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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

Time-histories of three coughs from a female (F1) and two male (M1 and M2) participants.
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Fig4: Time-histories of three coughs from a female (F1) and two male (M1 and M2) participants.

Mentions: It should be noted that the 12 participants had their coughs recorded on different days. For 3 participants, the results were poor due to low particle seeding levels and low numbers of validated velocity vectors (only about 0.8% of the total number of vectors were considered to be accurate, representing approximately 30 vectors per image). Three other participants were recorded in another session and showed the best results in terms of percentage of validated vectors, with values around 90% (their data are shown in Figure 4). The other 6 subjects were recorded on a separate day and showed acceptable validation levels in the 70 to 80% range. The findings for each of the three coughs by each of the twelve participants are given in Table 1, where the first character in the participant identifier (ID) indicates participant gender (F for female and M for male) and the second character is an integer index for each individual of that gender. The magnitude of each vector in each image pair was extracted with this quantity averaged (i.e. spatially) over the entire number of such validated vectors to produce a value representing the average air velocity within the field of view and the maximum mean value, occurring in each individual cough event, is shown in Table 1. A representative measure of processed data quality is included, together with observations. Furthermore, the peak value of velocity from each image pair was extracted and plotted against time for that cough.


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)

Time-histories of three coughs from a female (F1) and two male (M1 and M2) participants.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Time-histories of three coughs from a female (F1) and two male (M1 and M2) participants.
Mentions: It should be noted that the 12 participants had their coughs recorded on different days. For 3 participants, the results were poor due to low particle seeding levels and low numbers of validated velocity vectors (only about 0.8% of the total number of vectors were considered to be accurate, representing approximately 30 vectors per image). Three other participants were recorded in another session and showed the best results in terms of percentage of validated vectors, with values around 90% (their data are shown in Figure 4). The other 6 subjects were recorded on a separate day and showed acceptable validation levels in the 70 to 80% range. The findings for each of the three coughs by each of the twelve participants are given in Table 1, where the first character in the participant identifier (ID) indicates participant gender (F for female and M for male) and the second character is an integer index for each individual of that gender. The magnitude of each vector in each image pair was extracted with this quantity averaged (i.e. spatially) over the entire number of such validated vectors to produce a value representing the average air velocity within the field of view and the maximum mean value, occurring in each individual cough event, is shown in Table 1. A representative measure of processed data quality is included, together with observations. Furthermore, the peak value of velocity from each image pair was extracted and plotted against time for that cough.

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