Validation of rapid point-of-care (POC) tests for detection of hepatitis B surface antigen in field and laboratory settings in the Gambia, Western Africa

Real-Life Diagnostic Accuracy and Clinical Utility of Hepatitis B Virus (HBV) Nucleic Acid Testing Using the GeneXpert Point-of-Care Test System from Fresh Plasma and Dry Blood Spot Samples in The Gambia

The GeneXpert HBV Viral Load test is a simplified tool to scale up screening and HBV monitoring in resource-limited settings, where HBV is endemic and where molecular techniques to quantify HBV DNA are expensive and scarce. However, the accuracy of field diagnostics compared to gold standard assays in HBV-endemic African countries has not been well understood. We aim to validate the diagnostic performance of the GeneXpert HBV Viral Load test in freshly collected and stored plasma and dried blood spot (DBS) samples to assess turn-around-time (TAT) for sample processing and treatment initiation, to map GeneXpert machines and to determine limitations to its use in The Gambia. Freshly collected paired plasma and DBS samples (n = 56) were analyzed by the GeneXpert test. Similarly, stored plasma and DBS samples (n = 306, n = 91) were analyzed using the GeneXpert HBV test, in-house qPCR and COBAS TaqMan Roche. The correlation between freshly collected plasma and DBS is r = 0.88 with a mean bias of -1.4. The GeneXpert HBV test had the highest quantifiable HBV DNA viremia of 81.4% (n = 249/306), and the lowest was detected by in-house qPCR at 37.9% (n = 116/306) for stored plasma samples. Bland-Altman plots show strong correlation between GeneXpert and COBAS TaqMan and between GeneXpert and in-house qPCR with a mean bias of +0.316 and -1.173 log10 IU/mL, respectively. However, paired stored plasma and DBS samples had a lower mean bias of 1.831 log10 IU/mL, which is almost significant (95% limits of agreement: 0.66-3.001). Patients (n = 3) were enrolled in the study within a TAT of 6 days. The GeneXpert HBV test displayed excellent diagnostic accuracy by detecting HBV viremia in less than 10 IU/mL.

Prevalence of hepatitis B virus infection and its associated factors among students in N'Djamena, Chad

INTRODUCTION

Infection by hepatitis B virus (HBV) is a major issue in public health. The prevalence of HBV in Chad is 12.4%, all age groups considered. Here, we aimed to determine the prevalence of HBV and its associated factors among university students in N'Djamena, the country's capital.

METHODS

A cross-sectional survey of students at either the University of N'djamena or Emi Koussi University was conducted from 3 to 23 July 2021. All participating students provided signed, informed consent and were included in the study consecutively. Blood samples were collected, and serum tested for hepatitis B surface antigen (HBsAg) using the Determine HBsAg rapid test kit, with confirmation of positive tests on an Abbott Architect i1000SR analyzer. Descriptive analysis and logistic regression were used to determine associations between the outcome variable and independent/covariate variables.

RESULTS

A total of 457 students with a median age of 24 years were included across different faculties. The prevalence of HBV infection was 14.87% (68/457). Most students (75%) were aged 25 years or less. Unprotected sex was reported by 64.9% of the students and multiple sexual partners by 53.6%. Furthermore, 45.7% of them reported having no knowledge of hepatitis B. Having an HBsAg-positive mother (AOR: 2.11), having a history of transcutaneous medical procedures (AOR: 2.97) and living with a family (AOR: 4.63) were significantly associated with HBV status. Age ≥26 years appeared as a protective factor (AOR = 0.41).

CONCLUSION

Our study detected a high, 14.87% prevalence of HBV infection among students in N'djamena, Chad, and shed light on its associated factors. HBV prevention strategies should include raising awareness among students, making full hepatitis vaccination mandatory before children begin school, promoting mass screening to identify and treat chronic HBV carriers and reduce transmission, and reducing the cost of vaccination.

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.

Impact of COVID-19 on hepatitis B screening in Sierra Leone: insights from a community pharmacy model of care

Objectives

To assess the impact of COVID-19-related interruptions and seasonal patterns on hepatitis B virus (HBV) screening in a hyperendemic setting in Sierra Leone.

Methods

We conducted a retrospective study of HBV testing in a community pharmacy in Freetown, Sierra Leone, from October 01, 2019, through September 30, 2022. We compared participant characteristics using Pearson's chi-square test. We evaluated trends in HBV screening and diagnosis using one-way analysis of variance with Tukey's or Dunnett's post-test.

Results

Of 920 individuals screened, 161 had detectable HBV surface antigen (seroprevalence 17.5% [95% CI 14.9-20.4]). There was a 100% decrease in HBV screening during January-June of 2020; however, screening increased by 27% and 23% in the first and second years after COVID-19, respectively. Mean quarterly tests showed a significant upward trend: 55 ± 6 tests during January-March (baseline), 74 ± 16 tests during April-June, 101 ± 3 tests during July-September, and 107 ± 17 tests during October-December (one-way analysis of variance test for trend, F = 7.7, P = 0.0254) but not the mean quarterly number of people diagnosed with HBV (F = 0.34, P = 0.7992).

Conclusion

Community-based HBV screening dramatically improved following temporary disruptions related to COVID-19. Seasonal variation in HBV screening, but not HBV diagnosis, may have implications for HBV elimination efforts in Sierra Leone and other West African countries.

Pathway to global elimination of hepatitis B: HBV cure is just the first step

Hepatitis B (HBV) is a major cause of global morbidity and mortality, and the leading cause of liver cancer worldwide. Significant advances have recently been made toward the development of a finite HBV treatment that achieves permanent loss of HBsAg and HBV DNA (so-called "HBV cure"), which could provide the means to eliminate HBV as a public health threat. However, the HBV cure is just one step toward achieving WHO HBV elimination targets by 2030, and much work must be done now to prepare for the successful implementation of the HBV cure. In this review, we describe the required steps to rapidly scale-up future HBV cure equitably. We present key actions required for successful HBV cure implementation, integrated within the World Health Organization (WHO) Global Health Sector Strategy (GHSS) 2022-2030 framework. Finally, we highlight what can be done now to progress toward the 2030 HBV elimination targets using available tools to ensure that we are preparing, but not waiting, for the cure.

Enhancing interventions for prevention of mother-to-child- transmission of hepatitis B virus

Prevention of mother-to-child transmission of hepatitis B virus (HBV) infection is a cornerstone of efforts to support progress towards elimination of viral hepatitis. Current guidelines recommend maternal screening, antiviral therapy during the third trimester of high-risk pregnancies, universal and timely HBV birth dose vaccination, and post-exposure prophylaxis with hepatitis B immunoglobulin for selected neonates. However, serological and molecular diagnostic testing, treatment and HBV vaccination are not consistently deployed, particularly in many high endemicity settings, and models predict that global targets for reduction in paediatric incidence will not be met by 2030. In this article, we briefly summarise the evidence for current practice and use this as a basis to discuss areas in which prevention of mother-to-child transmission can potentially be enhanced. By reducing health inequities, enhancing pragmatic use of resources, filling data gaps, developing advocacy and education, and seeking consistent investment from multilateral agencies, significant advances can be made to further reduce vertical transmission events, with wide health, societal and economic benefits.

Global burden of hepatitis B virus: current status, missed opportunities and a call for action

Chronic hepatitis B virus (HBV) infection affects about 296 million people worldwide and is the leading aetiology of cirrhosis and liver cancer globally. Major medical complications also include acute flares and extrahepatic manifestations. In addition, people living with HBV infection also experience stigma. HBV-related cirrhosis resulted in an estimated 331,000 deaths in 2019, and it is estimated that the number of deaths from HBV-related liver cancer in 2019 was 192,000, an increase from 156,000 in 2010. Meanwhile, HBV remains severely underdiagnosed and effective measures that can prevent infection and disease progression are underutilized. Birth dose coverage for HBV vaccines remains low, particularly in low-income countries or regions where HBV burden is high. Patients with HBV infection are inadequately evaluated and linked to care and are undertreated worldwide, even in high-income countries or regions. Despite the goal of the World Health Organization to eliminate viral hepatitis as a public health problem by 2030, the annual global deaths from HBV are projected to increase by 39% from 2015 to 2030 if the status quo remains. In this Review, we discuss the current status and future projections of the global burden of HBV infection. We also discuss gaps in the current care cascade and propose future directions.

Current Challenges and Future Perspectives of Diagnosis of Hepatitis B Virus

It is estimated that approximately 260 million people worldwide are infected with the hepatitis B virus (HBV), which is one of the leading causes of liver disease and liver cancer throughout the world. Compared with developed countries, low-income and middle-income countries have limited access to resources and advanced technologies that require highly specialized staff for HBV diagnosis. In spite of the heavy burden caused by hepatitis B virus, 90% of people are still undiagnosed. The World Health Organization (WHO) goal of eliminating hepatitis B by 2030 seems very difficult to achieve due to the existing diagnostic infrastructure in low-resource regions. The majority of diagnostic laboratories still use hepatitis B surface antigen (HBsAg)-based tests. WHO's elimination plan is at risk of derailment due to phases like the window period, immune control, and occult HBV infection (OBI) not being detected by standard tests. Here, in this article, we are focusing on various diagnostic platforms for the better diagnosis of HBV. The aim of the elimination of HBV can only be achieved by detecting all phases of HBV infection, which can be executed by a combined approach of using new marker assays along with advanced pretesting and testing methods.

Factors associated with hepatitis B and C among adults in Buea, Cameroon: A community-based cross-sectional study

INTRODUCTION

Viral hepatitis is a major cause of death in Africa. A paucity of community-based studies on the determinants of viral hepatitis in Africa impedes efforts to appropriately target prevention, screening, and treatment interventions. We assessed factors associated with hepatitis B virus (HBV) and hepatitis C virus (HCV) in a semi-urban health district in Cameroon.

METHODS

We conducted a community-based, cross-sectional study from 28 February to 15 May 2021 in the Buea Health District in Buea, Cameroon. We recruited a sample of consenting individuals aged over 15 years old. Participants were surveyed for factors associated with HBV/HCV and were screened for HBV surface antigen (HBsAg) and HCV antibody using rapid point-of-care tests. We performed univariable and multivariable logistic regression analyses to identify factors associated with HBsAg and HCV seropositivity.

RESULTS

We screened 1144 participants (66% female) with a median age of 30 years (IQR: 23-44). HBsAg prevalence was 5.7% (95%CI: 4.5-7.2%) and HCV seropositivity was 1.9% (95%CI: 1.3-2.9%). Three people (0.3%) were seropositive for both HBsAg and HCV antibody. Male sex (adjusted OR [aOR] = 2.31; 95%CI: 1.28-4.18) and a history of traditional operation or scarification (aOR = 2.87; 95%CI: 1.67-4.92) were associated with HBsAg. None of the assessed factors was significantly associated with HCV antibody.

CONCLUSION

Men and participants with a history of traditional operation and scarification had higher odds of HBsAg. We did not observe any associations with HCV seropositivity. Prevention and screening efforts among adults in this setting should prioritize men and those with a history of traditional operation and scarification.

Viral Diagnosis of Hepatitis B and Delta: What We Know and What Is Still Required? Specific Focus on Low- and Middle-Income Countries

To achieve the World Health Organization's (WHO) goals of eradicating viral hepatitis globally by 2030, the regional prevalence and epidemiology of hepatitis B virus (HBV) and hepatitis delta virus (HDV) coinfection must be known in order to implement preventiveon and treatment strategies. HBV/HDV coinfection is considered the most severe form of vira l hepatitis due to it's rapid progression towards cirrhosis, hepatocellular carcinoma, and liver-related death. The role of simplified diagnosticsis tools for screening and monitoring HBV/HDV-coinfected patients is crucial. Many sophisticated tools for diagnoses have been developed for detection of HBV alone as well as HBV/HDV coinfection. However, these advanced techniques are not widely available in low-income countries and there is no standardization for HDV detection assays, which are used for monitoring the response to antiviral therapy. More accessible and affordable alternative methods, such as rapid diagnostic tests (RDTs), are being developed and validated for equipment-free and specific detection of HBV and HDV. This review will provide some insight into both existing and diagnosis tools under development, their applicability in developing countries and how they could increase screening, patient monitoring and treatment eligibility.

HBV continuum of care using community- and hospital-based screening interventions in Senegal: Results from the PROLIFICA programme

BACKGROUND & AIMS

Strategies to implement HBV screening and treatment are critical to achieve HBV elimination but have been inadequately evaluated in sub-Saharan Africa (sSA).

METHODS

We assessed the feasibility of screen-and-treat interventions in 3 real-world settings (community, workplace, and hospital) in Senegal. Adult participants were screened using a rapid HBsAg point-of-care test. The proportion linked to care, the proportion who had complete clinical staging (alanine transaminase [ALT], viral load, and FibroScan®), and the proportion eligible for treatment were compared among the 3 intervention groups.

RESULTS

In 2013-2016, a total of 3,665 individuals were screened for HBsAg in the community (n = 2,153) and in workplaces (n = 1,512); 199/2,153 (9.2%) and 167/1,512 (11%) were HBsAg-positive in the community and workplaces, respectively. In the hospital setting (outpatient clinics), 638 HBsAg-positive participants were enrolled in the study. All infected participants were treatment naïve. Linkage to care was similar among community-based (69.9%), workplace-based (69.5%), and hospital-based interventions (72.6%, p = 0.617). Of HBV-infected participants successfully linked to care, full clinical staging was obtained in 47.5% (66/139), 59.5% (69/116), and 71.1% (329/463) from the community, workplaces, and hospitals, respectively (p <0.001). The proportion eligible for treatment (EASL criteria) differed among community- (9.1%), workplace- (30.4%), and hospital-based settings (17.6%, p = 0.007). Acceptability of antiviral therapy, adherence, and safety at 1 year were very good.

CONCLUSIONS

HBV screen-and-treat interventions are feasible in non-hospital and hospital settings in Senegal. However, the continuum of care is suboptimal owing to limited access to full clinical staging. Improvement in access to diagnostic services is urgently needed in sSA.

LAY SUMMARY

Hepatitis B infection is highly endemic in Senegal. Screening for infection can be done outside hospitals, in communities or workplaces. However, the hepatitis B continuum of care is suboptimal in Senegal and needs to be simplified to scale-up diagnosis and treatment coverage.

Prevalence and Clinical Significance of Occult Hepatitis B Infection in The Gambia, West Africa

BACKGROUND

Prevalence and clinical outcomes of occult hepatitis B infection (OBI) have been poorly studied in Africa.

METHODS

Using the PROLIFICA cohort, we compared the prevalence of OBI between hepatitis B surface antigen (HBsAg)-negative healthy adults screened from the general population (controls) and HBsAg-negative patients with advanced liver disease (cases), and estimated the population attributable fraction for the effect of OBI on advanced liver disease.

RESULTS

OBI prevalence was significantly higher among cases (15/82, 18.3%) than controls (31/330, 9.4%, P = .03). After adjusting for age, sex, and anti-hepatitis C virus (HCV) serology, OBI was significantly associated with advanced liver disease (odds ratio, 2.8; 95% confidence interval [CI], 1.3-6.0; P = .006). In HBsAg-negative people, the proportions of advanced liver disease cases attributable to OBI and HCV were estimated at 12.9% (95% CI, 7.5%-18.1%) and 16.9% (95% CI, 15.2%-18.6%), respectively.

CONCLUSIONS

OBI is endemic and an independent risk factor for advanced liver disease in The Gambia, West Africa. This implies that HBsAg-negative people with liver disease should be systematically screened for OBI. Moreover, the impact of infant hepatitis B immunization to prevent end-stage liver disease might be higher than previous estimates based solely on HBsAg positivity.

Clinical utility of the 'Determine HBsAg' Point-of-Care Test for Diagnosis of Hepatitis B Surface Antigen in Africa

INTRODUCTION

Chronic infection with hepatitis B virus (HBV) is a leading cause of morbidity and death, especially in sub-Saharan Africa (SSA), where approximately 60 million adults are infected. More than 90% of these patients are unaware of their HBV status.

AREAS COVERED

Scaling-up of HBV screening programs in SSA are essential to increase diagnosis, linkage to care, and access to treatment, and will ultimately reduce HBV disease burden to achieve WHO hepatitis elimination targets. Such scale up will rely on inexpensive rapid point-of-care (POC) tests, especially in remote areas where gold standard serological assays are not routinely available. This review discusses the diagnostic performance and clinical utility of the Determine™ (Abbott, USA) hepatitis B surface Antigen (HBsAg) POC test for improving HBV screening in SSA, in light with others available HBsAg rapid tests.

EXPERT OPINION

The Determine™ HBsAg POC test has demonstrated relatively good diagnostic accuracy at the low cost, in the African field and laboratory and should be used for large scale mass screening of HBV infection in Africa.

Hepatitis B in Senegal: A Successful Infant Vaccination Program but Urgent Need to Scale Up Screening and Treatment (ANRS 12356 AmBASS survey)

Senegal introduced the infant hepatitis B virus (HBV) vaccination in 2004 and recently committed to eliminating hepatitis B by 2030. Updated epidemiological data are needed to provide information on the progress being made and to develop new interventions. We estimated the prevalence of hepatitis B surface antigen (HBsAg) in children and adults living in rural Senegal and assessed hepatitis B treatment eligibility. A cross-sectional population-based serosurvey of HBsAg was conducted in 2018-2019 in a large sample (n = 3,118) of residents living in the Niakhar area (Fatick region, Senegal). Individuals positive for HBsAg subsequently underwent clinical and biological assessments. Data were weighted for age and sex and calibrated to be representative of the area's population. Among the 3,118 participants, 206 were HBsAg positive (prevalence, 6.9%; 95% confidence interval [CI], 5.6-8.1). Prevalence varied markedly according to age group in individuals aged 0-4, 5-14, 15-34, and ≥35 years as follows: 0.0% (95% CI, 0.00-0.01); 1.5% (95% CI, 0.0-2.3); 12.4% (95% CI, 9.1-15.6); and 8.8% (95% CI, 6.1-11.5), respectively. Of those subsequently assessed, 50.9% (95% CI, 41.8-60.0) had active HBV infection; 4 (2.9%; 95% CI, 0.9-9.4) were eligible for hepatitis B treatment. Conclusion: In this first population-based serosurvey targeting children and adults in rural Senegal, HBsAg prevalence was very low in the former, meeting the World Health Organization's (WHO) < 1% HBsAg 2020 target; however, it was high in young adults (15-34 years old) born before the HBV vaccine was introduced in 2004. To reach national and WHO hepatitis elimination goals, general population testing (particularly for adolescents and young adults), care, and treatment scale-up need to be implemented.

Evaluation of three different rapid card tests for the detection of hepatitis B surface antigen

Rapid diagnostic card tests are crucial steps on the road to hepatitis B elimination and should be incorporated into diagnostic algorithms. However, all commercial rapid diagnostic card tests are not equal and require evaluation before clinical use. Thus, we aimed to compare the performance characteristics of three different rapid diagnostic card tests with chemiluminescence-based assay (CLIA) for the detection of hepatitis B surface antigen.We concluded rapid diagnostic card tests can be used to identify patients with high signal/cut-off ratio on CLIA, but patients with signal/cut-off ratio <200 may be missed. Rapid diagnostic card tests may help pave the way for decentralised testing, but should be used only after evaluation in the community.

Global Disparities in Hepatitis B Elimination-A Focus on Africa

In 2016, WHO member states at the World Health Assembly adopted a Global Health Sector Strategy that included a policy of eliminating viral hepatitis. Clear targets were established to assist in achieving this by 2030. The strategy, while achievable, has exposed existing global disparities in healthcare systems and their ability to implement such policies. Compounding this, the regions with most disparity are also those where the hepatitis B prevalence and disease burden are the greatest. Foundational to hepatitis B elimination is the identification of both those with chronic infection and crucially pregnant women, and primary prevention through vaccination. Vaccination, including the birth dose and full three-dose coverage, is key, but complete mother-to-child transmission prevention includes reducing the maternal hepatitis B viral load in the third trimester where appropriate. Innovations and simplified tools exist in order to achieve elimination, but what is desperately required is the will to implement these strategies through the support of appropriate investment and funding. Without this, disparities will continue.

Prevention of mother-to-child transmission of hepatitis B virus in antenatal care and maternity services, Mozambique

Objective

To pilot an intervention on the prevention of mother-to-child transmission (PMTCT) of hepatitis B virus (HBV) in an antenatal care and maternity unit in Maputo, Mozambique, during 2017–2019.

Methods

We included HBV in the existing screening programme (for human immunodeficiency virus (HIV) and syphilis) for pregnant women at their first consultation, and followed mother–child dyads until 9 months after delivery. We referred women who tested positive for hepatitis B surface antigen (HBsAg) for further tests, including hepatitis B e antigen (HBeAg) and HBV viral load. According to the results, we proposed tenofovir for their own health or for PMTCT. We administered birth-dose HBV vaccine and assessed infant HBV status at 9 months.

Findings

Of 6775 screened women, 270 (4.0%) were HBsAg positive; in those for whom data were available, 24/265 (9.1%) were HBeAg positive and 14/267 (5.2%) had a viral load of > 200 000 IU/mL. Ninety-eight (36.3%) HBsAg-positive women were HIV coinfected, 97 of whom were receiving antiretroviral treatment with tenofovir. Among HIV-negative women, four had an indication for tenofovir treatment and four for tenofovir PMTCT. Of 217 exposed liveborn babies, 181 (83.4%) received birth-dose HBV vaccine, 160 (88.4%) of these < 24 hours after birth. At the 9-month follow-up, only one out of the 134 tested infants was HBV positive.

Conclusion

Our nurse-led intervention highlights the feasibility of integrating PMTCT of HBV into existing antenatal care departments, essential for the implementation of the triple elimination initiative. Universal birth-dose vaccination is key to achieving HBV elimination.

Prevention of hepatitis B mother-to-child transmission in Namibia: A cost-effectiveness analysis

Despite access to a safe and effective vaccine, mother-to-child transmission (MTCT) of hepatitis B virus (HBV) persists in Africa. This is of concern since perinatally-infected infants are at highest risk of developing hepatocellular carcinoma, a life-threatening consequence of chronic HBV infection. While tools to prevent HBV MTCT are available, the cost implications of these interventions need consideration prior to implementation. A Markov model was developed to determine the costs and health outcomes of (1) universal HBV birth dose (BD) vaccination, (2) universal BD vaccination and targeted hepatitis B immunoglobulin (HBIG), (3) maternal antiviral prophylaxis using sequential HBV viral load testing added to HBV BD vaccination and HBIG, and (4) maternal antiviral prophylaxis using sequential HBeAg testing combined with HBV BD vaccination and HBIG. Health outcomes were assessed as the number of paediatric infections averted and disability-adjusted life years (DALYs) averted. Primary cost data included consumables, human resources, and hospital facilities. HBV epidemiology, transitions probabilities, disability weights, and the risks of HBV MTCT were extracted from the literature. Incremental cost-effectiveness ratios (ICERs) were calculated to compare successive more expensive interventions to the previous less expensive one. One-way sensitivity analyses were conducted to test the robustness of the model's outputs. At the Namibian cost/DALY averted threshold of US$3 142, the (1) BD vaccination + targeted HBIG, and (2) maternal antiviral prophylaxis with sequential HBeAg testing interventions were cost-effective. These interventions had ICERs equal to US$1909.03/DALY and US$2598.90/DALY averted, respectively. In terms of effectiveness, the maternal antiviral prophylaxis with sequential HBeAg testing intervention was the intervention of choice. The analysis showed that elimination of HBV MTCT is achievable using maternal antiviral prophylaxis with active and passive immunization. There is an urgent need for low cost diagnostic tests to identify those women who will most benefit from drug therapy to attain this laudable goal.

A global investment framework for the elimination of hepatitis B

BACKGROUND & AIMS

More than 292 million people are living with hepatitis B worldwide and are at risk of death from cirrhosis and liver cancer. The World Health Organization (WHO) has set global targets for the elimination of viral hepatitis as a public health threat by 2030. However, current levels of global investment in viral hepatitis elimination programmes are insufficient to achieve these goals.

METHODS

To catalyse political commitment and to encourage domestic and international financing, we used published modelling data and key stakeholder interviews to develop an investment framework to demonstrate the return on investment for viral hepatitis elimination.

RESULTS

The framework utilises a public health approach to identify evidence-based national activities that reduce viral hepatitis-related morbidity and mortality, as well as international activities and critical enablers that allow countries to achieve maximum impact on health outcomes from their investments - in the context of the WHO's 2030 viral elimination targets.

CONCLUSION

Focusing on hepatitis B, this health policy paper employs the investment framework to estimate the substantial economic benefits of investing in the elimination of hepatitis B and demonstrates how such investments could be cost saving by 2030.

LAY SUMMARY

Hepatitis B infection is a major cause of death from liver disease and liver cancer globally. To reduce deaths from hepatitis B infection, we need more people to be tested and treated for hepatitis B. In this paper, we outline a framework of activities to reduce hepatitis B-related deaths and discuss ways in which governments could pay for them.

Prevalence of hepatitis B among childbearing women and infant born to HBV-positive mothers in Togo

Background

Hepatitis B virus (HBV) infection is a public health problem in Togo and transmission to the child occurs mainly during childbirth. The objective of this study was to estimate the prevalence of HBV among childbearing women and infants born to HBV positive mothers in Togo.

Methods

A national cross-sectional study was carried out in six cities in Togo in the six health regions in Togo. Mother-child pairs were recruited from immunization centers or pediatric wards in Lomé, Tsévié, Atakpamé, Sokodé, Kara and Dapaong in 2017. Women aged 18 and over with one child of at least 6 months old were included. A standardized questionnaire was used for data collection and HBV screening was performed using Determine® rapid tests. The prevalence of HBV, defined by a positive HBV surface antigen (HBsAg), was estimated in mothers and then in infants of mothers who were positive for HBsAg. Logistic regression model was performed to identify risk factors for HBsAg positivity in mothers.

Results

A total of 2105 mothers-pairs child were recruited. The median age of mothers and infants was 29 years, interquartile range (IQR) [25–33] and 2.1 years, IQR [1–3] respectively. About 35% of women were screened for HBV during antenatal care and 85% of infants received three doses of HBV immunization. Among mothers, the prevalence of HBV was 10.6, 95% confidence interval (95% CI) [9.4–12.0%], and 177 had detectable HBV viral load (> 10 IU/mL). Among mothers with positive HBsAg, three infants also had positive HBsAg, a prevalence of 1.3, 95% CI [0.2–3.8%]. In multivariable analysis, HIV-infection (aOR = 2.19; p = 0.018), having at least three pregnancies (aOR = 1.46; p = 0.025) and living in Tsévié (aOR = 0.31; p < 0.001) compared to those living in Lomé, were associated to HBV infection in mothers.

Conclusion

In this study, one out of 10 childbearing women were infected with HBV, but less than 2% of infant born to HBV positive mothers under 5 years’ old who received immunization under the Expanded Program on Immunization were infected. Improving antenatal screening and providing targeted interventions in babies could help eliminate HBV in Togo.

[Rapid diagnosis of sexually transmitted infections : Joint statement of DSTIG, RKI, and PEI, as well as the reference centers for HIV, HBV, and HCV and consulting laboratories for Chlamydia, gonococci, and Treponema pallidum]

In February 2019, the fourth expert meeting on rapid diagnostic tests (RDTs) for sexually transmitted infections (STI) was held at the Robert Koch Institute (RKI) in Berlin. Novel technical developments and new aspects of RDT applications were discussed by representatives from the German STI Society (DSTIG); RKI; the Paul Ehrlich Institute; national reference centers for HIV, HBV, and HCV; and reference laboratories for Chlamydia, gonococci, and Treponema pallidum.As a result of this meeting, we present a revision of the joint statement on STI diagnostics with RDTs from 2017. The Regulation (EU) 2017/746 of the European Parliament and of the Council on in vitro diagnostic medical devices became effective in May 2017 and includes more stringent regulatory requirements for RDTs, mainly concerning conformity of manufacturing processes and performance characteristics of class D in vitro diagnostics (detection of HIV, HBV, HCV, and T. pallidum). Some RDTs for HIV, HCV, and T. pallidum have been evaluated in clinical studies and/or were WHO prequalified and may be used in low-threshold services. Among them are some HIV RDTs available and approved for self-testing. In addition, some HBV RDTs based on detection of HBs antigen (HBsAg) received WHO prequalification. However, false negative results may occur in samples with low HBsAg levels, as for instance in HIV-coinfected patients receiving antiretroviral therapy. For Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), antigen-based RDTs still do not allow reliable detection of infection. Only PCR-based CT/NG RDTs possess sufficient diagnostic accuracy to be used as point-of-care tests. Rapid PCR tests for NG, however, do not provide any information about antimicrobial resistance.

Point-of-Care Tests for Hepatitis B: An Overview

Despite the heavy disease burden posed by hepatitis B, around 90% of people living with hepatitis B are not diagnosed globally. Many of the affected populations still have limited or no access to essential blood tests for hepatitis B. Compared to conventional blood tests which heavily rely on centralised laboratory facilities, point-of-care testing for hepatitis B has the potential to broaden testing access in low-resource settings and to engage hard-to-reach populations. Few hepatitis B point-of-care tests have been ratified for clinical use by international and regional regulatory bodies, and countries have been slow to adopt point-of-care testing into hepatitis B programs. This review presents currently available point-of-care tests for hepatitis B and their roles in the care cascade, reviewing evidence for testing performance, utility, acceptability, costs and cost-effectiveness when integrated into hepatitis B diagnosis and monitoring programs. We further discuss challenges and future directions in aspects of technology, implementation, and regulation when adopting point-of-care testing in hepatitis B programs.

Screening and linkage to care for medical students with hepatitis B virus infection in Sierra Leone

Purpose

Hepatitis B virus (HBV) infection is considered a major public health concern for Sierra Leone. Although medical students are at increased occupational risk for HBV infection, little is known about the burden of HBV infection amongst medical students in Sierra Leone.

Methods

As part of a screening and vaccination campaign, a cross-sectional study on prevalence of HBV among medical students in Freetown was conducted in December 2019. Antigen point of care test was used for HBV screening and data on students' risk history and demographics were collected. Additionally, for students diagnosed positive with HBV, linkage to care and initial assessment data after diagnosis was collected from the HBV clinic they were linked to.

Results

One hundred and fifty-seven medical students (77.3%) from year three to six were screened for HBV infection. Almost all students (98.1%) had never been vaccinated against HBV and more than half (56.7%) reported a history of needle stick injuries. The prevalence of HBV infection (Hepatitis B surface antigen (HBsAg) positivity) was 10.2% (n = 16). Among HBsAg positive students, 75% (n = 12) were successfully enrolled at chronic HBV clinic within three months of diagnosis. Only one student had evidence of liver cirrhosis and was started on treatment with Tenofovir diproxil fumarate.

Conclusion

The prevalence of HBV infection is high among medical students in Sierra Leone. Despite the high prevalence, most of the students linked to care had no evidence of severe liver disease.

Evaluation of Four Rapid Tests for Detection of Hepatitis B Surface Antigen in Ivory Coast

Background

Hepatitis B virus (HBV) infection is a leading cause of liver disease worldwide. Hepatitis B surface antigen (HBsAg) rapid diagnostic tests (RDTs) could be an ideal tool for a large-scale HBV screening in settings with high endemicity but limited infrastructure. The aim of this study was to evaluate the diagnosis performance of such RDTs for screening HBV infection in Ivory Coast.

Methods

From September 2018 to January 2019, a cross-sectional phase I evaluation study of RDTs was conducted in three laboratories of Abidjan (CeDReS, CNTS and IPCI), on a panel of 405 whole blood samples and 699 plasmas. Four HBsAg RDTs (Determine™ HBsAg, SD Bioline HBsAg WB®, Standard Q HBsAg® and Vikia HBsAg®) were evaluated. The diagnostic performance (sensitivity and specificity) was calculated in comparison to the reference sequential algorithms of two EIA tests (Dia.Pro HBsAg® one version ULTRA and Monolisa™ HBsAg ULTRA).

Results

The Determine™ HBsAg and Vikia HBsAg® tests performed well, with 100% of sensitivity, specificity both on plasma and on whole blood. For SD Bioline HBsAg WB® and Standard Q HBsAg®, the specificities were 99.8% and the sensitivities 99.3% and 97.1% respectively. Finally, there were a total of 19 false negative results: 3 with SD Bioline HBsAg WB® and 16 with Standard Q HBsAg®.

Conclusion

Determine HBsAg® from Alere and Vikia HBsAg® from Biomérieux are the most suitable RDTs for screening for HBV in Ivory Coast. A phase II evaluation must be initiated.

Asian consensus recommendations on optimizing the diagnosis and initiation of treatment of hepatitis B virus infection in resource-limited settings

Asia has an intermediate-to-high prevalence of and high morbidity and mortality from hepatitis B virus (HBV) infection. Optimization of diagnosis and initiation of treatment is one of the crucial strategies for lowering disease burden in this region. Therefore, a panel of 24 experts from 10 Asian countries convened, and reviewed the literature, to develop consensus guidance on diagnosis and initiation of treatment of HBV infection in resource-limited Asian settings. The panel proposed 11 recommendations related to diagnosis, pre-treatment assessment, and indications of therapy of HBV infection, and management of HBV-infected patients with co-infections. In resource-limited Asian settings, testing for hepatitis B surface antigen may be considered as the primary test for diagnosis of HBV infection. Pre-treatment assessments should include tests for complete blood count, liver and renal function, hepatitis B e-antigen (HBeAg), anti-HBe, HBV DNA, co-infection markers and assessment of severity of liver disease. Noninvasive tests such as AST-to-platelet ratio index, fibrosis score 4 or transient elastography may be used as alternatives to liver biopsy for assessing disease severity. Considering the high burden of HBV infection in Asia, the panel adopted an aggressive approach, and recommended initiation of antiviral therapy in all HBV-infected, compensated or decompensated cirrhotic individuals with detectable HBV DNA levels, regardless of HBeAg status or alanine transaminase levels. The panel also developed a simple algorithm for guiding the initiation of treatment in noncirrhotic, HBV-infected individuals. The recommendations proposed herein, may help guide clinicians, to optimize the diagnosis and improvise the treatment rates for HBV infection in Asia.

Development of a Mobile Laboratory for Sudden Onset Disasters

OBJECTIVES

Clinical diagnostics in sudden onset disasters have historically been limited. We set out to design, implement, and evaluate a mobile diagnostic laboratory accompanying a type 2 emergency medical team (EMT) field hospital.

METHODS

Available diagnostic platforms were reviewed and selected against in field need. Platforms included HemoCue301/WBC DIFF, i-STAT, BIOFIRE FILMARRAY multiplex rt-PCR, Olympus BX53 microscopy, ABO/Rh grouping, and specific rapid diagnostic tests. This equipment was trialed in Katherine, Australia, and Dili, Timor-Leste.

RESULTS

During the initial deployment, an evaluation of FilmArray tests was successful using blood culture identification, gastrointestinal, and respiratory panels. HemoCue301 (n = 20) hemoglobin values were compared on Sysmex XN 550 (r = 0.94). HemoCue WBC DIFF had some variation, dependent on the cell, when compared with Sysmex XN 550 (r = 0.88-0.16). i-STAT showed nonsignificant differences against Vitros 250. Further evaluation of FilmArray in Dili, Timor-Leste, diagnosed 117 pathogens on 168 FilmArray pouches, including 25 separate organisms on blood culture and 4 separate cerebrospinal fluid pathogens.

CONCLUSION

This mobile laboratory represents a major advance in sudden onset disaster. Setup of the service was quick (< 24 hr) and transport to site rapid. Future deployment in fragmented health systems after sudden onset disasters with EMT2 will now allow broader diagnostic capability.

Point of care and oral fluid hepatitis B testing in remote Indigenous communities of northern Australia

Many Indigenous Australians in northern Australia living with chronic hepatitis B are unaware of their diagnosis due to low screening rates. A venous blood point of care test (POCT) or oral fluid laboratory test could improve testing uptake in this region. The purpose of this study was to assess the field performance of venous blood POCT and laboratory performance of an oral fluid hepatitis B surface antigen (HBsAg) test in Indigenous individuals living in remote northern Australian communities. The study was conducted with four very remote communities in the tropical north of Australia's Northern Territory. Community research workers collected venous blood and oral fluid samples. We performed the venous blood POCT for HBsAg in the field. We assessed the venous blood and oral fluid specimens for the presence of HBsAg using standard laboratory assays. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the POCT and oral fluid test, using serum laboratory detection of HBsAg as the gold standard. From 215 enrolled participants, 155 POCT and 197 oral fluid tests had corresponding serum HBsAg results. The POCT had a sensitivity of 91.7% and specificity of 100%. Based on a population prevalence of 6%, the PPV was 100% and NPV was 99.5%. The oral fluid test had a sensitivity of 56.8%, specificity of 98.1%, PPV of 97.3% and NPV of 65.9%. The venous blood POCT has excellent test characteristics and could be used to identify individuals with chronic HBV infection in high prevalence communities with limited access to health care. Oral fluid performance was suboptimal.

Mother-to-child transmission of hepatitis B: What more needs to be done to eliminate it around the world?

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a key component of the hepatitis B burden worldwide. Despite its efficacy to prevent HBV transmission, infant vaccination is not enough to control HBV MTCT. Additional efforts are urgently needed to evaluate and scale-up preventive strategies especially in endemic countries, which are most affected. This review highlights the efficacy and barriers of the currently validated measures for the prevention of HBV MTCT and proposes alternatives adapted to resource-limited settings to eventually achieve HBV elimination worldwide.

Hepatitis B Virus: Advances in Prevention, Diagnosis, and Therapy

Currently, despite the use of a preventive vaccine for several decades as well as the use of effective and well-tolerated viral suppressive medications since 1998, approximately 250 million people remain infected with the virus that causes hepatitis B worldwide. Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the leading causes of liver cancer and overall mortality globally, surpassing malaria and tuberculosis. Linkage to care is estimated to be very poor both in developing countries and in high-income countries, such as the United States, countries in Western Europe, and Japan. In the United States, by CDC estimates, only one-third of HBV-infected patients or less are aware of their infection. Some reasons for these low rates of surveillance, diagnosis, and treatment include the asymptomatic nature of chronic hepatitis B until the very late stages, a lack of curative therapy with a finite treatment duration, a complex natural history, and a lack of knowledge about the disease by both care providers and patients. In the last 5 years, more attention has been focused on the important topics of HBV screening, diagnosis of HBV infection, and appropriate linkage to care. There have also been rapid clinical developments toward a functional cure of HBV infection, with novel compounds currently being in various phases of progress. Despite this knowledge, many of the professional organizations provide guidelines focused only on specific questions related to the treatment of HBV infection. This focus leaves a gap for care providers on the other HBV-related issues, which include HBV's epidemiological profile, its natural history, how it interacts with other viral hepatitis diseases, treatments, and the areas that still need to be addressed in order to achieve HBV elimination by 2030. Thus, to fill these gaps and provide a more comprehensive and relevant document to regions worldwide, we have taken a global approach by using the findings of global experts on HBV as well as citing major guidelines and their various approaches to addressing HBV and its disease burden.

Modelling cost-effectiveness of tenofovir for prevention of mother to child transmission of hepatitis B virus (HBV) infection in South Africa

BACKGROUND

International sustainable development goals for the elimination of viral hepatitis as a public health problem by 2030 highlight the need to optimize strategies for prevention, diagnosis and treatment of hepatitis B virus (HBV) infection. An important priority for Africa is to have affordable, accessible and sustainable prevention of mother to child transmission (PMTCT) programmes, delivering screening and treatment for antenatal women and implementing timely administration of HBV vaccine for their babies.

METHODS

We developed a decision-analytic model simulating 10,000 singleton pregnancies to assess the cost-effectiveness of three possible strategies for deployment of tenofovir in pregnancy, in combination with routine infant vaccination: S1: no screening nor antiviral therapy; S2: screening and antiviral prophylaxis for all women who test HBsAg-positive; S3: screening for HBsAg, followed by HBeAg testing and antiviral prophylaxis for women who are HBsAg-positive and HBeAg-positive. Our outcome was cost per infant HBV infection avoided and the analysis followed a healthcare perspective.

RESULTS

Based on 10,000 pregnancies, S1 predicts 45 infants would be HBV-infected at six months of age, compared to 21 and 28 infants in S2 and S3, respectively. Relative to S1, S2 had an incremental cost of $3940 per infection avoided. S3 led to more infections and higher costs.

CONCLUSION

Given the long-term health burden for individuals and economic burden for society associated with chronic HBV infection, screening pregnant women and providing tenofovir for all who test HBsAg+ may be a cost-effective strategy for South Africa and other low/middle income settings.

High prevalence and poor linkage to care of transfusion-transmitted infections among blood donors in Dar-es-Salaam, Tanzania

Blood transfusion is one of the most commonly relied upon therapies in sub-Saharan Africa. Existing safeguards recommended include systematic screening for transfusion-transmitted infections and restricted voluntary nonremunerated blood donor selection. We report the transfusion-transmitted infection screening and notification practice at a large urban blood transfusion centre in Dar-es-Salaam, Tanzania. Between October 2016 and March 2017 anonymized records of all donors registered at the blood transfusion unit were accessed to retrospectively note demographic information, donor status, first-time status, transfusion-transmitted infection result and notification. 6402 consecutive donors were screened for transfusion-transmitted infections; the majority were family/replacement blood donors (88.0%) and male (83.8%). Overall transfusion-transmitted infections prevalence was 8.4% (95% CI 7.8-9.1), with hepatitis B being the most prevalent infection (4.1% (95% CI 3.6-4.6)). Transfusion-transmitted infections were more common in family/replacement blood donors (9.0% (95% CI 8.3-9.8)) as compared to voluntary nonremunerated blood donor (4.1% (95% CI 2.8-5.7)). A minority of infected-donors were notified of a positive result (8.5% (95% CI 6.3-11.2)). Although transfusion-transmitted infections are more prevalent among family/replacement blood donors, overall risk of transfusion-transmitted infections across all groups is considerable. In addition, existing efforts to notify donors of a positive transfusion-transmitted infection are poor. Future policies must focus on improving linkage to care for newly diagnosed patients with transfusion-transmitted infections.

[Prevention of liver fibrosis and liver cancer linked to hepatitis B virus in Africa: the Prolifica study]

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To overcome this and born from an international research collaboration within an EU project, the Prolifica study aimed at evaluating a screen-and-treat program to prevent HBV complications, and more particularly HCC. Based on communities, facilities and hospitals HBsAg+ detection, the study lasted from 2011 to 2016. From the "cost effectiveness" feasibility of such a program to the development of simple scores for antiviral treatment, Prolifica uncovered data of crucial importance in a region with low HBV infection awareness, transmissions modes and prevention means which could have impacts on public health policies.

Hepatitis B virus sero-prevalence amongst pregnant women in the Gambia

BACKGROUND

Infection with Hepatitis B virus (HBV) is a serious public health problem worldwide, with over 360 million carriers. Sixty million of these are resident in Sub-saharan Africa. Hepatitis B infection is the cause of Hepatocellular carcinoma (HCC), which is the second commonest cause of death from cancers among women in The Gambia. Vertical transmission is the commonest route of spread of Hepatitis B Virus in many endemic areas. The main aim of the study was to determine the sero-prevalence of Hepatitis B surface antigen (HBsAg) among pregnant women attending antenatal clinic at the Edward Francis Small Teaching Hospital, Banjul, The Gambia.

METHODS

Four hundred and twenty six pregnant women were recruited from our antenatal clinics and tested for HBsAg. Serum Hepatitis B surface antigen (HBsAg) was tested using commercial rapid diagnostic Elisa kits at the point of care.

RESULTS

A prevalence rate of 9.20% among all pregnant women studied was found. Women who were likely to have been vaccinated had a prevalence rate of 2.30% whiles those unlikely to have been vaccinated had a prevalence of 13.71%. There was a statistically significant difference between those likely to have been vaccinated and those unlikely to have been vaccinated.

CONCLUSION

The prevalence of hepatitis B infection is very high among pregnant women at EFSTH as in the high endemic zone that is more than 8%. However the prevalence rate is lower than the national average of 15%. The prevalence is of moderate endemicity among the women who likely received vaccination during childhood. More interventions during pregnancy need to be undertaken if more successes are to be registered.

A new combined predicting model using a non-invasive score for the assessment of liver fibrosis in patients presenting with chronic hepatitis B virus infection

OBJECTIVES

Several non-invasive markers have recently been proposed to predict liver fibrosis without percutaneous liver biopsy (PLB). We aimed to evaluate the performance of non-invasive scores and to highlight the value of a new combined score in the prediction of liver fibrosis in chronic hepatitis B (CHB) patients.

PATIENTS AND METHODS

We performed a retrospective study of patients presenting with CHB who underwent PLB between 2008 and 2016. We calculated ASAT/Platelet Ratio Index (APRI), Fibrosis-4 Score (FIB4), GGT-to-platelet ratio (GPR), and ASAT/ALAT Ratio (AAR). Then, we combined APRI and FIB-4 scores into a new combined score. We assessed their performance in predicting liver fibrosis according to the Metavir score.

RESULTS

A total of 179 patients presenting with CHB were included. Multivariate analysis showed that the APRI score was the only independent factor of significant fibrosis (OR=3.78; P=0.02), whereas the FIB-4 score was the only independent factor for severe fibrosis (OR=2.85; P<0.001) and cirrhosis (OR=2.5; P=0.001). At a threshold of severe fibrosis, APRI had the best specificity (75%) and FIB-4 had the greatest sensitivity (74%). Using the combined score, we improved the diagnostic performance of APRI and FIB-4 scores at the three thresholds of liver fibrosis. With this combined score, maximum 25.1% of patients presenting with CHB would undergo PLB.

CONCLUSION

APRI, FIB-4, and GPR scores were well performing to predict liver fibrosis during CHB. The new combined score using APRI and FIB-4 was more accurate at the three-fibrosis thresholds.

New and Old Biomarkers for Diagnosis and Management of Chronic Hepatitis B Virus Infection

Tests to detect the presence and activity of hepatitis B virus (HBV) are the cornerstones of diagnosis and management. Assays that detect or measure serum levels of HB surface antigen, HB surface antibody, and HB core antibody are used to identify patients with exposure to HBV, whereas other tests provide information on the level of virus replication, presence of specific variants, and presence of virus reservoirs. Newer diagnostic tests, used only in research settings so far, aim to quantify levels of intrahepatic HBV replication. Other tests have been developed to detect HBV infection in resource-limited settings. We review point-of-care tests (essential in global screening efforts), standard diagnostic tests used in routine clinical management, and newer tests that might be used in clinical trials of agents designed to cure HBV infection.

Usefulness of a serial algorithm of HBsAg and HBeAg rapid diagnosis tests to detect pregnant women at risk of HBV mother-to-child transmission in Cambodia, the ANRS 12328 pilot study

BACKGROUND

In Cambodia, access to hepatitis B surface antigen (HBsAg) screening is low for pregnant women and Hepatitis B Virus (HBV) DNA quantification is poorly accessible.

OBJECTIVES

To evaluate the performance of a serial algorithm using two HBV rapid diagnostic tests (RDTs), in which samples positive for HBsAg were further tested for HBeAg as a surrogate marker for HBV DNA quantification.

STUDY DESIGN

In 2015, we prospectively collected plasma samples from 250 pregnant women consulting for antenatal care in one hospital in Phnom Penh including 128 with a known positive HBsAg status. All specimens were tested with the SD BIOLINE HBsAg RDT and HBsAg ELISA assay. In ELISA-positive samples, HBeAg status was determined using the SD BIOLINE HBeAg RDT and HBV DNA quantification was assessed.

RESULTS

Sensitivity and specificity of HBsAg RDT were 99.2% (97.7-99.9) and 100% (97.0-100), respectively. Among the 128 ELISA-positive samples, 29 (23%) tested HBeAg positive and 34 (26.5%) had HBV DNA > 5.3 Log₁₀ IU/mL. Sensitivity and specificity of HBeAg RDT in identifying viremic samples were 76.5% (62.2.0-90.7) and 96.8% (93.3-100) for HBV DNA > 5.3 Log₁₀ IU/mL and 89.3% (77.8-100) and 96.0% (92.2-99.8) for HBV DNA > 7.3 Log₁₀IU/mL. Among the 99 negative HBeAg RDT women, 8 had HBV DNA > 5.3 Log10 IU/mL and 7 of them harbored BCP/PC HBV mutants.

CONCLUSIONS

A combination of HBsAg and HBeAg RDTs could be a low-cost strategy to identify HBV-infected pregnant women at risk of perinatal transmission in a country were HBV DNA quantification is not routinely available.

Development of a Rapid Automated Fluorescent Lateral Flow Immunoassay to Detect Hepatitis B Surface Antigen (HBsAg), Antibody to HBsAg, and Antibody to Hepatitis C

Background

Accurate, rapid, and cost-effective screening tests for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be useful in laboratories that cannot afford automated chemiluminescent immunoassays (CLIAs). We evaluated the diagnostic performance of a novel rapid automated fluorescent lateral flow immunoassay (LFIA).

Methods

A fluorescent LFIA using a small bench-top fluorescence reader, Automated Fluorescent Immunoassay System (AFIAS; Boditech Med Inc., Chuncheon, Korea), was developed for qualitative detection of hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to HCV (anti-HCV) within 20 minutes. We compared the diagnostic performance of AFIAS with that of automated CLIAs—Elecsys (Roche Diagnostics GmbH, Penzberg, Germany) and ARCHITECT (Abbott Laboratories, Abbott Park, IL, USA)—using 20 seroconversion panels and 3,500 clinical serum samples.

Results

Evaluation with the seroconversion panels demonstrated that AFIAS had adequate sensitivity for HBsAg and anti-HCV detection. From the clinical samples, AFIAS sensitivity and specificity were 99.8% and 99.3% for the HBsAg test, 100.0% and 100.0% for the anti-HBs test, and 98.8% and 99.1% for the anti-HCV test, respectively. Its agreement rates with the Elecsys HBsAg, anti-HBs, and anti-HCV detection assays were 99.4%, 100.0%, and 99.0%, respectively. AFIAS detected all samples with HBsAg genotypes A-F and H and anti-HCV genotypes 1, 1a, 1b, 2a, 2b, 4, and 6. Cross-reactivity with other infections was not observed.

Conclusions

The AFIAS HBsAg, anti-HBs, and anti-HCV tests demonstrated diagnostic performance equivalent to current automated CLIAs. AFIAS could be used for a large-scale HBV or HCV screening in low-resource laboratories or low-to middle-income areas.

Development of a simple score based on HBeAg and ALT for selecting patients for HBV treatment in Africa

BACKGROUND & AIMS

To eliminate hepatitis B virus (HBV) infection, it is essential to scale up antiviral treatment through decentralized services. However, access to the conventional tools to assess treatment eligibility (liver biopsy/Fibroscan®/HBV DNA) is limited and not affordable in resource-limited countries. We developed and validated a simple score to easily identify patients in need of HBV treatment in Africa.

METHODS

As a reference, we used treatment eligibility determined by the European Association for the Study of the Liver based on alanine aminotransferase (ALT), liver histology and/or Fibroscan and HBV DNA. We derived a score indicating treatment eligibility by a stepwise logistic regression using a cohort of chronic HBV infection in The Gambia (n = 804). We subsequently validated the score in an external cohort of HBV-infected Africans from Senegal, Burkina Faso, and Europe (n = 327).

RESULTS

Out of several parameters, two remained in the final model, namely HBV e antigen (HBeAg) and ALT level, constituting a simple score (treatment eligibility in Africa for the hepatitis B virus: TREAT-B). The score demonstrated a high area under the receiver operating characteristic curve (0.85, 95% CI 0.79-0.91) in the validation set. The score of 2 and above (HBeAg-positive and ALT ≥20 U/L or HBeAg-negative and ALT ≥40 U/L) had a sensitivity and specificity for treatment eligibility of 85% and 77%, respectively. The sensitivity and specificity of the World Health Organization criteria based on the aspartate aminotransferase-to-platelet ratio index (APRI) and ALT were 90% and 40%, respectively.

CONCLUSIONS

A simple score based on HBeAg and ALT had a high diagnostic accuracy for the selection of patients for HBV treatment. This score could be useful in African settings.

LAY SUMMARY

Limited access to the diagnostic tools used to assess treatment eligibility (liver biopsy/Fibroscan/hepatitis B virus DNA) has been an obstacle to the scale up of hepatitis B treatment programs in low- and middle-income countries. Using the data from African patients with chronic HBV infection, we developed and validated a new simple diagnostic score for treatment eligibility, which only consists of hepatitis B virus e antigen and alanine aminotransferase level. The diagnostic accuracy of the score for selecting patients for HBV treatment was high and could be useful in African settings.

New virological tools for screening, diagnosis and monitoring of hepatitis B and C in resource-limited settings

Worldwide, the increasingly dominant model of laboratory testing is the centralised laboratory, in which automation of analytical processes increases, enabling the analysis of large numbers of samples at a relatively low cost. However, this trend does not fulfil the requirements for care of patients with chronic hepatitis B and C in resource-limited settings. Alternative models using point-of-care (POC) tests and dried blood spots (DBSs) are increasingly being considered for viral hepatitis screening, diagnosis and monitoring. POC tests are small devices providing qualitative and/or quantitative determination of viral antibodies and/or antigens. They can use original specimen matrices, such as oral fluid or blood collected from a fingerstick. POC tests are particularly useful for large-scale screening, and to improve access to care in regions where laboratory access is limited. New POC devices that detect and quantify viral nucleic acids are at the developmental stage. DBSs offer the main advantage of enabling storage of desiccated blood that can be easily transported to reference centres, where state-of-the-art molecular and serological diagnostic tests are available. However, standardisation and better automation of DBS handling are needed. Herein, we review alternatives to classical hepatitis B and C virological tests, examining POC tests and DBSs, as well as alternatives to nucleic acid testing. Innovations in testing approaches resulting from the availability of these new assays are also discussed.

Hepatitis B in sub-Saharan Africa: strategies to achieve the 2030 elimination targets

The WHO global health sector strategy on viral hepatitis, created in May, 2016, aims to achieve a 90% reduction in new cases of chronic hepatitis B and C and a 65% reduction in mortality due to hepatitis B and C by 2030. Hepatitis B virus (HBV) is endemic in sub-Saharan Africa, and despite the introduction of universal hepatitis B vaccination and effective antiviral therapy, the estimated overall seroprevalence of hepatitis B surface antigen remains high at 6·1% (95% uncertainty interval 4·6-8·5). In this Series paper, we have reviewed the literature to examine the epidemiology, burden of liver disease, and elimination strategies of hepatitis B in sub-Saharan Africa. This paper reflects a supranational perspective of sub-Saharan Africa, and recommends several priority elimination strategies that address the need both to prevent new infections and to diagnose and treat chronic infections. The key to achieving these elimination goals in sub-Saharan Africa is the effective prevention of new infections via universal implementation of the HBV birth-dose vaccine, full vaccine coverage, access to affordable diagnostics to identify HBV-infected individuals, and to enable linkage to care and antiviral therapy.

Development of a Membrane-Based Method for Isolation of Genomic DNA from Human Blood

High quality and sufficient quantity of genomic DNA (gDNA) are the primary requisites of several molecular biologic applications, including clinical studies related to genetics, genomics, gene polymorphism, and DNA fingerprinting. Whole blood is the primary source of gDNA in most of the clinical investigations. Currently, commercial kits are primarily used to achieve these goals. However, the use of kits is limited by the cost and involvement of several centrifugal steps. Other methods reported are either laborious or do not produce high quality or quantity of gDNA or both. Here, we present the data on the development of a centrifugation-free, cost-effective, and user-friendly method for the isolation of human gDNA from the buffy coat of human blood that involves limited numbers of steps with about 15 min of hands-on time per sample.

A systematic review of hepatitis B screening economic evaluations in low- and middle-income countries

Background

Chronic hepatitis B infection is a significant cause of morbidity and mortality worldwide; low- and middle-income countries (LMICs) are disproportionately affected. Economic evaluations are a useful decision tool to assess costs versus benefits of hepatitis B virus (HBV) screening. No published study reviewing economic evaluations of HBV screening in LMICs has been undertaken to date.

Methods

The following databases were searched from inception to 21 April 2017: MEDLINE, PubMed, EMBASE, CINAHL Plus, the Cochrane Library, Global Health and the Cost-effectiveness Analysis Registry. English-language studies were included if they assessed the costs against the benefits of HBV screening in LMICs. PROSPERO registration: CRD42015024391, 20 July 2015.

Results

Nine studies fulfilled the eligibility criteria. One study from Thailand indicated that adding hepatitis B immunoglobulin (HBIG) to HBV vaccination for newborns following screening of pregnant women might be cost-effective for some LMICs, though inadequate total funding and health infrastructure were likely to limit feasibility. A similar study from China indicated a benefit to cost ratio of 2.7 from selective HBIG administration to newborns, if benefits were considered from a societal perspective. Of the two studies assessing screening amongst the general adult population, a single cost-benefit analysis from China found a benefit to cost ratio (BCR) of 1.73 with vaccination guided by HBV screening of adults aged 21–39, compared to 1.42 with vaccination with no screening, both from a societal perspective. Community-based screening of adults in The Gambia with linkage to treatment yielded an incremental cost per disability-adjusted life year averted of $566 (in 2017 USD), less than two-times gross domestic product per capita for that country.

Conclusions

Screening with ‘catch-up’ vaccination for younger adults yielded benefits above costs, and screening linked with treatment has shown cost-effectiveness that may be affordable for some LMICs. However, interpretation needs to account for total cost implications and further research in LMICs is warranted as there were only nine included studies and evidence from high-income countries is not always directly applicable.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5261-8) contains supplementary material, which is available to authorized users.

Impact of Antiretroviral Therapy on Liver Fibrosis Among Human Immunodeficiency Virus-Infected Adults With and Without HBV Coinfection in Zambia

Background

We investigated changes in hepatic fibrosis, based on transient elastography (TE), among human immunodeficiency virus (HIV)-infected patients with and without hepatitis B virus (HBV) coinfection on antiretroviral therapy (ART) in Zambia.

Methods

Patients' liver stiffness measurements (LSM; kiloPascals [kPa]) at ART initiation were categorized as no or minimal fibrosis (equivalent to Metavir F0-F1), significant fibrosis (F2-F3), and cirrhosis (F4). TE was repeated following 1 year of ART. Stratified by HBV coinfection status (hepatitis B surface antigen positive at baseline), we described LSM change and the proportion with an increase/decrease in fibrosis category. Using multivariable logistic regression, we assessed correlates of significant fibrosis/cirrhosis at 1 year on ART.

Results

Among 463 patients analyzed (61 with HBV coinfection), median age was 35 years, 53.7% were women, and median baseline CD4+ count was 240 cells/mm3. Nearly all (97.6%) patients received tenofovir disoproxil fumarate-containing ART, in line with nationally recommended first-line treatment. The median LSM change was -0.70 kPa (95% confidence interval, -3.0 to +1.7) and was similar with and without HBV coinfection. Significant fibrosis/cirrhosis decreased in frequency from 14.0% to 6.7% (P < .001). Increased age, male sex, and HBV coinfection predicted significant fibrosis/cirrhosis at 1 year (all P < .05).

Conclusion

The percentage of HIV-infected Zambian adults with elevated liver stiffness suggestive of significant fibrosis/cirrhosis decreased following ART initiation-regardless of HBV status. This suggests that HIV infection plays a role in liver inflammation. HBV-coinfected patients were more likely to have significant fibrosis/cirrhosis at 1 year on ART.

Clinical Trials Registration

NCT02060162.

Field performance of the Determine HBsAg point-of-care test for diagnosis of hepatitis B virus co-infection among HIV patients in Zambia

BACKGROUND

We evaluated the field performance of a rapid point-of-care (POC) test for hepatitis B surface antigen (HBsAg) that could support decentralization and scale-up of hepatitis B virus (HBV) diagnosis in Africa.

OBJECTIVE

To determine the field performance of the Determine HBsAg POC test for diagnosis of HBV co-infection among HIV patients in Zambia.

STUDY DESIGN

Between 2013-2014, we screened HIV-infected adults for HBsAg at two urban clinics in Zambia. A subset were tested with the POC Determine HBsAg (Alere, USA) by finger prick in the clinic and HBsAg serology (Access2Analyzer, Beckman Coulter) at a reference laboratory. If either test was reactive, we determined HBV viral load (VL) and genotype. We described patient demographic and clinical characteristics (including liver fibrosis) and assessed the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the Determine test. In secondary analyses, we assessed sensitivity among patients with replicating HBV (i.e., VL>20 IU/ml) and with high HBV VL (i.e.,>20,000IU/ml).

RESULTS

Among 412 participants with both HBsAg tests, median age was 34 years, 51% were women, and median CD4 was 208 cells/mm³. By serology, 66 (16%) were HBsAg-positive. Overall Determine had 87.9% sensitivity, 99.7% specificity, 98.3% PPV, and 97.7% NPV. Six of 8 patients with false negative results had undetectable HBV VL and no evidence of significant liver fibrosis. Test sensitivity was 95.9% among the 51 with replicating HBV and 100% among the 28 with high HBV VL.

CONCLUSIONS

Determine HBsAg is a cheaper alternative HBV testing option compared to the gold standard ELISA and has high specificity and good sensitivity in the field among HIV-infected individuals.

Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

BACKGROUND

Chronic Hepatitis B Virus (HBV) infection is characterised by the persistence of hepatitis B surface antigen (HBsAg). Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs) in addition to laboratory-based enzyme immunoassays (EIAs) to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs) was compared to enzyme immunoassay (EIA) and nucleic-acid test (NAT) reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type.

RESULTS

Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8) and 99.5% (95% CI: 99.4, 99.5) respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4) compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6) and 98.4% (95% CI: 97.8, 98.8), respectively. Accuracy of both RDTs and EIAs using a NAT reference were generally lower, especially amongst HIV-positive cohorts.

CONCLUSIONS

HBsAg RDTs have good sensitivity and excellent specificity compared to laboratory immunoassays as a reference standard. Sensitivity of HBsAg RDTs may be lower in HIV infected individuals.

Prevalence of chronic hepatitis B virus infection and infrastructure for its diagnosis in Madagascar: implication for the WHO's elimination strategy

Background

WHO developed a global strategy to eliminate hepatitis B by 2030 and set target to treat 80% of people with chronic hepatitis B virus (HBV) infection eligible for antiviral treatment. As a first step to achieve this goal, it is essential to conduct a situation analysis that is fundamental to designing national hepatitis plans. We therefore estimated the prevalence of chronic HBV infection, and described the existing infrastructure for HBV diagnosis in Madagascar.

Methods

We conducted a stratified multi-stage serosurvey of hepatitis B surface antigen (HBsAg) in adults aged ≥18 years using 28 sentinel surveillance sites located throughout the country. We obtained the list of facilities performing HBV testing from the Ministry of Health, and contacted the person responsible at each facility.

Results

A total of 1778 adults were recruited from the 28 study areas. The overall weighted seroprevalence of HBsAg was 6.9% (95% CI: 5.6–8.6). Populations with a low socio-economic status and those living in rural areas had a significantly higher seroprevalence of HBsAg. The ratio of facilities equipped to perform HBsAg tests per 100,000 inhabitants was 1.02 in the capital city of Antananarivo and 0.21 outside the capital. There were no facilities with the capacity to perform HBV DNA testing or transient elastography to measure liver fibrosis. There are only five hepatologists in Madagascar.

Conclusion

Madagascar has a high-intermediate level of endemicity for HBV infection with a severely limited capacity for its diagnosis and treatment. Higher HBsAg prevalence in rural or underprivileged populations underlines the importance of a public health approach to decentralize the management of chronic HBV carriers in Madagascar by using simple and low-cost diagnostic tools.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4630-z) contains supplementary material, which is available to authorized users.

Hepatitis B treatment eligibility in West Africa: Uncertainties and need for prospective cohort studies

BACKGROUND & AIMS

While universal screening of hepatitis B virus (HBV) is recommended in high burden countries, little is known about the proportion of HBV-infected persons in need of antiviral therapy in these settings.

METHODS

Prisoners in Senegal and Togo as well as female sex workers and men who have sex with men in Cote d'Ivoire were screened for HBV infection. All HBsAg-positive participants underwent transient elastography, alanine aminotransferase (ALT) and HBV viral load (VL) quantification. Individuals with cirrhosis or those aged >30 years with an HBV replication ≥20 000 IU/mL and elevated ALT were considered eligible for antiviral therapy.

RESULTS

Of 1256 participants, 110 (8.8%) were HBsAg positive; their median age was 30 years [interquartile range: 25-33] and 96 (86.5%) were men. Three individuals (2.7%) had cirrhosis, while 28 (29.5%) of 94 participants with available measurements had an HBV VL ≥20 000 IU/mL. Overall, 11 (10.0%) subjects were considered eligible for immediate antiviral treatment (2.1% of participants in Dakar, 7.7% in Abidjan and 21.6% in Lome, P=.001) and 59 (53.4%) for close monitoring due to the presence of significant liver fibrosis, elevated ALT or significant HBV replication.

CONCLUSIONS

Among vulnerable populations in West Africa, a minority of HBV-infected individuals were eligible for immediate antiviral therapy. Prospective cohort studies are necessary to evaluate anti-HBV treatment eligibility facing the significant proportion of individuals with active chronic HBV infection.

Point-of-care screening for hepatitis B virus infection in pregnant women at an antenatal clinic: A South African experience

BACKGROUND & AIMS

Elimination of HIV and syphilis mother-to-child transmission (MTCT) has received much attention but little consideration has been given to the possibility of elimination of HBV MTCT. In sub-Saharan Africa, HBV vertical transmission continues to be reported and it remains an important public health problem. This study aimed to assess the feasibility of screening pregnant women for HBV using a point-of-care (POC) test and implementing interventions to prevent HBV MTCT.

METHODS

In this observational prospective cohort study, HIV-uninfected pregnant women who consented to testing were screened for HBV using a rapid POC test for HBsAg. Positive results were laboratory-confirmed and tested for HBV DNA and serological markers. Women with viral loads ≥ 20 000 IU/ml received tenofovir (TDF) treatment and all infants received birth-dose HBV vaccine. Two blood samples collected six months apart from HBV-exposed infants within their first year of life were tested for HBV DNA.

RESULTS

Of 144 women who were approached, 134 consented to participating (93% acceptance rate of HBV POC test). Six women tested positive for HBsAg (4.5%; 95% CI 0.99%-8.01%), all confirmed by laboratory testing. Two mothers, M1 and M4, were treated with TDF during their third trimester of pregnancy. Six HBV-exposed infants received the HBV vaccine within 24 hours of birth, of whom two were lost to follow-up and four (including the two born to M1 and M4) had undetectable levels of HBV DNA when tested at the two time points.

CONCLUSION

We found that HBV screening using POC testing fulfilled the criteria considered necessary for implementation. It has acceptable performance, is inexpensive, reliable, and was well accepted by the study participants. Screening pregnant women as part of the HBV MTCT prevention strategy is therefore feasible in a South African clinical setting.