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

Molecular epidemiology of hepatitis B virus (HBV) in Ethiopia: A review article

Hepatitis B virus (HBV) belongs to the family Hepadnaviridae and is the smallest human DNA virus, with a genome that is only 3200 nucleotides long. The absence of proofreading function in HBV reverse transcriptase provides a wide range of genetic variants for targeted outgrowth at different stages of infection. A number of sub genotypes and ten HBV genotypes (A through J) have been identified through analyses of the divergence of HBV genomic sequences. Numerous clinical outcomes, including the emergence of chronicity, the course of the disease, the effectiveness of treatment, and the response to vaccination, have been related to differences in genotype between HBV isolates. There are just seven studies that have been done in Ethiopia that examine the molecular epidemiology of HBV. Moreover, these studies haven't been compiled and reviewed yet. In this review, we looked at the genetic diversity and molecular epidemiology of HBV, the relationship between HBV genotypes and clinical outcomes, the immunopathogenesis of HBV, and finally the molecular epidemiology of HBV in Ethiopia. PubMed, Embase, and Google Scholar search engines were used to find relevant articles for the review. By using HBV genotyping, clinicians can better tailor vaccination decisions and antiviral therapy for patients with chronic hepatitis B who are more likely to experience the disease's progression.

Seroprevalence of human immunodeficiency virus in African blood donors: a systematic review and meta-analysis

BACKGROUND

In developing countries, the safety of blood transfusions remains an important public health concern as it is associated with a higher risk of transfusion-transmissible infections (TTIs). In this study, we aimed to estimate the seroprevalence of HIV among blood donors in Africa and assess the temporal trends and regional differences within the continent through a systematic review and meta-analysis.

METHODS

Seven electronic databases (PubMed, Web of Science, Cochrane, Scopus, HINARI, Global Index Medicus and Clinical.

TRIAL

gov) were searched for relevant studies for our research. We included all primary studies that estimated the seroprevalence of HIV among blood donors in Africa with an age population from 16 to 65 years old, without language restrictions, from inception up to March 1st 2024. The pooled seroprevalence was estimated through the DerSimonian-Laird random effects model. The temporal trends and regional differences were assessed through subgroup and meta-regression analysis.

FINDINGS

We obtained 122 studies that met our inclusion criteria, comprising 7,814,996 blood donors tested for HIV. Sixty-six percent of the studies were from Western and Eastern Africa. The pooled seroprevalence of HIV among blood donors in Africa was 2.66% (95% CI: 2.17-3.20%; I2 = 99.80%, p < 0.01). The highest prevalence was observed in the Central African region, 3.28% (95% CI: 2.57%-4.06%), followed by the Eastern 3.21% (95% CI: 2.12%-4.52%), and the Western 2.66% (95% CI: 1.93%-3.49%) regions. Lower prevalences were observed in the Northern region, 0.57% (95% CI: 0.0%-2.10%), followed by the Southern African region with 0.45% (95% CI: 0.16%-0.86%). We observed a temporal decreased trend of HIV prevalence.

INTERPRETATION

The prevalence of HIV infection among African blood donors remains high and is not homogeneous across the continent. Efficient measures to strengthen HIV testing and prevent HIV transmission through blood transfusion are needed in Africa. Systematic review protocol registration: PROSPERO CRD42023395616.

FUNDING

This article was supported by National Funds through FCT - Fundação para a Ciência e a Tecnologia,I.P., within CINTESIS, R&D Unit (reference UIDP/4255/2020).

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.

Could Herpesviridae be the cause of severe acute hepatitis of unknown origin in children?

INTRODUCTION

Severe acute hepatitis (SAH) is defined by a severe inflammation of hepatocytes in the liver parenchyma which can lead to an acute liver failure, a clinical condition with high mortality rate that can be triggered by several factors but is usually associated to hepatotropic viruses' infection. In 2022, cases of children with severe acute hepatitis of unknown origin hospitalized in Glasgow, Scotland, were reported. Possible causes of this condition include, but are not limited to, undiagnosed viral (and non-viral) infections, autoimmune hepatitis, drug and/or chemical toxicity, mitochondrial chain respiratory and metabolic disorders.

AREAS COVERED

Herpesviruses can cause severe acute hepatitis, but little is known about the role and the mechanisms of herpesviruses as a causative agent of this type of hepatitis. We review the role of herpesviruses as causative agent of SAH in children and other possible mechanisms involved in this disease.

EXPERT OPINION

Differential diagnosis for herpesvirus in SAH should be implemented in all settings. Alternative fluids, such as saliva and dried blood, could be used in the diagnosis to overwhelm the availability of biological specimens at sufficient volume. In the future, genetic studies could also be added to increase the knowledge about severe acute hepatitis in children.

Seroprevalence of hepatitis B and C virus among highly active antiretroviral therapy experienced children in Gondar, Ethiopia

BACKGROUND

Globally, chronic viral hepatitis is the cause of mortality alongside human immunodeficiency virus/acquired immunodeficiency syndrome and tuberculosis. Published reports on the seroprevalence of hepatitis B and C viruses among HIV-infected children are lacking in sub-Saharan Africa. Hence, this study aimed to determine the seroprevalence of hepatitis B and C viruses among highly active antiretroviral therapy (HAART)-experienced children at the University of Gondar Comprehensive Specialized Hospital.

METHODS

We conducted a hospital-based cross-sectional study to determine the seroprevalence of hepatitis B and C viruses among HAART-experienced children from January to May 2020. We collected the socio-demographic characteristics of study participants with pretested questioners and clinical data from medical records. We performed enzyme-linked immunosorbent assay-based laboratory test for serum hepatitis B surface antigens and anti-hepatitis C virus antibodies. Finally, we analyzed the frequency of all variables, determined the association of independent variables with hepatitis B and C viruses by using univariable and then multivariable logistic regression.

RESULTS

A total of 241 HAART-experienced children were enrolled, 49.8% of whom were girls. The median age of participants was 13 years (interquartile range 11-14). The seroprevalence of hepatitis B and C virus infection among HAART-experienced children were 9.5% and 2.9%, respectively. Being underweight was significantly associated with both hepatitis B virus (AOR = 3.87: 95% CI; 1.04-14.46, P = 0.044) and hepatitis C virus infections (AOR = 4.54: 95% CI; 1.21-17.04, P = 0.025).

CONCLUSIONS

This study showed that the magnitude of hepatitis B and C viruses was high among HIV-infected children who were under HAART and did not know their hepatitis B and C infection status before. Being underweight was associated with both hepatitis viruses. Therefore, screening for hepatitis B and C viruses should be a routine measure for all HIV-infected children.

Genotype E: The neglected genotype of hepatitis B virus

Hepatitis B virus (HBV) (sub)genotypes A1, D3 and E circulate in sub-Saharan Africa, the region with one of the highest incidences of HBV-associated hepatocellular carcinoma globally. Although genotype E was identified more than 20 years ago, and is the most widespread genotype in Africa, it has not been extensively studied. The current knowledge status and gaps in its origin and evolution, natural history of infection, disease progression, response to antiviral therapy and vaccination are discussed. Genotype E is an African genotype, with unique molecular characteristics that is found mainly in Western and Central Africa and rarely outside Africa except in individuals of African descent. The low prevalence of this genotype in the African descendant populations in the New World, phylogeographic analyses, the low genetic diversity and evidence of remnants of genotype E in ancient HBV samples suggests the relatively recent re-introduction into the population. There is scarcity of information on the clinical and virological characteristics of genotype E-infected patients, disease progression and outcomes and efficacy of anti-HBV drugs. Individuals infected with genotype E have been characterised with high hepatitis B e antigen-positivity and high viral load with a lower end of treatment response to interferon-alpha. A minority of genotype E-infected participants have been included in studies in which treatment response was monitored. Of concern is that current guidelines do not consider patients infected with genotype E. Thus, there is an urgent need for further large-scale investigations into genotype E, the neglected genotype of HBV.

Hepatitis B Virus Genotype Study in West Africa Reveals an Expanding Clade of Subgenotype A4

Hepatitis B virus (HBV) classification comprises up to 10 genotypes with specific geographical distribution worldwide, further subdivided into 40 subgenotypes, which have different impacts on liver disease outcome. Though extensively studied, the classification of subgenotype A sequences remains ambiguous. This study aimed to characterize HBV isolates from West African patients and propose a more advanced classification of subgenotype A. Fourteen HBV full-length genome sequences isolated from patients from The Gambia and Senegal were obtained and phylogenetically analyzed. Phylogenetic analysis of HBV genotype A sequences isolated from Senegalese and Gambian patients exhibited separate clusters from the other known and confirmed subgenotypes A (A1, A2, A6). Most of the sequences (10/14) clustered with an isolate from Cuba, reported as subgenotype A4 (supported by maximal bootstrap value). Four isolates from The Gambia and Senegal clustered separately from all other subgenotypes and samples sequenced in the study. Three of which from The Gambia, designated as an expanding clade of subgenotype A4, exhibited a mean inter-subgenotypic nucleotide divergence over the entire genome sequence higher than 4% in comparison with the other subgenotypes and the other isolates sequenced in the study, except with subgenotype A4 isolates (3.9%), and this was supported by a maximal bootstrap value. The last one from Senegal seemed to be an expanding subgenotype close to the new clade of A4. Amino acid analysis unveiled a novel motif specific to these isolates. This study revealed an expanding evolution of HBV subgenotype A and novel amino acid motifs. It also highlighted the need for a consensus regarding the analysis and classification of HBV sequences.