News Release

Neither surgical nor cotton masks effectively filter SARS COV-2

New COVID-19 content in Annals of Internal Medicine

Peer-Reviewed Publication

American College of Physicians

Below please find a summary of new coronavirus-related content published today in Annals of Internal Medicine. The summary is not intended to substitute for the full article as a source of information. A collection of coronavirus-related content is free to the public at

1. Neither surgical nor cotton masks effectively filter SARS COV-2

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Both surgical and cotton masks were found to be ineffective for preventing the dissemination of SARS-CoV-2 from the coughs of patients with COVID-19. A study conducted at two hospitals in Seoul, South Korea, found that when COVID-19 patients coughed into either type of mask, droplets of virus were released to the environment and external mask surface. A brief research report is published in Annals of Internal Medicine.

During respiratory viral infection, face masks are thought to prevent transmission, leading health care experts to recommend their use during the COVID-19 pandemic. With a shortage of both N95 and surgical masks, which have been shown to prevent the spread of influenza virus, cotton masks have gained interest as a substitute. However, it is not known if surgical or cotton masks worn by patients with COVID-19 prevent contamination of the environment.

Researchers from Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea instructed 4 patients with COVID-19 to cough 5 times each onto a petri dish while wearing the following sequence of masks: no mask, surgical mask, cotton mask, and again with no mask. Mask surfaces were swabbed with aseptic Dacron swabs in the following sequence: outer surface of surgical mask, inner surface of surgical mask, outer surface of cotton mask, and inner surface of cotton mask. The researchers found SARS COV-2 on all surfaces. These findings suggest that recommendations to wear face masks to prevent the spread of COVID-19 may not be effective.

Media contacts : The lead author, Sung-Han Kim, M.D, can be reached at or +82-2-3010-3305.

2. Nonmedical health care personnel are at highest risk for psychological distress during the COVID-19 outbreak

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A survey of health care workers from two major tertiary institutions in Singapore who were caring for patients with COVID-19 suggests that nonmedical healthcare personnel are at highest risk for psychological distress related to the pandemic. A brief research report is published in Annals of Internal Medicine.

Researchers from National University Health System and Yong Loo Lin School of Medicine, National University of Singapore used a self-administered questionnaire to examine the psychological distress, depression, anxiety, and stress experienced by health care workers in Singapore in the midst of the COVID-19 outbreak and compared these outcomes between medically and non-medically trained hospital personnel. They found that the medically trained workers scored significantly lower on measures of depression and anxiety and impact of the event. Nonmedical health care workers had higher prevalence of anxiety even after adjustment for possible confounders. These findings are consistent with those of a recent COVID-19 study demonstrating that frontline nurses had significantly lower vicarious traumatization scores than non-frontline nurses and the general public. Reasons for this may include reduced accessibility to formal psychological support, less first-hand medical information on the outbreak, less intensive training on personal protective equipment and infection control measures.

Media contacts: Vijay K. Sharma, MD can be reached through Binny Tay at and Winnie Lim at

Also published today:

COVID-19: Peer Support and Crisis Communication Strategies to Promote Institutional Resilience

Albert W. Wu, MD, MPH1; Cheryl Connors, BSN, DNP2; George S. Everly, Jr, PhD1 Brief Research Report

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Media Contact: Lead author, Albert W. Wu, MD, MPH, an be reached directly at


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