Intracavity ultrasound transducer handles are not routinely immersed in liquid high-level disinfectants. We show that residual bacteria, including pathogens, persist on more than 80% of handles that are not disinfected, whereas use of an automated device reduces contamination to background levels. Clinical staff should consider the need for handle disinfection.Infect Control Hosp Epidemiol 2015;36(5): [581][582][583][584] Ultrasound transducers that contact broken skin or mucous membranes are considered semicritical devices and should undergo high-level disinfection (HLD) between patients. 1 Studies have shown residual contamination on ultrasound transducers when HLD is not performed 2,3 and cases of hepatitis B and C infection have been reported where transmission was thought to have been caused by improper reprocessing of ultrasound transducers. 4,5 HLD methods that involve soaking ultrasound transducers in liquid chemicals, such as glutaraldehyde or ortho-phthalaldehyde, do not typically disinfect the handle. Some major manufacturers specifically advise against submersion of the handle owing to the transducer not being fully sealed. There are no clear recommendations on whether transducer handles should be disinfected, nor is there any consensus on the risk that contaminated transducer handles might pose to patients.Although full immersion of transducers in liquid is not generally possible, approaches that allow the HLD of the entire transducer are now available. This study surveyed the residual contamination on transducer handles when not disinfected (routine soaking method) and also assessed the efficacy of an automated disinfection device capable of disinfecting both heads and handles of ultrasound transducers.
methodsThis study was a prospective, bi-centric, cross-sectional study, performed at an ultrasound clinic and public hospital. No patients were excluded and no patient data were collected so the study did not require ethics approval. Following routine ultrasound procedures, all transducers were cleaned with detergent and water and were dried with paper towels. Handle samples were then collected from 2 study groups after the handles were subjected to different disinfection methods. Groups were sampled sequentially in randomized order.The first group of transducers (hereafter referred to as "glutaraldehyde disinfection of head only" [GDHO]) underwent reprocessing according to the existing protocol at the clinic where the head of the transducer was soaked in a 2.4% solution of glutaraldehyde for 20 minutes at room temperature. Transducer handles were not disinfected (per normal practice).The second group of transducers (hereafter referred to as "automated disinfection of head and handle" [ADHH]) were subjected to HLD with an automated disinfection system that disinfects the entire transducer including the handle (trophon EPR; Nanosonics). The device was operated according to the manufacturer's instructions for use.Matched control samples (shams) were collected to quantify contamination occurring during...