Effectiveness of Mask Wearing to Control Community Spread of Covid

Before the coronavirus disease 2019 (COVID-19) pandemic, the effectiveness of community mask usage to limit the transmission of respiratory diseases was debatable due to a lack of reliable, relevant research to justify its use. The amount of scientific data has grown during the epidemic. Presently, compelling evidence shows that community mask use is a successful nonpharmacologic intervention to stop the spread of this virus, mainly as source control to prevent dissemination from infected people and as protection to lessen wearers' exposure to infection.

How COVID-19 Spreads

When infected persons breathe, speak, cough, sneeze, or sing, respiratory droplets are inhaled; that is the primary way that COVID-19 spreads. Most of these droplets, often referred to as aerosols, have a diameter of less than 10 m. As the airflow during exhalation increases in speed and power, the quantity of tiny droplets and particles also rises (e.g., shouting, vigorous exercise). The higher the exposure, the nearer one is to the exhalation source. Small droplets and the dry particles that emerge from them (i.e., droplet nuclei) may stay suspended in the air, whereas larger droplets quickly fall out of the air. Concentrations of these tiny droplets and particles may accumulate to the point that they can spread illness in environments with inadequate ventilation, most often inside confined places where an infected individual is present for a prolonged time.

Mask Wearing to Control Community Spread of Covid

Wearing a community mask significantly decreases the spread of the SARS-CoV-2 coronavirus in two ways. First, by preventing the emission of virus-containing droplets into the air, covers protect those afflicted from spreading SARS-CoV-2 to others. This element of mask usage is particularly significant since at least 50% or more of transmissions are thought to originate from people who never show symptoms or are in the presymptomatic stage of the COVID-19 sickness. 1 Recent laboratory tests showed that multilayer cotton masks blocked up to 50% to 70% more inhaled tiny droplets and particles than single-layer masks. 2,3 Cloth masks have sometimes provided source control results comparable to surgical or procedural masks. Second, healthy mask users are protected. Large breathing droplets that may fall on exposed mucosal surfaces of the eye, nose, or mouth are blocked by masks. Masks may filter out tiny droplets & particles from the air breathed. Higher thread counts textiles and fabrics with many layers enhance filtering. However, it has been shown that fabric masks are less effective for source control than for user protection3, and the filtering power of cloth masks may be significantly influenced by fit, design, and material choices. To aid customers in choosing the advertised items, cloth mask standards are required.

AUTHOR: Talha Nadeem