Bacterial contamination of multiple-use atomizers commonly used in Japan.

Before performing transnasal fiberscopy to observe the nasal cavity, pharynx and larynx in outpatient clinics, nasal anesthetics and vasoconstrictive agents are routinely sprayed into the nares in order to improve patients' comfort. Bacterial contamination of the nozzles of Venturi principle atomizer barrels and their solutions after being used for multiple patients over a long-term period without cleaning is controversial. We evaluated the potential risk of atomizer-associated cross-infection by using atomizers commonly available in Japan that use compressed air to atomize medication. Eighteen of the 23 samples (78.3%) from the external nozzle tips of the atomizers resulted in positive bacterial cultures. These detected bacteria are suggested to be colonized in the nares and to cause bacterial contamination of the atomizer. Of the 25 samples obtained from the spray of the drug solutions, 11 samples showed positive bacterial culture, whereas 16 control samples produced no growth of bacteria. The present study demonstrated that the atomizer widely used in the outpatient ENT clinics in Japan has a potential risk of causing cross-infection of patients.