Screening, characterisation and prevention of Hepatitis B virus (HBV) co-infection in HIV-positive children in South Africa

Weak Adoption and Performance of Hepatitis B Birth-Dose Vaccination Programs in Africa: Time to Consider Systems Complexity?-A Scoping Review

The persistent burden of chronic hepatitis B among ≤5-year-old children in Africa suggests missed opportunities for controlling mother-to-child transmission (MTCT) of the hepatitis B virus (HBV). This scoping review maps the evidence base on the risk of HBV MTCT, the status of HBV MTCT mitigation strategies including hepatitis B birth-dose vaccination, and the role of systems complexity on the suboptimal adoption and performance of hepatitis B birth-dose vaccination programs in Africa. Overall, 88 peer-reviewed and grey literature sources published between 2000-2022 were included in this review. The growing evidence base consistently argues for a heightened risk of HBV MTCT amidst the HIV co-epidemic in the region. Without universal HBV screening programs integrated within broader antenatal care services, current selective hepatitis B birth-dose vaccination is unlikely to effectively interrupt HBV MTCT. We underscore critical health systems-related barriers to universal adoption and optimal performance of hepatitis B birth-dose vaccination programs in the region. To better conceptualize the role of complexity and system-wide effects on the observed performance of the program, we propose an adapted systems-based logic model. Ultimately, exploring contextualized complex systems approaches to scaling-up universal hepatitis B birth-dose vaccination programs should form an integral part of the regional research agenda.

Effect of different antiviral regimens on the viral loads in pregnant women with hepatitis B virus infection and their impact on mother-to-child transmission

AIM

This study aimed to explore the benefits of different antiviral regimens in pregnant women with hepatitis B virus (HBV) infection in an attempt to provide scientific reference for clinically relevant interventions.

METHODS

The study cohort comprised 64 pregnant women with HBV infection who presented to our hospital from May 2018 to July 2020. The women were grouped according to the treatment administered: a control group consisting of 32 pregnant women who received routine intervention and an observation group consisting of 32 pregnant women who received routine intervention plus tenofovir disoproxil fumarate (TDF) tablets. The two groups were compared in terms of liver function; HBV load (HBV DNA); neonatal characteristics (hepatitis B surface antigen and HBV DNA positivity); levels of interleukin (IL)-2, IL-4, and IL-6; neonatal growth and development; Apgar scores; incidence of adverse events; and incidence of maternal adverse effects during treatment.

RESULTS

The observation group had lower levels of alanine aminotransferase, glutamic acid aminotransferase, IL-4, IL-6, and HBV DNA and higher levels of IL-2 than the control group after 1 month of treatment (p < 0.05). There was no significant difference in the incidence of adverse events between the two groups (p > 0.05).

CONCLUSION

The administration of TDF tablets significantly reduced the HBV DNA levels and did not increase the physiological burden or adverse effects in pregnant women with HBV infection.

Prevalence and molecular characterization of hepatitis B virus infection in HIV-infected children in Senegal

BACKGROUND AND AIMS

Sub-Saharan Africa (SSA) is the region with the most patients co-infected with the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) worldwide. However, few studies have focused on SSA children who are at a higher risk of developing a chronic infection than adults. Furthermore, children on first-line antiretroviral therapy (ART) including low genetic barrier drugs may develop both HBV and HIV resistance mutations. The aim of this work was to document HIV-HBV co-infection and to characterize the HBV isolates in children in Senegal.

METHODS

This is a retrospective study of 613 children infected with HIV on ART or not. Dried blood spot (DBS) specimens were used to detect hepatitis B surface antigen (HBsAg) with a rapid diagnostic test (RDT). Confirmation of HBsAg status and hepatitis B e antigen (HBeAg) detection was performed on an automated platform using the chemiluminescence assay technology. HBV viral DNA was quantified by real-time polymerase chain reaction (PCR) and the preS1/preS2/HBsAg region was genotyped by nested PCR followed by sequencing using the Sanger technique.

RESULTS

The prevalence of HIV-HBV co-infection was 4.1% (25/613). The median age of co-infected children was 13 years (2 years-16 years) and 40% (10/25) were girls. Almost all 19/20 (95%) were infected with HIV-1 and 79% (19/24) were treated with 3TC-based triple combination ART. The median duration of time on ART was 15 months (3 months-80 months). More than half of the children 53% (9/17) were experiencing HIV virologic failure and 75% (6/8) had at least one HIV-related resistance-associated mutation (RAM). Of the six children with resistance, none of the three administered treatments were effective on HIV. Of the 25 co-infected children, 82% (18/22) were HBeAg-positive, while the median HBV viral load (VL) was 6.20 log₁₀ IU/mL (24/25 patients), and 62,5% (10/16) of the children had a persistent HBV viremia. Combination of ART was the only factor associated with HBV viremia persistence. Amplification was successful in 15 out of 16 patients (rate of 94%), and the ensuing phylogenetic analysis revealed that eight strains (53%) belonged to genotype A and seven (47%) to genotype E. HBV-related 3TC RAMs were uncovered in 20% of these patients (3/15). HBsAg escape mutations were found in 20% of the children (3/15).

CONCLUSIONS

Our results showed a high level of drug resistance mutations to both HIV and HBV, a significant level of HBsAg escape mutations, HBV DNA persistence and HIV virologic failure in co-infected children in Senegal. The HBV genotypes found were A and E.

Hepatitis B virus drug resistance mutations in HIV/HBV co-infected children in Windhoek, Namibia

In patients who are HIV infected, hepatitis B virus (HBV) infection is an important co-morbidity. However, antiretroviral options for HIV/HBV co-infected children are limited and, at the time of this study, only included lamivudine. These children may remain on this regimen for many years until late adolescence. They are at high risk of developing HBV drug resistance and uncontrolled HBV disease. The aim of this study was to characterize HBV infection in HIV/HBV co-infected children. Known HIV-infected/HBsAg-positive children, previously exposed to lamivudine monotherapy against HBV, and their mothers were recruited at the Katutura Hospital paediatric HIV clinic in Windhoek, Namibia. Dried blood spot and serum samples were collected for HBV characterization and serological testing, respectively. Fifteen children and six mothers participated in the study. Eight of the 15 children (53.3%) tested HBV DNA positive; all eight children were on lamivudine-based ART. Lamivudine-associated resistance variants, together with immune escape mutants in the surface gene, were identified in all eight children. Resistance mutations included rtL80I, rtV173L, rtL180M, rtM204I/V and the overlapping sE164D, sW182*, sI195M and sW196LS variants. HBV strains belonged to genotypes E (6/8, 75%) and D3 (2/8, 25%). Further analysis of the HBV core promoter region revealed mutations associated with reduced expression of HBeAg protein and hepatocarcinogenesis. All six mothers, on HBV-active ART containing tenofovir and lamivudine, tested HBV DNA negative. This study confirms the importance of screening HIV-infected children for HBV and ensuring equity of drug access to effective HBV treatment if co-infected.

Prevalence and burden of HBV co-infection among people living with HIV: A global systematic review and meta-analysis

Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV.

Serological profile of hepatitis B in children after the introduction of its vaccination in Burkina Faso

Viral hepatitis B is a public health issue. We establish the children serological profile of hepatitis B in Bobo-Dioulasso, six years after the introduction of hepatitis B vaccine into the Expanded Program on Immunization. This was a descriptive study of prospective data collection carried out in the Department of Pediatrics and the laboratory of virology of the Centre MURAZ of Bobo-Dioulasso between March 2013 and May 2013. Blood samples were made in search of the following hepatitis B serological markers: anti-HBcAb total, HBsAg, Ac anti-HBs, HBeAg, AcHBs, IgM anti-HBc total. The ELISA method with the Monolisa BIORAD reagents was used. A total of 2015 children were included, 1026 (50, 9%) boys and 989 (49.1%) girls, at an average age of 58±48 months. Out of these 2015 children, 53 (2.6%) were positive to HBsAg including 19 vaccinated cases, one child has received 3 doses plus 1 booster dose of hepatitis B vaccine. We found no statistically significant difference in the carriage of serologic markers of hepatitis B between the unvaccinated group and the vaccinated group. Large-scale studies should be carried out in Burkina Faso to see the real impact of vaccination on the health of our populations.

Hepatitis B sero-prevalence in children under 15 years of age in South Africa using residual samples from community-based febrile rash surveillance

Introduction and methods

Hepatitis B is a vaccine preventable disease and is notifiable in South Africa. Hepatitis B vaccination was incorporated into the Expanded Programme on Immunisation in South Africa in 1995. We used a convenience sample from community-based febrile rash surveillance in 2013 to estimate hepatitis B sero-prevalence. Of samples serologically negative for acute measles infection, 450 samples spanning nine provinces of South Africa were tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc).

Results

Two children (2/450; 0.4%) tested positive for HBsAg. Three hundred and three children (67.3%) had evidence of vaccine induced immunity. Vaccine induced immunity was present in 80.2% of 1–5 year olds, but only 60.3% of 10–14 year olds. Natural immunity, indicating exposure to circulating hepatitis B, was present in 13/450 (2.9%) children.

Conclusion

Chronic hepatitis B in South African has decreased in prevalence from highly endemic levels prior to vaccine introduction to approximately 0.4% in this sample, demonstrating impact of a successful vaccination programme 18 years after introduction. Decreased vaccine-induced immunity with increasing age may reflect waning antibody titres over time.

The burden of vaccine-preventable diseases among HIV-infected and HIV-exposed children in sub-Saharan Africa: a systematic review and meta-analysis

There are knowledge gaps regarding evidence-based research on the burden of vaccine-preventable diseases among human immunodeficiency virus (HIV)-infected and HIV-exposed children aged <18 years in sub-Saharan Africa. It is therefore essential to determine the trend and burden of vaccine-preventable diseases. We completed a systematic review and meta-analysis to identify the incidence, prevalence and case-fatality rates (CFR) attributed to various vaccine-preventable diseases among HIV-infected and HIV-exposed children in sub-Saharan Africa. The trends in the prevalence of vaccine-preventable diseases among HIV-infected and HIV-exposed children were also determined. Nine studies on tuberculosis (TB) were pooled to give an overall incidence rate estimate of 60 (95% confidence interval [CI] 30-70) per 1,000 child-years. The incidence of pneumococcal infections varied between 109-1509 per 100,000 while pertussis was between 2.9 and 3.7 per 1000 child-year. Twenty-two TB prevalence studies reported an estimated prevalence of 16%. Fifteen prevalence studies on hepatitis B infection were pooled together with an estimated prevalence of 5%. The pooled prevalence for pneumococcal infections was 2% while rotavirus diarrhoea reported a prevalence of 13%. Twenty-nine studies on TB were pooled to give an overall CFR estimate of 17% while pneumococcal infections in HIV-infected and exposed children were pooled together with a resultant rate of 15%. Some of the vaccine-preventable diseases still have high incidences, prevalence and CFR among HIV-infected and HIV-exposed children. There is also a dearth of research data on the burden of several vaccine-preventable diseases among HIV-infected and exposed children and a need for more studies in this area.

HBV vaccination and PMTCT as elimination tools in the presence of HIV: insights from a clinical cohort and dynamic model

BACKGROUND

Sustainable Development Goals set a challenge for the elimination of hepatitis B virus (HBV) infection as a public health concern by the year 2030. Deployment of a robust prophylactic vaccine and enhanced interventions for prevention of mother to child transmission (PMTCT) are cornerstones of elimination strategy. However, in light of the estimated global burden of 290 million cases, enhanced efforts are required to underpin optimisation of public health strategy. Robust analysis of population epidemiology is particularly crucial for populations in Africa made vulnerable by HIV co-infection, poverty, stigma and poor access to prevention, diagnosis and treatment.

METHODS

We here set out to evaluate the current and future role of HBV vaccination and PMTCT as tools for elimination. We first investigated the current impact of paediatric vaccination in a cohort of children with and without HIV infection in Kimberley, South Africa. Second, we used these data to inform a new parsimonious model to simulate the ongoing impact of preventive interventions. By applying these two approaches in parallel, we are able to determine both the current impact of interventions, and the future projected outcome of ongoing preventive strategies over time.

RESULTS

Existing efforts have been successful in reducing paediatric prevalence of HBV infection in this setting to < 1%, demonstrating the success of the existing vaccine campaign. Our model predicts that, if consistently deployed, combination efforts of vaccination and PMTCT can significantly reduce population prevalence (HBsAg) by 2030, such that a major public health impact is possible even without achieving elimination. However, the prevalence of HBV e-antigen (HBeAg)-positive carriers will decline more slowly, representing a persistent population reservoir. We show that HIV co-infection significantly reduces titres of vaccine-mediated antibody, but has a relatively minor role in influencing the projected time to elimination. Our model can also be applied to other settings in order to predict impact and time to elimination based on specific interventions.

CONCLUSIONS

Through extensive deployment of preventive strategies for HBV, significant positive public health impact is possible, although time to HBV elimination as a public health concern is likely to be substantially longer than that proposed by current goals.

A blind spot? Confronting the stigma of hepatitis B virus (HBV) infection - A systematic review

Background: Stigma, poverty, and lack of knowledge present barriers to the diagnosis and treatment of chronic infection, especially in resource-limited settings. Chronic Hepatitis B virus (HBV) infection is frequently asymptomatic, but accounts for a substantial long-term burden of morbidity and mortality. In order to improve the success of diagnostic, treatment and preventive strategies, it is important to recognise, investigate and tackle stigma. We set out to assimilate evidence for the nature and impact of stigma associated with HBV infection, and to suggest ways to tackle this challenge.

Methods: We carried out a literature search in PubMed using the search terms ‘hepatitis B’, ‘stigma’ to identify relevant papers published between 2007 and 2017 (inclusive), with a particular focus on Africa.

Results: We identified a total of 32 articles, of which only two studies were conducted in Africa. Lack of knowledge of HBV was consistently identified, and in some settings there was no local word to describe HBV infection. There were misconceptions about HBV infection, transmission and treatment. Healthcare workers provided inaccurate information to individuals diagnosed with HBV, and poor understanding resulted in lack of preventive measures. Stigma negatively impacted on help-seeking, screening, disclosure, prevention of transmission, and adherence to treatment, and had potential negative impacts on mental health, wellbeing, employment and relationships.

Conclusion: Stigma is a potentially major barrier to the successful implementation of preventive, diagnostic and treatment strategies for HBV infection, and yet we highlight a ‘blind spot’, representing a lack of data and limited recognition of this challenge. There is a need for more research in this area, to identify and evaluate interventions that can be used effectively to tackle stigma, and to inform collaborative efforts between patients, clinical services, policy makers, traditional healers, religious leaders, charity organisations and support groups.

A blind spot? Confronting the stigma of hepatitis B virus (HBV) infection - A systematic review

Background: Stigma, poverty, and lack of knowledge present barriers to the diagnosis and treatment of chronic infection, especially in resource-limited settings. Chronic Hepatitis B virus (HBV) infection is frequently asymptomatic, but accounts for a substantial long-term burden of morbidity and mortality. In order to improve the success of diagnostic, treatment and preventive strategies, it is important to recognise, investigate and tackle stigma. We set out to assimilate evidence for the nature and impact of stigma associated with HBV infection, and to suggest ways to tackle this challenge. Methods: We carried out a literature search in PubMed using the search terms 'hepatitis B', 'stigma' to identify relevant papers published between 2007 and 2017 (inclusive), with a particular focus on Africa. Results: We identified a total of 32 articles, of which only two studies were conducted in Africa. Lack of knowledge of HBV was consistently identified, and in some settings there was no local word to describe HBV infection. There were misconceptions about HBV infection, transmission and treatment. Healthcare workers provided inaccurate information to individuals diagnosed with HBV, and poor understanding resulted in lack of preventive measures. Stigma negatively impacted on help-seeking, screening, disclosure, prevention of transmission, and adherence to treatment, and had potential negative impacts on mental health, wellbeing, employment and relationships. Conclusion: Stigma is a potentially major barrier to the successful implementation of preventive, diagnostic and treatment strategies for HBV infection, and yet we highlight a 'blind spot', representing a lack of data and limited recognition of this challenge. There is a need for more research in this area, to identify and evaluate interventions that can be used effectively to tackle stigma, and to inform collaborative efforts between patients, clinical services, policy makers, traditional healers, religious leaders, charity organisations and support groups.

A systematic review of hepatitis B virus (HBV) drug and vaccine escape mutations in Africa: A call for urgent action

International sustainable development goals for the elimination of viral hepatitis as a public health problem by 2030 highlight the pressing need to optimize strategies for prevention, diagnosis and treatment. Selected or transmitted resistance associated mutations (RAMs) and vaccine escape mutations (VEMs) in hepatitis B virus (HBV) may reduce the success of existing treatment and prevention strategies. These issues are particularly pertinent for many settings in Africa where there is high HBV prevalence and co-endemic HIV infection, but lack of robust epidemiological data and limited education, diagnostics and clinical care. The prevalence, distribution and impact of RAMs and VEMs in these populations are neglected in the current literature. We therefore set out to assimilate data for sub-Saharan Africa through a systematic literature review and analysis of published sequence data, and present these in an on-line database (https://livedataoxford.shinyapps.io/1510659619-3Xkoe2NKkKJ7Drg/). The majority of the data were from HIV/HBV coinfected cohorts. The commonest RAM was rtM204I/V, either alone or in combination with associated mutations, and identified in both reportedly treatment-naïve and treatment-experienced adults. We also identified the suite of mutations rtM204V/I + rtL180M + rtV173L, that has been associated with vaccine escape, in over 1/3 of cohorts. Although tenofovir has a high genetic barrier to resistance, it is of concern that emerging data suggest polymorphisms that may be associated with resistance, although the precise clinical impact of these is unknown. Overall, there is an urgent need for improved diagnostic screening, enhanced laboratory assessment of HBV before and during therapy, and sustained roll out of tenofovir in preference to lamivudine alone. Further data are needed in order to inform population and individual approaches to HBV diagnosis, monitoring and therapy in these highly vulnerable settings.

PARV4 prevalence, phylogeny, immunology and coinfection with HIV, HBV and HCV in a multicentre African cohort

Background: The seroprevalence of human parvovirus-4 (PARV4) varies considerably by region. In sub-Saharan Africa, seroprevalence is high in the general population, but little is known about the transmission routes or the prevalence of coinfection with blood-borne viruses, HBV, HCV and HIV.  Methods: To further explore the characteristics of PARV4 in this setting, with a particular focus on the prevalence and significance of coinfection, we screened a cohort of 695 individuals recruited from Durban and Kimberley (South Africa) and Gaborone (Botswana) for PARV4 IgG and DNA, as well as documenting HIV, HBV and HCV status.  Results: Within these cohorts, 69% of subjects were HIV-positive. We identified no cases of HCV by PCR, but 7.4% were positive for HBsAg. PARV4 IgG was positive in 42%; seroprevalence was higher in adults (69%) compared to children (21%) (p<0.0001) and in HIV-positive (52%) compared to HIV-negative individuals (24%) (p<0.0001), but there was no association with HBsAg status. We developed an on-line tool to allow visualization of coinfection data ( https://purl.oclc.org/coinfection-viz). We identified five subjects who were PCR-positive for PARV4 genotype-3. Ex vivo CD8+ T cell responses spanned the entire PARV4 proteome and we propose a novel HLA-B*57:03-restricted epitope within the NS protein.  Conclusions: This characterisation of PARV4 infection provides enhanced insights into the epidemiology of infection and co-infection in African cohorts, and provides the foundations for planning further focused studies to elucidate transmission pathways, immune responses, and the clinical significance of this organism.