hepatitis viruses seldom caused acute viral hepatitis in these communities.