Hepatitis B in sub-Saharan Africa-How many patients need therapy?

Real-world experience with nucleos(t)ide analogue therapy and patient survival rates in chronic viral hepatitis B treatment centers in Eritrea

Real-world data on treatment outcomes or the quality of large-scale chronic hepatitis B (CHB) treatment programs in sub-Saharan Africa (SSA) is extremely difficult to obtain. In this study, we aimed to provide data on the prevalence and incidence of mortality, loss to follow-up (LFTU), and their associated factors in patients with CHB in three treatment centres in Eritrea. Additional information includes baseline clinical profiles of CHB patients initiated on nucleos(t)ide analogue (NUCs) along with a comparison of treatment with Tenofovir disoproxil fumarate (TDF) vs. TDF + Lamuvudine (LAM) using specific biochemical, haematological and virologic parameters. A multicenter retrospective cohort study was conducted on CHB patients in Asmara, Eritrea (2018-2021). Demographic, clinical, and laboratory information was collected from medical records using a structured checklist. Relevant parametric and nonparametric statistics were employed to explore treatment outcomes and to evaluate differences between groups. Where appropriate, Kaplan-Meier (KM) curves and univariate and multivariate Cox regression models were implemented. A two-sided p-value < 0.05 was considered significant. A total of 413 patients with HBV (median age (IQR) at diagnosis: 39 (IQR: 28-50 years; females: 118(28.6%); followed for a total of 22,921 person days) were studied. HBV/HIV co-infection was observed in 15(3.6%) and baseline ALT and AST were elevated in 99(31.2%) and 101(32.8%), respectively. The Fibrosis-4 (FIB-4) index estimates suggested that cirrhosis was highly likely in 33 (14%) patients with 49 (20.8%) patients in the indeterminate FIB-4 score category. During the follow-up period, 4.6% (95% CI: 2.5-6.6%) died, while 23.9% (95% CI: 19.8-28%) were LTFU. In the adjusted Cox proportional hazards model, LTFU were independently associated with baseline serum HBV DNA (IU/mL) (aHR = 1.3, 95% CI 1.04-1.7; p-value = 0.02); Not initiated on NUC (aHR = 3.9, 95% CI: 1.1-13.7, p-value = 0.02); and FIB-4 Score (aHR = 1.05, 95% CI: 1-1.1; p-value = 0.01). Of the 413 patients enrolled in the study, 98 cases (23.73%) were initiated on treatment. In the head-to-head comparison of the results in TDF and TDF + LAM after 12 weeks of treatment, VR was observed in 14(45.2%) vs. 17(54.8%), respectively, translating into an overall VR of 60.7% (95% CI 46.9-74.6). Furthermore, VR in TDF vs. TDF + LAM were similar, 14(45.2%) vs. 17(54.4%) respectively, p-value = 0.3). This study uncovered multiple systems- and patient-centered gaps in the three HBV treatment programs in Asmara, Eritrea. These include late presentation, high incidence of LTFU, inconsistencies in routine data, and poor data management. Interventions should target improvements in laboratory infrastructure, adherence to patient monitoring guidelines, HBV literacy, better tracking of patients, and documentation of patient's information.

Malignancy and viral infections in Sub-Saharan Africa: A review

The burden of malignancy related to viral infection is increasing in Sub-Saharan Africa (SSA). In 2018, approximately 2 million new cancer cases worldwide were attributable to infection. Prevention or treatment of these infections could reduce cancer cases by 23% in less developed regions and about 7% in developed regions. Contemporaneous increases in longevity and changes in lifestyle have contributed to the cancer burden in SSA. African hospitals are reporting more cases of cancer related to infection (e.g., cervical cancer in women and stomach and liver cancer in men). SSA populations also have elevated underlying prevalence of viral infections compared to other regions. Of 10 infectious agents identified as carcinogenic by the International Agency for Research on Cancer, six are viruses: hepatitis B and C viruses (HBV and HCV, respectively), Epstein-Barr virus (EBV), high-risk types of human papillomavirus (HPV), Human T-cell lymphotropic virus type 1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV, also known as human herpesvirus type 8, HHV-8). Human immunodeficiency virus type 1 (HIV) also facilitates oncogenesis. EBV is associated with lymphomas and nasopharyngeal carcinoma; HBV and HCV are associated with hepatocellular carcinoma; KSHV causes Kaposi's sarcoma; HTLV-1 causes T-cell leukemia and lymphoma; HPV causes carcinoma of the oropharynx and anogenital squamous cell cancer. HIV-1, for which SSA has the greatest global burden, has been linked to increasing risk of malignancy through immunologic dysregulation and clonal hematopoiesis. Public health approaches to prevent infection, such as vaccination, safer injection techniques, screening of blood products, antimicrobial treatments and safer sexual practices could reduce the burden of cancer in Africa. In SSA, inequalities in access to cancer screening and treatment are exacerbated by the perception of cancer as taboo. National level cancer registries, new screening strategies for detection of viral infection and public health messaging should be prioritized in SSA's battle against malignancy. In this review, we discuss the impact of carcinogenic viruses in SSA with a focus on regional epidemiology.

Pathogen Detection Using Metagenomic Next-Generation Sequencing of Plasma Samples from Patients with Sepsis in Uganda

Metagenomic sequencing is a promising new method for pathogen detection. We aimed to detect pathogens from archived plasma using metagenomic sequencing in a previously well-characterized cohort of 254 predominantly HIV-infected patients with sepsis in Uganda. We used Illumina sequencing and the Chan Zuckerberg ID metagenomics platform to sequence and identify pathogens. On average, each plasma sample yielded 3,404,737 ± 2,201,997 reads (mean ± standard deviation), of which 220,032 ± 416,691 (6.3% ± 8.6%) were identified as nonhuman reads. Using a background model filter, 414 genus-specific pathogen identifications were found in the 254 samples. Nineteen pathogens were previously detected positive by quantitative PCR (qPCR), compared to sequencing, which demonstrated 30.2% sensitivity and 99.5% specificity. Sensitivity was higher for viral pathogens than nonviral pathogens (37% versus 5%). For example, HIV viremia was detected in 69% of samples using qPCR, and sequencing revealed 70% sensitivity and 92% specificity. There were 75 genus-specific potential pathogens identified by sequencing in this cohort, including hepatitis B and Epstein-Barr virus (EBV), among several others. qPCR showed a prevalence of hepatitis B and EBV viremia of 17% and 45%, respectively. In-hospital mortality was associated with a lower qPCR threshold cycle value for EBV (adjusted odds ratio, 0.85; P < .001) but not for hepatitis B or HIV. In conclusion, a broad range of potential pathogens were identified by metagenomic sequencing in patients with sepsis in Uganda. Unexpectedly high rates of hepatitis B and EBV viremia were found. Whether these viral infections in HIV patients with sepsis are clinically important requires further study. IMPORTANCE The use of next-generation sequencing (NGS) in blood samples is an emerging technology for clinical microbiology labs. In this work, we performed NGS on plasma samples from a well-characterized cohort, where all samples had been previously tested by PCR for 43 pathogens. Therefore, we could compare sequencing performance against that of PCR and identify clinical correlates. A broad range of potential pathogens were identified by metagenomic sequencing in patients with sepsis in Uganda, particularly viruses, which we confirmed by PCR. In addition to HIV viremia, unexpectedly high rates of hepatitis B and EBV viremia were found, which may have important clinical implications.

Hepatitis B Virus Research in South Africa

Despite being vaccine-preventable, hepatitis B virus (HBV) infection remains the seventh leading cause of mortality in the world. In South Africa (SA), over 1.9 million people are chronically infected with HBV, and 70% of all Black chronic carriers are infected with HBV subgenotype A1. The virus remains a significant burden on public health in SA despite the introduction of an infant immunization program implemented in 1995 and the availability of effective treatment for chronic HBV infection. In addition, the high prevalence of HIV infection amplifies HBV replication, predisposes patients to chronicity, and complicates management of the infection. HBV research has made significant progress leading to better understanding of HBV epidemiology and management challenges in the SA context. This has led to recent revision of the national HBV infection management guidelines. Research on developing new vaccines and therapies is underway and progress has been made with designing potentially curative gene therapies against HBV. This review summarizes research carried out in SA on HBV molecular biology, epidemiology, treatment, and vaccination strategies.

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.

Hepatitis B virus infection and hepatocellular carcinoma in sub-Saharan Africa: Implications for elimination of viral hepatitis by 2030?

Elimination of viral hepatitis in sub-Saharan Africa by 2030 is an ambitious feat. However, as stated by the World Health Organization, there are unprecedented opportunities to act and make significant contributions to the elimination target. With 60 million people chronically infected with hepatitis B virus (HBV) of whom 38800 are at risk of developing highly fatal hepatocellular carcinoma (HCC) every year, sub-Saharan Africa faces one of the greatest battles towards elimination of viral hepatitis. There is a need to examine progress in controlling the disproportionate burden of HBV-associated HCC in sub-Saharan Africa within the context of this elimination target. By scaling-up coverage of hepatitis B birth dose and early childhood vaccination, we can significantly reduce new cases of HCC by as much as 50% within the next three to five decades. Given the substantial reservoir of chronic HBV carriers however, projections show that HCC incidence and mortality rates in sub-Saharan Africa will double by 2040. This warrants urgent public health attention. The trends in the burden of HCC over the next two decades, will be determined to a large extent by progress in achieving early diagnosis and appropriate linkage to care for high-risk chronic HBV infected persons.

Viral hepatitis amidst COVID-19 in Africa: Implications and recommendations

Hepatitis, a significant cause of mortality worldwide, results in around 1.34 million deaths each year globally. Africa is not exempt from the plague of Hepatitis. Around 100 million estimated individuals are infected with Hepatitis B or C. Egypt has the highest prevalence of cases of Hepatitis followed by Cameroon and Burundi. The continent is severely affected by the onset of the COVID‐19 pandemic, as the virus has added an additional burden on the already fragile continent. With the pandemic, it is presumable that Hepatitis like other viral diseases will pose a threat to collapsing healthcare system. Therefore, for Africa to become more resilient in the face of such menaces, including Hepatitis, further prevention policies are required to be implemented

The global burden of chronic hepatitis B virus infection: comparison of country-level prevalence estimates from four research groups

Background

Progress towards viral hepatitis elimination goals relies on accurate estimates of chronic hepatitis B virus (HBV)-infection prevalence. We compared existing sources of country-level estimates from 2013 to 2017 to investigate the extent and underlying drivers of differences between them.

Methods

The four commonly cited sources of global-prevalence estimates, i.e. the Institute for Health Metrics and Evaluation, Schweitzer et al., the World Health Organization (WHO) and the CDA Foundation, were compared by calculating pairwise differences between sets of estimates and assessing their within-country variation. Differences in underlying empirical data and modelling methods were investigated as contributors to differences in sub-Saharan African estimates.

Results

The four sets of estimates across all ages were comparable overall and agreed on the global distribution of HBV burden. The WHO and the CDA produced the most similar estimates, differing by a median of 0.8 percentage points. Larger discrepancies were seen in estimates of prevalence in children under 5 years of age and in sub-Saharan African countries, where the median pairwise differences were 2.7 percentage and 2.4 percentage points for all-age prevalence and in children, respectively. Recency and representativeness of included data, and different modelling assumptions of the age distribution of HBV burden, seemed to contribute to these differences.

Conclusion

Current prevalence estimates, particularly those from the WHO and the CDA based on more recent empirical data, provide a useful resource to assess the population-level burden of chronic HBV-infection. However, further seroprevalence data in young children are needed particularly in sub-Saharan Africa. This is a priority, as monitoring progress towards elimination depends on improved knowledge of prevalence in this age group.