Screening for hepatitis C virus infection in a high prevalence country by an antigen/antibody combination assay versus a rapid test

Quality Assurance for Hepatitis C Virus Point-of-Care Diagnostics in Sub-Saharan Africa

As part of a multinational study to evaluate the Bioline Hepatitis C virus (HCV) point-of-care (POC) testing in sub-Saharan Africa (SSA), this narrative review summarises regulatory standards and quality indicators for validating and approving HCV clinical diagnostics. In addition, this review also provides a summary of their diagnostic evaluations using the REASSURED criteria as the benchmark and its implications on the WHO HCV elimination goals 2030.

Management of in- and out-of-hospital screening for hepatitis C

Because of insidious progression and no significant clinical symptoms at early stage, chronic hepatitis C (CHC) is often diagnosed after the occurrence of cirrhosis and hepatocellular carcinoma. Highly effective and low drug resistance of direct-acting antiviral agents (DAAs) have enabled cure of CHC, encouraging the World Health Organization to propose a global viral hepatitis elimination program. To Date, vaccine for CHC is still under research. Therefore, reducing the source of infection is an important means of eliminating CHC other than cutting off the transmission route, which requires screening, diagnosing and treating as many patients in the population as possible. Hospital-based screening strategy have been found to be cost-effective in the management of CHC screening, as reported both nationally and internationally. Currently, China has issued In-hospital process for viral hepatitis C screening and management in China (Draft) in April, 2021, which provides a standardized implementation process and direction for in-hospital hepatitis C screening and treatment, but still requires medical institution to develop its own management process, taking into account its current situation and learning from domestic and international experience. In addition, screening for CHC outside the hospital among special populations, such as blood donors, pregnant women, homosexuals, intravenous drug users, prisoners, and residents in rural areas with scarce medical care resources, also requires attention and development of targeted and rational screening strategies. In this paper, we analyze and recommend the management of hepatitis C screening from both in-hospital and out-of-hospital perspectives, with the aim of contributing to the formulation of hepatitis C screening strategies.

Multicenter performance evaluation of the Elecsys HCV Duo immunoassay

BACKGROUND

The diagnostic accuracy of the Elecsys® HCV Duo antigen-antibody combination immunoassay (Roche Diagnostics GmbH) was evaluated for the detection of hepatitis C virus (HCV) infection, versus commercially available comparators.

METHODS

This multicenter study (August 2020-March 2021) assessed the specificity of the Elecsys HCV Duo immunoassay and comparator assays in blood donor and routine clinical laboratory samples; sensitivity was determined in confirmed HCV-positive samples and seroconversion panels. The Elecsys HCV Duo immunoassay was compared with the Monolisa HCV Ag-Ab ULTRA V2, Murex HCV Ag/Ab Combination and ARCHITECT HCV Ag assays, as well as nucleic acid testing (NAT). The antibody (anti-HCV) module of the Elecsys HCV Duo immunoassay was compared with the Elecsys Anti-HCV II, Alinity s Anti-HCV, ARCHITECT Anti-HCV and RIBA HCV 3.0 SIA assays.

RESULTS

The specificity of the Elecsys HCV Duo immunoassay was 99.94% (95% confidence interval [CI], 99.89-99.97) and 99.92% (95% CI, 99.71-99.99) in blood donor (n = 20,634) and routine clinical laboratory samples (n = 2531), respectively. The specificity of the Elecsys HCV Duo immunoassay was similar or better than comparator assays. The sensitivity of the Elecsys HCV Duo immunoassay in confirmed HCV-positive samples (n = 257) was 99.6%. In seroconversion panels, the Elecsys HCV Duo immunoassay detected infections earlier (2.2-21.9 days) than all but one of the comparator assays and detected HCV 1.8 days later than NAT.

CONCLUSIONS

The Elecsys HCV Duo immunoassay shows high diagnostic accuracy, reduces the diagnostic window, and could be used when NAT is not possible.

Challenges in transfusion-transmitted infection screening in Sub-Saharan Africa

In Sub-Saharan Africa, high clinical demand for transfusion faces endemic bloodborne infections and limited resources. Blood screening for transfusion-transmitted bloodborne pathogens is the cornerstone of blood safety. Although there have been substantial improvements over the years, challenges in transfusion-transmitted infection screening that have been identified repeatedly long ago still need to be addressed. Affordability and sustainability of state-of-the-art quality assessed serological and molecular assays, and associated confirmation strategies remain of real concern. In addition, limited resources and infrastructures hamper the development of adequate facilities, quality management, and staff qualification, and exacerbate shortage of reagents and equipment maintenance. It is also important to maintain effort in constituting pools of repeat voluntary non-remunerated donors. Alternative strategies for blood screening that take into account local circumstances might be desirable but they should rely on appropriate field evaluation and careful economic assessment rather than dogma established from high-resource settings.

The prevalence of positive rapid diagnostic test of hepatitis C virus infection in Ghana

Introduction

hepatitis C virus (HCV) infection is one of the most common viral hepatitis in Africa. Rapid diagnostic test (RDT) is a useful tool to identify antibody anti-HCV in point of care. In this study, we decided to determine prevalence of cases with positive rapid diagnostic test of HCV infection.

Methods

this cross-sectional study was conducted in a polyclinic, Accra, Ghana. Using convenience sampling, 728 participants were screened with blood-based RDT and interviewed about personal risk behaviors for transmission of HCV. Data was entered in SPSS version 18 and analyzed.

Results

there was 1.6% positive RDT in our participants. The mean age of them was 29.58 ± 12.31 years old that were younger than the participants with negative RDT (p: 0.027). The rate of positive test was 66.67% in women and 33.33% in men. There was a negative association between age and RDT positive (aOR: 0.91, 95%CI 0.85-0.96). The odds of positive RDT in married participants was 6.32 fold others after adjusting model (p: 0.014). There were no important risk behavior for HCV, except one person with history of contacting blood or needles.

Conclusion

the risk of positive RDT has a reverse relationship with aging and also it has an increase in married individuals. Therefore preventive education and screening for HCV should be a priority in young and middle-aged adults because of more sexual activity.

The Prevalence of Hepatitis B, Hepatitis C and Human Immunodeficiency Viral Infections Among a Large Population of Afghans

Background: Viral infections are a public health problem. Objectives: We would like to evaluate the seroprevalence of hepatitis B, C, and human immunodeficiency virus infections (HIV) in a large sample of the Afghanistan population in Kabul. Methods: In total, 196516 Afghani citizens went to Fateme-al-Zahra clinic to perform obligatory checkup for traveling to Iran. The serum samples were primarily checked by rapid tests for HBV, HCV, and HIV, and in case of positive results, a commercial ELISA kit used as the confirmatory test. Results: Out of 196516 participants, 153763(78%) were men and 42753 (22%) were women. The seroprevalence of HBV, HCV, and HIV infections was 1.23% (2430), 0.13% (265) and 0.018% (16), respectively. The prevalence of HCV and HIV was significantly higher in males than females (m/f: 0.097%/0.037% vs. m/f: 0.008%/0%, respectively; P < 0.05). The simultaneous co-infection of HBV-HCV and HBV-HIV was 0.004% and 0.0005 %, respectively. Conclusions: This study showed a low prevalence of HBV, HCV, and HIV among the study group. Considering the selection bias, sensitivity, and specificity of rapid tests, the real prevalence expected to be quite higher. Proper strategies to improve the social awareness and implement preventive vaccination for HBV can decrease the incidence of these infections.

High rate of hepatitis C virus and human immunodeficiency virus false-positive results in serologic screening in sub-Saharan Africa: adverse impact on the blood supply

BACKGROUND

False positivity in blood screening may cause unnecessary deferral of healthy donors and exacerbate blood shortages. An international multicenter study was conducted to estimate the frequency of HCV and HIV false seropositivity in seven African countries (Burundi, Cameroon, Democratic Republic of Congo, Madagascar, Mali, Mauritania, and Niger).

STUDY DESIGN AND METHODS

Blood donations were tested for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) with rapid detection tests (RDTs), third-generation enzyme immunoassays (EIAs), or fourth-generation EIAs. HCV (456/16,613 [2.74%]) and HIV (249/16,675 [1.49%]) reactive samples were then confirmed with antigen/antibody assays, immunoblots, and nucleic acid testing. Partial viral sequences were analyzed when possible.

RESULTS

The HCV reactivity rate with RDTs was significantly lower than with EIAs (0.55% vs. 3.52%; p < 0.0001). The HIV reactivity rate with RDTs was lower than with third-generation EIAs (1.02% vs. 2.38%; p < 0.0001) but similar to a fourth-generation assay (1.09%). Only 16.0% (57/357) and 21.5% (38/177) of HCV and HIV initial reactive samples, respectively, were repeatedly reactive. HCV and HIV infections were confirmed in 13.2% and 13.7%, respectively, of repeated reactive donations. The predominant HCV genotype 2 and 4 strains in West and Central Africa showed high genetic variability. HIV-1 subtype CRF02_AG was most prevalent.

CONCLUSION

High rates (>80%) of unconfirmed anti-HCV and anti-HIV reactivity observed in several sub-Saharan countries highlights the need for better testing and confirmatory strategies for donors screening in Africa. Without confirmatory testing, HCV and HIV prevalence in African blood donors has probably been overestimated.

Metaanálisis de la validez y el desempeño de las pruebas de tamización del virus de la hepatitis C en bancos de sangre, 2000-2018

Este estudio evaluó la validez y desempeño del inmunodiagnóstico del virus de la hepatitis C (VHC), con base en estudios publicados en la literatura científica mundial. Se diseñó y validó un protocolo de búsqueda y selección de investigaciones en las fases de la guía PRISMA, se analizaron los parámetros de sensibilidad, especificidad, cocientes de probabilidad, razón de odds y curva ROC, en MetaDisc. Se tamizaron 4602 estudios, de los cuales sólo 545 se realizaron en bancos de sangre y 18 evaluaron la validez diagnóstica de las pruebas para el VHC. La mayoría de los estudios fueron de Europa y Asia, con un 78 % basados en determinación de anticuerpos. Los estudios con detección de anticuerpos se realizaron en 21 483 donantes sanos y 3 145 infectados en quienes se halló una sensibilidad de 97,8 % (IC 95 % = 97,3 - 98,2), especificidad 99,0 % (IC 95 % = 98,9 - 99,2), cociente de probabilidad positivo 75,4 (IC 95 % = 27,2 - 209,2) y negativo de 0,02 (IC 95 % = 0,01 - 0,07) y área bajo la curva de 99,8 %. Se concluye que la detección de anticuerpos presenta excelente validez, desempeño y utilidad diagnóstica para la detección del VHC en donantes de sangre y población general.

Differential reactivity of anti-hepatitis C virus screening assays in patients with waning antibodies

Hepatitis C virus (HCV) leads to persistent infection. Viral clearance can be obtained through pharmacological treatment or spontaneously. After viral clearance, anti-HCV antibodies (Abs) slowly decline and finally disappear. Subjects with a resolved HCV infection are reactive to anti-HCV screening assays for a long time. These subjects pose a diagnostic challenge, and therefore, a more accurate interpretation of laboratory tests is needed for cases with resolved HCV infection. However, the performances of anti-HCV screening assays against declining anti-HCV Abs have not been assessed. Here we evaluated 1509 samples with different screening assays. Screening assays provided discrepant results in patients with waning Abs. The identification of signal-to-cut-off values indicative of waning Abs for each anti-HCV assay could avoid unnecessary confirmatory tests and reduce the impact of misdiagnosis.

Addressing gaps in international blood availability and transfusion safety in low- and middle-income countries: a NHLBI workshop

In April 2017, a workshop sponsored by the National Heart, Lung, and Blood Institute, Division of Blood Diseases and Resources, and the Center for Translation Research and Implementation Science was held to discuss blood availability and transfusion safety in low- and middle-income countries (LMICs). The purpose of the workshop was to identify research opportunities for implementation science (IS) to improve the availability of safe blood and blood components and transfusion practices in LMICs. IS describes the late stages of the translational research spectrum and studies optimal and sustainable strategies to deliver proven-effective interventions. Regional working groups were formed to focus on opportunities and challenges in East Africa, Central/West Africa, Middle East and North Africa, Latin America and the Caribbean, Southeast Asia, Western Pacific Asia, Eastern Europe, and Central Asia. The need for an "adequate supply of safe blood" emerged as the major overriding theme. Among the regional working groups, common cross-cutting themes were evident. The majority of research questions, priorities, and strategies fell into the categories of blood availability, blood transfusion safety, appropriate use of blood, quality systems, health economics and budgeting, and training and education in IS. The workshop also brought into focus inadequate country-level data that can be used as the basis for IS initiatives. A mixed approach of needs assessment and targeted interventions with sufficient evidence base to move toward sustainment is an appropriate next step for blood availability and transfusion safety research in LMICs.

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature

BACKGROUND

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV.

METHODS

We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3.

RESULTS

A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%).

CONCLUSIONS

RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.

Seroprevalence of hepatitis C virus infection in Cameroon: a systematic review and meta-analysis

OBJECTIVE

Better knowledge of hepatitis C virus (HCV) seroprevalence at the national level can help to implement pertinent strategies to address the HCV-related burden. The aim of this paper was to estimate the seroprevalence of HCV infection in Cameroon.

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

People residing in Cameroon.

DATA SOURCES

Electronic databases including PubMed/MEDLINE, AJOL, WHO-Afro Library, Africa Index Medicus, National Institute of Statistics and National AIDS Control Committee, Cameroon from 1 January 2000 to 15 December 2016 were searched. English and French languages papers were considered. Two independent investigators selected studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale.

RESULTS

31 studies including 36 407 individuals were finally considered. There was no national representative study. The overall pooled prevalence was 6.5% (95% CI 4.5% to 8.8%; I²=98.3%). A sensitivity analysis of individuals at low risk of HCV infection showed a pooled prevalence of 3.6% (95% CI 2.3% to 5.2%, I²=97.7%, 18 studies) among 22 860 individuals (general population, blood donors and pregnant women), which was higher than for a high-risk population (healthcare workers and people with other identified comorbidities), 12.2% (95% CI 4.9% to 22.2%; I²=98.3%, 13 studies); p=0.018. The prevalence was higher in the East region, in rural settings, and when using an enzyme immunoassay technique for detecting HCV antibodies. Sex, sites, study period, sample size, timing of data collection and methodological quality of studies were not sources of heterogeneity.

LIMITATION

One-third of studies (29.0%) had a low risk bias in their methodology and most were facility-based (87.1%).

CONCLUSION

The seroprevalence of HCV infection in Cameroon indicates the need for comprehensive and effective strategies to interrupt HCV transmission in the Cameroonian population. Specific attention is needed for the East region of the country, rural settings and high-risk populations. A national representative study is needed to provide better estimates.

Hepatitis C virus infection in southwestern Saudi Arabia: Are we still in the plateau phase?

The aim was to study the seroprevalence of Hepatitis C virus (HCV) infection and related risk factors in Aseer region in southwestern Saudi Arabia, the region known to be of the highest endemicity of viral hepatitis. In a cross-sectional study, all participants were interviewed using structured questionnaire. HCV infection was diagnosed using fourth-generation ELISA. All positive and equivocal HCV serology results were further confirmed by using a qualitative confirmatory RT-PCR. The study enrolled 10,234 participants. A seroprevalence of 2.2% (95%CI: 1.9-2.5%) was found. In multivariate logistic regression analysis, the study showed that males had significantly more risk to become seropositive for HCV (aOR = 1.437, 95%CI: 1.071-1.927) compared to females. Similarly, participants having history of blood transfusion had more than two times the risk of becoming seropositive for HCV (aOR = 2.079, 95%CI: 1.037-4.149). HCV infection in the study area is still high in the plateau phase. It is recommended to have an active educational and media campaign about the risks of HCV infections. Workshops and training of qualified laboratory staff related to blood banking seem mandatory. J. Med. Virol. 89:867-871, 2017. © 2016 Wiley Periodicals, Inc.

Reducing risks of Transfusion-transmitted infections in a resource-limited hospital-based blood bank: the case of the Yaoundé University Teaching Hospital, Cameroon

BACKGROUND AND OBJECTIVES

Although interest in assessing risk of TTIs, very few trends in blood safety epidemiological data from resource-limited blood services are reported in the literature. This analysis aims at reporting trends in seroprevalences of TTIs in blood donations in the Yaoundé University Teaching Hospital (UTH) from 2011 to 2015 and to describe reasons for these changes.

MATERIALS AND METHODS

All donations of 2015 were tested for HIV 1&2 antibodies and the P24 antigen, HBsAg, HCV antibody and the Treponema pallidum antibody. Screening for HIV uses a national algorithm based on the systematic use of two assays of different principles: a rapid determination testing assay and an EIA HIV 1 & 2 Ab-Ag. The tests used for HBsAg and HCVAb screening were all based on EIA techniques. Treponema pallidum antibody screening was based on Treponema Pallidum hemagglutination assay (TPHA) and rapid immunochromatographic test (RIT). Screening techniques and results from 2015 were compared to retrospective data from 2011, 2012, 2013 and 2014.

RESULTS

In 2015, 13·4% (n = 214) of 1,596 blood donations were seropositive for at least one screened TTIs. The most frequent serological marker was HBsAg with 123 (7·7%) blood units contaminated. Nineteen (1·2%) and 18 (1·1%) blood units was positive for HIV and syphilis, respectively. There was a significant decrease in the total number of blood donations (P < 10^-4) and HIV, HBsAg and syphilis seroprevalences and an increase in the proportion of voluntary non-remunerated blood donor (P < 0·05). HCVAb seroprevalence was 3·8% in 2015 and has not decreased significantly over the years (P = 0·09).

CONCLUSION

Significant progress is noted in reduction in seroprevalences of HIV, HBV, HCV and syphilis since the beginning of a regular registration of data in 1990.

Update on hepatitis B and C virus diagnosis

Viral hepatitis B and C virus (HBV and HCV) are responsible for the most of chronic liver disease worldwide and are transmitted by parenteral route, sexual and vertical transmission. One important measure to reduce the burden of these infections is the diagnosis of acute and chronic cases of HBV and HCV. In order to provide an effective diagnosis and monitoring of antiviral treatment, it is important to choose sensitive, rapid, inexpensive, and robust analytical methods. Primary diagnosis of HBV and HCV infection is made by using serological tests for detecting antigens and antibodies against these viruses. In order to confirm primary diagnosis, to quantify viral load, to determine genotypes and resistance mutants for antiviral treatment, qualitative and quantitative molecular tests are used. In this manuscript, we review the current serological and molecular methods for the diagnosis of hepatitis B and C.

Sensitivity of hepatitis C virus core antigen and antibody combination assays in a global panel of window period samples

BACKGROUND

Hepatitis C virus (HCV) antigen and antibody combination assays have been launched as a cost-effective alternative to nucleic acid testing (NAT) for reducing the antibody-negative window period (WP). Later, a HCV antigen chemiluminescence immunoassay (CLIA) became available.

STUDY DESIGN AND METHODS

A panel composed of 337 HCV NAT-yield samples that were characterized for viral load (VL) and genotype was used to compare the sensitivity of two combination enzyme-linked immunosorbent assays (Monolisa, Bio-Rad; and Murex, formerly Abbott) and a HCV antigen CLIA (Abbott). Analytic sensitivity was compared with HCV RNA detection using Ultrio (Grifols) by testing serial dilutions of 10 genotype (gt)1 to gt4 samples.

RESULTS

HCV antigen CLIA detected 92.4% of samples, whereas Monolisa and Murex detected 38.3 and 47.5%, respectively. In the HCV RNA VL range of 10(5) to 10(7) IU/mL, Monolisa and Murex detected 38% to 56% of gt1, 85% to 78% of gt2, and 21% to 37% of gt3. The overall geometric mean 50% limit of detection (range) of Ultrio on gt1 to gt4 dilution series was 3.5 (1.2-7.7) copies/mL, compared to 3.3 × 10(6) (4.4 × 10(5) -2.7 × 10(7) ), 3.4 × 10(6) (2.2 × 10(5) -4.2 × 10(7) ), and 2728 (415-7243) copies/mL for Monolisa, Murex, and HCV antigen CLIA, respectively.

CONCLUSION

Analytical sensitivity of NAT was on average 1 million- and 780-fold higher than combination assays and HCV antigen CLIA, respectively. Relative sensitivities of combination assays differed for genotypes with Murex being more sensitive for gt1 and gt3 and Monolisa more sensitive for gt2. Although being less sensitive than NAT, combination assays could be considered in resource-limited settings since they detect 38% to 47% of seronegative WP donations.

Diagnostic accuracy of point-of-care tests for hepatitis C virus infection: a systematic review and meta-analysis

Background

Point-of-care tests provide a plausible diagnostic strategy for hepatitis C infection in economically impoverished areas. However, their utility depends upon the overall performance of individual tests.

Methods

A literature search was conducted using the metasearch engine Mettā, a query interface for retrieving articles from five leading medical databases. Studies were included if they employed point-of-care tests to detect antibodies of hepatitis C virus and compared the results with reference tests. Two reviewers performed a quality assessment of the studies and extracted data for estimating test accuracy.

Findings

Thirty studies that had evaluated 30 tests fulfilled the inclusion criteria. The overall pooled sensitivity, specificity, positive likelihood-ratio, negative likelihood-ratio and diagnostic odds ratio for all tests were 97.4% (95% CI: 95.9–98.4), 99.5% (99.2–99.7), 80.17 (55.35–116.14), 0.03 (0.02–0.04), and 3032.85 (1595.86–5763.78), respectively. This suggested a high pooled accuracy for all studies. We found substantial heterogeneity between studies, but none of the subgroups investigated could account for the heterogeneity. Genotype diversity of HCV had no or minimal influence on test performance. Of the seven tests evaluated in the meta-regression model, OraQuick had the highest test sensitivity and specificity and showed better performance than a third generation enzyme immunoassay in seroconversion panels. The next highest test sensitivities and specificities were from TriDot and SDBioline, followed by Genedia and Chembio. The Spot and Multiplo tests produced poor test sensitivities but high test specificities. Nine of the remaining 23 tests produced poor test sensitivities and specificities and/or showed poor performances in seroconversion panels, while 14 tests had high test performances with diagnostic odds ratios ranging from 590.70 to 28822.20.

Conclusions

Performances varied widely among individual point-of-care tests for diagnosis of hepatitis C virus infection. Physicians should consider this while using specific tests in clinical practice.

Reducing the neglected burden of viral hepatitis in Africa: strategies for a global approach

The burden of liver disease may dramatically increase in the near future in Africa, where screening and access to care and treatment are hampered by inadequate disease surveillance, lack of high-quality tools to assess chronic liver disease, and underestimated needs for human and financial resources. Chronic hepatitis may be considered as silent and neglected killer, fuelled by many years of global inertia from stakeholders and policy makers alike. However, the global battle against viral hepatitis is facing a new era owing to the advent of highly effective drugs, innovative tools for screening and clinical follow-up, and recent signs that governments, advocacy groups and global health organizations are mobilizing to advocate universal access-to-treatment. This review details the barriers to prevention, screening and treatment of viral hepatitis on the African continent, focuses on the urgent need for operational and research programmes, and suggests integrated ways to tackle the global epidemic.

Usefulness of a fourth generation ELISA assay for the reliable identification of HCV infection in HIV-positive adults from Gabon (Central Africa)

Background/Objectives

Guidelines for optimized HCV screening are urgently required in Africa, especially for patients infected with HIV, who sometimes show false positive or false negative reactivity in anti-HCV antibody assays. Here, we assessed the usefulness of a fourth-generation HCV Ag-Ab ELISA for the identification of active HCV infection in HIV-positive patients.

Methods

This cross-sectional study was conducted between 03/2010 and 01/2013 and included 762 Gabonese HIV-positive adult patients. The results of ELISA (Monolisa HCV Ag-Ab ULTRA, Bio-Rad) were compared with those obtained by RT-PCR (gold standard). The optimal ELISA signal-to-cutoff (S/CO) ratio to identify patients with active hepatitis C (positive HCV RNA) was determined. Specimens were further tested by the INNO-LIA HCV Score assay (Innogenetics) and the Architect HCV Ag kit (Abbott) to define the best diagnostic strategy.

Results

Sixty-seven patients tested positive for HCV (S/CO ratio ≥ 1) by ELISA. Of these, 47 (70.1%) tested positive for HCV RNA. The optimal S/CO associated with active HCV infection was 1.7. At this threshold, the sensitivity of ELISA was 97.9% (95% confidence interval (CI) 90.0–99.9%), its specificity was 91.3% (95% CI 85.0–95.5%), and HCV seroprevalence rate was 7.3% (56/762) (95% CI 5.6–9.4%). Among 57 HCV-seropositive patients with available INNO-LIA results, false reactivity was identified in 14 (24.6%), resolved HCV infection in two (3.5%), possible acute HCV infections in nine (15.8%) and likely chronic HCV infections in 32 (56.1%) patients. HCV core Ag was undetectable in 14/15 (93.3%) specimens that tested negative for HCV RNA whereas it was quantified in 34 (out of 39, 87.2%) samples that tested positive for HCV RNA.

Conclusions

Our study provides comprehensive guidance for HCV testing in Gabon, and will help greatly clinicians to improve case definitions for both the notification and surveillance of HCV in patients co-infected with HIV.

The use of rapid diagnostic tests for transfusion infectious screening in Africa: a literature review

Infectious risk associated with blood transfusion remains a major public health challenge in Africa, where prevalence rates of the major transfusion-transmissible infections (ie, hepatitis B, hepatitis C, human immunodeficiency virus, and syphilis) are among the highest in the world. Resource-limited blood services often operate with minimal predonation screening safeguards, prompting exclusive reliance on laboratory testing to mitigate infectious risk. Transfusion screening with rapid diagnostic tests (RDTs) has been adopted in areas that lack the capacity to support the routine use of more sophisticated technologies. However, uncertainty surrounding the performance of some RDTs in the field has spurred debate regarding their application to blood donation screening. Our review of the literature identified 17 studies that evaluated RDTs for the infectious screening of blood donors in Africa. The review highlights the variable performance of available RDTs and the importance of their use in a quality-assured manner. Deficiencies in performance observed with some RDTs underscore the need to validate test kits prior to use under field conditions with locally acquired samples. Suboptimal sensitivities of some available tests, specifically hepatitis B virus rapid assays, question their suitability in single-test algorithms, particularly in high-prevalence regions. Although RDTs have limitations, many of which can be addressed through improved training and quality systems, they are frequently the only viable option for infectious screening in resource-poor African countries. Therefore, additional studies and specific guidelines regarding the use of RDTs in the context of blood safety are needed.