What You Need To Know About Disinfectants
Introduction with Definitions
Microorganism (or microbes) are the germs that cause infection. They are mainly classified as bacteria, viruses or fungi. Each of these groups have a whole range of microbes within them. Different microbes infect their host and multiply by different means. As such, different chemicals, called disnfectants, are deployed to control these threats and also have varying modes of operations.
Disinfection is the process by which microorganisms are either removed or killed such that they do not pose a clinical threat.They may not necessarily bring about a 100% kill but will reduce the prevalence such that there is no threat of the microbe causing an infection. (Infection is the clinical manifestation of the effect of the spread of a microbe that has reached a level considered harmful to the host)
'Disinfectants' is the term use to describe agents that kill microorganisms on inanimate objects whilst an 'Antiseptics' kills germs on living tissue. Sterilisation is the complete removal of microorganisms threat on non-living surfaces usually brought about by extremes in temperature or strong chemicals.
How is Disinfection Measured
Disinfection is measured by 2 main criteria : The kill rate and extent of the microbial kill.
Kill rate refers to the speed with which the disinfectant acts and logically, it will depend on the microbe in question. Some microbes are more resistant than others and therefore require a longer time to kill.
Kill extent is reflected as a percentage reduction from the initial population. Also relevant is the the kill spectrum which refers to the range of microbes dealth with. It would stand to reason that an ideal disinfectant is both fast acting and kills a wide array of microbes. However, user safety is another element that must be met when considering the disinfectant. Harsh chemicals that may cause injury or unacceptable side effects upon administration are shunned.
Contact time refers to the required time the chemical agent must be in contact with the microbe, to effect the kill.
Some microbes are easier to kill than others and that is also why there is no single contact time that can be quoted for a disinfectant. Generally, disinfectants are regarded as useful only if they kill a wide enough range of microbes and reduce the microbial population to clinically significant reductions within 1-2 minutes. However, there is no standard time for this and users must read the instructions carefully on each product label and follow it to acheive best results.
If contcat time is no strictly adhered to, some microbes may be killed whilst others survive. When microorganisms are exposed to chemicals that do not fully kill them and anly attenutae them, they have a greater propensity to develop resistance. Also, in clinical settings, we must try to acheive a good surface disinfection by following contact times, to ensure the stemming of the nooscomial infections. Failure to do so is compromising the well being of all exposed.
Are there Cases where Disinfectants are used Ineffectively?
- Different chemical agents have different kill rates and spectrums and it is imperative that users know the possible microbes they are dealing with when choosing a disinfectant. Realising that all disinfectants have limitations, users must be wary that there may be gaps to their processes/protocols that may need to be handled by more than one disinfecting agent. Protocols must also be continuously reveiwed as new microbes and resistances strains are discovered from time to time.
- There are cases where users wrongly assume that contact time refers to a wiping a surface and waiting for the labelled timeframe without considering if the chemical is still present on the surface for the entire duration. This is particularly relevant in cases where the disinfectant is volatile like alcohol. Contact times on a single pass of volatile substances rarely go beyond 20 seconds and therefore multiple applications may be required to disinfectant a given surface, as described by the contact time. If a wipe is used, multple applications must be adminsitered by a fresh wipe each time.
- Also, chemical wipes, which are known to be superior as they act both mechanically and chemically, should not be used for too large an area as there may likely be recontamination. A wipe of a certain dimension can only be used to a certain limit beyond which the wipes is maximised and contaminates the surface it passes over after that point. Clinical judgement is required to establish the extent of utilisation of such wipes.
- Wiping technique used in cleaning surfaces should also best follow the figure"S" so that there is no overlap of wiped surfaces with the same disinfecting wipe. Moving a wipe from clean to dirty is fine and shoould never be the other way.
- Generally, disinfectant sprays are not as thorough as wipes because sprays depend on good nozzle dispersion mechanics to distribute the disinfectant, which is not a certainty. Hence, wipes, with the mechanical advantage of removing the bioload as well as leaving the chemical on the surface, is the best disinfecation method today. However, in hard to reach places, the disinfectant spray is still he only application viable.
What are Detergents and How Important Are They?
Detergents are basically soap based products that act as a surfactant and help remove bioload from the surface. This bioload is essentially organic matter likes oils and debris that can adhere to the surface and reduce the effect of the disinfectant because they can act as a barrier between the disinfectant and the microorganism.
Since microorganisms and other bioload matter remain invisible to the naked eye, it is best practice that all surfaces, whether skin or inanimate surfaces, should first be cleaned with a detergent, before applying the disinfectant. This way, the disinfectant will be sure to reach the microbes and be effective in the stated contact time if applied correctly.
As a note, even alocohol gels for hand cleansing are best used after hands are washed as alcohol itself does not remove bioload.
Disinfectant Product Reliability
Disinfectants are an essential part of keeping our environments safe, be it in a hospital, clinic, nursing home or even our own domicile. The problem is often compounded when we have a susceptible person in our midst who could be effected adversely by surface contamination.We all know about how contagious and lethal MRSA can be and statistics bear out the risk of such infection. Hospitals spend considerable resources to stem the spread of any lethal microbe on many fronts.
However, the information that is presented to clinicians are often distorted because companies behind products are often the ones providing such product skewed information. Clinicians or buyers who evaluate disinfectants for use would be advised to consider the following points :
- Ensure that the product comes from a reliable source, be it company or country of origin, where you can be assured that the providers have a reputation of professionalism and integrity.
- Ensure that you are able to appreciate the full content list of the product.
- Ensure that you have sound clinical test data from a reliable neutral party that has evlauated the claims and substantiated them.
- Ensure that the test data presented are validated (tests repeated to ensure findings are consistent).
- Ensure that the tests done are relevant to the usage scenarios you are expecting to use the product in and check that the test protocol is accredited to EN or similarly acceptable standards.
- In cases where accredited standards are unavailable and a private protocol established, ensure the relevance and inegrity of the protocol to the usage scenario.
- Be aware of the chemicals and its inherent disinfection properties and do not fall for baseless claims on product ability even if it is on the label. Labelled claims have been known to not be supported by sound clinical proof.
- Be aware that no disinfectant does everything and appreciate the limitations of the products you choose.
Are Disinfectants Costs Justified
Medical institutions are often faced with the dilemma of deciding on disinfection budgets. Infection spread is hard to detect specfically and associate to a particular process and therefore disinfection itself is not often outcome visible. Clinicians and administrators therefore often use statistics to extrapolate on the extent of the effort required.
It is clear, that infections cost both the patient and healthcare system considerable resources. Consider the extent of ICU stay for a acquired pneumonia case and cost associated with post surgical complications and we see the relevance. Million of dollars can be saved with a sound disinfection processes based on proper understanding and diligence. Disinfection does not burden the system but instead saves costs, morbidity and mortality.
However, misguided views and improper usage of products can easily harm the good we hope for. Education and vigilence on best practice is imperatives that go a long way to sustaning a safe environment. With this, healthcare costs will be managed a lot better with surpluses that can be well utilised in other live saving processes.
Let Trident show you how this is indeed achieveable. Call us at +65 62887723.