Dry Blood Spots a Reliable Method for Measurement of Hepatitis B Viral Load in Resource-Limited Settings

A comparative study of extraction free detection of HBV DNA using sodium dodecyl sulfate, N-lauroylsarcosine sodium salt, and sodium dodecyl benzene sulfonate

This study aimed to develop an extraction-free method for quantitative and qualitative detection of HBV DNA compared to traditional nucleic acid extraction. Paired serum and dried blood spot (DBS) samples from 67 HBsAg-positive and 67 HBsAg-negative individuals were included. Two samples with known HBV DNA titers (~ 109 copies/mL) were examined by extraction-free detection using three surfactants (0.2 to 1% of Sodium dodecyl sulfate:SDS, N-Lauroylsarcosine sodium salt:NL, Sodium dodecyl benzene sulfonate:SDBS), two stabilizing agents (0.1 or 0.01% 2-Mercaptoethanol:2ME and 3.5 or 7% Bovine Serum Albumin:BSA) and two Taq polymerases (Fast Advanced and Prime Direct Probe). HBV DNA in all 67 HBsAg-positive and 67 HBsAg-negative serum and DBS samples was directly quantified by Rt-PCR using 0.4% SDS or 0.4% NL with Fast Advance or Prime Direct Probe Taq. Extraction-free amplification was also performed. Detection limits were varied by different surfactants and Taq. SDS combined with Fast Advanced Taq showed lower detection limits, while SDS with Prime Direct Probe Taq outperformed NL or SDBS-based detection. Adding 2ME to SDS improved detection limit with Prime Direct Probe Taq but not significantly compared to SDS alone. BSA did not significantly enhance detection limits but provided insights into sample stability. The senitivity and specificity of 0.4% SDS and NL in combination with either Fast advanced or Prime Direct Probe Taq polymerase in serum samples were > 90% and 100% resepctively, while it was > 80% and 100% respectively in DBS samples. Extraction-free HBV DNA amplification provided 100% identity with original genomes. Our study suggests that SDS, NL or SDBS-based extraction-free HBV DNA detection strategies using Prime Direct Probe Taq have potential to simplify and accelerate HBV DNA detection with high sensitivity and specificity in both serum and DBS samples, with implications for resource-limited settings and clinical applications. Utilizing surfactants with 2ME is optional, and further research and validation are necessary to broaden its application in real-world diagnostics.

High prevalence of hepatitis B and HIV among women survivors of sexual violence in South Kivu province, eastern Democratic Republic of Congo

INTRODUCTION

Limited data are available on the prevalence rates of hepatitis B and acquired immunodeficiency syndrome (AIDS) among women survivors of sexual violence (WSSV) in South Kivu province, in the eastern part of the Democratic Republic of Congo (DRC), where armed conflicts persist. Here, we aimed to assess the prevalence of these two infections in this vulnerable local population.

METHODS

A total of 1002 WSSV, aged from 18 to 70 years old were enrolled from May 2018 to May 2020 at three healthcare facilities (Panzi, Mulamba and Bulenga hospitals), which are called "The One-Stop Centre Care Model" for the management of sexual violence in South Kivu. Blood samples were collected and tested for hepatitis B virus (HBV) and human immunodeficiency virus (HIV) antigens and antibodies using enzyme-linked immunoassay (ELISA) methods. Subsequently, viral load quantification for HBV and HIV were performed using the GeneXpert. Univariate and multivariate logistic regression models were used to assess factors associated with HIV-positive and HBV-positive status.

RESULTS

For HBV, overall prevalence was 8.9% (95% CI; 7.2-10.8%), 32.1% (95% CI; 29.3-35.0%), and 14.5% (95% CI; 12.3-16.8%) for HBsAg, anti-HBc and anti-HBs antibodies, respectively. Among the 89 HBsAg-positive patients, 17 (19.1%) were HBeAg-positive. The median age of individuals with a positive HBsAg test was higher than those with a negative test (median: 40 years (IQR 30-52) compared to 36 years (IQR 24-48)). Risk factors for HBV infection were age (≥35 years) (AOR = 1.83 [1.02-3.32]; p = 0.041), having no schooling (AOR = 4.14 [1.35-12.62]; p = 0.012) or only primary school-level (AOR = 4.88 [1.61-14.75]; p = 0.005), and multiple aggressors (AOR = 1.76 [1.09-2.84], p = 0.019). The prevalence of HIV was 4.3% [95% CI: 3.1-5.7%]. HIV/HBV co-infection occurred only in 5 individuals (0.5%). The HBV viral load was detectable (> 1 log10 UI/mL) in 61.8% of HBsAg-positive subjects and 64.8% HIV-positive subjects had a high viral load (≥ 3 log10 copies/mL).

CONCLUSION

This study revealed a high prevalence of HBV and HIV infections among WSSV in South Kivu. The results generated highlight the urgent need for systematic screening of HBV and HIV by integrating fourth-generation ELISA tests in HIV and HBV control programs.

The role of dried blood spot tests in the detection of hepatitis B infection: A systematic review

Hepatitis B remains a public health problem worldwide despite vaccine availability. Although the existing diagnostic tools help detect the infection, logistics support and limited resources and technologies affect their usefulness and reliability in developing countries. This systematic review evaluated the performance of dried blood spots (DBS) as a collection and storage tool for diagnosing an hepatitis B virus (HBV) infection. A comprehensive search using OVID, Scopus and CINAHL databases was performed to collate articles published up to April 2023 that detected Hepatitis B infections using DBS. Five reviewers independently performed identification, screening, quality assessment and data extraction. A qualitative synthesis of the included studies was conducted. Of the 402 articles, 78 met the inclusion criteria. The results show that most studies focused on populations with known HBV, HCV and/or HIV status. Approximately half (49%) of the included studies utilized the Whatman Protein Saver Card for DBS collection. The DBS samples were then predominantly stored in room temperature conditions. In line with this, storage conditions influenced the concentration and stability of the analyte from the DBS samples, affecting the accuracy of downstream diagnostic methods. ELISA methods, using hepatitis B surface antigen (HBsAg) as an HBV marker, were the most widely used diagnostic tool for detecting HBV infection in DBS samples. The simplicity and cost-effectiveness of the ELISA technique highlight its potential to be used in low-resource settings. In line with this, the detection of HBsAg using an ELISA immunoassay had higher sensitivity (85.6%-100%), and specificity (95%-100%) ranges as compared to other target molecules and methods. Although this review only performed a qualitative analysis, DBS offers a promising method for collecting and storing blood samples; however, the standardization of sampling, storing conditions and diagnostic techniques is required to ensure sustainable application.

Intermediate hepatitis B virus infection prevalence among 1622 pregnant women in rural Burkina Faso and implications for mother-to-child transmission

In highly endemic countries for hepatitis B virus (HBV) infection, childhood infection, including mother-to-child transmission (MTCT), represents the primary transmission route. High maternal DNA level (viral load ≥ 200,000 IU/mL) is a significant factor for MTCT. We investigated the prevalence of HBsAg, HBeAg, and high HBV DNA among pregnant women in three hospitals in Burkina Faso and assessed the performance of HBeAg to predict high viral load. Consenting pregnant women were interviewed on their sociodemographic characteristics and tested for HBsAg by a rapid diagnostic test, and dried blood spot (DBS) samples were collected for laboratory analyses. Of the 1622 participants, HBsAg prevalence was 6.5% (95% CI, 5.4-7.8%). Among 102 HBsAg-positive pregnant women in DBS samples, HBeAg was positive in 22.6% (95% CI, 14.9-31.9%), and viral load was quantified in 94 cases, with 19.1% having HBV DNA ≥ 200,000 IU/mL. HBV genotypes were identified in 63 samples and predominant genotypes were E (58.7%) and A (36.5%). The sensitivity of HBeAg by using DBS samples to identify high viral load in the 94 cases was 55.6%, and the specificity was 86.8%. These findings highlight the need to implement routine HBV screening and effective MTCT risk assessment for all pregnant women in Burkina Faso to enable early interventions that can effectively reduce MTCT.

Dried blood spot sampling for hepatitis B virus quantification, sequencing and mutation detection

Hepatitis B virus (HBV) diagnosis is performed on serum samples, but the access to this diagnosis is difficult in low-income regions. The use of dried blood spot (DBS) samples does not require special structure for collection, storage or transport. This study evaluates the use of DBS for detection, quantification and sequencing of HBV DNA using in-house techniques. Two study groups were included: 92 HBsAg + individuals and 49 negative controls. Serum and DBS samples were submitted to quantitative and qualitative in-house PCR for S/pol genes, sequencing and phylogenetic analyses. Total of 84 serum samples were successfully amplified. Of them, 63 paired DBS were also positive in qualitative PCR. Qualitative PCR in DBS presented a sensitivity of 75% and specificity of 100% (Kappa = 0.689). Quantitative PCR in DBS presented a detection limit of 852.5 copies/mL (250 IU/mL), sensitivity of 77.63% and specificity of 100% (Kappa = 0.731). A total of 63 serum samples and 36 DBS samples were submitted to sequencing, revealing the circulation of genotypes A (65.08%), D (4.8%), E (3.2%) and F (27%) with 100% of correspondence between serum and DBS. All sequenced samples displayed polymorphisms in HBsAg gene. An HIV-coinfected patient presented the rtM204V/I-rtL180M double resistance mutation in serum and DBS. In conclusion, DBS is an alternative to detect, quantify and characterize HBV DNA, being a possibility of increasing diagnosis in low-income settings, closing gaps in HBV control.

Rapid Diagnostics for Hepatitis B and C Viruses in Low- and Middle-Income Countries

The global health challenge posed by hepatitis B virus (HBV) and hepatitis C virus (HCV) persists, especially in low-and-middle-income countries (LMICs), where underdiagnosis of these viral infections remains a barrier to the elimination target of 2030. HBV and HCV infections are responsible for most liver-related mortality worldwide. Infected individuals are often unaware of their condition and as a result, continue to transmit these viruses. Although conventional diagnostic tests exist, in LMIC they are largely inaccessible due to high costs or a lack of trained personnel, resulting in poor linkage to care and increased infections. Timely and accurate diagnosis is needed to achieve elimination of hepatitis B and C by the year 2030 as set out by the World Health Organization Global Health Sector Strategy. In this review rapid diagnostic tests allowing for quick and cost-effective screening and diagnosis of HBV and HCV, are discussed, as are their features, including suitability, reliability, and applicability in LMIC, particularly those within Africa.

Real-world application of the Xpert® HBV viral load assay on serum and dried blood spots

As we strive towards the WHO goal of elimination of viral hepatitis as a public health threat by 2030, implementation of reliable, accurate diagnostic assays is crucial to identify those at risk of disease progression and those at risk of transmission. Ironically those at greatest risk of chronic hepatitis B are often in resource-poor regions with limited access to testing, collection, storage, and/or transportation of peripheral blood. The Xpert® HBV Viral Load assay provides an easy to use, convenient means of measuring load on GeneXpert platforms. In this study, the Xpert assay is evaluated against four commercially available high-throughput assays for Hepatitis B virus (HBV) loads. In addition application of dried blood spots (DBS) for estimation of viral load is assessed on real-world samples collected from a remote Pacific Island, Kiribati. A total of 107 serum/plasma samples were tested in the Xpert HBV load assay and compared with the Abbott m2000, Alinity m, and Roche Cobas CAP/CTM and 6800. Fifty-three DBS were tested in the Xpert assay and compared with matching serum samples. Overall 82% serum/plasma samples demonstrated good correlation between the Xpert and Roche and Abbott assays, to within 0.5 log10 IU/ml. The greatest discrepancies were seen at the limits of quantification of all assays. About 85.4% DBS gave estimable viral loads to within 1 log10 IU/ml of the serum load. The Xpert HBV viral load assay is recommended for all settings but particularly useful for resource-poor settings. Utility of DBS with the Xpert assay provides a simple means for testing in remote settings.

Comparison of four extraction methods for the detection of hepatitis B virus DNA in dried blood spot samples

The dried blood spot (DBS) samples are a useful resource for viral DNA isolation and important in increasing access to HBV diagnosis. However, the choice of the DNA extraction method is crucial for reliable results. We compared the reliability of four DNA extraction methods using DBS samples for the qualitative and quantitative detection of HBV. A panel of serially diluted HBV DNA in whole blood was spotted onto filter paper (Whatman 903 paper and Whatman FTA cards). Four methods were used to extract DNA: QIAamp^® DNA Blood Mini Kit (Qiagen); High Pure Viral Nucleic Acid Kit (Roche); Invisorb Spin Blood Midi Kit (Invitek), and DBS Genomic DNA Isolation Kit (Norgen Biotek). Two qualitative PCRs for the core and surface gene regions of HBV were used, and in‐house real‐time PCR was also evaluated. It was possible to detect HBV DNA using all extraction and PCR protocols. The lowest limit of detection was found using Whatman 903 paper, Roche extraction, and qualitative PCR (20 copies of HBV DNA per ml) for the surface/polymerase HBV region. In the case of in‐house real‐time PCR, the lowest limit of detection was found using both Roche and Qiagen assays (estimated 2 × 10³ copies per ml). These results suggest the importance of both the extraction method and PCR protocol in detecting HBV DNA in DBS. This study provides insights into the utility of DBS samples in HBV molecular diagnosis and their feasibility in low resource areas where cold storage and transportation may be difficult.

Improving care of migrants is key for viral hepatitis elimination in Europe

By 2040, deaths from chronic viral hepatitis worldwide are projected to exceed those from human immunodeficiency virus infection, tuberculosis and malaria combined. The burden of this disease is predominantly carried by low-resource countries in Africa and Asia. In resource-rich countries, the epidemiological spread of viral hepatitis is partially driven by migrant movements from areas of high endemicity. In the last decade, Member States of the European Union and the European Economic Area have experienced an unprecedented influx of migrants, which has resulted in the polarization of political views about migration. In addition, the coronavirus disease 2019 pandemic has worsened the economic and health conditions of migrants and contributed to hostility to ensuring their health rights. Moreover, the implementation of hostile laws in some host nations has increased the vulnerability of marginalized migrant subgroups, such as asylum seekers and undocumented individuals. These developments have complicated the historical challenge of identifying high-risk migrant groups for screening and treatment. However, if European countries can apply the simplified assessment tools and diagnostic tests for viral hepatitis that have been used for decentralized screening and monitoring in resource-poor countries, the uptake of care by migrants could be dramatically increased. Given the global calls for the elimination of viral hepatitis, European nations should recognize the importance of treating this vulnerable migrant population. Political and health strategies need to be adapted to meet this challenge and help eliminate viral hepatitis globally.

Evaluation of the Aptima™ HBV Quant Dx assay for semi-quantitative HBV viral load from dried blood spots

BACKGROUND

The detection and quantification of hepatitis B virus (HBV) DNA from dried blood spots (DBS) is a major tool for chronic hepatitis B management in resource-limited settings. This strategy fits in perfectly with the hepatitis control plan promoted by the World Health Organization. However, few commercial methods are validated for viral load (VL) measurement on DBS.

OBJECTIVES

Our objective was to evaluate the performance of the HBV VL measurement of the Aptima™ HBV Quant Dx assay on DBS compared to plasma samples on the Panther® platform (Hologic).

STUDY DESIGN

266 whole blood samples for routine measurement were included. Five spots of 75 μL of whole blood were loaded onto a card before centrifugation and plasma settling.

RESULTS

149 samples were quantifiable and 117 were not detected. We achieved excellent linearity (r² = 0.994) over a wide range of measurements suitable for clinical practice, and a 95 % lower limit of detection (LLOD-95 %) at 2.65 log₁₀ IU/mL (445 IU/mL). A good performance of this assay was observed for samples with HBV VL > LLOD-95 % and 100 % of samples were detected if HBV VL was above 2.95 log₁₀ IU/mL. The correlation between the two matrices for quantitative VLs was good (r² = 0.978) with a very low bias (-0.002 log₁₀ IU/mL).

CONCLUSION

The Aptima™ assay can properly detect and quantify HBV DNA in DBS, providing a satisfactory use in clinical monitoring and therapeutic decisions. DBS represents an excellent alternative to plasma, especially in resource-limited countries, while maintaining the performance and advantages of an automated technique.

Seroepidemiology of Hepatitis B in the Democratic Republic of the Congo

Hepatitis B virus (HBV) is endemic throughout Africa, but its prevalence in the Democratic Republic of the Congo (DRC) is incompletely understood. We used dried blood spot (DBS) samples from the 2013 to 2014 Demographic and Health Survey in the DRC to measure the prevalence of HBV using the Abbott ARCHITECT HBV surface antigen (HBsAg) qualitative assay. We then attempted to sequence and genotype HBsAg-positive samples. The weighted national prevalence of HBV was 3.3% (95% CI: 1.8-4.7%), with a prevalence of 2.2% (95% CI: 0.3-4.1%) among children. Hepatitis B virus cases occurred countrywide and across age strata. Genotype E predominated (60%), and we found a unique cluster of genotype A isolates (30%). In conclusion, DBS-based HBsAg testing from a nationally representative survey found that HBV is common and widely distributed among Congolese adults and children. The distribution of cases across ages suggests ongoing transmission and underscores the need for additional interventions to prevent HBV infection.

Evaluation of accuracy of hepatitis B virus antigen and antibody detection and relationship between epidemiological factors using dried blood spot

Dried blood spots (DBS) testing might increase the access for Hepatitis B virus (HBV) diagnosis, but little is known about the performance of these assays in real life conditions. This study aims to evaluate the diagnostic accuracy of HBsAg, anti-HBc and anti-HBs detection in DBS in clinical settings and field studies and to evaluate demographic and risk behaviour according the presence of HBsAg and anti-HBc. Paired sera and DBS samples were obtained from 2309 individuals from 3 groups, defined as follows: G1: clinical setting (n = 5-19), G2: general population (n = 1305) and G3: vulnerable individuals that could be more exposed to blood contact (n = 485). Sera and DBS were tested using commercial enzyme immunoassay (EIA), with some modifications added. Using DBS samples, the specificity values were above 90 % for HBsAg and anti-HBc in all groups and for anti-HBs range from 58.6%-85%. HBsAg testing had the best performance in GI (sensitivity = 84.4 %) and among those samples that the paired serum also presented anti-HBc marker (sensitivity = 91.6 %). High sensitivity of anti-HBc testing in DBS samples was observed in GI (80.8 %) and among HBV active cases (HBsAg+/anti-HBc+) (98.4 %). Testing of anti-HBs in DBS showed the highest sensitivity in GIII (65.5 %), in previous HBV exposed and cured individuals and when serum titers were above 100 IU/mL (86.7 %). DBS samples could be used for screening and prevalence studies for HBsAg and anti-HBc, particularly in clinical settings and among HBV active cases in field studies.

Utility of dried blood spots in detecting helicobacter pylori infection

Purpose

Identifying infectious pathogens by collecting intravenous blood (IVB) is a well-established procedure, however, the collection of IVB in field epidemiological study is challenging. The dried blood spot (DBS) as an alternative to IVB has been introduced, although, there is a limited study to demonstrate the utility of DBS stored at various storage conditions and transported at different periods. This is an observational study, which evaluates the effectiveness of DBS in field epidemiological studies to identify infectious pathogens.

Materials and Methods

A total of 264 paired DBS samples prepared from IVB, stored at 4°C, -20°C after period 24, 48 and 72 h. Serologically, enzyme-linked immunosorbent assay [ELISA] IgG antibody detected against Helicobacter pylori infection from DBS and compared with IVB.

Results

Quantitatively, IgG antibody reactivity showed >87% correlation between IVB and DBS samples stored at 4°C or -20°C within 48 h of transport duration. DBS stored at 4°C shows, equal sensitivity 87.5% and specificity 95% before 48 h of transport duration, while at -20°C storage similar sensitivity 87.5% observed but slightly less specificity 86.36% observed as compared to 24 h of transport duration. One-way analysis of variance showed, nonsignificant difference at both (-20°C and 4°C) the stored condition with P value (P > 0.851) and (P > 0.477). Kappa values showed good inter-rater reliability between DBS and IVB in a range (0.77-0.81).

Conclusion

No significant difference was observed in detecting H. pylori when ELISA was conducted using IVB or DBS stored at 4°C and transported even after 48 h. This confirms that DBS collected even in compromised conditions in the field can be used for detecting infection.

Screening for retroviruses and hepatitis viruses using dried blood spots reveals a high prevalence of occult hepatitis B in Ghana

Background:

Recent advances in antiviral therapy show potential for a cure and/or control of most human infections caused by hepatitis viruses and retroviruses. However, medical success is largely dependent on the identification of the large number of people unaware of these infections, especially in developing countries. Dried blood spots (DBS) have been demonstrated to be a good tool for collecting, storing and transporting clinical specimens from rural areas and limited-resource settings to laboratory facilities, where viral infections can be more reliably diagnosed.

Methods:

The seroprevalence and virological characterization of hepatitis B virus (HBV) and hepatitis C virus (HCV), as well as human retroviruses (HIV-1, HIV-2, human T-cell leukaemia virus type 1 [HTLV-1] and human T-cell leukaemia virus type 2 [HTLV-2]), were investigated in clinical specimens collected from DBS in Ghana.

Results:

A total of 305 consecutive DBS were collected. A high prevalence of chronic HBV (8.5%) and occult hepatitis B (14.2%) was found, whereas rates were lower for HIV-1, HTLV-1 and HCV (3.2%, 1.3% and 0.6%, respectively). HIV-2 and HTLV-2 were absent. CRF02_AG was the predominant HIV-1 subtype, whereas genotype E was the most frequent HBV variant.

Conclusions:

DBS are helpful in the diagnosis and virological characterization of hepatitis and retrovirus infections in resource-limited settings. The high rate of hepatitis B in Ghana, either overt or occult, is noteworthy and confirms recent findings from other sub-Saharan countries. This should encourage close clinical follow up and antiviral treatment assessment in this population, as well as universal HBV vaccine campaigns.

Evaluation of dried blood spots for hepatitis B and D serology and nucleic acid testing

Areas with the highest burden of hepatitis B virus (HBV) infection are often low-middle-income countries with limited access to diagnosis due to isolation, affordability, and/or feasibility. Dried blood spots (DBSs) provide an alternative for remote areas where collection and transportation of serum is impractical. In this study, the application of DBS for serological and molecular detection of HBV and hepatitis D virus (HDV) was evaluated. Hepatitis B surface antigen was detected in 87 of 91 (95.6%) DBS. Seventeen of 21 (81%) had detectable HBeAg and 52 of 71 (73.2%) were anti-HBe positive. Anti-HD was detectable in 11 of 12 (91.6%) spiked control DBS after an initial failure to detect in patient DBS. HBV DNA was detected from 50 of 70 (71.4%) DBS with serum loads greater than 200 IU/mL in an in-house assay and 18 of 24 (75%) DBS with loads exceeding 389 IU/mL in a commercial assay. Using linear regression, HBV DNA loads from DBS were able to predict serum loads in 46 of 50 (92%) samples to within 1 log of actual serum load. HDV RNA was detected in 42 of 47 (89%) DBS with serum levels greater than 7200 IU/mL. DBSs are recommended for diagnosis of HBV, monitoring, and detection of high loads in pregnant women where peripheral blood testing remains unfeasible. Detection of HDV RNA from DBS may prove useful in endemic areas.

Applicability of Oral Fluid and Dried Blood Spot for Hepatitis B Virus Diagnosis

Hepatitis B virus (HBV) is one of the major causes of chronic liver disease worldwide; however most of individuals are not aware about the infection. Oral fluid and dried blood spot (DBS) samples may be an alternative to serum to HBV diagnosis to increase the access to diagnosis in remote areas or high-risk groups. The main objective of this review is to give an insight about the usefulness of oral fluid and DBS for detecting HBV markers. Several groups have evaluated the detection of HBsAg, anti-HBc, and anti-HBs markers in oral fluid and DBS samples demonstrating 13 to 100% of sensitivity and specificity according different groups, sample collectors, and diagnosis assays. In the same way, HBV DNA detection using oral fluid and DBS samples demonstrate different values of sensitivity according type of collection, studied group, extraction, and detection methods. Thus, serological and molecular diagnostic tests demonstrated good performance for detecting HBV using oral fluid and DBS according some characteristics and could be useful to increase the access to the diagnosis of HBV.

Treatment of chronic hepatitis B in sub-Saharan Africa: 1-year results of a pilot program in Ethiopia

BACKGROUND

The World Health Organization has set an ambitious goal of eliminating viral hepatitis as a major public health threat by 2030. However, in sub-Saharan Africa, antiviral treatment of chronic hepatitis B (CHB) is virtually unavailable. Herein, we present the 1-year results of a pilot CHB treatment program in Ethiopia.

METHODS

At a public hospital in Addis Ababa, CHB patients were treated with tenofovir disoproxil fumarate based on simplified eligibility criteria. Baseline assessment included liver function tests, viral markers, and transient elastography (Fibroscan). Changes in laboratory markers were analyzed using Wilcoxon signed-rank tests. Adherence to therapy was measured by pharmacy refill data.

RESULTS

Out of 1303 patients, 328 (25.2%) fulfilled the treatment criteria and 254 (19.5%) had started tenofovir disoproxil fumarate therapy prior to September 1, 2016. Of the patients who started therapy, 30 (11.8%) died within the first year of follow-up (28 of whom had decompensated cirrhosis), 9 (3.5%) self-stopped treatment, 7 (2.8%) were lost to follow-up, and 4 (1.6%) were transferred out. In patients who completed 12 months of treatment, the median Fibroscan value declined from 12.8 to 10.4 kPa (p < 0.001), 172 of 202 (85.1%) patients with available pharmacy refill data had taken ≥ 95% of their tablets, and 161 of 189 (85.2%) patients with viral load results had suppressed viremia. Virologic failure (≥ 69 IU/mL) at 12 months was associated with high baseline HBV viral load (> 1,000,000 IU/mL; adjusted OR 2.41; 95% CI 1.04-5.55) and suboptimal adherence (< 95%; adjusted OR 3.43, 95% CI 1.33-8.88).

CONCLUSIONS

This pilot program demonstrated that antiviral therapy of CHB can be realized in Ethiopia with good clinical and virologic response. Early mortality was high in patients with decompensated cirrhosis, underscoring the need for earlier detection of hepatitis B virus infection and timely initiation of treatment, prior to the development of irreversible complications, in sub-Saharan Africa.

TRIAL REGISTRATION

NCT02344498 (ClinicalTrials.gov identifier). Registered 16 January 2015.

Comparison of the performance of enzyme immunoassays for hepatitis B and C detection in dried blood spot

Dried blood spots (DBSs) could be an alternative to serum for hepatitis B virus (HBV) and hepatitis C virus (HCV) diagnosis. This study aims to evaluate two enzyme immunoassays (EIAs) for HBsAg and anti-HCV detection using DBS. Serum was tested using commercial EIA. DBS was tested using optimized EIA developed for serum and commercial EIA developed for DBS (Imunoscreen). Concordances between DBS and serum samples for both markers and EIAs were higher than 97%. Both EIAs demonstrated good performance for HBsAg and anti-HCV detection using DBS, and these methods could be used unchangeably increasing the access for HBV and HCV diagnosis.

How to improve access to therapy in hepatitis B patients

Despite the availability of a preventive vaccine and active antiviral treatments that stop disease progression and reduce the risk of hepatocellular carcinoma, hepatitis B is still a major public health problem. Only an estimated 10% of the 257 million people living with HBV have been diagnosed and as few as 1% are being adequately treated. Barriers to diagnosis and treatment include: (i) limited awareness and lack of knowledge about HBV infection and HBV-related diseases; (ii) under-diagnosis with insufficient screening and referral to care; (iii) limited treatment due to drug availability, costs, reimbursement policies and the need for long-term or life-long therapy. These barriers and the actions needed to improve access to treatment are strongly influenced by the prevalence of infection and affect middle-high vs low-middle income countries differently, where most HBV carriers are found. In high-prevalence regions and low-to middle-income countries, the main challenges are availability and cost while in low-prevalence regions and middle-to high-income countries low screening rates, public awareness, social stigma and discrimination play an important role. Overcoming these challenges on a global scale is a complex clinical and public health challenge and multilateral commitment from pharmaceutical companies, governments, funders and the research community is lacking. The new WHO 2016 Global Health Sector Strategy on viral hepatitis targets testing and treatment, suggesting that important but strong actions are needed from advocacy groups, scientific societies and funding agencies to foster awareness and access to cure.

Diagnostic accuracy of detection and quantification of HBV-DNA and HCV-RNA using dried blood spot (DBS) samples - a systematic review and meta-analysis

BACKGROUND

The detection and quantification of hepatitis B (HBV) DNA and hepatitis C (HCV) RNA in whole blood collected on dried blood spots (DBS) may facilitate access to diagnosis and treatment of HBV and HCV infection in resource-poor settings. We evaluated the diagnostic performance of DBS compared to venous blood samples for detection and quantification of HBV-DNA and HCV-RNA in two systematic reviews and meta-analyses on the diagnostic accuracy of HBV DNA and HCV RNA from DBS compared to venous blood samples.

METHODS

We searched MEDLINE, Embase, Global Health, Web of Science, LILAC and Cochrane library for studies that assessed diagnostic accuracy with DBS. Heterogeneity was assessed and where appropriate pooled estimates of sensitivity and specificity were generated using bivariate analyses with maximum likelihood estimates and 95% confidence intervals. We also conducted a narrative review on the impact of varying storage conditions or different cut-offs for detection from studies that undertook this in a subset of samples. The QUADAS-2 tool was used to assess risk of bias.

RESULTS

In the quantitative synthesis for diagnostic accuracy of HBV-DNA using DBS, 521 citations were identified, and 12 studies met the inclusion criteria. Overall quality of studies was rated as low. The pooled estimate of sensitivity and specificity for HBV-DNA was 95% (95% CI: 83-99) and 99% (95% CI: 53-100), respectively. In the two studies that reported on cut-offs and limit of detection (LoD) - one reported a sensitivity of 98% for a cut-off of ≥2000 IU/ml and another reported a LoD of 914 IU/ml using a commercial assay. Varying storage conditions for individual samples did not result in a significant variation of results. In the synthesis for diagnostic accuracy of HCV-RNA using DBS, 15 studies met the inclusion criteria, and this included six additional studies to a previously published review. The pooled sensitivity and specificity was 98% (95% CI:95-99) and 98% (95% CI:95-99.0), respectively. Varying storage conditions resulted in a decrease in accuracy for quantification but not for reported positivity.

CONCLUSIONS

These findings show a high level of diagnostic performance for the use of DBS for HBV-DNA and HCV-RNA detection. However, this was based on a limited number and quality of studies. There is a need for development of standardized protocols by manufacturers on the use of DBS with their assays, as well as for larger studies on use of DBS conducted in different settings and with varying storage conditions.

Hepatitis C Virus (HCV) RNA screening and sequencing using dry plasma spots

BACKGROUND

HCV RNA screening of large sample repositories provides data on HCV epidemic patterns that may help guide control policies. In resource-limited settings, shipment of frozen samples to molecular laboratory facilities and testing of individual samples may be prohibitively expensive.

OBJECTIVE

Our aim was to detect and sequence HCV RNA in a large HIV-positive cohort from Kumasi, Ghana, using pooled and individual dried plasma spots (DPS) produced from samples stored at -80°C.

STUDY DESIGN

In the validation phase, replicate DPS were prepared with six dilutions (500-10,000 IU/ml) of the 4^th International Standard for HCV and tested in three independent experiments. In the testing phase, DPS prepared with plasma samples from 875 HIV-positive subjects were pooled for screening, followed by testing of individual DPS of positive pools. Input from individual DPS was two 6mm punches; pools comprised two punches from each of five DPS. Genotypes were determined by Sanger sequencing of HCV core and NS5B.

RESULTS

With the dilution series, sensitivity of HCV RNA detection was ≥2500 IU/ml. Replicate DPS gave intra-assay and inter-assay coefficients of variation ≤1.4%. With the stored samples, HCV RNA was detected in 5/175 DPS pools and in one DPS from each positive pool, yielding a HCV RNA prevalence of 5/875 (0.57%; 95% confidence interval 0.07-1.07%). The five samples were sequenced as HCV genotypes 2l and 2r.

DISCUSSION

DPS allowed reproducible HCV RNA detection, and pooling effectively contained the cost and labour of screening a previously untested, low-prevalence cohort. DPS were also suitable for HCV sequencing.