Publications by authors named "Keertan Dheda"

COVID-19 remains a global public health issue and an improved understanding of vaccine performance in immunocompromised individuals, including people living with HIV (PLWH), is needed. Initial data from the present study's pre-crossover/booster phase were previously reported. This phase 2a/b clinical trial in South Africa (2019nCoV-501/NCT04533399) revisits 1:1 randomly assigned HIV-negative adults (18-84 years) and medically stable PLWH (18-64 years) who previously received two NVX-CoV2373 doses (5 μg recombinant Spike protein with 50 μg Matrix-M™ adjuvant) or placebo.

View Article and Find Full Text PDF
Article Synopsis
  • Tuberculous pleural effusion (TPE) is a common form of tuberculosis outside the lungs, but current diagnostic methods like Xpert Ultra are not very effective, with a sensitivity of around 30%.
  • A study in South Africa and India tested a new quick diagnostic method called IRISA-TB, comparing it against other assays and examining biopsy samples for TB confirmation.
  • Results showed IRISA-TB had significantly better sensitivity (81.8%) and negative predictive value than Xpert Ultra and also outperformed other methods, indicating it could be a more reliable diagnostic tool for TPE.
View Article and Find Full Text PDF

Background: Tuberculous meningitis (TBM) mortality is high and current diagnostics perform suboptimally. We evaluated the diagnostic performance of a DNA-based assay (GeneXpert Ultra) against a new same-day immunodiagnostic assay that detects unstimulated interferon-gamma (IRISA-TB).

Methods: In a stage 1 evaluation, IRISA-TB was evaluated in biobanked samples from Zambia (n = 82; tuberculosis [TB] and non-TBM), and specificity in a South African biobank (n = 291; non-TBM only).

View Article and Find Full Text PDF

Objectives: Computer-aided detection (CAD) software packages quantify tuberculosis (TB)-compatible chest X-ray (CXR) abnormality as continuous scores. In practice, a threshold value is selected for binary CXR classification. We assessed the diagnostic accuracy of an alternative approach to applying CAD for TB triage: incorporating CAD scores in multivariable modeling.

View Article and Find Full Text PDF

Simpler, shorter, safer and more effective treatments for tuberculosis that are easily accessible to all people with tuberculosis are desperately needed. In 2016, the World Health Organization (WHO) developed target regimen profiles for the treatment of tuberculosis to make drug developers aware of both the important features of treatment regimens, and patient and programmatic needs at the country level. In view of recent ground-breaking advances in tuberculosis treatment, WHO has revised and updated these regimen profiles.

View Article and Find Full Text PDF

Tools to evaluate and accelerate tuberculosis (TB) vaccine development are needed to advance global TB control strategies. Validated human infection studies for TB have the potential to facilitate breakthroughs in understanding disease pathogenesis, identify correlates of protection, develop diagnostic tools, and accelerate and de-risk vaccine and drug development. However, key challenges remain for realizing the clinical utility of these models, which require further discussion and alignment among key stakeholders.

View Article and Find Full Text PDF

Objectives: To evaluate diagnostic yield and feasibility of integrating testing for TB and COVID-19 using molecular and radiological screening tools during community-based active case-finding (ACF).

Methods: Community-based participants with presumed TB and/or COVID-19 were recruited using a mobile clinic. Participants underwent simultaneous point-of-care (POC) testing for TB (sputum; Xpert Ultra) and COVID-19 (nasopharyngeal swabs; Xpert SARS-CoV-2).

View Article and Find Full Text PDF

Tuberculosis (TB) remains the foremost cause of death by an infectious disease globally. Multidrug-resistant or rifampicin-resistant TB (MDR/RR-TB; resistance to rifampicin and isoniazid, or rifampicin alone) is a burgeoning public health challenge in several parts of the world, and especially Eastern Europe, Russia, Asia and sub-Saharan Africa. Pre-extensively drug-resistant TB (pre-XDR-TB) refers to MDR/RR-TB that is also resistant to a fluoroquinolone, and extensively drug-resistant TB (XDR-TB) isolates are additionally resistant to other key drugs such as bedaquiline and/or linezolid.

View Article and Find Full Text PDF

Background: Tuberculous pericarditis (TBP) is a paucibacillary disease, where host biomarkers such as unstimulated interferon γ (IRISA-TB) have high diagnostic accuracy. However, DNA-based diagnostic tests (GeneXpert Ultra), more sensitive than an earlier versions, have recently become available. Given that the diagnosis of TBP is challenging, we performed a comparative diagnostic accuracy study comparing both assays.

View Article and Find Full Text PDF
Article Synopsis
  • Computer-aided detection (CAD) may serve as a beneficial screening tool for tuberculosis (TB), especially in communities affected by HIV, but limited data exist on its effectiveness in such settings.
  • A systematic review of 1,748 articles published between January 2012 and February 2023 identified only 5 studies that met rigorous criteria for evaluating CAD against established TB testing standards, revealing a pooled sensitivity of 0.87 and specificity of 0.74.
  • Despite its potential as a cost-effective screening tool, the review highlights significant methodological concerns, indicating a need for caution in applying these findings more broadly due to biases and limited study quality.
View Article and Find Full Text PDF
Article Synopsis
  • COVID-19 self-testing strategies (COVIDST) are effective in identifying both symptomatic and asymptomatic cases of SARS-CoV-2, potentially lowering virus transmission.
  • A systematic review analyzed 70 studies from 25 countries, finding high specificity (98.37-99.71%) for COVIDST, with the highest sensitivity in symptomatic individuals and when using supervised testing methods or digital tools.
  • Overall acceptability of self-testing was high (91.0-98.7%), though daily self-testing had lower acceptance, and the feasibility varied significantly, especially for repeated testing.
View Article and Find Full Text PDF

In the upper respiratory tract, replicating (culturable) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is recoverable for ∼4-8 days after symptom onset, but there is a paucity of data about the frequency and duration of replicating virus in the lower respiratory tract (i.e., the human lung).

View Article and Find Full Text PDF

Background: Bedaquiline is a life-saving tuberculosis drug undergoing global scale-up. People at risk of weak tuberculosis drug regimens are a priority for novel drug access despite the potential source of Mycobacterium tuberculosis-resistant strains. We aimed to characterise bedaquiline resistance in individuals who had sustained culture positivity during bedaquiline-based treatment.

View Article and Find Full Text PDF
Article Synopsis
  • This global study investigates the long-term outcomes of patients with tuberculosis (TB) and COVID-19, highlighting a lack of prior longitudinal data on this combined condition.
  • Data was collected from 788 patients across 31 countries from March 2020 to September 2022, showing a mortality rate of 10.8% during the study period.
  • Key factors influencing mortality included older age, HIV infection, and the need for invasive ventilation, with patients suffering from both diseases experiencing significantly lower survival rates compared to those with only one of the diseases.
View Article and Find Full Text PDF

The pathogenesis of coronavirus disease 2019 (COVID-19) pneumonia remains poorly understood. The urine proteome of hospitalized patients with severe COVID-19 pneumonia, compared with severe non-COVID-19 pneumonia controls, was distinct and associated with lower abundance of several host proteins. Protein-specific machine learning analysis outlined biomarker combinations able to differentiate COVID-19 pneumonia from non-COVID-19 pneumonia controls.

View Article and Find Full Text PDF

Objective: Studying treatment duration for rifampicin-resistant and multidrug-resistant tuberculosis (MDR/RR-TB) using observational data is methodologically challenging. We aim to present a hypothesis generating approach to identify factors associated with shorter duration of treatment.

Study Design And Setting: We conducted an individual patient data meta-analysis among MDR/RR-TB patients restricted to only those with successful treatment outcomes.

View Article and Find Full Text PDF

Background: Meropenem in combination with β-lactamase inhibitors (BLIs) and other drugs was tested to identify alternative treatment regimens for multidrug-resistant tuberculosis (MDR-TB).

Methods: The following were performed: (1) MIC experiments; (2) static time-kill studies (STKs) with different BLIs; and (3) a hollow fibre model system of TB (HFS-TB) studies with meropenem-vaborbactam combined with human equivalent daily doses of 20 mg/kg or 35 mg/kg rifampin, or moxifloxacin 400 mg, or linezolid 600 mg vs. bedaquiline-pretonamid-linezolid (BPaL) for MDR-TB.

View Article and Find Full Text PDF

Objectives: This meta-analysis examined the effect of macrolides on resolution of community-acquired pneumonia (CAP) and interpretation of clinical benefit according to microbiology; emphasis is given to data under-reported countries (URCs).

Methods: This meta-analysis included 47 publications published between 1994 and 2022. Publications were analysed for 30-d mortality (58 759 patients) and resolution of CAP (6465 patients).

View Article and Find Full Text PDF

Background: Tuberculosis (TB) is a global health challenge and one of the leading causes of death worldwide. In the last decade, the TB treatment landscape has dramatically changed. After long years of stagnation, new compounds entered the market (bedaquiline, delamanid, and pretomanid) and phase III clinical trials have shown promising results towards shortening duration of treatment for both drug-susceptible (Study 31/A5349, TRUNCATE-TB, and SHINE) and drug-resistant TB (STREAM, NiX-TB, ZeNix, and TB-PRACTECAL).

View Article and Find Full Text PDF

Despite the success of COVID-19 vaccines, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern have emerged that can cause breakthrough infections. Although protection against severe disease has been largely preserved, the immunological mediators of protection in humans remain undefined. We performed a substudy on the ChAdOx1 nCoV-19 (AZD1222) vaccinees enrolled in a South African clinical trial.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the effectiveness of urine-based lipoarabinomannan tests for diagnosing active tuberculosis compared to traditional sputum-based tests, especially considering that many HIV patients cannot produce sputum.* -
  • A systematic review and meta-analysis were conducted using data from several sources, focusing on cases where tuberculosis was microbiologically confirmed across various studies and participant backgrounds.* -
  • The findings suggest that urine tests could provide viable diagnostic alternatives in tuberculosis detection, potentially improving testing accessibility for populations like those living with HIV.*
View Article and Find Full Text PDF