New research published in the Annals of Internal Medicine has found that neither surgical nor cotton masks effectively filter the SARS-CoV-2 virus which causes Covid-19 from an infected patient’s cough.
A previous study reported that surgical masks and N95 masks were equally effective in preventing the dissemination of influenza virus, which informed recommendations that surgical masks could potentially help prevent the spread of Covid-19. Clinicians and patients alike have also turned to cotton masks in the face of the ongoing shortages of both N95 and surgical options.
The researchers had Covid-19 patients cough into a petri dish 20cm from their mouths wearing no mask, a surgical mask, a cotton mask and then again with no mask. Neither surgical nor cotton masks effectively filtered out the pathogen. N95 masks were not included in the study.