Cloth masks increased “Influenza Like Illness” by SIX TIMES vs “standard practices” of only wearing masks sometimes, and by TWELVE TIMES vs wearing medical masks during all work shifts. 95 wards, 1600 participants, Hanoi. Cloth masks allowed infiltration of disease on 97% of the masks, vs 44% of the N95 masks. It’s expected that the moisture from exhaling is what allowed migration of contagions.
This goes back to the suggestion that if you *are* going to use a cloth mask, sanitize and/or replace it often throughout the day, but that procedure has not yet been tested/proven effective or not.