Do I have to wear a mask if I don't have any symptoms?
Text updated on 2020-05-03
Yes. Since most infected people are asymptomatic, one does not know if they are contagious. Wear a mask to act as a barrier to the SARS-CoV-2 virus!
Yes, even if a person has no symptoms, they can be a carrier (asymptomatic, pre-symptomatic, or post-symptomatic) and can exhale viral particles that may infect others. Epidemiological studies have shown that healthy people have been infected by people who did not have symptoms.
Putting on your mask is a civic act: together, we reduce the spread of the virus and the contamination of vulnerable people.
The mask reduces the amount of seasonal human coronavirus and influenza viruses in expired droplets and aerosols.Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med (2020).
Five people were infected by an asymptomatic carrier.Bai, Y., Yao, L., Wei, T., Tian, F., Jin, D. Y., Chen, L., & Wang, M. (2020). Presumed asymptomatic carrier transmission of COVID-19. Jama.
Cases of transmission by pre-symptomatic carriers.Wei, W. E., Li, Z., Chiew, C. J., Yong, S. E., Toh, M. P., & Lee, V. J. (2020). Presymptomatic Transmission of SARS-CoV-2-Singapore, January 23-March 16, 2020. Morbidity and Mortality Weekly Report, 69(14), 411.
The viral load in asymptomatic patients is similar to that in symptomatic patients.Zou, L., Ruan, F., Huang, M., Liang, L., Huang, H., Hong, Z., ... & Guo, Q. (2020). SARS-CoV-2 viral load in upper respiratory specimens of infected patients. New England Journal of Medicine, 382(12), 1177-1179.
A pre-symptomatic person infected two people following a business meeting that lasted more than a day. One of the contaminated individuals then contaminated two other colleagues following 2 (and 4) brief contacts at the workplace when she was not yet symptomatic.Rothe, C., Schunk, M., Sothmann, P., Pretzel, G., Froeschl, G., Wallrauch, C., ... & Seilmaier, M. (2020). Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. New England Journal of Medicine, 382(10), 970-971.