Publications by authors named "Tongai Maponga"

Chronic Hepatitis B Virus (HBV) infection remains a significant public health concern, particularly in Africa, where the burden is substantial. HBV is an enveloped virus, classified into ten phylogenetically distinct genotypes (A-J). Tests to determine HBV genotypes are based on full-genome sequencing or reverse hybridization.

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Article Synopsis
  • Chronic hepatitis B infection (CHB) affects 300 million people and is part of a global effort by the United Nations and WHO to eliminate it as a health threat by 2030.
  • Peer support workers (PSWs) are people who have experienced similar health issues and can help others by providing education and emotional support, especially for those with CHB.
  • Investing in peer support can help improve healthcare access, reduce stigma, and ultimately contribute to the goal of eliminating hepatitis B around the world.
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Background: Hepatitis B virus (HBV) elimination requires expanding and decentralising HBV care services. However, peripheral health facilities lack access to diagnostic tools to assess eligibility for antiviral therapy. Through the Hepatitis B in Africa Collaborative Network (HEPSANET), we aimed to develop and evaluate a score using tests generally available at lower-level facilities, to simplify the evaluation of antiviral therapy eligibility in people living with HBV.

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The WHO African region bears a disproportionate burden of morbidity and mortality related to chronic hepatitis B virus (HBV) infection and accounts for an estimated 70% of new HBV infections worldwide. We investigated the extent to which HBV clinical trials represented populations in this region by searching the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov for interventional clinical trials published in English between database inception and May 29, 2023, using the search term "Hepatitis B".

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Chronic hepatitis B virus (HBV) infection remains a significant public health concern, particularly in Africa, where there is a substantial burden. HBV is an enveloped virus, with isolates being classified into ten phylogenetically distinct genotypes (A - J) determined based on full-genome sequence data or reverse hybridization-based diagnostic tests. In practice, limitations are noted in that diagnostic sequencing, generally using Sanger sequencing, tends to focus only on the S-gene, yielding little or no information on intra-patient HBV genetic diversity with very low-frequency variants and reverse hybridization detects only known genotype-specific mutations.

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Approximately 80 million people live with chronic hepatitis B virus (HBV) infection in the WHO Africa Region. The natural history of HBV infection in this population is poorly characterised, and may differ from patterns observed elsewhere due to differences in prevailing genotypes, environmental exposures, co-infections, and host genetics. Existing research is largely drawn from small, single-centre cohorts, with limited follow-up time.

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High profile international goals have been set for the elimination of hepatitis B virus (HBV) infection as a public health threat by the year 2030. Developing and expanding equitable, accessible translational HBV research programmes that represent real-world populations are therefore an urgent priority for clinical and academic communities. We present experiences and insights by an expert interdisciplinary group focusing on barriers that impede adults living with HBV infection from participating in clinical studies.

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Hepatitis B virus (HBV) infection represents a significant global health threat, accounting for 300 million chronic infections and up to 1 million deaths each year. HBV disproportionately affects people who are under-served by health systems due to social exclusion, and can further amplify inequities through its impact on physical and mental health, relationship with stigma and discrimination, and economic costs. The 'inclusion health' agenda focuses on excluded and vulnerable populations, who often experience barriers to accessing healthcare, and are under-represented by research, resources, interventions, advocacy, and policy.

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  • In sub-Saharan Africa, there's a need for simple liver fibrosis biomarkers to improve hepatitis B treatment, based on a study of 3,548 patients across eight countries.
  • The study used a Bayesian bivariate model to evaluate existing biomarkers against a reliable test (transient elastography) and found that the current World Health Organization (WHO) threshold for cirrhosis was too high, resulting in low sensitivity for detecting fibrosis.
  • The researchers proposed new optimized thresholds for the aspartate aminotransferase-to-platelet ratio index, which enhance the ability to identify patients requiring treatment while reducing misdiagnoses in this context.
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The geographic and evolutionary origins of the SARS-CoV-2 Omicron variant (BA.1), which was first detected mid-November 2021 in Southern Africa, remain unknown. We tested 13,097 COVID-19 patients sampled between mid-2021 to early 2022 from 22 African countries for BA.

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Objectives: The aim of this study was to describe the pattern of admissions during the fourth wave of COVID-19 in order to inform future public health policies.

Methods: This was a retrospective descriptive study of an early cohort of all adult patients with SARS-CoV-2 infection admitted to a tertiary hospital in Cape Town, South Africa, at the start of the country's fourth wave. This was compared with an early cohort from the first wave at the same institution.

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Earlier variants of SARS-CoV-2 have been associated with hypercoagulability and an extensive formation of fibrin amyloid microclots, which are considered to contribute to the pathology of the coronavirus 2019 disease (COVID-19). The newer omicron variants appear to be far more transmissible, but less virulent, even when taking immunity acquired from previous infections or vaccination into account. We here show that while the clotting parameters associated with omicron variants are significantly raised over those of healthy, matched controls, they are raised to levels significantly lower than those seen with more severe variants such as beta and delta.

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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.

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Article Synopsis
  • A lot of money has been spent on studying the COVID-19 virus in Africa, leading to over 100,000 virus samples being analyzed to understand the spread of the disease.
  • *More countries in Africa are now able to do these studies themselves, which helps them get results faster and keep a close watch on the virus.
  • *To keep fighting COVID and other diseases, more funding and support for testing and research in Africa is really important for the future.
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A 22-year-old woman with uncontrolled advanced human immunodeficiency virus (HIV) infection was persistently infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) beta variant for 9 months, the virus accumulating >20 additional mutations. Antiretroviral therapy suppressed HIV and cleared SARS-CoV-2 within 6 to 9 weeks. Increased vigilance is warranted to benefit affected individuals and prevent the emergence of novel SARS-CoV-2 variants.

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Early in the coronavirus disease 2019 (COVID-19) pandemic, global governing bodies prioritized transmissibility-based precautions and hospital capacity as the foundation for delay of elective procedures. As elective surgical volumes increased, convalescent COVID-19 patients faced increased postoperative morbidity and mortality and clinicians had limited evidence for stratifying individual risk in this population. Clear evidence now demonstrates that those recovering from COVID-19 have increased postoperative morbidity and mortality.

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  • Global genomic surveillance has found a new SARS-CoV-2 variant, C.1.2, in South Africa and eleven other countries, which shows increased transmissibility and potentially greater disease severity.
  • C.1.2 has a high substitution rate in its spike protein, related to reduced neutralization sensitivity, making it harder for antibodies from vaccinated individuals or those infected with earlier strains to effectively combat it.
  • Previous infections with variants Beta or Delta may provide some protection against C.1.2, suggesting that the vaccine's effectiveness against this new variant could be similar to that against the earlier concerning variants.
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