Pilot study to detect airborne Mycobacterium tuberculosis exposure in a South African public healthcare facility outpatient clinic

Abstract

BACKGROUND : Airborne transmission of Mycobacterium tuberculosis (TB) remains an occupational health hazard particularly in crowded and resource limited healthcare settings. AIM : The study aimed to quantify airborne TB in a busy outpatient clinic in Gauteng, South Africa. METHODS : Personal (HCWs) and stationary air samples were collected in the Polyclinic and Administrative block. Quantitative real-time PCR was used to detect airborne TB. Walkthrough observations and work practices of HCWs were also recorded. FINDINGS : TB was detected in 11/49 (22.4%) of the 9/25 (36%) personal and 2/24 (8.3%) stationary samples. Samples from 5 of 10 doctors (50%) and 3 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 worr respiratory masks despite been training. CONCLUSION : The use of air sampling coupled with real-time qPCR is a simple and effective tool to demonstrate the risk of TB exposure. The findings provide an impetus for hospital management to strengthen TB infection prevention and control measures.