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Keeping Patients Safe.

Patients that are continuously exposed to a hospital setting are at increased risk for these HAIs, particularly exposure to multidrug-resistant organisms (MDROs). MDROs are bacteria (microorganisms) that have become resistant to specific and/or multiple antibiotics, and these antibiotics can no longer be used to control or kill the bacteria. They are found mainly in hospitals and other healthcare settings including skilled nursing facilities and outpatient clinics. Unfortunately, MDROs can spread from patient to patient on the hands of health-care workers, especially when hand washing is not properly done or not done at all.

Another route of transmission could be via objects in the healthcare environment such as medication cart handles, bed rails, bedside tables, and intravenous poles. They can also spread from person-to-person through direct contact. Microorganisms can also be carried by airborne routes, dispersed over long distances by air currents, and be inhaled by susceptible individuals. This type of transmission is most often prevented by the use of special air-handling and ventilation systems, to contain and safely remove the infectious agent (tuberculosis, measles, chickenpox, etc.). To decrease the risk and occurrence of HAIs, most healthcare facilities have many infection control interventions in place (called bundles), which mainly include proper cleaning of the environment and hand hygiene (appropriate cleaning of hands to prevent the spread of germs).

The two categories of isolation precautions are standard precautions and transmission-based precautions. Standard precautions are a set of basic infection prevention practices intended to prevent transmission of infectious diseases from one person to another. Because we do not always know if a person is contagious or has a transmissible infection, standard precautions are applied to every person, every time to decrease the likelihood that transmission will occur. These standard precautions include hand hygiene, safe injection practices, and sometimes the use of gowns, gloves, masks, and eye protection. Transmission based precautions are designed to protect patients, staff, and visitors from contact with infectious agents. These additional precautions used in certain situations and are applied to specific infections or organisms, and most include the use of bundles--groups of prevention practices rather than individual practices. The bundled elements vary from site to site, but most include strict hand hygiene, active surveillance, placing patients on isolation, geographic and personnel cohorting, and aggressive environmental decontamination.

Patients with documented evidence of MDROs are likely to contribute to the contamination of the hospital environment mainly in their close surroundings (their hospital rooms). Many of these organisms may survive for months on dry surfaces, if not adequately cleaned, which then pose a risk to other patients and health-care workers. A number of published studies describe the association between the contamination of patient environments and the increase in healthcare associated infections from organisms in the environment.

Health-care workers are also likely to contaminate their gloved hands when touching surfaces in the patient room, such as when touching the patient. Hence, thorough environmental cleaning may reduce contamination, prevent transmission, and reduce HAIs. For years, hospitals strived to keep the health-care environment clean, especially when the rates of MDROs are increasing and many patients are affected after admission to the hospital. Many environmental interventions were implemented in efforts to improve effectiveness of cleaning and disinfection practices. These efforts included substitution of surface disinfectants to more effective products when available, monitoring the thoroughness of cleaning by checking patients' rooms, and retraining housekeeping personnel periodically. Although interventions geared towards improved thoroughness and adherence to manual cleaning protocols has decreased the environmental burden of harmful organisms, a large majority of facilities struggle with maintaining compliance for various reasons. Some barriers include time pressure, training issues, and high turnover rate of staff. This is where emerging technologies can play an important role in decontaminating the environment and keeping our patients safer. In recent years, automated surface decontamination systems aimed exclusively at environmental decontamination, have evolved to meet the specific needs of health-care facilities.

Automated devices that have been shown to be effective in reducing environmental contamination in hospital rooms include hydrogen peroxide vapor or aerosolized and ultraviolet light devices. These methods are used in addition to proper cleaning to enhance the efficacy of disinfection. The hydrogen peroxide decontamination method has been used successfully to decontaminate rooms, furniture, and equipment. This method delivers the hydrogen peroxide vapor uniformly over all exposed surfaces in a room, and it has been shown to be more effective than cleaning with 0.5% sodium hypochlorite solution (bleach). Two of the major drawbacks of this method, which make it impractical to use routinely, is the excessive time from room preparation to the end of delivery of the hydrogen peroxide and the use of chemicals. The process can take up to three hours and requires staff to shut down ventilation outlets in the room.

Another automated system that we routinely use at our institution is a portable device with a xenon gas flash lamp that produces pulsed-xenon UV light. Pulsed Xenon lamps produce a flash of full spectrum germicidal light across the entire disinfecting spectrum (200320 nm), delivered in millisecond pulses that cause cellular damage to most if not all living bacteria, viruses and fungi. Additionally, no warm-up or cool-down time is required between cycles, so the devices can be used in many rooms each day. Studies on the disinfection times for pulsed xenon UV light have shown reductions of C. difficile spores and many vegetative organisms within 5 minutes. After we routinely incorporated this method into our cleaning processes, in addition to standard cleaning, we found a significant decrease in the rates of HAIs during specified time. Other studies reported similar decreases in the rates of MDROs infections after using these portable devices in their hospitals. (1,2,3)

Some of the possible disadvantages of these automated methods are: (1) requiring the areas to be vacated; (2) more expensive than conventional disinfection; (3) requiring special equipment; and (4) the process is time-consuming, resulting in a longer room turnaround time (potentially leading to delays in bed availability), but these apply mainly to the hydrogen peroxide method. The cost-effectiveness of these no-touch methods and the determination of whether they have a significant effect on clinical outcomes needs to be further explored.

In conclusion, environmental cleaning is an important part of the bundle to control the spread of health-care associated infections. Growing evidence has accumulated suggesting that improvements in environmental decontamination may prevent transmission of microorganisms, mainly MDROs, thereby reducing HAIs. The various available systems have all demonstrated the ability to destroy harmful organisms on surfaces in the hospital environment. As the adoption of automated systems is increasing, hospitals are faced with evaluating which of the technologies are best suited for their institution, how to deploy the systems most efficiently, and whether they actually reduce HAIs.


(1.) Ghantoji, S.S., et al. 2015. "Non-inferiority of pulsed xenon UV light versus bleach for reducing environmental Clostridium difficile contamination on high-touch surfaces in Clostridium difficile infection isolation rooms." Journal of Medical Microbiology 64(2):191-194.

(2.) Levin, J., et al. 2013. "The effect of portable pulsed xenon ultraviolet light after terminal cleaning on hospital-associated Clostridium difficile infection in a community hospital." Am J Infect Control 41:746-8.

(3.) Simmons, S., et al. 2013. "Impact of a multi-hospital intervention utilising screening, hand hygiene education and pulsed xenon ultraviolet (PX-UV) on the rate of hospital associated meticillin resistant Staphylococcus aureus infection." J. Infect. Prevent. 14:172-174.

Sherry S. Cantu is a certified infection preventionist at MD Anderson Cancer Center in Houston. Roy F. Chemaly, M.D., is a professor of medicine and the director of infection control at MD Anderson Cancer Center in Houston.

Caption: UV light technology used in the operating room environment.

Caption: UV technology used in various health-care environments when a patient is discharged. The reams are first cleaned using traditional methods by housekeeping staff, then followed with UV disinfection.
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Title Annotation:Emerging Technologies
Author:Cantu, Sherry S.; Chemaly, Roy F.
Publication:ASHRAE Journal
Article Type:Report
Date:Aug 1, 2016
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