https://link.springer.com/article/10.1007/s11356-023-27944-9
"Airborne transmission is one of the main routes of SARS-CoV-2 spread. It is
important to determine the circumstances under which the risk of airborne
transmission is increased as well as the effective strategy to reduce such
risk. This study aimed to develop a modified version of the Wells-Riley model
with indoor CO2 to estimate the probability of airborne transmission of
SARS-CoV-2 Omicron strains with a CO2 monitor and to evaluate the validity of
this model in actual clinical practices. We used the model in three suspected
cases of airborne transmission presented to our hospital to confirm its
validity. Next, we estimated the required indoor CO2 concentration at which R0
does not exceed 1 based on the model. The estimated R0 (R0, basic reproduction
number) based on the model in each case were 3.19 in three out of five infected
patients in an outpatient room, 2.00 in two out of three infected patients in
the ward, and 0.191 in none of the five infected patients in another outpatient
room. This indicated that our model can estimate R0 with an acceptable
accuracy. In a typical outpatient setting, the required indoor CO2
concentration at which R0 does not exceed 1 is below 620 ppm with no mask, 1000
ppm with a surgical mask and 16000 ppm with an N95 mask. In a typical inpatient
setting, on the other hand, the required indoor CO2 concentration is below 540
ppm with no mask, 770 ppm with a surgical mask, and 8200 ppm with an N95 mask.
These findings facilitate the establishment of a strategy for preventing
airborne transmission in hospitals. This study is unique in that it suggests
the development of an airborne transmission model with indoor CO2 and
application of the model to actual clinical practice. Organizations and
individuals can efficiently recognize the risk of SARS-CoV-2 airborne
transmission in a room and thus take preventive measures such as maintaining
good ventilation, wearing masks, or shortening the exposure time to an infected
individual by simply using a CO2 monitor."
Via Violet Blue’s
Pandemic Roundup: June 15, 2023
https://www.patreon.com/posts/pandemic-roundup-84605385
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
