Welcome to the "ABC of Hospital Sensory Control", everyone knows that cleaning and disinfection is the basis of infection control in hospitals, but there are so many disinfection supplies and disinfection methods, you know how to choose the right one? This issue, we will talk about these dazzling disinfection supplies!
Is alcohol a cure-all?
Do you still use alcohol to disinfect during an outbreak of hand, foot and mouth disease?
What is high level disinfection? What is medium level disinfection? What is low-level disinfection?
Do you have to use high-level disinfectants in the event of a multidrug-resistant bacterial infection?
In this issue, we talk about what's in a disinfectant.
Figure: What is the difference between the various types of disinfectants?
- How to choose the right disinfectant-
Q
Is cleaning, disinfecting and sterilizing the same?
Certainly not the same!
Cleaning is the physical removal of dirt, dust and organic matter from the surface of an object. It can remove and reduce microorganisms, but not kill them. Common methods include water washing, mechanical decontamination and decontaminant decontamination.
Disinfection (disinfection) refers to the use of physical or chemical methods to eliminate or kill all pathogenic microorganisms other than spores. Can only reduce the number of harmful microorganisms to the degree of non-pathogenic, but can not completely kill microorganisms, that is, can only be effective on the propagation body, can not kill the bacterial spores, the disinfectant drug used is called disinfectant.
Sterilization (sterillization) refers to physical or chemical methods to kill all microorganisms, including pathogenic and non-pathogenic microorganisms and spores. Commonly used sterilization methods include high-pressure steam sterilization, boiling method, hydrogen peroxide low-temperature plasma sterilization, ethylene peroxide sterilization method. After sterilization, uncontaminated articles are called sterile articles. After sterilization treatment, the area that is not contaminated is called the sterile area.
Q
What do high level sterilization, medium level sterilization and low level sterilization refer to?
According to the level of disinfection, there are high level disinfection, medium level disinfection and low level disinfection.
High-level disinfection means killing all bacterial organisms including mycobacteria, viruses, fungi and their spores, and most bacterial spores. To achieve a high level of disinfection commonly used methods include the use of chlorine-containing preparations, chlorine dioxide, o-phthalaldehyde, peroxyacetic acid, hydrogen peroxide, ozone, tincture of iodine, acid oxidizing electrolytic water (AEOW), and other chemical disinfectants that can achieve the sterilizing effect in the specified conditions, at the appropriate concentration and the effective time of action of disinfection methods.
Medium level disinfection means killing various pathogenic microorganisms including mycobacteria except bacterial spores. Commonly used methods to achieve medium-level disinfection include the use of iodine-based disinfectants (iodophor, chlorohexidine iodine, etc.), compounding of alcohols and chlorohexidine iodine, compounding of alcohols and quaternary ammonium compounds, and phenols, etc., to disinfect at a suitable concentration and for an effective duration of time under specified conditions.
Low-level disinfection refers to chemical disinfection methods that can kill bacterial propagules (except mycobacteria) and lipophilic viruses, as well as mechanical decontamination methods such as ventilation and flushing. Such as the use of quaternary ammonium disinfectants (benzalkonium bromide, etc.), bisguanidine disinfectants (chlorhexidine, etc.), under the specified conditions, the method of disinfection at the appropriate concentration and effective duration of action.
Q
How resistant are common pathogenic microorganisms to disinfectants?
The common disease-causing microorganisms are, in descending order of resistance to disinfectants: lipophilic viruses, bacterial propagules, fungi, hydrophilic viruses, branchiobacteria, bacterial spores, and prions. Among them, lipophilic viruses are fat-soluble, can directly cross the cell membrane and are easily killed by disinfectants, including hepatitis B virus, hepatitis C virus, human immunodeficiency virus (AIDS) virus, influenza virus, herpesvirus, respiratory syncytial virus, elasmobranchial virus (rabies virus), SARS virus and so on. Hydrophilic viruses cannot cross cell membranes and are less likely to be killed by disinfectants, including hepatitis A virus, hand, foot and mouth virus, poliovirus, etc. Bacterial propagules are bacteria that have a reproductive state, as opposed to spores that are in a dormant state.
Low level disinfection can only kill the weakest lipophilic viruses and bacterial propagules, medium level disinfection can't kill the spores, high level disinfection can kill most of the spores, and sterilized level can kill all the spores.
Figure: Resistance of common disease-causing microorganisms to disinfectants
Q
Does a high-level disinfectant always achieve high-level disinfection?
Not necessarily.
Chlorine-based disinfectants are the most commonly used high-level disinfectants. Therefore, it can kill most bacterial spores, as well as branching bacilli, hydrophilic viruses, fungi, reproducing bacteria, and lipophilic viruses. However, its disinfection effect is also affected by the disinfection concentration and time, for example, high concentration of effective chlorine (2000mg/L~5000mg/L) when the action time is more than 30 minutes, it can kill all the pathogens, including bacterial spores, and it can achieve high level disinfection, while low concentration of effective chlorine (400~700mg/L) when it acts for more than 10 minutes, it can not kill bacterial spores, and it only achieves Medium level disinfection. In addition, organic contamination on the effective chlorine sterilization effect has a great impact, that is, clean or not, if the disinfection is not thoroughly cleaned before disinfection, will also affect its disinfection level. Therefore, when using chlorine-containing disinfectants and other disinfectants, it is necessary to evaluate the items to be disinfected and the types of pathogens contaminated to determine the level of disinfection that needs to be achieved, so as to correctly configure the appropriate concentration of disinfection in order to achieve a reliable disinfection effect.
Q
Is it always possible to achieve the desired disinfection effect when the right disinfectant is selected?
Cleaning and disinfection of hospital environmental surfaces, in addition to focusing on the choice of disinfectant and the use of concentration, should also focus on the following points:
1, should follow the principle of cleaning and then disinfection, to take the wet hygiene cleaning;
2, cleaning tools are appropriate for the use of microfiber material wipes cloth towels and floor towels, should be partitioned to use the implementation of the color marking, after using the Cleaning, disinfection, ready to dry standby;
3, follow the cleaning unitization of the operation, the implementation of a bed, a towel, a disinfection;
4, there are patients with blood and body fluids and other contaminants, should be readily available for spot cleaning and disinfection;
5, should not be used or contaminated cloth towels or floor towels repeatedly immersed in clean water, cleaning agents in use and disinfectants.
6, where invasive operations, suction and other highly dangerous diagnostic and therapeutic activities, should be implemented immediately after the end of environmental cleaning and disinfection.
Of course, all the disinfection, cleaning is the most basic work, no qualified cleaning, and then good disinfectant is difficult to achieve the desired disinfection effect.
Q
Is alcohol-based hand sanitizer a cure-all?
Alcohol-based hand sanitizers are not foolproof.
Alcohol is a medium-acting disinfectant and is ineffective against spores, and since C. difficile produces spores, 75% alcohol is ineffective against C. difficile compared to hand washing. Additionally, alcohol is very ineffective against hydrophilic viruses. This is because the mechanism of alcohol disinfection is because alcohol can absorb the water of bacterial proteins, make it dehydrated, denatured and coagulated, so as to achieve the purpose of killing bacteria. 75% alcohol and bacteria osmotic pressure similar to the bacteria, can be in the bacterial surface proteins before denaturation of the bacterial body gradually and continuously penetrate into the internal body, so that all the bacterial proteins are dehydrated, denatured and coagulated, and ultimately kill the bacteria. 75% alcohol can also destroy the lipophilic viral 75% alcohol can also destroy the surface of the lipid layer of lipophilic viruses, so it can destroy lipophilic viruses. Hydrophilic viruses do not have cell membranes and are therefore difficult to kill with alcohol. Common hydrophilic viruses include hepatitis A virus, hand, foot, and mouth virus, poliovirus, norovirus, and so on. HFMD is mainly caused by enteroviruses, and the main pathogens include coxsackievirus, echovirus partial serotypes and enterovirus 71 (EV-A71).
Misconceptions about the use of disinfectants
Misconceptions 1: The higher the concentration of disinfectant, the better
Disinfectants have certain toxic side effects, the concentration is too high will stimulate the human mouth, respiratory tract, lungs, and may lead to damage to the organs and tissues to become fragile over time, but instead susceptible to infection. Therefore, it is necessary to choose the right concentration, do not pursue a high concentration.
Myth 2: Not clear about the expiration date of the disinfectant, use it beyond the expiration date
When using disinfectant, pay attention to the expiration date of the disinfectant. A small disinfectant liquid, if it fails to work, can not play a proper role in disinfection, will cause great losses.
Generally, opened volatile alcohols are good for no more than 30 days after the bottle is opened. Unopened bottles of non-volatile products should not be used for more than 60 days after opening. Iodophor for skin disinfection should not exceed 7 days after opening, alcohol cotton balls for external disinfection should not exceed 24 hours, and chlorine disinfectants should not exceed 24 hours in general, and chlorine concentration can be determined by chlorine test paper.
Myth 3: Do I need to increase the concentration of disinfectant when there is an outbreak of multi-drug resistant bacteria?
No need.
Multi-drug-resistant bacteria are bacteria that are resistant to multiple antimicrobial drugs. Multidrug-resistant bacteria are not necessarily resistant to disinfectants. Therefore, it is not necessary to increase the concentration of disinfectant in the event of an outbreak of multi-drug resistant bacteria. Instead, cleaning and disinfection should be intensified, contact isolation measures should be implemented, the frequency of cleaning and disinfection should be increased, and disinfectants should be selected according to the type of pathogen, disinfectant selection and disinfection.
Myth 4: several disinfectants stacked with better results?
Common combination of contraindications include: quaternary ammonium disinfectants (such as Neosporin, benzalkonium bromide, disinfectant wipes, etc.) belong to the cationic surfactants, if mixed with anionic surfactants such as soaps and laundry detergents, it will produce antagonistic effects, reducing its disinfection effect, similarly, quaternary ammonium can be used with iodine or peroxides (such as potassium permanganate, hydrogen peroxide, etc.). Chlorine disinfectant is acidic, toilet bowl cleaner is mostly strong alkaline, the two meet will produce a violent reaction, resulting in a large number of toxic gases chlorine, mildly caused by coughing, chest tightness, the heavier will cause chlorine poisoning, resulting in respiratory difficulties. Therefore, disinfection products can not be mixed.
The correct choice of disinfectant, standardized use of disinfection products, not only can effectively disinfect sterilization, more importantly, to protect the environment, to protect themselves. Clinical medical workers need to be clear about what circumstances to choose what disinfection products, the correct choice of disinfection method is the premise of disinfection isolation