Cough-generated aerosols of Mycobacterium tuberculosis: a new method to study infectiousness.

Abstract

The concentration and size distribution of infectious aerosols produced by patients with pulmonary tuberculosis (TB) has never been directly measured. We aimed to assess the feasibility of a method that we developed to collect and quantify culturable cough-generated aerosols of Mycobacterium tuberculosis. Subjects were recruited from a referral hospital and most had multidrug-resistant TB. They coughed into a chamber containing microbial air samplers while cough frequency was measured during two 5-minute sessions. Cough-generated aerosol cultures were positive in 4 of 16 subjects (25%) with smear-positive pulmonary TB. There was a rapid decrease in the cough-generated aerosol cultures within the first 3 weeks of effective treatment. Culture-positive cough aerosols were associated with lack of treatment during the previous week (p = 0.007), and there was a trend in the association with cough frequency (p = 0.08). The size distributions of these aerosols were variable, but most particle sizes were in the respirable range. Quantification of viable cough-generated aerosols is feasible and offers a new approach to study infectiousness and transmission of M. tuberculosis and other airborne pathogens.

• Authors: Kevin P Fennelly, John W Martyny, Kayte E Fulton, Ian M Orme, Donald M Cave, Leonid B Heifets
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 169 Issue 5 Pg. 604-9 (Mar 01 2004) ISSN: 1073-449X [Print] United States
• PMID: 14656754 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Aerosols
• DNA, Bacterial

Topics

• Aerosols
• Air Microbiology
• Cough (microbiology)
• DNA Fingerprinting
• DNA, Bacterial (analysis, genetics)
• Environmental Monitoring (methods, standards)
• Epidemiological Monitoring
• Feasibility Studies
• Female
• Humans
• Male
• Molecular Epidemiology
• Mycobacterium tuberculosis (genetics, isolation & purification, pathogenicity)
• Particle Size
• Reproducibility of Results
• Selection Bias
• Sensitivity and Specificity
• Sputum (microbiology)
• Tuberculosis, Multidrug-Resistant (complications, drug therapy, epidemiology, microbiology, transmission)
• Tuberculosis, Pulmonary (complications, drug therapy, epidemiology, microbiology, transmission)