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Western Cold and Flu (WeCoF) aerosol study--preliminary results.

Savory E, Lin WE, Blackman K, Roberto MC, Cuthbertson LR, Scott JA, Mubareka S - BMC Res Notes (2014)

Bottom Line: The peak value of velocity was also extracted and compared with the average velocity.Preliminary results show that there is significant air motion associated with a cough (on the order of 0.5 m/s) as far away as 1 m from the mouth of the healthy person who coughs.The results from this pilot study provide the framework for a more extensive participant recruitment campaign that will encompass a statistically-significant cohort.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical & Materials Engineering, The University of Western Ontario, 1151 Richmond Street North, London N6A 5B9, Canada. wlin26@uwo.ca.

ABSTRACT

Background: Influenza virus is responsible for annual deaths due to seasonal epidemics and is the cause of major pandemics which have claimed millions of human lives over the last century. Knowledge about respiratory virus transmission is advancing. Spread is likely through the air, but much work remains to be done to characterize the aerosols produced by infected individuals, including viral particle survival and infectivity. Although coughs have been characterized, little work has been done to examine coughs from infected individuals. The WeCoF project aims at providing evidence to support prevention measures to mitigate person-to-person influenza transmission in critical locations, such as hospitals, and during pandemics.

Findings: A novel experimental cough chamber facility - the FLUGIE - has been developed to study the far-field aerodynamics and aerosol transport of droplets produced by the coughs from humans naturally-infected with influenza. The flow field of each cough is measured using Particle Image Velocimetry (PIV). A preliminary study involving 12 healthy individuals has been carried out in order to quantify the strengths of their coughs at a distance of 1 m from the mouth. The spatially averaged maximum velocity was determined and the average value was 0.41 m/s across 27 coughs of good data quality. The peak value of velocity was also extracted and compared with the average velocity.

Conclusions: Preliminary results show that there is significant air motion associated with a cough (on the order of 0.5 m/s) as far away as 1 m from the mouth of the healthy person who coughs. The results from this pilot study provide the framework for a more extensive participant recruitment campaign that will encompass a statistically-significant cohort.

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Related in: MedlinePlus

Diagram of the bioaerosol sampling cassette assembly (top), photograph of a cassette attached to a sampling pump (centre) and photograph of the cassettes in operation in the cough chamber (bottom).
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Fig2: Diagram of the bioaerosol sampling cassette assembly (top), photograph of a cassette attached to a sampling pump (centre) and photograph of the cassettes in operation in the cough chamber (bottom).

Mentions: In order to quantify the viral content of the aerosols produced during coughs, particles are sampled by collection onto polytetrafluoroethylene (PTFE) membrane filters of 1.0 μm pore size and 37 mm diameter. As shown by Figure 2, a filter and cellulose support pad is held between a clear styrene cassette ring and bottom. The open-faced cassettes are suspended from the chamber roof, on the chamber centreline, at two distances from the cough inlet (0.5 m and 1.0 m). The constant-flow air sampling pumps (SKC Inc., Airchek 224-PCXR3) are operated at a flow rate of 4000 ± 40 mL/min. Expelled pathogens are collected upon the membranes with the assistance of the air flow samplers.Figure 2


Western Cold and Flu (WeCoF) aerosol study--preliminary results.

Savory E, Lin WE, Blackman K, Roberto MC, Cuthbertson LR, Scott JA, Mubareka S - BMC Res Notes (2014)

Diagram of the bioaerosol sampling cassette assembly (top), photograph of a cassette attached to a sampling pump (centre) and photograph of the cassettes in operation in the cough chamber (bottom).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4150972&req=5

Fig2: Diagram of the bioaerosol sampling cassette assembly (top), photograph of a cassette attached to a sampling pump (centre) and photograph of the cassettes in operation in the cough chamber (bottom).
Mentions: In order to quantify the viral content of the aerosols produced during coughs, particles are sampled by collection onto polytetrafluoroethylene (PTFE) membrane filters of 1.0 μm pore size and 37 mm diameter. As shown by Figure 2, a filter and cellulose support pad is held between a clear styrene cassette ring and bottom. The open-faced cassettes are suspended from the chamber roof, on the chamber centreline, at two distances from the cough inlet (0.5 m and 1.0 m). The constant-flow air sampling pumps (SKC Inc., Airchek 224-PCXR3) are operated at a flow rate of 4000 ± 40 mL/min. Expelled pathogens are collected upon the membranes with the assistance of the air flow samplers.Figure 2

Bottom Line: The peak value of velocity was also extracted and compared with the average velocity.Preliminary results show that there is significant air motion associated with a cough (on the order of 0.5 m/s) as far away as 1 m from the mouth of the healthy person who coughs.The results from this pilot study provide the framework for a more extensive participant recruitment campaign that will encompass a statistically-significant cohort.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical & Materials Engineering, The University of Western Ontario, 1151 Richmond Street North, London N6A 5B9, Canada. wlin26@uwo.ca.

ABSTRACT

Background: Influenza virus is responsible for annual deaths due to seasonal epidemics and is the cause of major pandemics which have claimed millions of human lives over the last century. Knowledge about respiratory virus transmission is advancing. Spread is likely through the air, but much work remains to be done to characterize the aerosols produced by infected individuals, including viral particle survival and infectivity. Although coughs have been characterized, little work has been done to examine coughs from infected individuals. The WeCoF project aims at providing evidence to support prevention measures to mitigate person-to-person influenza transmission in critical locations, such as hospitals, and during pandemics.

Findings: A novel experimental cough chamber facility - the FLUGIE - has been developed to study the far-field aerodynamics and aerosol transport of droplets produced by the coughs from humans naturally-infected with influenza. The flow field of each cough is measured using Particle Image Velocimetry (PIV). A preliminary study involving 12 healthy individuals has been carried out in order to quantify the strengths of their coughs at a distance of 1 m from the mouth. The spatially averaged maximum velocity was determined and the average value was 0.41 m/s across 27 coughs of good data quality. The peak value of velocity was also extracted and compared with the average velocity.

Conclusions: Preliminary results show that there is significant air motion associated with a cough (on the order of 0.5 m/s) as far away as 1 m from the mouth of the healthy person who coughs. The results from this pilot study provide the framework for a more extensive participant recruitment campaign that will encompass a statistically-significant cohort.

Show MeSH
Related in: MedlinePlus