This article is Part 1 of a two-part series.
Surveillance has always been one of the foundations of infection prevention practice. Much of what we know about healthcare-associated infections within our own organizations comes from the time Infection Preventionists spend reviewing microbiology results, applying surveillance definitions, investigating infections, calculating rates, identifying trends, and trying to understand what the data are telling us. Surveillance gives us a way to move beyond individual observations and determine whether there is a pattern that requires attention.
Anyone who has worked in a hospital IP department also knows that surveillance consumes a significant amount of time. There are only so many hours available, and some of that work is driven by external reporting requirements. Hospitals participating in applicable CMS quality programs report healthcare-associated infection data through the CDC's National Healthcare Safety Network (NHSN), with measures that can include central line-associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI), selected surgical site infections (SSI), MRSA bacteremia, and Clostridioides difficile infection. The exact reporting requirements vary by facility type and CMS program, but these measures have become familiar parts of hospital infection prevention and quality programs.
The importance of performing surveillance on these measures extends well beyond submitting data to NHSN. These infections can result in significant patient morbidity and mortality, longer hospital stays, additional treatment, and increased healthcare costs. At the organizational level, HAI performance may also affect CMS quality programs, reimbursement, publicly reported quality information, accreditation and regulatory readiness, and the priorities established by hospital leadership. As a result, hospitals have developed extensive systems around these measures. CLABSI and CAUTI rates are reviewed by committees and clinical leadership, surgical site infections are discussed with surgeons and perioperative teams, and changes in C. difficile or MRSA bacteremia will prompt additional investigation. When performance changes, surveillance can provide data to demonstrate that change and a structure in place for responding to it.
This type of surveillance has also influenced the way many of us practice infection prevention. When a CLABSI occurs, for example, we rarely stop after determining that the patient meets the NHSN definition. We review what happened before the infection. We may examine line insertion, dressing integrity, maintenance practices, line access, device necessity, and other factors that could have contributed. Over time, those investigations and the process measures surrounding them help an organization understand where prevention efforts are working and where additional attention may be needed. Ultrasound probe reprocessing is one area where that kind of data rarely exists.
Where Surveillance Doesn't Reach: Ultrasound Probes
There are many areas of infection prevention, however, where we do not have the same amount of information available to us due to time and staffing constraints to perform surveillance. Medical device reprocessing is one of them, particularly when the device does not fall within a routinely monitored infection outcome. Ultrasound probes are a good example because their use has expanded into so many areas of healthcare while surveillance of the processes surrounding them has not necessarily expanded at the same pace.
Ultrasound probes can now be found throughout many departments in a healthcare organization. In addition to diagnostic imaging, they may be used in the emergency department, operating room, intensive care unit, labor and delivery, cardiology, anesthesia, vascular access, wound care, procedural departments, and ambulatory settings. The type of patient contact varies considerably. Some probes are used only on intact skin, while others contact mucous membranes or non-intact skin or are used during procedures where blood and body fluids are present. Those differences determine how the probe should be reprocessed and can also mean that responsibility for reprocessing is spread across several departments.
Most hospitals do not have a surveillance system that brings all of this information together for Infection Prevention. We generally do not know how many ultrasound procedures requiring high-level disinfection occurred during a particular month unless we specifically seek that information. We may not routinely review whether every probe was successfully reprocessed or whether the documentation could be traced back to the patient and procedure. In many organizations, those records exist within the clinical department or reprocessing area and are reviewed primarily when there is a reason to look at them.
This is quite different from the surveillance structure surrounding many of our traditional HAIs. If a patient develops a CLABSI, there is a defined surveillance process that helps us identify the event and examine the associated care. If a patient develops an infection following a procedure involving an ultrasound probe, the connection may be much less apparent. The infection could develop after discharge or be treated in another setting. Even when it occurs within the same healthcare organization, there may be no reason initially to associate the infection with an ultrasound procedure performed several days earlier. A single infection is also unlikely to reveal a shared exposure in the way that a recognized cluster eventually might.
What the Ultrasound Gel Outbreaks Teach Us
A large outbreak associated with contaminated ultrasound gel in 2021 provides a useful example of how these connections may eventually be recognized.1 The investigation began after a Virginia hospital identified eight patients with invasive Burkholderia stabilis infections, most of which were bloodstream infections. At least seven of those patients had undergone ultrasound-guided procedures. Investigators subsequently cultured unopened bottles of nonsterile ultrasound gel and identified B. stabilis, with whole-genome sequencing demonstrating that patient and product isolates were closely related. As the investigation expanded, CDC ultimately identified 119 infections across 10 states associated with contaminated ultrasound gel, with most reported infections involving the bloodstream. The investigation also found that nonsterile gel had frequently been used during ultrasound-associated percutaneous procedures, creating an opportunity for organisms in the contaminated product to be introduced into normally sterile sites.
The outbreak was associated with ultrasound gel rather than inadequate probe reprocessing, but it is relevant to surveillance of ultrasound practices for precisely that reason. The initial signal was an unusual cluster of infections, not an ultrasound-specific surveillance measure. Once that signal was recognized, investigators had to examine what the affected patients had in common and work through the procedures, products, and practices associated with their care. Ultrasound exposure became important because the investigation connected it to the patients, rather than because an existing ultrasound surveillance system had identified a problem. This is part of the difficulty with relying on infection outcomes to evaluate reprocessing practices. An organization may have no known infections associated with ultrasound probes and still have vulnerabilities within the process. Unless patient outcomes, procedure information, device use, and reprocessing records can be connected, we have limited ability to use the absence of identified infections as evidence that the process is functioning reliably.
In Part 2, we will look at how Infection Preventionists can apply process surveillance to ultrasound probe reprocessing in a practical, low-burden way, and why traceability matters if an exposure investigation is ever needed.
Have questions about surveillance or reprocessing of your ultrasound or TEE probes? The CS Medical team is here to help you evaluate your high-level disinfection process, strengthen documentation and traceability, and support your staff education. Contact CS Medical's Medical Affairs Manager and Infection Preventionist Jill Holdsworth or explore more articles on IP Insights.
References
- Hudson MJ, Park SC, Mathers A, et al. Outbreak of Burkholderia stabilis infections associated with contaminated nonsterile, multiuse ultrasound gel—10 states, May–September 2021. MMWR Morb Mortal Wkly Rep. 2022;71(48):1517-1521. doi:10.15585/mmwr.mm7148a3.
