Mother-to-child transmission of hepatitis B in sub-Saharan Africa

Knowledge, attitudes, and factors associated with vertical transmission of hepatitis B among pregnant women in Gurage Zone, Ethiopia

Hepatitis B virus is a highly contagious virus and a significant public health issue globally. Its prevalence among the general and prenatal populations indicates its endemicity in Ethiopia. Mother-to-child transmission is a key route of transmission, and preventing this is crucial to controlling the spread of HBV. Effective prevention requires sufficient knowledge and a positive attitude toward HBV and its modes of transmission. However, research on pregnant women's knowledge and attitudes regarding mother-to-child transmission of HBV in Ethiopia is limited. To assess pregnant women's knowledge, attitudes, and associated factors regarding vertical transmission of HBV among women attending the ANC clinic at Gurage Zone Hospitals, Central Ethiopia. An institutional-based cross-sectional study was conducted among 419 pregnant women attending antenatal care at Atat Hospital from January to March 2024. A systematic sampling technique was used, and data were collected through a pre-tested, structured, interviewer-administered questionnaire. The data were entered into Epi Data 4.6 and analyzed using SPSS 26. Binary logistic regression was used to determine associations between the outcome and explanatory variables, with a P value < 0.05 considered statistically significant. Of the 414 participants (98% response rate), 80.7% were not knowledgeable about the vertical transmission of HBV, and 77.1% had a favorable attitude toward the vertical transmission of HBV. Factors associated with knowledge included urban residence (AOR 8.7, 95% CI 4.3, 17.64), being single (AOR 5.6, 95% CI 1.17, 27.4), and educational level (AOR 6.8, 95% CI 2.4, 19.1). Attitude was associated with) urban residence (AOR 4.9, 95% CI 2.1, 11.3), being single (AOR 5, 95% CI 1.17-27.39), income of 2000-4000 ETB (AOR 17.3, 95% CI 5.0-60.03), and primigravidity (AOR 17.8, 95% CI 5.6-56.6). Residence was associated with both knowledge and attitude. Overall knowledge of vertical transmission of HBV was poor, and attitudes toward transmission, screening, and vaccination were generally positive. Residence, being single, educational level, and monthly income were significantly associated with knowledge and attitude. There is a need for enhanced education and awareness-creation programs on HBV transmission and prevention in this population.

Characterizing hepatitis B virus infection in children in the Democratic Republic of Congo to inform elimination efforts

Objective

Despite global reductions in hepatitis B virus (HBV) prevalence, an estimated 6.2 million children are infected, two-thirds of whom live in the WHO Africa region. We sought to characterize childhood HBV to inform elimination efforts in the Democratic Republic of Congo (DRC), one of the largest and most populous African countries.

Methods

Using the most recent (2013-14) nationally representative Demographic and Health Survey in the DRC, we analyzed HBV surface antigen (HBsAg) on dried blood spots and associated survey data from children aged 6-59 months. We estimated HBsAg-positivity prevalence nationally, regionally, and by potential correlates of infection. We evaluated spatial variation in HBsAg-positivity prevalence, overall and by age, sex, and vaccination status.

Findings

Using data from 5,679 children, we found national HBsAg-positivity prevalence was 1.3% (95% CI: 0.9%-1.7%), but ranged from 0.0% in DRC's capital city province, Kinshasa, to 5.6% in northwestern Sud-Ubangi Province. Prevalence among boys (1.8%, 95% CI: 1.2%-2.7%) was double that among girls (0.7%, 95%CI: 0.4%-1.3%). Tetanus antibody-negativity, rurality, and lower household wealth were also significantly associated with higher HBsAg-positivity prevalence. We observed no difference in prevalence by age. Children had higher HBsAg-positivity odds if living with ≥1 HBsAg-positive adult household member (OR: 2.3, 95%CI: 0.7-7.8), particularly an HBsAg-positive mother (OR: 7.2, 95%CI:1.6-32.2).

Conclusion

In the largest national survey of HBV among children and household contacts in the DRC, we found that childhood HBV prevalence was 10-60 times the global target of 0.1%. We highlight specific regions and populations for further investigation and focused prevention efforts.

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.

Altered TLR7 Expression-Mediated Immune Modulation Is Supportive of Persistent Replication and Intrauterine Transmission of HBV

Hepatitis B Virus (HBV) is posing as a serious public health threat mainly due to its asymptomatic nature of infection in pregnancy and vertical transmission. Viral sensing toll-like receptors (TLR) and Interleukins (IL) are important molecules in providing an antiviral state. The study aimed to assess the role of TLR7-mediated immune modulation, which might have an impact in the intrauterine transmission of HBV leading to mother to child transmission of the virus. We investigated the expression pattern of TLR7, IL-3, and IL-6 by RT-PCR in the placentas of HBV-infected pregnant women to see their role in the intrauterine transmission of HBV. We further validated the expression of TLR7 in placentas using Immunohistochemistry. Expression analysis by RT-PCR of TLR7 revealed significant downregulation among the Cord blood (CB) HBV DNA positive and negative cases with mean ± standard deviation (SD) of 0.43 ± 0.22 (28) and 1.14 ± 0.57 (44) with p = 0.001. IL-3 and IL-6 expression revealed significant upregulation in the CB HBV DNA-positive cases with p = 0.001. Multinomial logistic regression analysis revealed that TLR7 and IL-3 fold change and mother HBeAg status are important predictors for HBV mother to child transmission. Immunohistochemistry revealed the decreased expression of TLR7 in CB HBV DNA-positive cases. This study reveals that the downregulation of TLR7 in the placenta along with CB HBV DNA-positive status may lead to intrauterine transmission of HBV, which may lead to vertical transmission of HBV.

Prevalence of hepatitis B infection in the Gambian population: A narrative review of recent developments

Hepatitis B is a "silent epidemic", fifty to a hundred (50-100) times more infectious than HIV, a potentially life-threatening liver infection caused by the hepatitis B virus (HBV). HBV can cause acute and chronic infection and subsequently results in a high risk of death from cirrhosis and liver cancer. Despite the availability of a safe and effective vaccine, HBV continues to be a global burden including in The Gambia. This study reviewed the recent trends in the epidemiological characteristics of HBV in the Gambia. The researchers conducted an online literature search for primary studies on HBV prevalence published in the past two decades from Jan 1992 to Feb 2022 inclusive on Google Scholar, PubMed, and Scopus. All retrieved studies were assessed for eligibility according to specific inclusion/exclusion criteria, data completeness, and methodological coherence. We found that HBV infection prevalence is above 8% in The Gambia. Moreover, HBV is the most common cause of hepatocellular carcinoma (HCC) in Gambia. Liver cirrhosis and HCC have the highest mortality contribution among hepatitis patients, with occult HBV carriers as major culprits. Also, vaccination coverage has declined from 91% to 88% according to reports from current literature. To achieve the WHO goal of eliminating HBV by 2030, policies targeting infection transmission control among risk groups, community awareness programs, research, price reduction of drugs, mass vaccinations, and diagnostics should be urgently instituted.

The Hepatitis B Virus Genotypes E to J: The Overlooked Genotypes

Hepatitis B virus (HBV) genotypes E to J are understudied genotypes. Genotype E is found almost exclusively in West Africa. Genotypes F and H are found in America and are rare in other parts of the world. The distribution of genotype G is not completely known. Genotypes I and J are found in Asia and probably result from recombination events with other genotypes. The number of reported sequences for HBV genotypes E to J is small compared to other genotypes, which could impact phylogenetic and pairwise distance analyses. Genotype F is the most divergent of the HBV genotypes and is subdivided into six subgenotypes F1 to F6. Genotype E may be a recent genotype circulating almost exclusively in sub-Saharan Africa. Genotype J is a putative genotype originating from a single Japanese patient. The paucity of data from sub-Saharan Africa and Latin America is due to the under-representation of these regions in clinical and research cohorts. The purpose of this review is to highlight the need for further research on HBV genotypes E to J, which appear to be overlooked genotypes.

Advanced Theranostic Strategies for Viral Hepatitis Using Carbon Nanostructures

There are several treatment protocols for acute viral hepatitis, and it is critical to recognize acute hepatitis in its earliest stages. Public health measures to control these infections also rely on rapid and accurate diagnosis. The diagnosis of viral hepatitis remains expensive, and there is no adequate public health infrastructure, while the virus is not well-controlled. New methods for screening and detecting viral hepatitis through nanotechnology are being developed. Nanotechnology significantly reduces the cost of screening. In this review, the potential of three-dimensional-nanostructured carbon substances as promising materials due to fewer side effects, and the contribution of these particles to effective tissue transfer in the treatment and diagnosis of hepatitis due to the importance of rapid diagnosis for successful treatment, were extensively investigated. In recent years, three-dimensional carbon nanomaterials such as graphene oxide and nanotubes with special chemical, electrical, and optical properties have been used for the diagnosis and treatment of hepatitis due to their high potential. We expect that the future position of nanoparticles in the rapid diagnosis and treatment of viral hepatitis can be better determined.

Screening for Hepatitis B in partners and children of women positive for surface antigen, Burkina Faso

Objective

To evaluate the implementation of a screening strategy for the partners and children of pregnant women with hepatitis B virus (HBV) attending antenatal care.

Methods

We identified pregnant women positive for HBV surface antigen (HBsAg) at antenatal consultation in Ouagadougou, Burkina Faso. At post-test counselling, women were advised to disclose their HBV status to partners and to encourage their partner and children to be screened for HBsAg. We used multivariable logistic regression to explore factors associated with uptake of screening and HBsAg positivity among family members.

Findings

Of 1000 HBsAg-positive women, 436/1000 partners and 215/1281 children were screened. HBsAg was detected in 55 (12.6%) partners and 24 (11.2%) children. After adjusting for confounders, uptake of screening was higher in partners who were married, who attended the woman's first post-test consultation and to whom the woman had disclosed her HBV status. In children, HBsAg positivity was associated with being born before the introduction of infant hepatitis B vaccination in Burkina Faso (not significant in the multivariable analysis), having a mother positive for HBV e-antigen (adjusted OR: 8.57; 95% CI: 2.49-29.48) or having a mother with HBV DNA level ≥ 200 000 IU/mL (OR: 6.83; 95% CI: 1.61-29.00).

Conclusion

In low-income countries, the antenatal consultation provides a cost-effective opportunity to identify HBV-infected household contacts and link them to care. Children born before the introduction of infant hepatitis B vaccination and whose mother has higher viral load or infectivity should be a priority for testing and linkage to care.

Challenges for hepatitis B virus cure in resource-limited settings in sub-Saharan Africa

PURPOSE OF REVIEW

The aim of this article is to highlight the unique challenges for hepatitis B virus (HBV) cure faced in resource-limited settings (RLS) in sub-Saharan Africa (SSA), where access to disease prevention measures, medical testing, and treatment are limited.

RECENT FINDINGS

SSA RLS face challenges, which need to be anticipated as HBV cure research advances. There is a paucity of data because of lack of HBV surveillance and limited access to laboratories. Interruption of transfusion-transmitted infections, perinatal mother-to-child-transmissions, and transmission in people-who-infect-drug networks has not been achieved fully. Although RLS in SSA are within the epicenter of the HIV pandemic, unlike for HIV, there is no population-based testing for HBV. Public health response to HBV is inadequate with concomitant political inertia in combatting HBV infection.

SUMMARY

A functional HBV cure will improve the diagnosis/treatment cascade, decrease costs and accelerate HBV elimination. There is a concerted effort to find a HBV cure, which will be finite, not require life-long treatment, adherence, and continued monitoring. Increased research, improved financial, infrastructural and human resources will positively impact on implementation of HBV cure, when available. We can emulate major strides made in tackling HIV and the strength of advocacy groups in soliciting policymakers to take action.

Impact of Introducing Hepatitis B Birth Dose Vaccines into the Infant Immunization Program in Burkina Faso: Study Protocol for a Stepped Wedge Cluster Randomized Trial (NéoVac Study)

To achieve global hepatitis elimination by 2030, it is critical to prevent the mother-to-child transmission (MTCT) of hepatitis B virus (HBV). Since 2009, the WHO has recommended administering hepatitis B vaccine to all neonates within 24 h of birth to prevent MTCT. However, many countries in sub-Saharan Africa only provide hepatitis B immunization at the age of 6, 10, and 14 weeks or 8, 12, and 16 weeks using a combined vaccine. To accelerate the introduction of the hepatitis B birth dose vaccine (HepB-BD) into sub-Saharan Africa, it is critical to establish to what extent the addition of HepB-BD can further reduce HBV transmission in areas where three-dose infant vaccination has been implemented. We therefore designed a study to evaluate the impact, acceptability, and cost-effectiveness of incorporating the HepB-BD into the routine immunization program in a real-life field condition in Burkina Faso, where the hepatitis B vaccination is currently scheduled at 8-12-16 weeks. Through a multidisciplinary approach combining epidemiology, anthropology, and health economics, the Neonatal Vaccination against Hepatitis B in Africa (NéoVac) study conducts a pragmatic stepped wedge cluster randomized controlled trial in rural areas of the Hauts-Bassins Region. The study was registered in ClinicalTrials.gov (identifier: NCT04029454). A health center is designated as a cluster, and the introduction of HepB-BD will be rolled out sequentially in 24 centers. Following an initial period in which no health center administers HepB-BD, one center will be randomly allocated to incorporate HepB-BD. Then, at a regular interval, another center will be randomized to cross from the control to the intervention period, until all 24 centers integrate HepB-BD. Pregnant women attending antenatal care will be systematically invited to participate. Infants born during the control period will follow the conventional immunization schedule (8-12-16 weeks), while those born in the interventional period will receive HepB-BD in addition to the routine vaccines (0-8-12-16 weeks). The primary outcome, the proportion of hepatitis B surface antigen (HBsAg) positivity in infants aged at 9 months, will be compared between children born before and after HepB-BD introduction. The study will generate data that may assist governments and stakeholders in sub-Saharan Africa to make evidence-based decisions about whether to add HepB-BD into the national immunization programs.

Diagnostic performance evaluation of hepatitis B e antigen rapid diagnostic tests in Malawi

Background

The World Health Organization (WHO) has targeted a reduction in viral hepatitis-related mortality by 65% and incidence by 90% by 2030, necessitating enhanced hepatitis B treatment and prevention programmes in low- and middle-income countries. Hepatitis B e antigen (HBeAg) status is used in the assessment of eligibility for antiviral treatment and for prevention of mother-to-child transmission (PMTCT). Accordingly, the WHO has classified HBeAg rapid diagnostic tests (RDTs) as essential medical devices.

Methods

We assessed the performance characteristics of three commercially available HBeAg RDTs (SD Bioline, Alere, South Africa; Creative Diagnostics, USA; and Biopanda Reagents, UK) in two hepatitis B surface antigen-positive cohorts in Blantyre, Malawi: participants of a community study (n = 100) and hospitalised patients with cirrhosis or hepatocellular carcinoma (n = 94). Two investigators, blinded to the reference test result, independently assessed each assay. We used an enzyme-linked immunoassay (Monolisa HBeAg, Bio-Rad, France) as a reference test and quantified HBeAg concentration using dilutions of the WHO HBeAg standard. We related the findings to HBV DNA levels, and evaluated treatment eligibility using the TREAT-B score.

Results

Among 194 HBsAg positive patients, median age was 37 years, 42% were femaleand 26% were HIV co-infected. HBeAg prevalence was 47/194 (24%). The three RDTs showed diagnostic sensitivity of 28% (95% CI 16–43), 53% (38–68) and 72% (57–84) and specificity of 96–100% for detection of HBeAg. Overall inter-rater agreement κ statistic was high at 0.9–1.0. Sensitivity for identifying patients at the threshold where antiviral treatment is recommended for PMTCT, with HBV DNA > 200,000 IU/ml (39/194; 20%), was 22, 49 and 54% respectively. Using the RDTs in place of the reference HBeAg assay resulted in 3/43 (9%), 5/43 (12%) and 8/43 (19%) of patients meeting the TREAT-B treatment criteria being misclassified as ineligible for treatment. A relationship between HBeAg concentration and HBeAg detection by RDT was observed. A minimum HBeAg concentration of 2.2–3.1 log₁₀IU/ml was required to yield a reactive RDT.

Conclusions

Commercially available HBeAg RDTs lack sufficient sensitivity to accurately classify hepatitis B patients in Malawi. This has implications for hepatitis B public health programs in sub-Saharan Africa. Alternative diagnostic assays are recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06134-3.

Eliminating mother-to-child transmission of human immunodeficiency virus, syphilis and hepatitis B in sub-Saharan Africa

Triple elimination is an initiative supporting the elimination of mother-to-child transmission of three diseases – human immunodeficiency virus (HIV) infection, syphilis and hepatitis B. Significant progress towards triple elimination has been made in some regions, but progress has been slow in sub-Saharan Africa, the region with the highest burden of these diseases. The shared features of the three diseases, including their epidemiology, disease interactions and core interventions for tackling them, enable an integrated health-systems approach for elimination of mother-to-child transmission. Current barriers to triple elimination in sub-Saharan Africa include a lack of policies, strategies and resources to support the uptake of well established preventive and treatment interventions. While much can be achieved with existing tools, the development of new products and models of care, as well as a prioritized research agenda, are needed to accelerate progress on triple elimination in sub-Saharan Africa. In this paper we aim to show that health systems working together with communities in sub-Saharan Africa could deliver rapid and sustainable results towards the elimination of mother-to-child transmission of all three diseases. However, stronger political support, expansion of evidence-based interventions and better use of funding streams are needed to improve efficiency and build on the successes in prevention of mother-to-child transmission of HIV. Triple elimination is a strategic opportunity to reduce the morbidity and mortality from HIV infection, syphilis and hepatitis B for mothers and their infants within the context of universal health coverage.

Identifying gaps across the cascade of care for the prevention of HBV mother-to-child transmission in Burkina Faso: Findings from the real world

BACKGROUND

Prevention of mother-to-child transmission (PMTCT) is a challenge for controlling the hepatitis B epidemic. In Sub-Saharan countries, pilot interventions including the screening of pregnant women for HBsAg, implementation of anti-HBV therapy and infant immunization within 24 hours of life are initiated and need to be evaluated. This pilot study aimed to describe the cascade of care for hepatitis B PMTCT in a real life situation, and to identify sociodemographic factors associated with adequate management of pregnant women and infants.

METHOD

The study was conducted from October 1st, 2014 to February 28th, 2016 in the antenatal clinics (ANCV) of Baskuy district which comprises nine first-level public health centres. Univariate and multivariate logistic regression analysis were used to identify sociodemographic factors associated with the likelihood of retention in the cohort, HBV DNA testing, birth dose delivery and HBsAg testing of the children at 6 months of age; P ˂ .05 was selected as cut off for significance.

RESULTS

In this prospective cohort study, of 5200 pregnant women consulting for the antenatal visit, 2261 (43.5%) were proposed pre-test counselling and HBsAg screening and 2220 (98.2%) have agreed to screening. Among 1580 (71.2%) women that came back for the post-counselling interview, 75 were positive for HBsAg (4.8%), 73 (97.3% of the women provided HBsAg result) consented to medical consultation with hepatogastroenterologists and 53 (72.6%); performed the HBV DNA testing. Forty-seven out of 60 (78.3%; 65.8-87.9) children born alive were immunized for HBV within 24 hours of life. Retention in care was associated with the level of education of the infant's father, secondary school or higher was associated with a better retention in care of the women (OR: 6.6; P = .03).

CONCLUSION

Our study shows large gaps in HBV PMTCT. Resources for hepatitis B screening, care and prevention including universal access to the vaccine birth dose should be allocated to reduce infection in HBV exposed infants born in Burkina Faso.

Hepatitis B virus infection in children and adolescents

Hepatitis B virus (HBV) infection is a major cause of acute and chronic liver disease and associated morbidity and mortality worldwide. Vertical (mother-to-child) and horizontal early childhood transmission are the main routes of HBV transmission and are responsible for most chronic infections, including among adults who bear the greatest burden of morbidity and mortality. Universal hepatitis B immunisation at birth and in infancy is the key strategy for global elimination of HBV infection, and has been highly effective in reducing new vertical infections. However, global progress in scale-up of HBV testing and treatment has been slow in adults and children. In this Series paper, we summarise knowledge on the epidemiology, natural history, and treatment of chronic HBV infection in adolescents and children, and we highlight key differences from HBV infection in adults. The estimated global prevalence of HBV infection in children aged 5 years or younger is 1·3%. Most children are in the high-replication, low-inflammation phase of infection, with normal or only slightly raised aminotransferases; cirrhosis and hepatocellular carcinoma are rare. Although entecavir is approved and recommended for children aged 2-17 years, and tenofovir for those aged 12-18 years, a conservative approach to treatment initiation in children is recommended. Key actions to address current policy gaps include: validation of non-invasive tests for liver disease staging; additional immunopathogenesis studies in children with HBV infection; long-term follow-up of children on nucleoside or nucleotide analogue regimens to inform guidance on when to start treatment; evaluation of different treatment strategies for children with high rates of HBV replication; and establishment of paediatric treatment registries and international consortia to promote collaborative research.

Hepatitis B Virus (HBV) Infection and Re-activation During Nucleos(t)ide Reverse Transcriptase Inhibitor-Sparing Antiretroviral Therapy in a High-HBV Endemicity Setting

Background

We monitored the evolution of markers of hepatitis B virus (HBV) infection in virologically suppressed HIV-positive patients switching to nucleoside reverse transcriptase inhibitor (NRTI)–sparing antiretroviral therapy within a randomized trial in Cameroon.

Methods

 HBV surface antigen (HBsAg), HBV DNA, and antibodies against surface (anti-HBs), core (total anti-HBc), and e-antigen (anti-HBe) were measured retrospectively in samples collected at study entry and over 48 weeks after NRTI discontinuation.

Results

Participants (n = 80, 75% females) had a plasma HIV-1 RNA <60 copies/mL, a median CD4 count of 466 cells/mm³, and undetectable HBsAg and HBV DNA at study entry. After NRTI discontinuation, 3/20 (15.0%) anti-HBc-negative patients showed evidence indicative or suggestive of incident HBV infection (163 cases/1000 person-years); 6/60 (10.0%) anti-HBc-positive patients showed evidence indicative or suggestive of HBV reactivation (109 cases/1000 person-years). In one case of reactivation, anti-HBs increased from 14 to >1000 IU/L; sequencing showed HBV genotype A3 and 3 escape mutations in surface (Y100C, K122R, Y161FY). Alongside new-onset detection of HBsAg or HBV DNA, 1 patient experienced acute hepatitis and 6 patients experienced mild or marginal increases in serum transaminase levels.

Conclusions

Evolving treatment strategies for sub-Saharan Africa must be accompanied by the formulation and implementation of policy to guide appropriate assessment and management of HBV status.

Poor Sensitivity of Commercial Rapid Diagnostic Tests for Hepatitis B e Antigen in Senegal, West Africa

Limited access to nucleic acid tests for hepatitis B virus (HBV) DNA is a significant barrier to the effective management of chronic HBV infection in resource-poor countries. Alternatively, HBV e antigen (HBeAg) may accurately indicate high viral replication. We assessed the diagnostic performance of three commercially available rapid diagnostic tests (RDTs) for HBeAg (SD Bioline, Insight and OneStep) against a quantitative chemiluminescent immunoassay (CLIA, Architect). Using stored sera from adults with chronic HBV infection, we tested RDTs in three groups in Senegal (48 HBeAg-positive, 196 HBeAg-negative, and 117 cases with high HBV DNA (≥ 10⁶ IU/mL)) and one group in France (17 HBeAg-positive East Asians). In Senegal, the sensitivity and specificity for HBeAg detection were 29.8% and 100% for SD Bioline, 31.1% and 100% for Insight, and 42.5% and 98.4% for OneStep, respectively. The lower limits of detection of these RDTs were very high (> 2.5 log10 Paul Ehrlich Institut units/mL). Their low sensitivity was also confirmed in HBeAg-positive Asian samples (35.3-52.9%). The prevalence of HBeAg in highly viremic (≥ 10⁶ IU/mL) Senegalese patients was low: 58.1% using CLIA and 24.5-37.5% using RDTs. Hepatitis B e antigen prevalence was similarly low in a subgroup of 28 Senegalese women of childbearing age with a high viral load (≥ 10⁶ IU/mL). Approximately, half of highly viremic adults do not carry HBeAg in Africa, and HBeAg RDTs had remarkably poor analytical and diagnostic sensitivity. This implies that HBeAg-based antenatal screening, particularly if using the currently available HBeAg RDTs, may overlook most pregnant women at high risk of mother-to-child transmission in Africa.

Diagnosis of viral hepatitis

PURPOSE OF REVIEW

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and HIV-HBV and HCV coinfection are major causes of chronic liver disease worldwide. Testing and diagnosis is the gateway for access to both treatment and prevention services, but there remains a large burden of undiagnosed infection globally. We review the global epidemiology, key challenges in the current hepatitis testing response, new tools to support the hepatitis global response (2016-2020 Global Hepatitis Health Sector strategy, and 2017 WHO guidelines on hepatitis testing) and future directions and innovations in hepatitis diagnostics.

RECENT FINDINGS

Key challenges in the current hepatitis testing response include lack of quality-assured serological and low-cost virological in-vitro diagnostics, limited facilities for testing, inadequate data to guide country-specific hepatitis testing approaches, stigmatization of those with or at risk of viral hepatitis and lack of guidelines on hepatitis testing for resource-limited settings. The new Global Hepatitis Health Sector strategy sets out goals for elimination of viral hepatitis as a public health threat by 2030 and gives outcome targets for reductions in new infections and mortality, as well as service delivery targets that include testing, diagnosis and treatment. The 2017 WHO hepatitis testing guidelines for adults, adolescents and children in low-income and middle-income countries outline the public health approach to strengthen and expand current testing practices for viral hepatitis and addresses who to test (testing approaches), which serological and virological assays to use (testing strategies) as well as interventions to promote linkage to prevention and care.

SUMMARY

Future directions and innovations in hepatitis testing include strategies to improve access such as through use of existing facility and community-based testing opportunities for hepatitis testing, near-patient or point-of-care assays for virological markers (nucleic acid testing and HCV core antigen), dried blood spot specimens used with different serological and nucleic acid test assays, multiplex and multi-disease platforms to enable testing for multiple analytes/pathogens and potential self-testing for viral hepatitis.

Systematic review with meta-analysis: the risk of mother-to-child transmission of hepatitis B virus infection in sub-Saharan Africa

BACKGROUND

The risk of mother-to-child transmission of hepatitis B virus (HBV) has been quoted as 70-90% among women positive for hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), and 5-30% among HBsAg-positive HBeAg-negative women. These risks are derived from Asia; little is known about sub-Saharan Africa.

AIM

To determine the risk of mother-to-child transmission in sub-Saharan Africa, according to maternal HBeAg and type of prophylaxis.

METHODS

We searched Medline, Global Health, Embase, African Journals Online and African Index Medicus. We included observational or interventional studies that enrolled infants of HBV-infected women, and that tested for HBsAg or HBV DNA between 3 and 12 months of age.

RESULTS

Fifteen articles from 11 African countries were included. Among HBeAg-positive women, the pooled risk was 38.3% (95% CI: 7.0-74.4%) without prophylaxis, which was significantly lower than the lower bound of 70-90% risk in the literature (P = 0.007). Among HBeAg-negative women, the pooled risk was 4.8% (95% CI: 0.1-13.3%) without prophylaxis, which lays within the lower range of the 5-30% risk in Asia. By extrapolating the pooled transmission risks to the number of births to infectious mothers, an estimated 1% of newborns (n = 367 250) are annually infected with HBV at birth in sub-Saharan Africa.

CONCLUSIONS

Compared to Asia, the risk of mother-to-child transmission is low in sub-Saharan Africa. However, the annual number of infants perinatally infected with HBV is twice the number of incident paediatric HIV infections in sub-Saharan Africa (n = 190 000). This highlights the importance of preventing mother-to-child transmission of HBV in sub-Saharan Africa, which has been long neglected.