(1/3) Study of 2 hairstylists with #COVID19. Both wore masks at work, as did clients. No cases were reported among their 139 clients (67 of whom tested negative). In contrast, all family contacts of one hairstylist tested positive. Good evidence for masks.
cdc.gov/mmwr/volumes/6…
cdc.gov/mmwr/volumes/6…
(2/3) The study does have some limitations (as detailed in the paper), and it's possible some cases were missed. Nonetheless, it strongly suggests masks can help prevent transmission of #SARSCoV2. One hairstylist wore a cotton mask, the other a cotton mask or surgical mask.
(3/3) Of 104 interviewed clients, most wore a cotton mask (47%) or surgical mask (46%). Five wore a N95 respirator (5%). This suggests that cotton and surgical masks are effective when used by the general public, even though these types of masks do not offer complete protection.
