Detection of airborne Mycobacterium tuberculosis complex in high-risk areas of health care facilities in Thailand

• Published in: The international journal of tuberculosis and lung disease 2019-04, Vol.23 (4), p.465-473
• Main Authors: Sornboot, J., Aekplakorn, W., Ramasoota, P., Bualert, S., Tumwasorn, S., Jiamjarasrangsi, W.
• Format: Article
• Language: English
• Subjects: Air Microbiology; Air sampling; Bronchoscopy; Collection; Copy number; Cough; Cough - microbiology; Cross-Sectional Studies; Emergency medical services; Health care; Health care facilities; Health facilities; Health Facilities - standards; Health Personnel; Health risks; Humans; Indoor Air; Mechanical ventilation; Medical personnel; Mycobacterium tuberculosis; Mycobacterium tuberculosis - isolation & purification; Nosocomial Transmission; Occupational Exposure - analysis; Polymerase chain reaction; Real time; real-time qPCR; Relative humidity; Risk; Sputum; Thailand; Tuberculosis; Tuberculosis - prevention & control; Ventilation; Ventilation - standards
• ISSN: 1027-3719; 1815-7920
• DOI: 10.5588/ijtld.18.0218

SETTING: In high-risk areas (sputum collection room in a tuberculosis [TB] clinic, patient rooms in a TB ward, the emergency department and the bronchoscopy unit) in seven health care facilities located in central Thailand.OBJECTIVE: To detect airborne Mycobacterium tuberculosis complex and other environmental parameters using the liquid impinger and real-time quantitative polymerase chain reaction (real-time qPCR) technique in high-risk areas.DESIGN: Cross-sectional study.RESULTS: M. tuberculosis was detected in 3 of 99 (3.0%, 95%CI 0.6-8.6) areas: one sputum collection room and one TB in-patient room in one facility and one sputum collection room in another facility. In these three areas, the M. tuberculosis copy number/m3 ranged from 9.6 to 1671. Lower air change rate (65%), and contact with coughing patient(s) were more common in airborne M. tuberculosis-positive areas than in M. tuberculosis-negative areas.CONCLUSIONS: Air sampling using a liquid impinger followed by real-time qPCR is effective for quantitative detection of airborne M. tuberculosis in high-risk areas. Our findings indicate TB risk among health care workers, and suggest that improved ventilation, enhanced appropriate cough etiquette and respiratory protection are needed to mitigate M. tuberculosis transmission.