Bacterial dispersion associated with various patient face mask designs during simulated intravitreal injections

Patel, Samir N.; Mahmoudzadeh, Raziyeh; Salabati, Mirataollah; Soares, Rebecca R.; Hinkle, John; Hsu, Jason; Garg, Sunir J.; Regillo, Carl D.; Ho, Allen C.; Cohen, Michael N.; Khan, M. Ali; Yonekawa, Yoshihiro; Chiang, Allen; Gupta, Omesh P.; Kuriyan, Ajay E.

PURPOSE: To investigate bacterial dispersion with patient face mask use during simulated intravitreal injections. DESIGN: Prospective cross-sectional study METHODSSETTING: Single-center STUDY POPULATION: Fifteen healthy subjects were recruited INTERVENTION: Each participant was instructed not to speak for 2-minutes, simulating a “no-talking” policy, while in an ophthalmic examination chair with an blood agar plate secured to the forehead and wearing various face masks (no mask, loose fitting surgical mask, tight-fitting surgical mask without tape, tight-fitting surgical mask with adhesive tape securing the superior portion of the mask, N95 mask, and cloth mask). Each scenario was then repeated while reading a 2-minute script, simulating a talking patient. MAIN OUTCOME MEASURES: Number of colony-forming units (CFU) and microbial species. RESULTS: During the “no-talking” scenario, subjects wearing a tight-fitting surgical mask with tape developed fewer CFUs compared to subjects wearing the same mask without tape (difference, 0.93CFU; 95%CI, 0.32–1.55; P=.003). During the speech scenarios, subjects wearing a tight-fitting surgical mask with tape had significantly fewer CFUs compared to subjects without a face mask (difference, 1.07CFU; P=.001), subjects with a loose face mask (difference, 0.67; P=.034), and subjects with a tight face mask without tape (difference, 1.13; P<.001). There was no difference between those with a tight-fitting surgical mask with tape and an N95 mask in the “no-talking” (P>.99) and “speech” (P=.831) scenarios. No oral flora was isolated in “no-talking” scenarios, but was isolated in 8/75 (11%) cultures in speech scenarios (P=.02). CONCLUSION: Addition of tape to the superior portion of a patient’s face mask reduced bacterial dispersion during simulated intravitreal injections, and had no difference in bacterial dispersion compared to wearing N95 masks.