Authors: O. Matuka, T. Singh, E. Bryce, A. Yassi, O. Kgasha, M. Zungu, K. Kyaw, M. Malotle, K. Renton, L. O\’Hara

Source: Journal Of Hospital Infection Vol 87, Issue 3, Pages 192-196


Background: Airborne transmission of Mycobacterium tuberculosis remains an occupational health hazard, particularly in crowded and resource-limited healthcare settings.

Aim: To quantify airborne M. tuberculosis in a busy outpatient clinic in Gauteng, South Africa.

Methods: Stationary air samples and samples from healthcare workers (HCWs) were collected in the polyclinic and administrative block. Quantitative real-time polymerase chain reaction (PCR) was used to detect airborne M. tuberculosis. Walkthrough observations and work practices of HCWs were also recorded.

Findings: In total, M. tuberculosis was detected in 11 of 49 (22.4%) samples: nine of 25 (36%) HCW samples and two of 24 (8.3%) stationary air samples. Samples from five of 10 medical officers (50%) and three of 13 nurses (23%) were positive. Repeat measurements on different days showed variable results. Most of the HCWs (87.5%) with positive results had been in contact with coughing patients and had not worn respiratory masks despite training.

Conclusion: The use of air sampling coupled with quantitative real-time PCR is a simple and effective tool to demonstrate the risk of M. tuberculosis exposure. The findings provide an impetus for hospital management to strengthen infection prevention and control measures for tuberculos.

Keywords: Tuberculosis, Healthcare workers, Infection prevention and control, Occupational exposure, Air sampling, Polymerase chain reaction