Reply to Letter to the Editor, Reply to Yasri & Wiwanitkit.

We wish to thank Yasri et al. 1 for their interest and discussion regarding our recent publication ‘“Double-surgical-mask-with-slit” method: reducing exposure to aerosol generation at upper gastrointestinal endoscopy during the COVID-19 pandemic’ 2 . As stated in that publication 2 , our method adopts the same rationale that governs universal surgical mask use: to reduce airborne exposure to droplets and aerosols by introducing a physical barrier for truncation at source of the “shotgun effect” of aerosol spread 2 3 . Our method was never designed or claimed to replace other precautionary methods such as the use of any recommended personal protective equipment (PPE) or negative pressure rooms, but only to serve as an additional physical barrier, to potentially further reduce the risk of environmental contamination by fine droplets and aerosols. Through our routine practice, we also note that the “double-surgical-mask-with-slit,” by its design, intrinsically leads to slight misalignment of the slits of the two masks, and this in turn enhances the curtain-like effect of the physical barrier around the scope, which further mitigates any potential “leakage” of droplets.

Although we are confident that with the adoption of increased preprocedural testing of patients for COVID-19, as recommended by more recent guidelines 4 , the risk of potential environmental contamination and cross-infection would be reduced even further, it remains our opinion that the use of readily available, inexpensive, additional physical barriers; such as the one described by our group and by others 5 , remains worthy of consideration for application in daily clinical practice.