There are a number of studies (7) linked in the 1st article which has prompted the advice for cloth face Coverings in the US and a simple video to make one from cloth. The studies make interesting reading and have found 6 of them online -
Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility — King County, Washington, March 2020 | MMWR https://www.cdc.gov/mmwr/volumes/69/wr/mm6913e1.htm
New advice in the US -
Recommendation Regarding the Use of Cloth Face Coverings | CDC
https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html
https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html
There are a number of studies (7) linked in the 1st article which has prompted the advice for cloth face Coverings in the US and a simple video to make one from cloth. The studies make interesting reading and have found 6 of them online -
Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany | NEJM
https://www.nejm.org/doi/full/10.1056/NEJMc2001468
SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients | NEJM
https://www.nejm.org/doi/full/10.1056/NEJMc2001737
Asymptomatic cases in a family cluster with SARS-CoV-2 infection - The Lancet Infectious Diseases
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30114-6/fulltext
Presumed Asymptomatic Carrier Transmission of COVID-19 | Global Health | JAMA | JAMA Network
https://jamanetwork.com/journals/jama/fullarticle/2762028
Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility — King County, Washington, March 2020 | MMWR
https://www.cdc.gov/mmwr/volumes/69/wr/mm6913e1.htm
Substantial Undocumented Infection Facilitates the Rapid Dissemination of Novel Coronavirus (SARS-CoV2) - PubMed
https://pubmed.ncbi.nlm.nih.gov/32179701/