What is "Rotational Disinfection"?
Rotational disinfection makes reference to "bioburden", which is the number of bacteria living on an unsterilized surface. With this type of disinfecting, you are not just trying to remove particles of dirt, dust, cell debris and such, you are also trying to remove and kill the living elements of contamination, which are the micro-organisms that are present. During cleaning, a portion of the microbial population will undoubtedly be removed. However, it is unlikely that all of it will be removed, which is why additional steps are required to kill any microbes that have not been eliminated by cleaning.
Disinfectants are used to control the bioburden, as they have properties that can kill micro-organisms. But two or more disinfectants will need to be used in rotation, and this is why the process of killing micro-organisms during the entire cleaning process is called "rotational disinfection". Where disinfectants are used, more than one type should be employed.
Why use more than one disinfectant?
The simple answer is to stop "resistance". There are two main types of resistance: naturally occurring and that derived through selection for resistant strains.
The development of genetic resistance has been reported in organisms such as Methicillin-resistant Staphylococcus aureus (MRSA). Just as this bacterium, once controlled by methicillin, has developed a genetic resistance over time and can no longer be controlled by that antibiotic, there is also the potential for this to happen to other microbes when employing disinfectants.
Over time, bacteria that were once controlled by alcohols, for example, would develop a genetic resistance to that disinfectant, making it no longer an effective agent. For this reason it is advisable to use different disinfectants. In simple terms, for resistance to develop, a few bacteria must barely survive a dose of whatever agent has been employed to kill that type of bacteria. These bacteria then have the chance to multiply, and the genetic advantage they had over other strains that allowed them to survive will be passed on, leaving behind a surviving strain that grows and thrives.
Once again, if a few of these bacteria survive a dose of agent and then multiply, the advantage that allowed them to survive is passed on yet again and gets stronger. This happens over and over with continued use of that same agent. The advantage grows until what is left is a strain that is totally resistant to that agent.
Most disinfectants have a very broad action, making it less likely that selection can take place. The process of selection for resistant strains is one that develops gradually. The resistance is not inherent in that organism and this is the main difference between this type of resistance and the naturally occurring resistance.
Naturally occurring resistance
Naturally occurring resistance occurs due to the fact that disinfectants have different modes of action. This means that not all disinfectants are equally effective at killing all microbes. Some may be very effective against bacteria but not fungi, whereas some may be effective against viruses but not endospores. Depending on the method by which that particular disinfectant kills, some micro-organisms will naturally be better able to resist its actions. This is not learned, selected for or genetically passed on – it is down to the nature of the micro-organism itself and the properties it already has. In the same way, tall humans may naturally be better at basketball. It is not that they have learned to be good, or have a better understanding of the game that was passed on to them by their parents – they just happen to be closer to the hoop.
Disinfectant mode of action
Alcohol-based disinfectants tend to be effective against most micro-organisms, but not endospores. Their mode of action is to denature proteins in the cell that can cause them to clump together and lose their function. When this happens to the cell wall it can lose structure and collapse. Quaternary Ammonium Compounds (QACs or Quats) work by causing disorganization of the cell membrane and the cell's insides to leak out and degrade. They are effective against bacteria, enveloped viruses and fungi, but have little activity on non-enveloped viruses or endospores. Biguanides alter the permeability of the cell membrane. They can damage the outer layers and attack the inner layers and this will also cause leakage. They have similar effects to Quats. Chlorine is a highly active oxidising agent. It oxidises DNA and cell proteins, destroying their activity. Disinfectants containing chlorine kill most things, including endospores at higher concentrations. Hydrogen peroxide is highly reactive and acts as an oxidant, producing free hydroxyl radicals. These free radicals can then attack the essential cell components. Hydrogen peroxide-based disinfectants tend to kill everything including endospores. So because a biguanide kills by affecting the cell wall and cell membrane, it may not be very effective against a micro-organism with a very strong cell wall. That type of micro-organism would be naturally resistant to the effects of a biguanide. Different types of disinfectant have different active chemicals and different modes of action
Endospores
Endospores are extremely difficult to kill. The endospore is a state that a bacteria or virus can enter into when conditions are unfavorable, for example, lack of food, lack of water or nutrients, temperature or pH changes. They build an ultra-strong coat around the cell's nucleus and essential parts to protect it. They can remain in this dormant state until conditions improve, when the coat will break down and the cell returns to normal. This strong coat means that in this state the endospore can be very difficult to kill, as it will resist the effects of gamma irradiation and many disinfectants. Chlorines and hydrogen peroxide are two disinfectants that do have an effect on endospores, and are often referred to as sporicidal. Chlorines can increase the permeability of the endospore coat and hydrogen peroxide can remove proteins from the coat.
Kill spectrum
Using different disinfectants will increase the kill spectrum – the total portion of the microbial population that can be killed. It can be helpful to think of the kill spectrum in a similar way to the light spectrum. If one considers only visible light, a huge portion of the light spectrum is being ignored, what about X-rays and UV rays? In the same way, if disinfectants that kill only bacteria are used, nothing is being done to combat endospores and other types of micro-organisms. Companies need to select disinfectants that, when used in rotation, cover as much of the spectrum as possible, therefore increasing the kill spectrum to the maximum. It must also be taken into consideration that using a disinfectant that kills bacteria but not viruses creates the conditions for viruses to thrive. It will create an environment where viruses will flourish, and the disinfectant chosen to try and prevent this from happening will be unable to make an impact.
Choosing a disinfectant
What disinfectants should you use? It is clear that using a sporicide is highly important, but agents that have sporicidal activity tend to be harsh and unacceptable for everyday use. For this reason it is recommended that a sporicide is used in rotation with another effective disinfectant that is more suitable for regular use. It would also be advisable to use an alcohol as well, as they have good efficacy against most microbes and can also remove any residues that may build up from the use of other disinfectants.
Rotational cleaning is the use of more than one disinfectant in rotation to control the bioburden in the room, area or vehicle to be disinfected. A written cleaning and disinfecting protocol needs to be developed and enforced which clearly specifies how and when specific cleaning and disinfecting materials are used, and a written record documenting the applications as well.
Studies have documented that when using disinfectants, more than one must used to prevent resistance. This applies both to naturally occurring resistance, where microbes are just not affected by a particular disinfectant, and to selection for resistant strains, where microbes that were once controlled by a disinfectant have developed resistant strains that are no longer controlled by the same disinfectant. Use different types of disinfectants with different active chemicals because each possesses a different mode of action. This means that they are effective against different types of microbes, and using more than one maximizes the kill spectrum. There are many factors that will affect the choice and frequency of use of disinfectant, including the process and residues, what format the disinfectant is available in, how easy it is to use and the environmental impact. So, as a guide, it seems sensible to rotate three agents – an alcohol, another general disinfectant and a sporicide.
Modes of Application
There are two basic modes of application to employ when disinfecting rooms, vehicles, equipment and other surfaces, direct surface application and dry mist application. Direct surface application is usually performed by cleaning personnel or employees using a simple spray and dwell or spray and wipe procedure. However, many disinfectants contain harmful chemicals and fragrances that are corrosive to skin and dangerous when inhaled. These products should only be used when employees are provided with eye or face protection, respirator or filter, gloves and protective clothing. Refer to the product's Material Safety Data Sheet to be certain all protective procedures are employed.
HOWEVER, VitalProductsCo recommends VITAL OXIDE as an excellent, highly effective direct surface application disinfectant. It is EPA registered, NSF approved for food contact (in proper dilutions), much safer than bleach, and approved to kill Ebola, Noroviruses and 99.999% of dangerous organisms. VITAL OXIDE is rated by the EPA as a Category IV for Toxicity...the lowest category on the scale and is designed for substances that are the least hazardous! Click on the link to view a PDF file of the Material Safety Data Sheet for VITAL OXIDE. (http://vitalproductsco.com/pdf/04_vo_msds.pdf ) You will see that there are NO PERSONAL PROTECTIVE DEVICES REQUIRED when using VITAL OXIDE. When diluted for use on food contact surfaces, VITAL OXIDE can simply be sprayed directly on the surface. After the proper dwell time, there is NO RINSING REQUIRED. For more information on VITAL OXIDE Ready-To-Use Disinfectant, please CLICK HERE
Dry mist application is achieved through the use of a mechanical device capable of atomizing a disinfectant into a "fog" of particles so minute, that they resemble visible smoke. This atomization allows the particles to permeate the area, vehicle or room with the ability to sanitze surfaces under counters and furniture as well as on window blinds, window sills and other surfaces that are difficult to dinifect using a spray and dwell or spray and wipe procedure. VitalProductsCo is an authorized distributor for the SANOSIL HALO FOGGER™ and the corresponding SANOSIL HALO MIST™ Disinfectant Fogging Solution.
Room fogging with the SANOSIL HALO FOGGER™ and the corresponding SANOSIL HALO MIST™ Disinfectant Fogging Solution is proven to be a most thorough and cost effective method for treating all the exposed surfaces within a room while reducing the labor and skills required to perform an effective treatment, and it is safe for use with sensitive electronic equipment. The Halo Disinfection System reaches into nooks, crevices and corners that disinfecting sprays & wipes can't, reaching every exposed surface in a room, not just the primary or "high-touch" surfaces, and reducing the risk of cross-contamination associated with using a rag, wipe or sponge. The Halo healthcare-grade hydrogen peroxide-based disinfectants are EPA approved, unscented and bleach free. For more information on the Sanosil HALO Disinfection System, please CLICK HERE