Publications by authors named "P A Macpherson"

Objective: To measure concentrations of tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) among individuals taking tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC) or tenofovir alafenamide plus emtricitabine (TAF/FTC) who were scheduled to undergo or had already undergone bariatric surgery.

Methods: We enrolled pre-exposure prophylaxis (PrEP) users attending clinics in Toronto or Ottawa who were undergoing or had undergone bariatric surgery. After participants completed a minimum of 7 days of consecutive PrEP dosing, we collected DBS samples immediately before they administered their next daily dose of PrEP.

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Unlabelled: Urgent improvements in the diagnosis and management of infection are required to reach End TB goals. Conventional interferon-gamma release assays (IGRAs), such as QuantiFERON-TB Gold Plus (QFT-Plus), require substantial laboratory infrastructure and large blood volumes, limiting use in high-burden settings. The QIAreach QuantiFERON-TB (QIAreach QFT) was developed to overcome these challenges but has not previously been evaluated in field conditions in a low-income, high-burden country, or at scale in children.

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Despite 30 years as a public health emergency, tuberculosis (TB) remains one of the world's deadliest diseases. Most deaths are among persons with TB who are not reached with diagnosis and treatment. Thus, timely screening and accurate detection of TB, particularly using sensitive tools such as chest radiography, is crucial for reducing the global burden of this disease.

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Community-based active case finding (ACF) for tuberculosis (TB) involves an offer of screening to populations at risk of TB, oftentimes with additional health promotion, community engagement and health service strengthening. Recently updated World Health Organization TB screening guidelines conditionally recommend expanded offer of ACF for communities where the prevalence of undiagnosed pulmonary TB is greater than 0.5% among adults, or with other structural risk factors for TB.

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