Comparison of bioaerosol collection methods in the detection of airborne influenza virus

91 Pages·2016·1.73 MB·English

University of Iowa
Iowa Research Online
Theses and Dissertations
Spring 2015
Comparison of bioaerosol collection methods in
the detection of airborne influenza virus
Laura L. Kienlen
University of Iowa
Copyright 2015 Laura Lucille Kienlen
This thesis is available at Iowa Research Online: https://ir.uiowa.edu/etd/1658
Recommended Citation
Kienlen, Laura L.. "Comparison of bioaerosol collection methods in the detection of airborne influenza virus." MS (Master of Science)
thesis, University of Iowa, 2015.
https://doi.org/10.17077/etd.9pmuoelr.
Follow this and additional works at:https://ir.uiowa.edu/etd
Part of theOccupational Health and Industrial Hygiene Commons
COMPARISON OF BIOAEROSOL COLLECTION METHODS IN THE DETECTION
OF AIRBORNE INFLUENZA VIRUS

by

Laura L. Kienlen

A thesis submitted in partial fulfillment
of the requirements for the Master of Science
degree in Occupational and Environmental Health in the
Graduate College of
The University of Iowa

May 2015

Thesis Supervisor: Assistant Professor Matthew W. Nonnenmann
Copyright by

LAURA L. KIENLEN

2015

All Rights Reserved
Graduate College
The University of Iowa
Iowa City, Iowa

CERTIFICATE OF APPROVAL

____________________________

MASTER’S THESIS

_________________

This is to certify that the Master’s thesis of

Laura L. Kienlen

has been approved by the Examining Committee for
the thesis requirement for the Master of Science degree
in Occupational and Environmental Health at the May 2015 graduation.

Thesis Committee: ____________________________________________
Matthew W. Nonnenmann, Thesis Supervisor

____________________________________________
Thomas Peters

____________________________________________
Travis Henry
ACKNOWLEDGEMENTS

I would like to thank my advisor, Matt Nonnenmann, for obtaining funding for this
project so that I could perform my thesis research in an area of interest to me. Also, for
being a mentor throughout my time in this program, and supporting and directing me
during both the data collection and writing process. This research would not have been
possible without your help.
I would also like to thank Dr. Renée Anthony for supplying us with the NGIAS
samplers used in this experiment, as well as her guidance throughout my time here at
Iowa. To my other thesis committee members, Dr. Tom Peters and Dr. Travis Henry,
thank you for your assistance and the knowledge you contributed from your areas of
expertise for this project. Dr. Peters, thank you for supplying me with the knowledge
base of aerosol science so that I could complete and more importantly understand the
various aspects of my project, as well as designing the bioaerosol chamber used in this
experiment along with Dr. Jae Hong Park. Dr. Henry, thank you for taking time out of
your already busy schedule to teach me the basics of sample analysis, and helping me
reach the point where I was comfortable enough to run the analyses on my own. I
learned a great deal, and hope future students continue to collaborate with the State
Hygienic Lab, as there is so much that can be learned from those that are employed there.
I also want to thank my family for always being there for me when I need them
and supporting me throughout my entire life. To my parents, thank you for being my
rocks and grounding me when all I wanted to do was pull my hair out, and for always
encouraging me to follow my dreams and heart wherever it may lead me. You all have
helped me more than words can express.
ii
ABSTRACT
Detection of airborne influenza virus is needed in order to determine exposure and
prevent and control infections. Few researchers have successfully detected airborne
influenza virus in environmental settings with current bioaerosol samplers. Therefore,
new sampling strategies should be considered to increase the likelihood of detection.
This study compared four bioaerosol samplers in collection of airborne influenza
virus – the SKC Biosampler, NIOSH Biosampler, Andersen N6 single-stage impactor
containing a liquid media, and the newly developed Next Generation Inhalable Aerosol
Sampler (NGIAS). Ten 30-minute laboratory trials were completed by aerosolizing
active influenza virus (H1N1) in a bioaerosol chamber to compare the ability of four
bioaerosol samplers to collect aerosolized virus. Samples were analyzed using RT-
qPCR.
The mean total virus particles per liter of sampled air (TVP) recovered with the
NGIAS was significantly less than that measured by all other samplers (p < 0.001). The
TVP recovered with the SKC Biosampler (111.41) and Andersen N6 sampler (102.36)
was substantially larger than that recovered with the NIOSH Biosampler (58.59),
however the difference in TVP between these samplers was not statistically significant
(SKC – NIOSH p-value = 0.187 ; Andersen – NIOSH p-value = 0.297).
Our results demonstrated that liquid based bioaerosol samplers recovered more
TVP than dry collection samplers. The high flow rate sampler, the Andersen N6, did not
collect more TVP, but had a lower limit of detection than other samplers. Furthermore,
the SKC Biosampler collected the most TVP. Therefore, future investigators should
iii
design a liquid based personal bioaerosol sampler to maximize the likelihood of influenza
virus detection.
iv
PUBLIC ABSTRACT

The World Health Organization estimates annual influenza epidemics could
generate up to 5 million cases of severe illness and 500,000 deaths worldwide. Few
researchers have been successful in determining personal exposures to influenza viruses
through the airborne route with samplers that are currently available. Therefore, new
sampling strategies should be considered.
This study compared four samplers in the collection of airborne influenza virus –
the SKC Biosampler, NIOSH Biosampler, Andersen N6 single-stage impactor containing
a liquid media, and the newly developed NGIAS sampler. Ten 30-minute trials were
completed by aerosolizing influenza virus (H1N1) in a laboratory chamber.
Analyses determined the NGIAS recovered significantly less viral particles per
liter of sampled air (TVP) than all other samplers (p-value < 0.001). The TVP recovered
by both liquid based samplers (SKC and Andersen N6) was substantially larger than that
recovered by both dry collection based samplers (NIOSH and NGIAS). The high flow
rate sampler, the Andersen N6, did not collect more TVP, but had a lower limit of
detection than other samplers. Therefore, the Andersen N6 sampler may be more
efficient at detecting influenza viruses in settings where virus concentrations are lower
(hospitals, schools, daycares, etc.). Furthermore, the SKC Biosampler collected the most
TVP. Future research should consider designing a liquid based personal sampler that
operates at a high airflow rate to increase the probability of influenza virus detection.

v
TABLE OF CONTENTS
LIST OF TABLES ............................................................................................................ vii
LIST OF FIGURES ......................................................................................................... viii
CHAPTER
I. LITERATURE REVIEW ............................................................................................1
Impact of Respiratory Virsues on the Human Population ................................1
Transmission and Survival of Respiratory Viruses ..........................................3
Respiratory Viruses in the Healthcare Setting .................................................6
Influenza Virus .................................................................................................9
Current Samplers used for Bioaerosols ..........................................................11
Liquid Impingers .....................................................................................11
Solid Impactors .......................................................................................12
Cyclones ..................................................................................................13
Filter Collection Media ...........................................................................14
Problems with Detection of Airborne Viruses ................................................15
Analysis of Virus Samples ..............................................................................17
Objective .........................................................................................................18
II. COMPARISON OF SAMPLER PERFORMANCE IN THE COLLECTION
OF AIRBORNE INFLUENZA VIRUS .........................................................20
Introduction .....................................................................................................20
Methods ..........................................................................................................22
Generation of Influenza Virus Aerosol: Experimental Apparatus ..........22
Virus Aerosol Sampling ..........................................................................25
Virus Extraction and Real Time Detection Methodology ......................27
Total Viral Particle Calculations .............................................................28
Results.............................................................................................................30
Discussion .......................................................................................................35
Limitations ..............................................................................................37
Conclusions.....................................................................................................40
III. CONCLUSION .....................................................................................................42
APPENDIX A: SOP BIOAEROSOL CHAMBER ...........................................................48
APPENDIX B: STANDARD CURVE ..............................................................................58
APPENDIX C: CALCULATIONS ...................................................................................59
APPENDIX D: RAW DATA ............................................................................................63
APPENDIX E: STATISTICAL ANALYSIS ....................................................................70
REFERENCES .................................................................................................................75
vi
LIST OF TABLES
Table
1. Total influenza viral particles (TVP) per liter of air sampled (Normalized
Data)..........................................................................................................................32
D1. Mean cycle threshold values .....................................................................................63
D2. Cycle threshold values to viral copy number............................................................64
D3. Total amount of virus in sample ...............................................................................65
D4. Pre and pose calibration flow rates ...........................................................................66
D5. Sample volume .........................................................................................................67
D6. Total influenza viral particles per liter of sampled air ..............................................68
D7. Particle counter total viral particles per liter of sampled air .....................................69

vii