Publications by authors named "Henry Mwandumba"

Macrophages are the primary host cell type for infection by Mycobacterium tuberculosis in vivo. Macrophages are also key immune effector cells that mediate the control of bacterial growth. However, the specific macrophage phenotypes that are required for optimal immune control of M.

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Protection against infections with intracellular bacteria requires the interaction of macrophages and T-lymphocytes, including CD8 T cells. Recently, the expression of natural killer cell receptors NKG2A and NKG2C was introduced as markers of CD8 T-cell subsets. The goal of this study was to functionally characterize human NKG2A and NKG2C-expressing T cells using the major pathogen () as a model organism.

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Unlabelled: Cryptococcal meningitis causes an estimated 112,000 global deaths per annum. Genomic and phenotypic features of the infecting strain of spp. have been associated with outcomes from cryptococcal meningitis.

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Tuberculosis (TB) transmission and prevalence are dynamic over time, and heterogeneous within populations. Public health programmes therefore require up-to-date, accurate epidemiological data to appropriately allocate resources, target interventions, and track progress towards End TB goals. Current methods of TB surveillance often rely on case notifications, which are biased by access to healthcare, and TB disease prevalence surveys, which are highly resource-intensive, requiring many tens of thousands of people to be tested to identify high-risk groups or capture trends.

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Article Synopsis
  • HIV-associated cryptococcal meningitis is a major cause of AIDS deaths, prompting research to establish a faster method for detecting fungal load, which traditionally relies on CFU counts.
  • The study developed qPCR assays to identify and quantify different Cryptococcus species in cerebrospinal fluid from patients in sub-Saharan Africa, analyzing samples at various stages of antifungal treatment.
  • Results showed high sensitivity in detecting fungal load and identified a significant prevalence of Cryptococcus neoformans in both Botswana and Malawi, with some patients showing viable but non-culturable yeasts after treatment.
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The proliferation of various forms of artificial intelligence (AI) brings many opportunities to improve health care. AI models can harness complex evolving data, inform and augment human actions, and learn from health outcomes such as morbidity and mortality. The global public health challenge of antimicrobial resistance (AMR) needs large-scale optimisation of antimicrobial use and wider infection care, which could be enabled by carefully constructed AI models.

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Tuberculosis (TB) remains a major challenge in many domains including diagnosis, pathogenesis, prevention, treatment, drug resistance and long-term protection of the public health by vaccination. A controlled human infection model (CHIM) could potentially facilitate breakthroughs in each of these domains but has so far been considered impossible owing to technical and safety concerns. A systematic review of mycobacterial human challenge studies was carried out to evaluate progress to date, best possible ways forward and challenges to be overcome.

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Background  COVID-19 is currently a global health threat. Healthcare workers are on the front-line of the COVID-19 outbreak response and therefore at heightened risk of infection. There is a dearth of evidence from Sub-Saharan Africa about healthcare worker experiences in managing COVID-19.

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Background: There are limited data describing clinical flucytosine pharmacokinetics (PK). The variability of flucytosine partitioning into the CNS is not known. We described the interindividual variability in flucytosine PK in patients with HIV-associated cryptococcal meningoencephalitis.

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Background: Compared to the abundance of clinical and genomic information available on patients hospitalised with COVID-19 disease from high-income countries, there is a paucity of data from low-income countries. Our aim was to explore the relationship between viral lineage and patient outcome.

Methods: We enrolled a prospective observational cohort of adult patients hospitalised with PCR-confirmed COVID-19 disease between July 2020 and March 2022 from Blantyre, Malawi, covering four waves of SARS-CoV-2 infections.

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Background: Dyslipidaemia drives the process of atherosclerosis, and hence a significant modifiable risk factor complicating hypertension and diabetes. In Malawi, the prevalence, screening and management of dyslipidaemia among persons with diabetes mellitus have not been reported. This study aimed to investigate the prevalence, biochemical characteristics, screening and management practices for dyslipidaemia among persons with diabetes mellitus, hypertension, and diabetes mellitus and hypertension comorbidity at Queen Elizabeth Central hospital in Blantyre, Malawi.

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Background: Single, high-dose liposomal amphotericin B (LAmB; AmBisome, Gilead Sciences) has demonstrated non-inferiority to amphotericin B deoxycholate in combination with other antifungals for averting all-cause mortality from HIV-associated cryptococcal meningitis. There are limited data on the pharmacokinetics (PK) of AmBisome. The aim of this study was to describe population PK of AmBisome and conduct a meta-analysis of the available studies to suggest the optimal dosing for cryptococcal meningoencephalitis.

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Background: HIV-associated cryptococcal meningitis is a leading cause of AIDS-related mortality. The AMBITION-cm trial showed that a regimen based on a single high dose of liposomal amphotericin B deoxycholate (AmBisome group) was non-inferior to the WHO-recommended treatment of seven daily doses of amphotericin B deoxycholate (control group) and was associated with fewer adverse events. We present a five-country cost-effectiveness analysis.

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Article Synopsis
  • Cryptococcus neoformans causes cryptococcosis, which leads to around 180,000 deaths annually, particularly affecting patients with HIV, highlighting a need to understand the link between genetic diversity of the fungus and clinical outcomes.
  • A genome-wide association study (GWAS) of 284 C. neoformans isolates from Malawi reveals variants associated with fungal growth rates and burdens, with significant variations in genes related to metabolism and growth.
  • The findings demonstrate that glycolysis is crucial for the fungus's survival in the central nervous system and may influence patient mortality, suggesting that understanding these genetic factors can improve treatment outcomes for cryptococcosis.
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 We aim to investigate whether circulating microparticle (CMPs) subsets were raised amongst people presenting with a new diagnosis of HIV and advanced immune suppression in Malawi, and whether they associated with arterial stiffness. : Microparticle characterisation and carotid femoral Pulse Wave Velocity (cfPWV) were carried out in a cohort of adults with a new HIV diagnosis and CD4 <100 cells/µL at 2 weeks post ART initiation. HIV uninfected controls were matched on age, systolic BP and diastolic BP in a 1:1 ratio.

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People Living with HIV (PLHIV) are at an increased risk of pneumococcal pneumonia than HIV-uninfected adults, but the reasons for this are still not well understood. We investigated whether alveolar macrophages (AM) mediated control of pneumococcal infection is impaired in PLHIV compared to HIV-uninfected adults. We assessed anti-bactericidal activity against of primary human AM obtained from PLHIV and HIV-uninfected adults.

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The AmBisome Therapy Induction Optimization (AMBITION-cm) trial, conducted in eastern and southern Africa, showed that a single, high dose (10 mg/kg) of liposomal amphotericin B, given with an oral backbone of fluconazole and flucytosine, was noninferior to the World Health Organization (WHO)-recommended regimen of 7 days of amphotericin B deoxycholate plus flucytosine for treatment of human immunodeficiency virus (HIV)-associated cryptococcal meningitis and has been incorporated into WHO treatment guidelines. We believe that the trial also has important implications for the treatment of HIV-associated cryptococcal meningitis in high-income settings. We advance the arguments, supported by evidence where available, that the AMBITION-cm trial regimen is likely to be as fungicidal as the currently recommended 14-day liposomal amphotericin-based treatments, better tolerated with fewer adverse effects, and confer significant economic and practical benefits and, therefore, should be included as a treatment option in guidance for HIV-associated cryptococcal treatment in high-income settings.

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Article Synopsis
  • The study investigates COVID-19 patient outcomes and viral lineages in Malawi, highlighting a lack of data from low-income countries.
  • Conducted from July 2020 to March 2022, researchers analyzed 314 hospitalized patients, discovering distinct variants during each wave—B.1, Beta, Delta, and Omicron.
  • Results indicated that patients during the Delta wave had higher mortality rates compared to earlier waves, while those infected with Omicron showed fewer chronic conditions and required less intensive treatment.
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Background: Human immunodeficiency virus-exposed uninfected (HEU) infants are a rapidly expanding population in sub-Saharan Africa and are highly susceptible to encapsulated bacterial disease in the first year of life. The mechanism of this increased risk is still poorly understood. We investigated whether human immunodeficiency virus (HIV)-exposure dysregulates HEU immunity, vaccine-antibody production, and human herpes virus amplify this effect.

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Background: Binding and neutralising anti-Spike antibodies play a key role in immune defence against SARS-CoV-2 infection. Since it is known that antibodies wane with time and new immune-evasive variants are emerging, we aimed to assess the dynamics of anti-Spike antibodies in an African adult population with prior SARS-CoV-2 infection and to determine the effect of subsequent COVID-19 vaccination.

Methods: Using a prospective cohort design, we recruited adults with prior laboratory-confirmed mild/moderate COVID-19 in Blantyre, Malawi, and followed them up for 270 days (n = 52).

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Background: Intrapulmonary pharmacokinetics may better explain response to tuberculosis (TB) treatment than plasma pharmacokinetics. We explored these relationships by modeling bacillary clearance in sputum in adult patients on first-line treatment in Malawi.

Methods: Bacillary elimination rates (BER) were estimated using linear mixed-effects modelling of serial time-to-positivity in mycobacterial growth indicator tubes for sputum collected during the intensive phase of treatment (weeks 0-8) for microbiologically confirmed TB.

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Background: Cryptococcal meningitis is a leading cause of human immunodeficiency virus (HIV)-related death in sub-Saharan Africa. Whether a treatment regimen that includes a single high dose of liposomal amphotericin B would be efficacious is not known.

Methods: In this phase 3 randomized, controlled, noninferiority trial conducted in five African countries, we assigned HIV-positive adults with cryptococcal meningitis in a 1:1 ratio to receive either a single high dose of liposomal amphotericin B (10 mg per kilogram of body weight) on day 1 plus 14 days of flucytosine (100 mg per kilogram per day) and fluconazole (1200 mg per day) or the current World Health Organization-recommended treatment, which includes amphotericin B deoxycholate (1 mg per kilogram per day) plus flucytosine (100 mg per kilogram per day) for 7 days, followed by fluconazole (1200 mg per day) for 7 days (control).

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A 34-year-old man presented to Queen Elizabeth Central Hospital in Blantyre, Malawi with multiple enlarged right cervical lymph nodes. He had no associated constitutional symptoms. Fine-needle aspirate (FNA) of one of the lymph nodes was negative for acid-fast bacilli (AFB) by smear microscopy.

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