Are Face Masks Effective in Preventing Transmission of Viruses Like Coronavirus?

Effectiveness of face masks in preventing transmission of viruses like coronavirus

Check out this answer from Consensus:

The collective evidence from multiple studies strongly supports the effectiveness of face masks in reducing the transmission of viruses, including SARS-CoV-2. Masks are particularly effective when used in combination with other preventive measures such as physical distancing and hand hygiene. High-filtration masks like N95 respirators offer greater protection, especially in high-risk environments. Universal mask use in the community can significantly reduce the spread of COVID-19, highlighting the importance of this simple yet effective public health measure.

The use of face masks has been a widely discussed and researched topic, especially in the context of the COVID-19 pandemic. Various studies have investigated the effectiveness of face masks in preventing the transmission of viruses, including SARS-CoV-2, the virus responsible for COVID-19.

Key Insights from Research Papers

• Reduction in Virus Transmission with Face Masks:
  • Face masks significantly reduce the risk of infection by lowering the transmission of viruses, including SARS-CoV-2, especially in community settings1 2 4 5 6 7.
  • The use of face masks by both infected individuals and healthy contacts within households can reduce secondary transmission of the virus6.
• Effectiveness of Different Types of Masks:
  • N95 respirators and similar high-filtration masks are more effective than disposable surgical masks or reusable cloth masks in preventing virus transmission1 4 7.
  • Even simple surgical masks can be effective in environments with low virus abundance, but more advanced masks are required in high-risk settings like hospitals2 4.
• Face Masks in Combination with Other Measures:
  • The effectiveness of face masks is enhanced when combined with other preventive measures such as physical distancing, hand hygiene, and proper ventilation2 4 6 10.
• Community and Healthcare Settings:
  • Universal face mask use in the community can be beneficial, particularly in preventing pre-symptomatic transmission of COVID-194 6 10.
  • Continuous use of respirators by healthcare workers during their shifts is crucial for preventing infections in high-risk healthcare settings4.
• Airborne Transmission and Face Masks:
  • Face masks are effective in mitigating airborne transmission of COVID-19, which is a dominant route for the spread of the virus5 9 10.

Are face masks effective in preventing transmission of viruses like coronavirus?

Kelly Reynolds has answered Unlikely

An expert from University of Arizona in Microbiology, Public Health

There are two primary types of face masks. One is a surgical mask and another an N95 mask. Surgical masks are commonly used by healthcare workers to minimize exposure to large aerosol particles, blood and tissue. These masks are also recommended for sick individuals to contain aerosols from coughing and sneezing. N95 masks are designed to remove 95% of particulates larger than 0.3 microns in size. For maximum efficacy, these masks need to be fit tested to individuals and are prone to improper use.

Face masks are generally not recommended for healthy individuals as a means to avoid the risk of infection unless you are a healthcare worker or someone caring for a sick individual. 

Masks are likely not effective without the use of other infection control measures, such as frequent handwashing, and may even increase exposure if improperly handled or re-used.

Are face masks effective in preventing transmission of viruses like coronavirus?

Dale Fisher has answered Near Certain

An expert from National University of Singapore in Infectious diseases

Definitely; there is no doubt. The vast majority of spread in MERS and SARS came from people not identified. When patients became suspect and precautions were applied then spread was very rare. Same as all respiratory infections.

Are face masks effective in preventing transmission of viruses like coronavirus?

Abrar Ahmad Chughtai has answered Uncertain

An expert from UNSW Sydney in Epidemiology

We need to understand that there are two uses of masks for OCIVID-19 in the community.

1.           Use by sick people, i.e. as source control and all health organisations (including WHO and CDC) recommend that use. In fact recent WHO change in policy of community masks use is also based on high rate of asymptomatic infection (a recent study showed 16 to 45% cases may be asymptomatic) and they may transmit infection. So in high transmission zone everyone should use mask. If surgical masks are not available, then cloth masks may be used. Many recent studies show that mask are effective in preventing spread of infections from sick (and also asymptomatic) cases.
2.           Second use of masks is by healthy people and there is less evidence in support of this. Studies show that masks are effective in the community if intervention is coupled with hand hygiene. In pandemic situation, it is very difficult to say who is sick or healthy (due to high rates of asymptomatic infection). So as mentioned above, at least, in high transmission areas, everyone should use masks.

 In health care settings, all health workers should use a N95 or equivalent respirators. If respirators are not available, then masks may be used. Selection between masks and respirators is a long debate. But many studies showed that respirators are more protective and should be used by all frontline healthcare workers.

 When/where should people wear masks? 

That depend on COVID-19 situation in the country. In high transmission settings (like Wuhan and New York before and currently in Brazil), universal mask use should be adopted, i.e. everyone should use masks as we do not know who is sick and who is healthy. The rate of asymptomatic infection of COVID-19 is very high. In these situations, masks should be used outdoor, in public places, etc. 

In low COVID-19 transmission settings (like in Australia), universal masks use may be not needed. However if someone cannot manage safe distancing then they should mask in low transmission settings as well.

Are DIY masks better than nothing?

Yes, cloth masks can be used as a last resort. Cloth masks are at least good to prevent the spread of infection. Our group did many studies on cloth masks. The efficacy and filtration effectiveness of cloth masks are lower compared to medical masks and respirators, but some cloth masks are better than other and if we improve design and fabrics and increase number of layers, cloth masks can provide reasonable protection.