Bacterial dispersal associated with speech in the setting of intravitreous injections

Arch Ophthalmol. 2011 Dec;129(12):1551-4. doi: 10.1001/archophthalmol.2011.227. Epub 2011 Aug 8.


Objective: To investigate the amount of bacterial dispersal associated with speech in a simulated intravitreous injection.

Methods: Fifteen volunteers were recruited. Each volunteer was positioned over an open blood agar plate and did the following: read a 5-minute script with a face mask, read a 5-minute script without a face mask, read a 5-minute script with the face turned away from the plate without a face mask, and stood in silence for 5 minutes. Each volunteer then read a 5-minute script while reclined in a standard ophthalmic examination chair with an open blood agar plate secured to the forehead to simulate bacterial dispersal associated with a talking patient. Total numbers of colony-forming bacteria per plate were counted, and the bacteria were identified.

Results: Significantly less bacterial growth occurred in the face mask and silence conditions compared with the no face mask condition (both P < .001). Bacterial growth was significantly greater in the reclined condition compared with the room control (P = .02). Oral streptococcal species represented 66.7% to 82.6% of bacterial colonies in the no face mask, face turned, and reclined conditions.

Conclusions: During simulated intravitreous injection, wearing a face mask or remaining silent significantly decreases culture plate contamination from talking. Talking from above and talking in the reclined position were associated with a significant increase in culture plate contamination. Physicians performing intravitreous injections should be aware of these patterns of bacterial contamination, should consider either wearing a face mask or minimizing speech, and should encourage patients to minimize speech during the procedure.

MeSH terms

  • Bacteria / isolation & purification*
  • Bacterial Infections / transmission*
  • Colony Count, Microbial
  • Endophthalmitis / microbiology
  • Equipment Contamination / prevention & control
  • Eye Infections, Bacterial / prevention & control*
  • Humans
  • Intravitreal Injections*
  • Masks / microbiology*
  • Mouth / microbiology*
  • Pharmaceutical Preparations / administration & dosage
  • Respiratory System / microbiology
  • Speech*


  • Pharmaceutical Preparations