Review| Volume 103, ISSUE 2, P175-184, October 2019

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Indoor hospital air and the impact of ventilation on bioaerosols: a systematic review

  • R.E. Stockwell
    Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia

    Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
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  • E.L. Ballard
    Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
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  • P. O'Rourke
    Statistical Support Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
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  • L.D. Knibbs
    School of Public Health, The University of Queensland, Herston, Queensland, Australia
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  • L. Morawska
    International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
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  • S.C. Bell
    Corresponding author. Address: Lung Bacteria Group, QIMR Berghofer Medical Research Institute, 300 Herston Road, Herston, Brisbane, QLD, 4006, Australia. Tel.: +61 7 3139 4770.
    Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia

    Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia

    Adult Cystic Fibrosis Centre, The Prince Charles Hospital, Chermside, Queensland, Australia
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      Healthcare-acquired infections (HAIs) continue to persist in hospitals, despite the use of increasingly strict infection-control precautions. Opportunistic airborne transmission of potentially pathogenic bioaerosols may be one possible reason for this persistence. Therefore, this study aimed to systematically review the concentrations and compositions of indoor bioaerosols in different areas within hospitals and the effects of different ventilation systems. Electronic databases (Medline and Web of Science) were searched to identify articles of interest. The search was restricted to articles published from 2000 to 2017 in English. Aggregate data was used to examine the differences in mean colony forming units per cubic metre (cfu/m3) between different hospital areas and ventilation types. A total of 36 journal articles met the eligibility criteria. The mean total bioaerosol concentrations in the different areas of the hospitals were highest in the inpatient facilities (77 cfu/m3, 95% confidence interval (CI): 55–108) compared with the restricted (13cfu/m3, 95% CI: 10–15) and public areas (14 cfu/m3, 95% CI: 10–19). Hospital areas with natural ventilation had the highest total bioaerosol concentrations (201 cfu/m3, 95% CI: 135–300) compared with areas using conventional mechanical ventilation systems (20 cfu/m3, 95% CI: 16–24). Hospital areas using sophisticated mechanical ventilation systems (such as increased air changes per hour, directional flow and filtration systems) had the lowest total bioaerosol concentrations (9 cfu/m3, 95% CI: 7–13). Operating sophisticated mechanical ventilation systems in hospitals contributes to improved indoor air quality within hospitals, which assists in reducing the risk of airborne transmission of HAIs.


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