Why Continuous Disinfection is Necessary in the HealthCare Environment


The word “endemic” is used in many ways, but few relate it to “organisms” that may live within a hospital, nursing home or other healthcare establishment.  Endemic is defined as “characteristic of or prevalent in a particular field, area, or environment.”  Common examples would include certain species of tick carrying Lyme disease which are prevalent in the Eastern United States, another would be a high load of MRSA or Pseudomonas in a healthcare environment.

Hospitals are supposed to be clean environments, but often we find that certain organisms are or can be reservoirs for Hospital or HealthCare Associated Infections (HAI’s) in our patients.  A lot of effort and monies are allocated to cleaning the environment to prevent the transfer of environmental contaminants to patients.  We further spend more money placing patients with known multi-drug resistant organisms/infections (MDROs) on contact isolation or precautions.

Does this practice really make a difference in the transmission of organisms to our patient? Does it result in fewer numbers of HAI’s?  Certain organisms such as VRE, MRSA, and resistant Pseudomonas are often the target of contact precautions.  A recent discussion at the 2018 SHEA meeting suggest that there may be a shift away from using contact precautions as many hospitals have stopped doing surveillance culture for the presence of MRSA or VRE.  Dr. G. Bearman at Virginia Commonwealth University (VCU) suggests that the focus should not be on a single organism but on multiple organisms (See Contagion Live, 4/2018). 

The environment is a reservoir for both pathogenic and non-pathogenic organisms including bacteria, bacteria spores, fungi, fungi spores, viruses and perhaps certain protozoans.  Patients and staff can contribute to the microbial load, as they can be carriers of organisms.  So, when charged with keeping our patients safe from infections, prevention is the key.  What methods do we have that will aid in our quest?  Horizontal approaches to infection prevention according to Dr. Bearman include: hand hygiene, Chlorhexidine bathing, central line and Foley insertion bundles, ventilator bundles and “bare below the elbows” policy for the staff.  Interestingly, he does not mention the environment.

Although it is the environment that contributes greatly to the endemicity of organisms in the healthcare setting.  Each setting is being affected by their local microbiological profiles and bioburden pressures based on their patient demographics, disease acuity and antimicrobial resistance profiles.

Many new devices known as “hands-free” systems are available in the market place.  These include: ultraviolet systems, fogging systems, and other micro aerosol dispersal systems.  A key advantage to all these “hands-free” systems versus a “wipe and spray” method is the ability to reach more areas/spaces/crevices. These spaces are often left with the offending organism untouched after cleaning with only a wipe and spray method.  Each hands-free technology, whether UV, H2O2, and/or alcohol vary in the degree of reachability to these areas.  In many cases, older hospitals have additional burdens of water leaks and other issues adding to the microbial load.  Data even suggest that hospitals still using shared rooms have a 33% higher rate of Central Line Blood Stream Infections (CLABSI) then patients in semi-private rooms, in addition to a shorter length of stay (SHEA Spotlight 08/2018).  The question is why?  It is suggested that studies need to be performed to discern the reason.  Shared rooms often use privacy curtains and many studies have revealed the amount of contamination these curtains carry.  Often these curtains are not changed prior to the next patient even if the patient was on contact isolation.  When the environment is contaminated, all the high touch items in a room will also be contaminated. This occurs in a very short time.  Data suggests that it takes less than 24 hours to contaminate all high touch areas in a room.

The use of hands-free disinfection systems throughout the healthcare facility overtime gives an opportunity to reduce the number of endemic organisms in the environment.  If there are fewer organisms, there should be less infection transmission to both patients and staff.  If there is a flu outbreak or a norovirus outbreak, the facility is treated with an aerosolized disinfection mist leaving all surfaces decontaminated, and the transmission reduced. The repeated disinfection of hard surfaces should also reduce the chance transmission of MDROs to both patients and staff. The key is continuous, consistent use of the hands-free disinfection process.

A performance model used by an inner-city hospital employs a hands-free system using peroxide solution which is passed through a patented DARPA technology that uses an atmospheric cold plasma arc to alter low percentage hydrogen peroxide into a radical which destroys pathogens leaving only oxygen and humidity as its by-product. This technology is known as SteraMistTM owned by TOMI™ Environmental Solutions. The EPA registered solution and equipment combination utilizes iHP™ technology. BIT solution’s only active ingredient is 7.8% hydrogen peroxide.  The process allows the dispersal of an OH radical into the environment killing organisms in seconds.  The SteraMistTM system is registered by the EPA and is sporicidal for C. diff spores and has activity against many, fungi, viruses, Gram + and Gram – organisms.  The system has been in place for four years and was originally selected by this inner-city hospital for use in Ebola preparedness.  The system today is routinely used for all isolation rooms, monthly treatments of non-isolation rooms, end-of day OR treatment, Emergency Rooms, pharmacy hood disinfection, and is even used throughout the holding and visitor lounges on a daily basis.  Additionally, the hospital had replaced all cloth curtains with polypropylene disinfectant containing privacy curtains which are compatible with the BIT™ solution.

So, what has this done for the facility?  The facility has one of the lowest infection rates with a composite Standard Infection ratio (SIR) for CAUTI, CLABSI, SSI-colon, C. diff, and MRSA of 0.23.  The maintenance of that number takes constant vigilance and pro-active measures to prevent infectious agent dispersal. As mentioned by Dr. H Bearman, prevention of infection is not just one organism or process; it’s the additive values of the interventions.

Stay tuned for further case control studies on the use of SteraMist™ to reduce endemic load.

Helene Paxton, MS, MT(ASCP), PhD, CIC