The CDC currently recommends all Americans wear cloth masks in public to curtail transmission of COVID-19 coronavirus, but another form of personal protective equipment might be a better idea: plastic face shields.
A JAMA Viewpoint recently published by Eli Perencevich, MD, of the University of Iowa, and colleagues discussed how limitations to the supply chain have made obtaining medical masks for the community difficult, and face shields for the community may be a viable alternative.
"While medical masks have limited durability and little potential for reprocessing, face shields can be reused indefinitely and are easily cleaned with soap and water, or common household disinfectants," they wrote. "They are comfortable to wear, protect the portals of viral entry, and reduce the potential for autoinoculation by preventing the wearer from touching their face."
And unlike medical masks, face shields do not have to be removed to communicate with others, they said.
Moreover, they noted a simulation study of influenza virus found face shields reduced viral exposure by 96% when worn within 18 inches of a cough, and when this study was repeated using the recommended distancing protocol of 6 feet, inhaled virus was reduced by 92%.
No studies have examined the benefits of face shields on source control, or their ability to contain a sneeze or cough, when worn by those who are asymptomatic or symptomatic. But studies on this should be completed quickly, Perencevich and colleagues suggested.
They added that guidelines from the Infectious Diseases Society of America, along with the Society for Healthcare Epidemiology of America (SHEA) and the Pediatric Infectious Diseases Society "included societal use" of personal protective equipment (PPE) such as face shields and masks when discussing how the U.S. can safely ease COVID-19 distancing restrictions.
Judy Guzman-Cottrill, DO, pediatric and infectious diseases liaison to the SHEA Board of Trustees, who was not involved with the research, told MedPage Today face shields are "definitely a potential alternative to 'universal masking' in the community."
Face shields are also an important PPE component for healthcare workers, as "manufacturing of face shields in the U.S. has ramped up very quickly," she noted.
"What we still need to clarify is if a face shield alone is adequate protection for healthcare workers from respiratory viruses while caring for symptomatic patients, or do healthcare workers need a face shield plus surgical mask?" said Guzman-Cottrill, of Oregon Health & Science University. "I don't think we have enough evidence yet to answer this question."
Perencevich and colleagues said randomized trials would likely not be completed in time to verify the efficacy of face shields, and advised, "taken as a bundle, the effectiveness of adding face shields as a community intervention to the currently proposed containment strategies should be evaluated using existing mathematical models."
The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the U.S. government.
Perencevich disclosed no conflicts of interest.
One co-author disclosed support from bioMerieux.