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. 2013;8(2):e56278.
doi: 10.1371/journal.pone.0056278. Epub 2013 Feb 13.

Influenza aerosols in UK hospitals during the H1N1 (2009) pandemic--the risk of aerosol generation during medical procedures

Katy-Anne Thompson  1 , John V Pappachan, Allan M Bennett, Himanshu Mittal, Susan Macken, Brian K Dove, Jonathan S Nguyen-Van-Tam, Vicky R Copley, Sarah O'Brien, Peter Hoffman, Simon Parks, Andrew Bentley, Barbara Isalska, Gail Thomson; EASE Study Consortium
Collaborators, Affiliations

Influenza aerosols in UK hospitals during the H1N1 (2009) pandemic--the risk of aerosol generation during medical procedures

Katy-Anne Thompson et al. PLoS One. 2013.

Abstract

Background: Nosocomial infection of health-care workers (HCWs) during outbreaks of respiratory infections (e.g. Influenza A H1N1 (2009)) is a significant concern for public health policy makers. World Health Organization (WHO)-defined 'aerosol generating procedures' (AGPs) are thought to increase the risk of aerosol transmission to HCWs, but there are presently insufficient data to quantify risk accurately or establish a hierarchy of risk-prone procedures.

Methodology/principal findings: This study measured the amount of H1N1 (2009) RNA in aerosols in the vicinity of H1N1 positive patients undergoing AGPs to help quantify the potential risk of transmission to HCWs. There were 99 sampling occasions (windows) producing a total of 198 May stages for analysis in the size ranges 0.86-7.3 µm. Considering stages 2 (4-7.3 µm) and 3 (0.86-4 µm) as comprising one sample, viral RNA was detected in 14 (14.1%) air samples from 10 (25.6%) patients. Twenty three air samples were collected while potential AGPs were being performed of which 6 (26.1%) contained viral RNA; in contrast, 76 May samples were collected when no WHO 2009 defined AGP was being performed of which 8 (10.5%) contained viral RNA (unadjusted OR = 2.84 (95% CI 1.11-7.24) adjusted OR = 4.31 (0.83-22.5)).

Conclusions/significance: With our small sample size we found that AGPs do not significantly increase the probability of sampling an H1N1 (2009) positive aerosol (OR (95% CI) = 4.31 (0.83-22.5). Although the probability of detecting positive H1N1 (2009) positive aerosols when performing various AGPs on intensive care patients above the baseline rate (i.e. in the absence of AGPs) did not reach significance, there was a trend towards hierarchy of AGPs, placing bronchoscopy and respiratory and airway suctioning above baseline (background) values. Further, larger studies are required but these preliminary findings may be of benefit to infection control teams.

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Conflict of interest statement

Competing Interests: KAT, BD, SM, SP, JP, GT, VC, HM, SO, PH, AB and BI have no conflict of interest. JVT: The University of Nottingham Health Protection Research Group is currently in receipt of research funds from GlaxoSmithKline plc (GSK), who are manufacturers/distributors of a virucidal respirator; this research funding is entirely unrelated to the performance or use of the virucidal respirator. Furthermore the research funding from GSK did not support any aspect of the work described in this manuscript. JVT has also received consultancy fees from GSK; but all forms of personal remuneration ceased in September, 2010. JVT is a former employee of SmithKline Beecham plc. (now GSK) prior to 2002, with no outstanding pecuniary interests in GSK by way of shareholdings, share options or accrued pension rights. This does not alter the authors’ adherence to all PLOS ONE policies on sharing data and materials.

Figures

Figure 1
Figure 1. The recruitment and data analysis flowchart.
See this image and copyright information in PMC

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References

    1. McDonald LC, Simor AE, Su IJ, Maloney S, Ofner M, et al. (2004) SARS in healthcare facilities, Toronto and Taiwan. Emerging Infectious Diseases 10: 777–781. - PMC - PubMed
    1. Booth CM, Matukas LM, Tomlinson GA, Rachlis AR, Rose DB, et al. (2003) Clinical features and short-term outcomes of 144 patients with SARS in the greater Toronto area. JAMA 289: 2801–2809. - PubMed
    1. CDC (2003) Severe acute respiratory syndrome–Taiwan, 2003. MMWR Morb Mortal Wkly Rep 52: 461–466. - PubMed
    1. Tran K, Cimon K, Severn M, Pessoa-Silva CL, Conly J (2012) Aerosol Generating Procedures and Risk of Transmission of Acute Respiratory Infections to Healthcare Workers: A Systematic Review. PLoS ONE 7(4): e35797 doi:10.1371/journal.pone.0035797. - DOI - PMC - PubMed
    1. Davies A, Thomson G, Walker J, Bennett AM (2009) A review of the risks and disease transmission associated with aerosol generating medical procedures. Journal of Infection Prevention 10: 122–126.

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This study was funded by the Health Protection Agency. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.