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BIBTEX RIS

Host Determinants of Infectiousness in Smear-Positive Patients With Pulmonary Tuberculosis

2019; Oxford University Press; Volume: 6; Issue: 6 Linguagem: Inglês

10.1093/ofid/ofz184

ISSN

2328-8957

Autores

Carlos Acuña-Villaorduña, Irene Ayakaka, Luiz Guilherme Schmidt-Castellani, Francis Mumbowa, Patrícia Marques-Rodrigues, Mary Gaeddert, Laura F. White, Moisés Palaci, Jerrold J. Ellner, Reynaldo Dietze, Moses Joloba, Kevin P. Fennelly, Edward C. Jones‐López,

Tópico(s)

Pneumonia and Respiratory Infections

Resumo

Epidemiologic data suggests that only a minority of tuberculosis (TB) patients are infectious. Cough aerosol sampling is a novel quantitative method to measure TB infectiousness.We analyzed data from three studies conducted in Uganda and Brazil over a 13-year period. We included sputum acid fast bacilli (AFB) and culture positive pulmonary TB patients and used a cough aerosol sampling system (CASS) to measure the number of colony-forming units (CFU) of Mycobacterium tuberculosis in cough-generated aerosols as a measure for infectiousness. Aerosol data was categorized as: aerosol negative (CFU = 0) and aerosol positive (CFU > 0). Logistic regression models were built to identify factors associated with aerosol positivity.M. tuberculosis was isolated by culture from cough aerosols in 100/233 (43%) TB patients. In an unadjusted analysis, aerosol positivity was associated with fewer days of antituberculous therapy before CASS sampling (p = .0001), higher sputum AFB smear grade (p = .01), shorter days to positivity in liquid culture media (p = .02), and larger sputum volume (p = .03). In an adjusted analysis, only fewer days of TB treatment (OR 1.47 per 1 day of therapy, 95% CI 1.16-1.89; p = .001) was associated with aerosol positivity.Cough generated aerosols containing viable M. tuberculosis, the infectious moiety in TB, are detected in a minority of TB patients and rapidly become non-culturable after initiation of antituberculous treatment. Mechanistic studies are needed to further elucidate these findings.

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