Cross-contamination and cross-infection risk of otoscope heads

Adequate disinfection level of the medical equipments should be maintained to prevent cross-contamination between patients. Otoscope specula are usually cleaned and disinfected appropriately after each use by disinfectant solutions. However, since otoscope heads are electrical instruments with irregular inner surface they may still harbor pathogenic microorganisms. According to manufacturers’ instructions, otoscope heads can be cleaned externally with a damp cloth and they can be disinfected with aldehydes, tensides, and alcohols. Instrument heads should not be placed in liquids. Alcohols cannot be used on glass surfaces. How often an otoscope head must be cleaned to limit contamination is not well established. This study aimed to determine whether the otoscope heads harbor pathogenic microorganisms or not. A total of 53 otoscope heads were included in the study. Swab samples were obtained from the inner parts of the otoscope heads. For bacteriological examination, cotton swabs were inoculated onto 5 % sheep blood agar, chocolate agar, and eosine methylene blue agar plates. For fungal evaluation, cotton swabs were inoculated onto Sabouraud dextrose agars. Cultured microorganisms were evaluated macroscopically and microscopically. Of the 53 otoscope heads, 22 were found to be contaminated with bacteria and/or fungi. Eleven of them were colonized by one organism, 11 were colonized by more than one organism. Only one Pseudomonas species isolated as gram-negative microorganism. Gram-positive microorganisms were isolated from the remaining 19 samples. Staphylococcus species were the most common bacteria isolated. The most common fungal isolates were Aspergillus species. Two cultures were positive with Candida albicans. The results show that decontamination of the otoscope heads is usually ignored. However, they can harbor considerable amount of pathogenic microorganisms. The probability of contamination and the risk of cross-infection is high if they are used by otolaryngologists. In order to prevent cross-contamination between patients, guidelines indicating appropriate methods and frequency of cleaning and disinfection of otoscope heads needed to be described.