Medical masks

These masks cover the mouth and nose and, if worn properly, maybe effective in helping prevent transmission of respiratory viruses and bacteria.

There are two main types of masks use to prevent respiratory infection: surgical masks (face masks), and respirators.

Medical masks differ by the type and size of infectious particles they are capable of filtering.

Facemasks are used more commonly for respiratory viruses that spread via droplets which travel short distances and are transmitted by cough or sneeze.

Face masks prevent the spread of large sprays and droplets, as well as preventing hand-to-face contact.

N95 respirators block 95% of airborne particles.

N95 respirators are tight fitting and prevent inhalation of small infectious particles they can spread through the air over long distances after an infected person coughs or sneezes.

Diseases that require the use of an N95 respirator include tuberculosis, measles, and chickenpox.

N95 respirators cannot be used in patients with facial hair or by children because of the difficulty in achieving an adequate fit.

Face masks should be used by individuals with respiratory infections with cough, and sneeze, or in some cases with a fever, by healthcare workers, by individuals who are taken care of or in close contact with individuals with respiratory infections,

Face masks is not worn by healthy individuals to protect themselves from acquiring respiratory infection because there is no evidence to suggest that face masks worn by healthy individuals are effective in preventing people from becoming ill (Desai A).

With face mask utilization washing hands with soap and water for at least 20 seconds prior to putting on the mask is important.

Face masks should have no gaps between the face mask and the face, and a tight seal should be ensured.

Avoiding touching the face mask when wearing it is appropriate.

Face masks should be discarded after use.

Hand hygiene is an important way to prevent acquiring and spreading respiratory infections.

The hands should be washed often and avoiding touching the nose, eyes, or mouth is important.

Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2

 

 

In an experimental study of face masks and COVID-virus:

 

 

The  protective efficiency of such masks against airborne transmission of infectious severe acute respiratory syndrome CoV-2 (SARS-CoV-2) droplets/aerosols is unknown. 

 

 

Cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of COVID-19 and that the protective efficiency was higher when masks were worn by a virus spreader. 

 

 

Medical masks, surgical masks and even N95 masks, are not able to completely block the transmission of virus droplets/aerosols even when completely sealed. 

 

 

When a mannequin exposed to the virus was equipped with various masks: cotton mask, surgical mask, or N95 mask), the uptake of the virus droplets/aerosols was reduced. 

 

 

A cotton mask led to an approximately 20% to 40% reduction in virus uptake compared to no mask.

 

 

The N95 mask had the highest protective efficacy, approximately 80% to 90% reduction of the various masks examined.

 

 

Infectious virus penetration was measurable even when the N95 mask was completely fitted to the face with adhesive tape.

 

 

Cotton and surgical masks blocked more than 50% of the virus transmission, whereas the N95 mask showed considerable protective efficacy.

 

 

There was a synergistic effect when both the virus receiver and virus spreader wore masks- cotton masks or surgical masks to prevent the transmission of infective droplets/aerosols.

 

 

The protective efficacy of masks when the amount of exhaled virus the N95 mask sealed with adhesive tape showed approximately 90% protective efficacy.

 

 

Our airborne simulation experiments showed that cotton masks, surgical masks, and N95 masks had a protective effect with respect to the transmission of infective droplets/aerosols and that the protective efficiency was higher when masks were worn by the virus spreader. 

 

 

Considerable viral loads have been detected in the nasal and throat swabs of asymptomatic and minimally symptomatic patients, as well as those of symptomatic patients, which suggests transmission potential.

 

 

It is desirable for individuals to wear masks in public spaces. 

 

 

Importantly, medical masks, surgical masks and even N95 masks, were not able to completely block the transmission of virus droplets/aerosols even when fully sealed under the conditions that were tested. 

 

 

These results indicate that it is difficult to completely block this virus even with a properly fitted N95 mask. 

 

 

However, it remains unknown whether the small amount of virus that was able to pass through the N95 masks would result in illness.

 

 

The stability of the virus in the air changes depending on the droplet/aerosol components, such as inorganics, proteins, and surfactants.

 

 

The permeation efficiency of masks is also affected by the components of viral droplets/aerosols.

 

No direct data is available but studies suggest cloth masks can also substantial filtration, in some cases equivalent to some medical masks.

 

Cloth masks have been shown to be less effective than medical mask for prevention of communicable respiratory illnesses.

 

Face shields provide a clear plastic barrier that covers the face.

 

Face shields have advantages: they can be reused indefinitely, are easily cleaned with soap or household disinfectants, more comfortable to wear, protect the portals of viral entry, and they reduce the potential for autoinoculation  by preventing the wearer from touching their face.

Face shields can be used without removing them to communicate with others, allows visibility of facial expressions and lip movements for speech perception.

Face shields appear to significantly reduce the amount of inhalation exposure to influenza virus.