On March 17, 2015, FDA published new guidance describing testing and labeling requirements for reusable medical devices. The updated guidance is timely, since recent outbreaks of CRE from endoscopes exposed several missing validation studies from implicated manufacturers.
Wound Dressing Microbial Ingress Test
Microbial Ingress Testing is the evaluation of the ability of a medical device to resist or inhibit the transfer of infectious microorganisms under repeated simulated use conditions. Many medical devices have features that could potentially allow microorganisms a point of entry directly into a patient or into sterile fluids during the course of clinical or home use, increasing the risk of infection. This is especially true with repeated use, product misuse, or in the event of product failure. Additionally, because surfaces can become contamina
Microbial Ingress testing is the evaluation of the ability of a medical device to resist or inhibit the transfer of infectious microorganisms under repeated simulated use conditions. Many medical devices have features that could potentially allow microorganisms a point of entry directly into a patient or into sterile fluids during the course of clinical or home use, increasing the patient's risk of infection. This is especially true with repeated use, product misuse, or in the event of product failure.
Xenex Healthcare Services is a San Antonio, Texas company that produces a highly effective whole-room disinfection system for hospitals. Though the company has been around for just a few years, it has enjoyed an explosion in popularity of its devices within top-tier hospitals, such as MD Anderson Cancer Center in Houston, Texas.
The Xenex device is powered by pulsed-xenon ultraviolet (UV) light. To visualize how the device works, think of a timed strobe light placed into the center of a room that emits a surplus of high-power UV light. The intense UV light bounces off of surfaces all around the room and is absorbed by pathogens on surfaces, deactivating them.
The concept of using pulsed-UV for surface disinfection in US hospitals was developed by Drs. Mark Stibich and Julie Stachowiak after spending time in Russia, where they observed the use of UV light to control the spread of tuberculosis in healthcare settings.
In 2009, Mark and Julie, energized by the concept and working with Xenex co-founder Brian Cruver, met Morris Miller, a San Antonio businessman with a keen eye for new and important technologies. The team was thrilled with the potential of the device to reduce infections, so they assembled a business team and set to work.
One of the first steps was to verify the effectiveness of the device in a laboratory setting. Although ultraviolet light has long been relied upon for disinfection, they needed proof that it would work well for their specific applications and wanted to quickly identify areas for improvement of the technology.
Finding a good independent laboratory for testing an antimicrobial device can be tough. Mark and Julie had an advantage; they had met a scientist from Microchem Laboratory at an infection control conference in 2008. They called the lab and were pleased to learn that it was located "next door" near Austin, Texas.
Dr. Stibich (now Chief Scientific Officer for Xenex) and Dr. Benjamin Tanner from Microchem Laboratory discussed the project at length. A series of studies was designed to determine appropriate treatment duration, characterize the efficacy of reflected UV light, and assess the influence of organic matter on disinfection efficiency.
The results from the first wave of testing were stunning. Most notably, efficacy against the disinfectant-resistant spore form of Clostridium difficile was excellent and >99.9% reductions in contaminant microorganisms were seen within just 5-12 minutes of treatment.
This led to a host of follow-on studies running in parallel with a series of device improvements. Most of this testing was done in Microchem Laboratory's device-testing room, where dozens of inoculated test surfaces were placed throughout the room on multiple occasions, treated with Xenex, then evaluated afterwards. Microorganisms ranging from VRE to MRSA to C. difficile were all tested. Recently, Xenex worked with Microchem Laboratory to evaluate efficacy of the device when certain visible wavelengths of light are filtered, resulting in a less distracting user experience.
With "proof of concept" firmly in hand, Xenex set off on a series of pioneering studies to evaluate the effect of using the device in hospitals. The first of these studies have since been published in prestigious journals, such as Infection Control and Hospital Epidemiology. More studies will be published in the years to come.
As a general matter, the Xenex approach to surface disinfection outperforms traditional chemical approaches. Consider this: A recent peer-reviewed by Philip Carling, et al., showed that nearly half of all high-risk surfaces that should have been cleaned in a group of 36 acute care hospitals were missed during the cleaning process. Xenex UV light contacts virtually every high-risk surface every time it is used.
Mark and the Xenex team recognized the inherent advantages of the pulsed-UV approach, but could not have envisioned the dramatic effect it would have when used diligently in healthcare settings. Recent research has shown an 82% reduction in C. difficile infection rates at Cooley dinkinson Hospital in Massachusetts. As a result of decreased hospital-associated infections, Cone Health in North Carolina reported a $2.3 million cost savings within 6 months.
Though the Xenex device and technology have matured rapidly, Microchem Laboratory continues to play an important role in developing the science of UV surface disinfection. The lab frequently analyzes blinded environmental samples collected from hospitals using the device for the presence of MRSA, VRE, and C. difficile. This data helps Xenex better understand the performance of the device and assures customers that they are getting the promised impact from the device. With Microchem Laboratory's fast turnaround times and robust microbiological methodology, the data is reliable and available to them right away.
Xenex believes that the faster their technology is adopted in healthcare settings, the more lives and unnecessary costs will be saved as a direct result of decreased infection rates. To that end, they worked closely with Microchem Laboratory, a fast-turnaround, technically capable, specialized organization capable of understanding and rapidly characterizing exciting new technologies. The future is bright for the Xenex approach to room disinfection, and Microchem Laboratory looks forward to doing its part to help reduce hospital infection rates.
UV light is a reliable, well-studied antimicrobial technology. It works primarily by destroying the DNA inside bacteria, viruses and fungi. The high-energy portion of the UV spectrum called UV-C is most effective. UV-C light has been used for decades to disinfect industrial surfaces and sanitize drinking water. It is especially advantageous for use in hospitals because it kills the spore-forming bacteriumClostridium difficile, which is a major source of hospital-acquired infections.
On March 17, 2015, FDA published new guidance describing testing and labeling requirements for reusable medical devices. The updated guidance is timely, since recent outbreaks of CRE from endoscopes exposed several missing validation studies from implicated manufacturers.
If your company's high-level disinfectant research and development phase is complete and you have finished all of the GLP in vitro efficacy tests required by FDA, then you are ready to conduct the final test, the clinical "in-use" test. Passing this test proves that your product will perform under the rigors and stresses of clinical use.
