CMAAO Coronavirus Facts and Myth Buster: Understanding Masking

Health Care Comments Off

With input from Dr Monica Vasudev

1083: Round Table Expert Zoom Meeting on “Considerations for Wearing Face Masks in Pandemic era in different situations”

12th September, 2020, 11am-12pm

Participants: Dr KK Aggarwal, Dr AK Agarwal, Dr Suneela Garg, Dr Jayakrishnan Alapet, Dr JA Jayalal, Dr KK Kalra, Dr AM Kochhar, Dr Atul Pandya, Dr Anoop Mohta, Dr DR Rai, Dr Anil Kumar, Mrs Upasana Arora, Dr Pragati Sawhney, Ms Ira Gupta, Dr S Sharma

Key points from the discussion

When virus enters the cell (naso oropharyngeal), different scenarios can result.
One, it is taken up and is killed by the macrophages. No antibodies are formed, the patient remains asymptomatic.
In some persons, the virus enters the blood → dendritic cells in thymus →T cells and then to B cells and produces IgG and IgM. The patient is asymptomatic, but antibodies are formed.
In a third scenario, the cells produce IFN-1 on Day 1, which initiates neutrophils, NK cells and monocytes. The NK cells and monocytes produce IFN-γ, which kills the virus as do the neutrophils. The patient is asymptomatic because of adequate immunity.
Another scenario, the IFN-γ will produce TNF-α, which causes inflammation. The person will be symptomatic on Day 1 (fever, diarrhea, headache, rash, loss of smell/taste).
If the immunity is inadequate, the virus is not killed. The cells do not form IFN-1 in such a situation, alternate pathway opens up on Day 3. Macrophages produce NLRP3, which produces IL-1β and IL-18. IL-1β increases ferritin levels, glucuronidase causing tissue damage. IL-18 adds to the inflammation. Cells, through the cellular dendritic cells, produce Th1 cells, which produce IL-6 (formed on Day 3), TNF-α and IL-8. IL-6 causes clot formation, TNF-α (formed on Day 1), IL-8 and IL-1β (formed on Day 3), cause inflammation.
Masks can be medical masks or fabric masks. Medical masks (surgical and N95) are part of PPE kit, while fabric masks are not.
Respirators are rated “N,” if they are not resistant to oil, “R” if somewhat Resistant to oil, and “P” if they are oil proof, i.e., strongly resistant to oil.
The number 95 means that these masks have 95% filtration efficiency.
In areas with known or suspected community transmission, medical masks and not fabric masks in patient caremust be used, irrespective of whether patient is confirmed positive or not.
Medical masks must meet three criteria: High filtration, adequate breathability and fluid penetration resistance.
Medical masks must filter droplets (3 µm) and particles (0.1 µm).
The WHO recommends that persons with any symptoms suggestive of COVID-19 should wear a medical mask.
The selection of material is important; higher the filtration efficiency, the more of a barrier provided.
Breathability is measured in millibars (mbar) or Pascals (Pa). Acceptable breathability of a medical mask should be below 49 Pa/cm2. For non-medical masks, it should be below 100 Pa.
Non-medical masks should have a minimum of three layers. Nylon or polyester fabric masks may be 2-layered or 4-layered. Cotton handkerchiefs used as masks have only 17% filtration efficiency. Gauze has only 3% filtration efficiency, even if multiple layers are used.
Users are confused about which mask to use for themselves.
Guidelines need to be redefined based on whether there is suspected community transmission or not.
If there is a suspected case in a house, everyone should wear a medical mask.
All patients coming to a healthcare setting, especially in clinics/OPDs or those who have corona-like illness, should wear a medical mask.
Even fabric masks should be regulated. It should not be left upon the user to decide the quality of the mask in the event of a pandemic.
HCFI may file a question to the ministry or even file a PIL.
Masks have to be combined with other prevention measures such as physical distancing, hand washing.
Correct and consistent use of masks is important if physical distancing is not possible.
There is a greater need for education of public about masks.
Fit of the mask is also important.
Electrostatic charge of the mask is lost by UV, washing, etc.
As per CPCB guidelines, the mask should be stored for 72 hours in a paper bag after use before disposing or kept in sodium hypochlorite solution for 15 minutes.
Hand hygiene before and after wearing a mask is very important.
Awareness needs to be created about the correct method of wearing and removing a mask and its disposal.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA