Effectiveness of a Hydrogen Peroxide Mist (Trophon) System in Inactivating Healthcare Pathogens on Surface and Endocavitary Probes

Ultrasound probes are used in sonographic scanning and are commonly used as either surface probes or endocavitary probes. Surface probes are used on intact skin, such as the abdomen; they are considered noncritical and require at least low-level disinfection between patients. Endocavitary probes (eg, transvaginal, transrectal, or transesophageal probes) are considered semicritical because they have direct contact with mucous membranes (eg, vagina, rectum, or pharynx) or non-intact skin. While one could argue that the use of the probe cover changes the category for the endocavitary probe, the Centers for Disease Control and Prevention (CDC) guideline for disinfection and sterilization recommends that a new condom/probe cover should be used for each patient, and because condoms/probe covers and low-level disinfection may fail, 1,2 high-level disinfection of the probe should be performed. 3 The relevance of this recommendation is reinforced by the finding that sterile ultrasound probe covers and condoms can have a perforation rate from 0% to 81% before and after use. 1 These studies underscore the need for high-level disinfection of endocavitary probes between examinations. Ultrasound probes may also be used during surgical procedures and may have contact with sterile body sites. These probes may be covered with a sterile sheath to reduce the level of contamination on the probe and reduce the risk of infection. However , because the sheath does not provide complete protection of the probe, the probes should be sterilized between each patient use, as are other critical items. If this is not possible, then high-level disinfection of the probe should be performed and the probe should be covered with a sterile probe cover. Although the most common method of performing high-level disinfection of contaminated endocavitary probes is by immersion in a high-level disinfectant cleared by the Food and Drug Administration (eg, glutaraldehyde), an alternative procedure for disinfecting the endocavitary and surface probes uses a proprietary hydrogen peroxide mist system, which utilizes 35% hydrogen peroxide at 56°C with the probe reaching no more than 40°C (ie, Trophon EPR, Nanosonics, Alexandria, Australia). The effectiveness of this technology, which has been cleared by the Food and Drug Administration for high-level disinfection, is evaluated in this research brief. This study was conducted at the University of North Carolina (UNC) Hospitals, an 853-bed academic medical center. Trophon EPR and 5 ultrasound probes were loaned to UNC Hospitals for use in the study. In a biological safety cabinet, at least 3 replicates …