Publications by authors named "Charles M Bark"

Reductions in tuberculosis (TB) incidence require identification of individuals at high risk of developing active disease, such as those with recent () infection. Using a prospective household contact (HHC) study in Kampala, Uganda, we diagnosed new infection using both the tuberculin skin test (TST) and interferon-gamma release assay (IGRA). Our study aimed to determine if the TST adds additional value to the characterization of IGRA converters.

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Recent advances in the treatment of tuberculosis (TB) have led to improvements unprecedented in our lifetime. Decades of research in developing new drugs, especially for multidrug-resistant TB, have created not only multiple new antituberculous agents but also a new approach to development and treatment, with a focus on maximizing the benefit to the individual patient. Prevention of TB disease has also been improved and recognized as a critical component of global TB control.

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Multidrug-resistant Mycobacterium tuberculosis remains a major public health threat; its management poses a significant economic burden. Treatment requires a programmatic approach with access to laboratory services, second-line medications, and adequate clinical resources. In recent years, we have seen rapid developments in diagnostic techniques with whole genome sequencing-based drug susceptibility prediction now in reach, an array of new drugs that transform treatment regimens to purely oral formulations, and a steady stream of multinational trials that inform us about most efficient combinations.

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Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major public health problem. Household contact studies identify children and adults along the spectrum from Mtb exposure to disease. In the Kawempe Community Health Study (conducted in Kampala, Uganda), 872 culture-confirmed pulmonary TB cases and their 2,585 contacts were enrolled during 2002-2012 and followed for up to 2 years each.

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The objective of this study was to identify blood-based protein biomarkers of early stage Mycobacterium tuberculosis (Mtb) infection. We utilized plasma and serum specimens from TB patients and their contacts (age≥12) enrolled in a household contact study in Uganda. In the discovery phase cross-sectional samples from 104 HIV-uninfected persons classified as either active TB, latent Mtb infection (LTBI), tuberculin skin test (TST) converters, or persistent TST-negative were analyzed.

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Antimicrobial resistance is a natural evolutionary process, which in the case of Mycobacterium tuberculosis is based on spontaneous chromosomal mutations, meaning that well-designed combination drug regimens provided under supervised therapy will prevent the emergence of drug-resistant strains. Unfortunately, limited resources, poverty, and neglect have led to the emergence of drug-resistant tuberculosis throughout the world. The international community has responded with financial and scientific support, leading to new rapid diagnostics, new drugs and regimens in advanced clinical development, and an increasingly sophisticated understanding of resistance mechanisms and their application to all aspects of TB control and treatment.

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We retrospectively analyzed time to detection of 3747 positive MGIT sputum cultures at a laboratory in a country with heavy burden of tuberculosis. Ninety-nine percent of diagnostic cultures turned positive within 28days, suggesting that physicians may consider alternative diagnoses if sputum cultures remain negative after 4weeks of incubation.

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Additional drugs are needed for the treatment of multidrug-resistant tuberculosis (TB). Sulfamethoxazole has been shown to have in vitro activity against Mycobacterium tuberculosis; however, there is concern about resistance given the widespread use of trimethoprim-sulfamethoxazole prophylaxis among HIV-infected patients in sub-Saharan Africa. Thirty-eight of 40 Mycobacterium tuberculosis isolates (95%) from pretreatment sputum samples from Ugandan adults with pulmonary TB, including HIV-infected patients taking trimethoprim-sulfamethoxazole prophylaxis, were susceptible with MICs of ≤38.

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We report a case of disseminated cutaneous Mycobacterium chelonae infection in a patient with head and neck cancer on salvage chemotherapy, including the epidermal growth factor receptor inhibitor cetuximab. Mycobacterium chelonae should be considered in the differential diagnosis of cutaneous infections in cancer patients receiving epidermal growth factor receptor inhibitors.

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