COVID-19 Insights: We All SHOULD Wear Surgical Masks for SARS-COV-2

In this live session we discussed the types of masks and their usage. I offered my opinion that we should all wear surgical masks.

Here are the links to studies and sites that can be valuable when thinking about my talk.

Droplet size:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894888/
Droplets can be 0.6 to more than a 1000 micro-meters

Droplet types
Respirable. Smaller, stay in the air for longer. Lesser 10 micro meter
Inspirable. Larger, falls to the ground much earlier. 10 to 100 micro meter

Agreement on sizes
Virus size: 90-110 nanometer (0.05 to 0.2 microns)
Hole size in the mask = 0.3 micrometer or 300 nanometer
Droplet size 100 micrometer or 100,000 nanometer
Aerosol droplet size 10 micrometer or 10,000 nanometer

General literature uses lesser then or equal to 5 microns as the aerosol. Anything larger is called a droplet.
Spread
Protection needs
Sick making other sick
HCP (health care professionals) becoming sick due to greater exposure.
Healthy people getting the virus

Asymptomatic people can shed as well.
https://jamanetwork.com/journals/jama/article-abstract/2762028
Presumed asymptomatic transmission by COVID-19 patients.

Masks
Putting on is donned
Taking off is doffing

Surgical masks:
https://en.wikipedia.org/wiki/Surgical_mask

Respirators
https://en.wikipedia.org/wiki/N95_mask
Made by melt blowing technique from the non woven polypropylene fabric

OSHA’s PDF for the mask difference
https://www.osha.gov/Publications/OSHA3219.pdf
Efficiency of the masks
Human Coronavirus droplets are blocked by the surgical mask but not the aerosol particles
https://www.nature.com/articles/s41591-020-0843-2
https://www.tandfonline.com/doi/abs/10.1080/15459624.2016.1237029?src=recsys&journalCode=uoeh20
Surgical masks with electret layer may be better than the facemarks
NIOSH
National institute of occupational safety and health (NIOSH)

Extended use and Reuse by CDC
https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html
Extended use is OK as long as the mask is not deteriorated.
Usual specifications are 8 hours of use. However, you have to make a call as you know how contaminated or deteriorated the mask is.
Discard
Following aerosol generating procedures
When contaminated with blood, nasal secretions, or other bodily fluids.
Discard after seeing a patient that is co-infected with an infectious disease that requires contact precautions.
Prefer use of cleanable face shields
Perform hand hygiene (washing with soap or alcohol based hand-sanitizers) before and after touching the respirators.

For reuse, all of the above plus:
Avoid touching the inside of the respiratory. If inadvertently touched then discard.
use clean non-sterile gloves to when donning and checking the seal. Discard gloves.
https://www.healthline.com/health/coronavirus-mask

PPE
https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirator-use-faq.html

Valved vs. unvalved respirator
Use unvalved with a face shield
What are surgical N95 masks?
What are regular N95 masks?
What are valveless N95 masks? Don’t have an exhaust valve. Can make the inside area warm and exhaling difficult. Preferred.

A respirator with exhaust can keep the inside cooler, but also allows the exhaled air to go in to the field. These should not be used when a sterile field is to be maintained.

NOISH approval example: https://www.cdc.gov/niosh/npptl/pdfs/N95-Infographic-Mask-Labeling-508.pdf

NOISH certified approval list: https://www2a.cdc.gov/drds/cel/cel_form_code.asp
https://www.cdc.gov/niosh/npptl/topics/respirators/cel/default.html

False certification claims are posted here: https://www.cdc.gov/niosh/npptl/usernotices/counterfeitResp.html

NOISH is extending the usage reccommendation beyond the manufacturer’s shelf life suggestion: https://www.cdc.gov/coronavirus/2019-ncov/hcp/release-stockpiled-N95.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcoronavirus%2F2019-ncov%2Frelease-stockpiled-N95.html

Study for the home made masks vs. surgical masks.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/
Surgical masks performed twice as better as the home made masks
FFP2 masks performed 50 times better than the home-made masks and 25 times better than surgical masks.

Study
https://www.ncbi.nlm.nih.gov/pubmed/24229526
Both masks i.e. home-made and surgical significantly reduced the number of microorganisms expelled by the volunteer.
Study showing surgical masks performing 3x better than home-made masks in bacterial filtration test and twice better to block the droplets.
This study also finds that the medical fit factor of the home-made masks is half as good as the surgical masks.
Difference between a surgical mask and a respirator
https://www.cdc.gov/niosh/npptl/pdfs/UnderstandDifferenceInfographic-508.pdf
Face masks not useful
https://www.businessinsider.com/wuhan-coronavirus-face-masks-not-entirely-effective-2020-1

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