The first high-profile Ebola case in the U.S. States has led to a clamor in the public for more thorough methods of ensuring screening, disinfection, and containment of the virus. Xenex’s xenon light-emitting robot may offer the best solution for quickly and efficiently killing Ebola in hospitals so that it doesn’t spread further.
You’ve likely seen news footage of technicians in hazmat suits washing down the front door area of the Dallas apartment where U.S. Ebola Fever “patient zero,” Thomas Duncan, had been staying. Mr. Duncan, a Liberian visitor to the U.S. who was treated at Texas Health Presbyterian Hospital in Dallas, and died Wednesday morning. The family that had been hosting Mr. Duncan have been evacuated from the apartment and quarantined elsewhere while they wait out a 21-day incubation period for the virus, and their home subjected to extreme disinfection processing.
According to the Centers for Disease Control and Prevention (CDC), Ebola viruses, responsible for going-on 7,000 infections and more than 3,500 deaths in the current outbreak so far, are transmitted through direct contact with blood or body fluids/substances (e.g., urine, feces, vomit) of an infected person with symptoms or through exposure to objects (such as needles) that have been contaminated with infected blood or body fluids.
The CDC cites a study data that indicating that under favorable conditions Ebola viruses can remain viable for up to six days on solid surfaces, with concentrations falling slowly, over several days. In a follow up study, Ebola virus was found, relative to other enveloped viruses, to be quite sensitive to inactivation by ultraviolet light and drying; yet sub-populations did persist in organic debris. And while there is no epidemiologic evidence of Ebola virus transmission via either the environment or fomites (objects that could become contaminated during patient care that may become contaminated with infectious organisms and serve as vectors in their transmission, such as bed rails, doorknobs, bathroom surfaces, or laundry) the CDC advises that given the apparent low dose required to transmit infection, potential of high virus titers in the blood of ill patients, and the disease’s severity, high levels of precaution are warranted to reduce potential risk posed by contaminated surfaces in the patient care environment.
On August 1, 2014, CDC released guidance titled, ”Infection Prevention and Control Recommendations for Hospitalized Patients with Known or Suspected Ebola Hemorrhagic Fever in U.S. Hospitals,” recommending that in the care of patients who are persons under investigation, or with probable or confirmed Ebola virus infections, hospitals are advised to apply and exercise stringent personal protective equipment (PPE) and disinfection/decontamination protocols.
The directive notes that enveloped viruses such as Ebola are susceptible to a broad range of hospital disinfectants used to disinfect hard, non-porous surfaces in contrast with non-enveloped viruses that are more resistant to disinfectants. And that as a precaution, use of disinfectant products with a higher potency than what is normally required for an enveloped virus is being recommended at this time, and that EPA-registered hospital disinfectants with label claims against non-enveloped viruses (e.g., norovirus, rotavirus, adenovirus, poliovirus) are broadly antiviral and capable of inactivating both enveloped and non-enveloped viruses.
The recommendations include daily cleaning and disinfection of hard, non-porous surfaces (e.g., high-touch surfaces such as bed rails and over bed tables, housekeeping surfaces such as floors and counters) using chemical disinfectants.
Xenex’s Novel, Light-Based Solution for Ebola & Other Infections
San Antonio-based Xenex Disinfection Services, a leader in ultraviolet environmental disinfection systems, say while they believe risk of an Ebola outbreak in the US is low, the Ebola threat has served to educate hospital decision-makers about their outbreak response programs status, and notwithstanding the unliklihood of a U.S. Ebola epidemic breakout, nearly 300 people die in the U.S. every day from iatrogenic infections acquired from more commonplace pathogens lurking in hospitals already — e.g.: superbugs like C.difficile that pose a present and much greater threat to U.S. hospital patients.
Xenex’s marquee hospital disinfection product is a robot that uses xenon UV light to quickly destroy bacteria, viruses, bacterial spores, and other microbial pathogens. The company stresses that the xenon part is very important and that while UV light has been used for disinfection for decades — it’s been powered by mercury bulbs.
In contrast, Xenex have patented use of xenon gas (instead of mercury) to power their UV light, claimed to be 25,000 times more intense than mercury systems. They note that while there are dozens of companies marketing mercury UV disinfectant systems, theirs is the only one using xenon UV — an attribute that makes Xenex robots much faster and more effective (UV destroys microorganisms like the Ebola virus four different ways compared with mercury systems that only do one mode of damage). Xenex say their UV robot can disinfect a patient room in just 5-10 minutes (depending on the size of the room).
Xenex adds that it’s also important to note that they are the only UV disinfection system provider that has hospitals publishing infection reduction results with their equipment in peer-reviewed journals, noting that while it’s one thing to show that UV light disinfection works in a lab setting, it’s far more difficult (although more important) to demonstrate that it works to reduce infections in real-world hospital settings. Several U.S. hospitals have recently published healthcare associated infection (HAI) reduction results after implementing an infection prevention program that includes ultraviolet (UV) light room disinfection. Xenex says as a result of this success and declining reimbursements for hospitals with high infection rates, many healthcare facilities are now considering UV light room disinfection as part of their bundled approach to infection control. Therefore, it is imperative for hospital decision-makers to understand the significant scientific differences between UV disinfection technologies because not all UV light is the same.
The company explains that killing Ebola viruses is all about physics. The Ebola virus is a single stranded RNA virus which is sensitive to ultraviolet light, with a dose of approximately 10 J/m2 needed to deactivate the deadly germ. Xenex’s system has been validated and tested against the MS2 Bacteriophage, which required a dose of approximately 200 J/m2 for deactivation. Xenex deactivated MS2 Bacteriophage in five minutes at two meters, which they claim means that they can deactivate (destroy) the Ebola virus in under two minutes.
Another advantage of xenon UV in disinfection systems is that traditional mercury bulbs contain elemental mercury, which means they are classified as hazardous and toxic, and may require special handling if a bulb is damaged. If a bulb breaks, mercury vapor is absorbed by the lungs at a 90 percent rate which is far more dangerous than a broken thermometer, which uses liquid mercury, and many disinfection device manufacturers neglect disclosure that they use mercury vapor in their devices.
In 2010, Xenex Disinfection Services launched its new UV light room disinfection system utilizing environmentally friendly xenon, which is an inert gas whose vastly superior functional efficiency enables Xenex’s germ-zapping robots to disinfect healthcare facilities in a fraction of the time it takes for mercury bulb devices to disinfect rooms.
Xenex explains that pulsed xenon emits high intensity UVC light across a broad germicidal spectrum (200-280 nanometers, versus the single spectrum of 253.7 nanometers for mercury bulbs). This broad germicidal spectrum enables Xenex devices to eliminate a wider range of pathogens at a much faster rate than mercury devices. The Xenex robot can disinfect a typical patient/procedure room in 5-10 minutes, as demonstrated in multiple peer-reviewed published studies. SUV-C passes through cell walls and its energy is absorbed by DNA. The amount of energy absorbed causes DNA’s adenine-thymine bonds to break and thymine-thymine bonds to form, which are called “thymine dimers.” These are errors in the DNA. An overwhelming amount of DNA errors is incompatible with cell function. – See more at:
“Eliminating pathogens from patient rooms is the quickest and easiest way to lower the risk of additional infections. Our customers report in peer-reviewed, published studies that after using our patented germ-zapping robots to disinfect surfaces, they experienced significant reductions in hospital acquired infections. That’s because our devices are faster, more effective and easier to use than mercury-based UV room disinfection systems,” says Mark Stibich, PhD, co-founder and Chief Scientific Officer of Xenex. “Our customers have proven that they can reduce C.diff and MRSA infection rates by more than 50 percent by using our robots for surface disinfection. Only Xenex’s broad spectrum UV light is capable of damaging microorganisms four different ways and ensuring the pathogens are destroyed. We believe in evidence-based medicine and challenge anyone considering UV room disinfection to look at the science behind the competing technologies before making a decision. Not all UV light is the same and our patented pulsed xenon technology has truly set itself apart.”
In an interview this week with BioNews Texas Editor-In-Chief Michael Nace (MN), Dr. Stibich (MS) expanded on the topic of Xenex technologies, Ebola and related matters.
MN – What makes the Xenex robot the best solution for killing Ebola? And how do you know that the Xenex robot in fact kills Ebola?
MS – “There are two different ways that we determined that we kill Ebola. The first way is that we know the kill dose for Ebola approximately 10 Jules per meter squared. We’ve tested the Xenex robot in the lab against other viruses that take about 20 times the UV dose to kill, such as the MS2 bacteriophage, which take 200 Jules per meter squared to kill. So, if we can kill that, we can certainly kill Ebola.
“In addition, after the current Ebola outbreak started, we quickly went into the lab and ran the EPA surrogate virus — viruses with a very similar structure to Ebola — in order to confirm that we could kill them in 5 minutes or less using the robot. We knew that our dose is much, much higher than what is needed to kill Ebola, but these lab tests confirmed that our technology can kill the virus quickly and effectively.
“In the hospital setting, the major risk of Ebola or any contagious infection is having it spread to healthcare workers. This is where we see us fitting into the Ebola response. One of the primary uses of the Xenex robot is to protect the healthcare workers in a hospital setting so that they can continue to stay healthy, effectively treat patients, and not ultimately spread infection outside of the hospital.
“At any point in a disinfection process where manual disinfection is being done by hospital staff — where things are being wiped and cleaned with chemicals — that’s a point where we want to step in and say, is this an opportunity to use Xenon UV? Is this a situation where we really want the extra assurance of having an automated process that doesn’t leave to chance a maintenance worker missing a spot in the disinfection process?
“We’re also talking with a number of government agencies and non-profits who are coordinating the Ebola response in Africa and with that we’re offering our services and expertise as part of the effort. Currently, health authorities there are spraying the healthcare workers with a chlorine solution as they exit an exposed area. We can see the role there for ultraviolet disinfection to ensure that nothing is missed.
“We know from studies conducted in hospital settings that they would go out and track which surfaces were cleaned by housekeeping personnel in standard patient rooms, and they miss about 50% of the high-touch surfaces. So theres really good knowledge out there that the manual cleaning process has a high level of human error associated with it.”
MN – How does killing Ebola with Xenex differ from killing some of the dangerous bacteria found in hospitals, such as C.Diff?
MS – With C.Diff in particular, it’s a spore, so the organism is protected by a shell around it. That’s why these bacterial spores are some of the hardest things to kill with UV, because that extra layer has to be penetrated. As a result, when we design our hospital protocols, we focus on getting an adequate C.Diff kill. So, when we talk about running Xenex in a hospital bathroom for 5 minutes, that’s to kill C.Diff. In fact, to kill other things like MRSA or Ebola, there is even less time needed in terms of UV exposure. But because C.Diff is such a prevalent problem in the U.S., we just set everything for C.Diff kill.”
MN – Are there other possible applications for Xenex outside of the Hospital?
MS – “We are contemplating that question all the time. We’ve recently used the technology in the locker rooms of some high schools in San Antonio to prevent the spread of staph or MRSA among the players. We’re also in talks with professional sports organization as well. Not only have there been important games affected by the spread of infection, but also ensuing lawsuits as well, which organizations would like to avoid. We’re talking with them on how we can integrate with their disinfection plan.
“That being said, as an early-stage company, our main focus continues to be on addressing HAI (Healthcare-associated infections) which kill 275 people in the U.S. per day. We have to balance that with our goal of expanding into other areas as well.”
Xenex recommends that healthcare facility administrators ask the following questions when evaluating the purchase of disinfection technologies:
• Does the device contain mercury?
• Does the vendor have studies demonstrating efficacy in the hospital environment, under real-world conditions? Are they more effective than housekeeping at eliminating bioburden?
• Is there a residual odor in the room after the device has been operated?
• What is the cycle time to eliminate C.diff spores?
• Are the device placement guidelines evidence-based? Do they recommend multiple positions to account for the effects of shadowing?
• Do they have peer-reviewed, published studies by hospitals that have experienced 50 percent and greater reductions in infection rates after using their UV technology for surface disinfection?
• Do they offer a customized infection prevention protocol? Do they have Infection Preventionists and Epidemiology staff available to consult with you and provide recommendations specific to your facility and the pathogens in your facility?
• What is their customer base? Do they have references from prestigious hospitals and hospital systems?
• Have they developed best practice guidelines for the use of UV disinfection?
The Speed of Xenex’s System: When Time is a Factor
Xenex observes that room turnover time is a serious factor for busy hospitals, and their Environmental Services (EVS) teams, and that Mercury UV room disinfection systems utilizing mercury bulbs require two to three minutes to warm up, and 15 minutes to cool down. They cite the Association of Professionals in Infection Control & Epidemiology (APIC) guidelines (Carrico, R., Guide To Preventing Clostridium Difficile Infections. 2013. Association Of Professionals In Infection Control And Epidemiology. Washington, D.C.) for mercury UV systems recommending 45 minute cycles to eliminate C. difficile spores in the patient environment. This brings minimum treatment time for a patient room for a mercury-based UV room disinfection system to approximately three hours as compared to three five- minute cycles for pulsed xenon UV devices.
“Many companies produce UV devices with mercury bulbs and none of these mercury companies have achieved peer reviewed patient outcomes from the use of their devices in hospitals. Hospital decision- makers need to understand the significant scientific differences between UV light technologies as they evaluate room disinfection systems,” says Xenex CEO Morris Miller. “Only Xenex is non-mercury and only Xenex has published studies by hospitals that have experienced reductions in infection rates after using Xenex’s pulsed xenon UV light technology. Links to peer-reviewed studies demonstrating a reduction in actual patient infection rates for surface disinfection can be found at:
One such study at Westchester Medical Center n Valhalla, New York reported a 20 percent drop in C. diff and MDRO infections when using Xenex robots to disinfect 22 percent of their overall discharges. This retrospective study was published in the June 2014 issue of the American Journal of Infection Control entitled “Implementation and impact of ultraviolet environmental disinfection in an acute care setting” (Am J Infect Control 2014, 42:586-590 Volume 42, Issue 6, Pages 586–590, June 2014) authored by Janet P. Haas, PhD, RN (Corresponding Author); Jonathan Menz, MBA; Stephen Dusza, DrPH; and Marisa A. Montecalvo, MD.
The study analyzed 52 months of hospital-acquired MDROs plus C. difficile before and during UV disinfection use. During the pre-UV disinfection period (January 2009 – June 2011), the hospital used standard cleaning protocols [sodium hypochlorite (bleach)] to disinfect MDRO patient rooms upon discharge. Once the hospital leased two Xenex UV disinfection machines and trained the staff to use them, the second phase began (July 2011 – April 2013), during which UV disinfection was added to the cleaning regimen. In addition to use for contact precaution discharges, UV disinfection was used weekly in the dialysis unit, and for all burn unit discharges. UV disinfection could be requested for rooms of long-stay patients or for discharges in units with high prevalence of MDRO or C.diff.
According to the authors, “In our study, overall decreases in MDRO plus C. diff infections were led by a decrease in VRE infections, which is our most common hospital-acquired MDRO. Although there were many other simultaneous infection control interventions occurring at our hospital that could have contributed to the reduction in VRE acquisition, the rates experienced during ultraviolet disinfection are the lowest incidence rates of VRE at our institution for the past 10 years and were sustained for 22 months.”
For more see:
A study at MD Anderson Cancer Center in Houston showed a 30% facility-wide C. diff reduction and a 30% VRE reduction. You can find out more about that study at:
Xenex emphasizes that understanding shortcomings in the use of mercury bulbs in room disinfection technology is not marketing hype, and as evidence of the dangers of high toxicity of mercury to human health builds, hospitals and health organizations are looking for and often requiring mercury-free solutions. They observe that in January 2013, the World Health Organization (WHO.org) and Health Care Without Harm, (HCWH.org), an international coalition of medical professionals, community groups and hospitals, approved Mercury-Free Healthcare by 2020, and in 2009, President Obama signed Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, which states that the government will promote pollution prevention and the generation of waste by reducing and minimizing the quantity of toxic and hazardous chemicals and materials acquired, used, or disposed of.
Xenex’s patented pulsed xenon UV room disinfection system is a pesticidal device used for the advanced cleaning of healthcare facilities. Due to its speed and ease of use, the Xenex system has proven to integrate smoothly into hospital cleaning operations. Xenex affirms that its mission is to eliminate harmful bacteria, viruses and spores that can cause hospital acquired infections in the patient environment, and to become the new standard method for disinfection in healthcare facilities worldwide.
For more information, visit:
Xenex Disinfection Services
Centers for Disease Control and Prevention
American Journal of Infection Control
Xenex Disinfection Services