title: 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.affiliation: Department of Medicine, Center for the Study of Emerging and Re-Emerging Pathogens, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA. fennelkp@umdnj.edu
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Fennelly
authors.forename: John W
authors.initials: JW
authors.lastname: Martyny
authors.forename: Kayte E
authors.initials: KE
authors.lastname: Fulton
authors.forename: Ian M
authors.initials: IM
authors.lastname: Orme
authors.forename: Donald M
authors.initials: DM
authors.lastname: Cave
authors.forename: Leonid B
authors.initials: LB
authors.lastname: Heifets
mesh_terms: D000336:Aerosols; D000391:Air Microbiology; D003371:Cough / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D062665:Epidemiological Monitoring; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D010316:Particle Size; D015203:Reproducibility of Results; D015983:Selection Bias; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*
chemical_list: D000336:Aerosols; D004269:DNA, Bacterial