Efficacy and Use of Cloth Masks: A Scoping Review

During the coronavirus disease 2019 (COVID-19) pandemic, there has been a global shortage of personal protective equipment (PPE). In this setting, cloth masks may play an important role in limiting disease transmission; however, current literature on the use of cloth masks remains inconclusive. This review aims to integrate current studies and guidelines to determine the efficacy and use of cloth masks in healthcare settings and/or the community. Evidence-based suggestions on the most effective use of cloth masks during a pandemic are presented. Embase, MEDLINE, and Google Scholar were searched on March 31, 2020, and updated on April 6, 2020. Studies reporting on the efficacy, usability, and accessibility of cloth masks were included. Additionally, a search of guidelines and recommendations on cloth mask usage was conducted through published material by international and national public health agencies. Nine articles were included in this review after full-text screening. The clinical efficacy of a face mask is determined by the filtration efficacy of the material, fit of the mask, and compliance to wearing the mask. Household fabrics such as cotton T-shirts and towels have some filtration efficacy and therefore potential for droplet retention and protection against virus-containing particles. However, the percentage of penetration in cloth masks is higher than surgical masks or N95 respirators. Cloth masks have limited inward protection in healthcare settings where viral exposure is high but may be beneficial for outward protection in low-risk settings and use by the general public where no other alternatives to medical masks are available.