FAQ: Are Probe Covers Enough?

Is using a probe cover or condom enough to eliminate the need for high-level disinfection?

In short, no; using a probe cover or condom on transvaginal, transrectal, surface, and transesophageal echocardiogram (TEE) ultrasound probes is not sufficient to eliminate the need for high-level disinfection between uses. While probe covers provide a physical barrier between the ultrasound probe and the patient, and can minimize the bacterial load, they do not guarantee complete protection against contamination. High-level disinfection of ultrasound probes between uses is essential for ensuring patient safety and preventing the spread of healthcare-associated infections (HAIs).

Probe covers or condoms are designed to minimize direct contact between the ultrasound probe and the patient’s mucous membranes, reducing the risk of cross-contamination. However, they do not provide a hermetic seal and may not completely prevent the transmission of infectious agents. Residual contamination or biofilm, which may still be present on the surface or within crevices of an improperly reprocessed probe, may make it through a perforated condom.

Probe covers are very thin to achieve high-quality ultrasound images. However, this makes them prone to rips and tears. Accessories, like needle guides, attached to ultrasound probes for procedures also increase the risk of perforations.

It may seem like perforations are few and far between, but that depends on various factors. According to a statement released by the Society for Maternal-Fetal Medicine (SMFM), “Some commercially produced ultrasound probe covers have unacceptably high rates of leakage (8% to 81%) and cannot realistically be considered to offer an effective barrier against transmission of infection, particularly viruses.” Another study states, “Of 173 cases, 8 (5%) had a positive H2O2 test for contamination. In only 3 of these 8 cases was gross contamination seen. Latex condoms are ineffective in preventing contamination of the transvaginal ultrasound transducer head.”

High-level disinfection is necessary to eliminate microbial pathogens, including bacteria, viruses, and fungi, from the surface of ultrasound probes. These pathogens can survive on surfaces for extended periods and pose a risk of infection transmission between patients. High-level disinfection destroys or inactivates a broad spectrum of microorganisms, ensuring the probe is safe for subsequent examinations.

Failure to perform high-level disinfection on ultrasound probes can have serious consequences, including transmitting HAIs between patients. HAIs can lead to prolonged hospital stays, increased healthcare costs, and even patient morbidity and mortality. Additionally, non-compliance with infection control guidelines can result in regulatory penalties and damage healthcare facilities' reputations.

The CDC utilizes the Spaulding Classification System to categorize medical devices into three categories based on their risk of transmitting infectious agents: critical, semi-critical, and non-critical. Transvaginal, transrectal, TEE, and surface ultrasound probes fall into the semi-critical category. As such, the CDC requires "at a minimum, high-level disinfection for semi-critical patient-care equipment… that touches either mucous membranes or nonintact skin" between uses to prevent the transmission of infectious agents and protect patient safety.

While probe covers or condoms provide an additional layer of protection, high-level disinfection complements these measures by ensuring that the entire surface of the ultrasound probe is free from microbial contamination. By thoroughly disinfecting each ultrasound probe between uses, healthcare providers can mitigate the risk of infection transmission and uphold the highest patient safety standards.

Always verify that disinfectants being used are compatible with the materials of the ultrasound probe and capable of achieving a high level of microbial kill. Additionally, healthcare facilities should always follow manufacturer instructions for proper disinfection procedures and encourage using proper personal protective equipment (PPE) during the disinfection process.