Reduction in COVID-19 Infection Using Surgical Facial Masks Outside the Healthcare System

Background In the current COVID-19 pandemic with coronavirus, SARS-COV2, the Danish Health Authorities recommend using facial masks in the health care sector when handling patients presumed or proven to be infected with the virus. However, the use of facial masks outside the healthcare system is not recommended by the Danish Health Authorities. Challenges when using facial masks outside the health care system include wearing the mask consistently, an efficacy of the mask of app. 8 hours necessitating a change of mask throughout the day, and that it is not sufficiently tight enough to safely keep the virus out. Moreover, the eyes (mucous membrane) remain exposed. Compliance could also be another challenge. Health Authorities in other countries have different recommendations for the use of facial masks and the authors of the Lancet study concluded; "Universal use of face masks could be considered if supplies permit. In parallel, urgent research on the duration of protection of face masks, the measures to prolong life of disposable masks, and the invention on reusable masks should be encouraged."

SARS-COV2 is assumed to primarily enter the body via the mouth through respiratory droplets or possibly through inhalation of aerosol containing the virus. From the mouth the virus is assumed to spread to the airways and the gastro-intestinal tract. SARS-COV2 is also known to be transmitted via physical contact, helped along by the fact that the virus can survive on surfaces for at least 72 hours. Touching such a contaminated surface can transfer the virus to the mouth via the hand - and thus lead to infection of the person. A study with 26 medical students showed that they touched their face on average 23 times per hour, and that in 44 % of the incidents they touched their mucous membranes3. A Japanese questionnaire study showed that facial masks reduced the risk for school children for getting influenza by 15 %4. N95 mask and surgical facial masks are presumed to have the same effect for healthcare personnel when providing protecting from infection with influenza.

Facial masks are assumed to protect against viral infection in two ways;

1. By reducing the risk of getting the virus via mouth or nose through the air via respiratory droplets or aerosol
2. By reducing the transfer from virus-contaminated hands to the mouth or nose

About 10 % of the Danish population is estimated to get COVID-19 during the present pandemic-wave; this corresponds to 600,000 Danes. Later COVID-19 waves are expected to occur. The epidemic in Denmark is expected to be at the highest point in medio April. In April and May it be estimated that >2 % of the population will be infected per month.