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Figure M2-1 Tip of an unsterilized needle seen under high (200x) magnification using an electron microscope. The tip is not much wider than a human hair. Does it look clean? THIS MAKES IT DIFFICULT TO KNOW EXACTLY WHERE OR HOW MANY THERE ARE, AND WHAT TYPES MAY BE PRESENT ON OR IN YOUR HANDS, THE WA...

Figure M2-1 Tip of an unsterilized needle seen under high (200x) magnification using an electron microscope. The tip is not much wider than a human hair. Does it look clean? THIS MAKES IT DIFFICULT TO KNOW EXACTLY WHERE OR HOW MANY THERE ARE, AND WHAT TYPES MAY BE PRESENT ON OR IN YOUR HANDS, THE WATER, THE AIR AND YOUR WORKING ENVIRONMENT, INCLUDING REUSABLE MEDICAL DEVICES. IT ALSO MEANS THAT IT IS IMPOSSIBLE TO TELL VISUALLY WHEN ALL MICROBES HAVE BEEN REMOVED DURING THE DECONTAMINATION PROCESSES. THE PRESENCE OF MICROSCOPIC ORGANISMS ARE DETECTED BY TWO METHODS— VIEWING THEM UP CLOSE WITH LIGHT AND ELECTRON MICROSCOPES OR BY CULTURING THE MICROBES UNTIL THEY GROW INTO A DETECTABLE FORM. THESE PROCESSES REQUIRE SPECIALIST TRAINING AND EQUIPMENT AND TAKE A CONSIDERABLE AMOUNT OF TIME. THE SPECIALISTS WHO DO THIS WORK ARE CALLED MICROBIOLOGISTS. BELOW IS A CLOSER VIEW OF THE TIP OF THE SAME NEEDLE UNDER MUCH HIGHER MAGNIFICATION. YOU CAN SEE LARGE NUMBERS OF BACTERIA, TWO MICRONS LONG, STICKING TO THE NEEDLE. TO DECONTAMINATE THIS NEEDLE, YOU WOULD FIRST CLEAN IT TO REMOVE ANY DIRT, SOIL AND AS MANY BACTERIA AS POSSIBLE. YOU WOULD THEN PUT IT THROUGH A DISINFECTION PROCESS TO KILL AS MANY OF THE REMAINING MICROBES AS POSSIBLE. A STERILIZATION PROCESS WILL KILL ALL REMAINING MICROBES. Figure M2-2 Clear view of the top of a needle, with bacteria 2 microns in length. LOOK AT HOW UNEVEN THE SUPPOSEDLY SMOOTH SURFACE IS WHEN VIEWED UNDER HIGH MAGNIFICATION (SEE FIGURE M2—2). UNEVENNESS OF REUSABLE MEDICAL DEVICE SURFACES CAN MAKE IT DIFFICULT TO CLEAN REUSABLE MEDICAL DEVICES PROPERLY. DIRT AND MICROBES MAY RESIST REMOVAL BY LODGING IN ANY CREVICES OR SURFACE IMPERFECTIONS. THIS IS WHY DISINFECTION OR STERILIZATION COMES AFTER THE CLEANING PROCESS—IN ORDER TO KILL ANY MICROBES MISSED BY THE CLEANING PROCEDURES. AS FIGURES M2-—1 AND M2-—2 SHOW, MICROSCOPIC ORGANISMS CAN’T BE SEEN WITH THE HUMAN EYE AND ARE EVEN DIFFICULT TO SEE WITH HIGH MAGNIFICATION. FIGURE M2—3 SHOWS THE RANGE OF SIZES THE HUMAN EYE, THE LIGHT MICROSCOPE AND THE ELECTRON MICROSCOPE ALLOW US TO SEE. Relative Sizes and Detection Devices 1m 1dm Icm Imm 100um 10um 1pm = 100nm 10nm~— iInm 1A 0.1A Im 10°’m 10m 103m 104m 105m 10°°m 10°77m 10°8m 10°9m 10°71 107!!m Human Eye Electron Microscope Light Microscope o| Apple Cell Virus Small Molecule Electron Orbital Human Wasp Hair Bacteria Atom Figure M2-3 Relative Sizes and Detection Devices (Source: http//penpals.web.unc.edu/) SINCE MICROBES ARE NOT VISIBLE TO THE HUMAN EYE, SPECIALISTS IN CSSD DO NOT LOOK FOR MICROBES ON THE EQUIPMENT AND REUSABLE MEDICAL DEVICES THEY PROCESS. INSTEAD, THEY STRICTLY COMPLY WITH VALIDATED PROCEDURES AND PROCESSES PROVEN TO CLEAN AND DECONTAMINATE— ENSURING THE SAFETY AND STERILITY OF THEIR REUSABLE MEDICAL DEVICES. THESE PROCEDURES ARE DEVELOPED AND THOROUGHLY CHECKED BY MICROBIOLOGISTS. MANUFACTURERS ALSO SUPPLY INSTRUCTIONS FOR USE (IFU) FOR PROPER DECONTAMINATION OF THEIR REUSABLE MEDICAL DEVICES. IT IS IMPORTANT FOR THE CSSD SPECIALIST TO KNOW ABOUT MICROBIOLOGY AND MICROBES TO UNDERSTAND WHERE THE RISKS ARE, WHY THEY ARE DOING THINGS IN A PARTICULAR WAY AND WHAT THE CONSEQUENCES ARE IF THINGS GO WRONG. THERE MAY NOT BE PROCEDURES TO COVER EVERY CONTAMINATION RISK IN THE DECONTAMINATION WASH ROOM, SO IT IS VERY IMPORTANT FOR SPECIALISTS TO BE VIGILANT AND TO UNDERSTAND THE BASIC PRINCIPLES OF WHAT THEY ARE DOING AND HOW TO MINIMIZE THE RISKS. MICROORGANISMS WHAT ARE THEY AND WHICH TYPES MIGHT YOU ENCOUNTER? THERE ARE MILLIONS OF DIFFERENT MICROBIAL SPECIES. IT IS ESTIMATED THAT LESS THAN 10% OF THESE HAVE BEEN IDENTIFIED OR STUDIED. THE BEST STUDIED MICROBES ARE THE ONES THAT CAUSE DISEASE—THESE MICROBES ARE REFERRED TO AS PATHOGENS. ALTHOUGH ALL TYPES MAY BE ENCOUNTERED, BACTERIA AND VIRUSES ARE THE MOST COMMONLY OCCURRING CONTAMINATING MICROBES. EVERY YEAR, NEW VARIETIES OF MICROORGANISMS ARE DISCOVERED. SCIENTISTS ARE BECOMING BETTER AT FINDING AND RECOGNIZING THEM, AND MUTATIONS AND GENETIC EXCHANGE REGULARLY CREATE NEW FORMS FROM EXISTING MICROBES. SOME TYPES, SUCH AS THE INFLUENZA VIRUS, HAVE A HIGH RATE OF MUTATION. THEY AVOID BEING RECOGNIZED BY OUR IMMUNE SYSTEM AND CREATE AN OUTBREAK RISK. MANY MICROBIAL INFECTIONS ARE NO LONGER TREATABLE USING ANTIBIOTICS. BACTERIA, FUNGI AND YEASTS CAN DEVELOP OR PICK UP ANTIBIOTIC RESISTANCE GENES FROM OTHER MICROBES. IT BECOMES A SERIOUS PROBLEM WHEN INFECTIONS CAN NO LONGER BE TREATED SUCCESSFULLY USING THE PREVIOUSLY EFFECTIVE ANTIBIOTICS. IN SOME CASES, THEY MAY BECOME RESISTANT TO MANY OR ALL OF THE AVAILABLE ANTIBIOTICS, MAKING THE INFECTION UNTREATABLE. RECENT EXAMPLES OF THIS ARE METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA), MULTI-DRUG RESISTANT TUBERCLE BACILLUS (MDR TB) AND CARBAPENEM-RESISTANT ENTEROBACTERIACEAE (CRE). ENVIRONMENTAL CONDITIONS WHAT ENVIRONMENTAL CONDITIONS DO MICROBES LIKE? ALL MICROORGANISMS GROW AND REPRODUCE IN AN OPTIMAL RANGE OF CONDITIONS. THEIR BASIC REQUIREMENTS ARE FOOD AND MOISTURE. ANYTHING THAT CHANGES THESE CONDITIONS TO A RANGE THAT IS NOT TOLERABLE WILL INHIBIT OR KILL THE MICROORGANISMS. HUMAN-INFECTING MICROORGANISMS TEND TO HAVE OPTIMAL GROWTH CONDITIONS SIMILAR TO HUMAN TISSUE. SOME MICROORGANISMS, INCLUDING PROTOZOA, FUNGI AND BACTERIA, DEVELOP SURVIVAL STRATEGIES TO COPE WITH STRESSFUL CONDITIONS. CYSTS IN PROTOZOA; SPORES, SOMNICELLS (NON- CULTURABLE CELLS) AND BIOFILMS IN BACTERIA; AND SPORES AND ALTERED METABOLISM IN FUNGI ARE ALL EXAMPLES OF SURVIVAL STRATEGIES. BACTERIA, UNDER OPTIMAL GROWTH CONDITIONS, CAN MULTIPLY VERY RAPIDLY, DOUBLING IN NUMBER EVERY 20-30 MINUTES. THIS IS WHY IT IS SO IMPORTANT TO CLEAN REUSABLE MEDICAL DEVICES AS SOON AS POSSIBLE AFTER USE. Figure M2—4 One bacteria can become hundreds in just two hours and many millions in 10 hours Further Information HOn Go to YouTube on the internet and search for video number zrx7Xg0gkQ4, “Bacteria Multiplying” to see a video on the subject. SOME YEASTS, LIKE CANDIDA, CAN ALSO MULTIPLY AS QUICKLY AS BACTERIA. FUNGI GROW MORE SLOWLY BUT CAN REPRODUCE IN LARGE QUANTITIES. BECAUSE VIRUSES, PRIONS AND SOME PROTOZOA ARE UNABLE TO GROW OR REPRODUCE OUTSIDE OF HOST CELLS, THEY DO NOT INCREASE IN NUMBER IN THE ENVIRONMENT. THEY MAINTAIN THEIR CAPABILITY TO INFECT HOST CELLS, REMAIN BIOLOGICALLY INERT, AND PERSIST FOR VARIOUS LENGTHS OF TIME— DEPENDING ON STRUCTURE AND TYPE. IN THE CASE OF BOTH PRIONS AND VIRUSES, THEY MAY PERSIST WHEN ATTACHED TO SOIL OR DIRT CONTAINING TRACES OF MOISTURE. Some viruses such as Hepatitis B, HIV, Herpes, chickenpox and influenza pucelcadd lipoprotein envelope are surrounded by a lipid envelope. It resembles a bubble and tends to be more fragile and susceptible to protein heat and drying. When left on = a contact surface, they may only be infectious for minutes or a few hours. Non-enveloped viruses such as adenoviruses, polio and norovirus do not Figure M2-5 Enveloped virus vs. non-enveloped virus have the same susceptibility and may be infectious days later. protein molecule WHY ARE BIOFILMS IMPORTANT? BECAUSE MOST STUDIES ON MICROBES WERE CARRIED OUT IN LABORATORIES ON ARTIFICIAL GROWTH MEDIUM IN UNNATURAL CONDITIONS, IT WAS NOT REALIZED UNTIL 1978 THAT THE NATURAL FORM OF GROWTH FOR MOST MICROBES IS AS A BIOFILM. A BIOFILM DEVELOPS BY MICROBES (USUALLY BACTERIA) EITHER STICKING TO EACH OTHER OR TO A NEARBY SURFACE. ONCE THIS HAPPENS, THEY SECRETE A MATRIX OF SLIME WHICH COVERS THEM LIKE A TENT. THIS PROTECTION FROM DISINFECTANTS AND VARIOUS OTHER STRESSFUL SITUATIONS ALLOWS THEM TO CONTINUE MULTIPLYING, AND RESIST REMOVAL. ONCE A BIOFILM HAS FORMED, OTHER TYPES OF MICROBES CAN ALSO TAKE REFUGE IN IT. THEY HAVE GREAT PROTECTION THERE— LIKE LIVING WITHIN A WALLED CITY. WITHIN OUR BODIES WE HAVE USEFUL NATURAL BIOFILMS GROWING IN OUR INTESTINES, ORAL CAVITY, RESPIRATORY TRACT AND SKIN. PATHOGENS CAN ALSO FORM BIOFILMS IN ALL OF THESE AREAS AND IN WOUNDS, AND ON SURGICAL IMPLANTS AND CATHETERS, MAKING THEM MORE DIFFICULT TO ERADICATE. MICROBES OR PIECES OF BIOFILM IN BLOOD OR SOIL CAN FORM MORE BIOFILMS ON REUSABLE MEDICAL DEVICES IF LEFT ON THEM FOR ANY LENGTH OF TIME. THEIR DEGREE OF ATTACHMENT BECOMES STRONGER WITH TIME SO BY THE TIME THEY GET TO THE DECONTAMINATION ZONE IN THE CSSD, THEY ARE MORE DIFFICULT TO DETACH IN THE CLEANING PROCESS. IT IS BEST PRACTICE TO AVOID DELAYS BEFORE STARTING DECONTAMINATION OF USED REUSABLE MEDICAL DEVICES. WHEN THIS IS NOT POSSIBLE, KEEP THE REUSABLE MEDICAL DEVICES MOIST AND TREAT THEM WITH A NEUTRAL DETERGENT AND CLEANING ENZYMES UNTIL THEY CAN BE PROPERLY DECONTAMINATED. BIOFILMS ALSO BECOME A PROBLEM IN A NUMBER OF AREAS OF THE CSSD. THEY CAN FORM ON, AND INSIDE, ULTRASONIC BATHS, HOSES, HOUSEKEEPING CLEANING EQUIPMENT, THE WATER SYSTEM, WASH BASINS, WASTE PIPES, TAPS, PLUMBING OF WASHERS AND WASHER DISINFECTORS, AND MOIST SURFACES. STRICT REGULAR CLEANING AND DECONTAMINATION PROTOCOLS MUST BE IN PLACE TO PREVENT SPREAD OF MICROBES TO PROCESSED REUSABLE MEDICAL DEVICES AND STAFF WITHIN THE CSSD. REGULAR MICROBIOLOGICAL TESTING MONITORS THE EFFICACY OF THESE PROTOCOLS. Microorganism Types and Characteristics = Protozoa POU th pace ar © Poy ee) Protozoa are large complex Ses Sued WH shee one-celled parasites thatmay 4 Shey x * $3 re ~*~) Grp spend part of their lifecycle Y Sdet AP AS ee . ; bf Sarto.) 4. Ok in our bodies. They cause Vite xe Mae FAL) 7 r co Oh ak td Fahy diseases like malaria or aie 0. a’ ans ENE | dysentery as they multiply I. sp gs ogre ihe Ea thin our bod Pa Si Pat ad si within our body. “952. OVER eee DS Nae Sie Figure M2-6 Intestinal amoeba within a cyst in a fecal sample (protozoa 20 microns) Lad : 2. S Cleaning: They are relatively easy to remove from reusable medical devices during decontamination but some have life-cycle stages which are encysted (within a tough protective capsule). These stages are more difficult to kill as they resist disinfectants but heat will kill them. Identification: The identification of protozoan pathogens is mainly based upon direct microscopical observation in clinical specimens or by detection of specific serological immune reactions of the host. Fungi Fungi are large to medium- sized microorganisms that grow filamentous root-like structures called hyphae. Some fungi live on our skin and in our gut naturally. They may cause Oiseases called mycoses when they invade our tissues. Figure M2-8 Aspergillus (fungus 40-50 microns) Cleaning: Fungi are relatively easy to clean from reusable medical devices, however, their thick cell walls and spores are often resistant to disinfectants but heat will kill them. Identification: Fungi are usually identified by growing them in the laboratory. Although one fungal cell is invisible to the naked eye, when allowed to multiply on an agar plate, one cell becomes millions and they form Figure M2-9 Fung! Colony a pile of particular shape, size and color referred to as a colony. By noting colony appearance and examining parts of this microscopically, it is usually possibly for an experienced specialist to identify the type of fungus. Newer methods based on biochemical reactions are becoming available, as are genetic methods. Figure M2—10 Various Fungi Yeasts . ene Figure M2-11 Candida (yeast 5-10 microns) Cleaning: They are relatively easy to remove from reusable medical devices when cleaning and are susceptible to disinfectants and heat. Identification: The identification of yeasts is similar to that for bacteria. It is based on culture in the laboratory to form colonies and then noting the characteristic features of colony shape, size and color. This is followed by examining cell shapes under the microscope, followed by testing for production or consumption of particular chemicals. Recently, special chromogenic (color forming) growth media has been introduced which can help identify yeast species by causing them be a particular color. Genotyping using molecular methods is now also being introduced. Yeasts are single-celled organisms with a nucleus and are a type of fungus. Yeasts are larger than bacteria, and multiply mainly by budding. Some yeasts live in our bodies naturally. Yeasts like Candida can infect the gut, urogenital tract, respiratory tract and oral cavity. Figure M2-12 Different yeast species on routine agar Figure M213 Different yeast species identifiable on chromogenic agar Bacteria Bacteria are small microorganisms that come in many shapes and types. They lack a nucleus and multiply by cell division. Some types, like Clostridium difficile, can produce tough protective spores. Harmful bacteria may produce toxins which can damage host tissues while some produce chemicals that protect themselves against the immune system, allowing them to spread. Bacteria are usually the most frequent Cause of infection in hospitals. Figure M2-15 Bacterial colonies on an agar plate Figure M2—14 Various bacterial types Figure M2-18 Loading test cards in automated system.eps Figure M2—17 Miniaturized biochemical test card for automated system Figure M2—16 Biochemical testing shows identity profiles based on color reactions Cleaning: Bacteria are quite small and can be difficult to remove from uneven surfaces during cleaning. Most can be killed by disinfectants and heat although spores often resist disinfectants. Identification: Many different methods are available for identifying bacteria because, of all the microbes, they have been studied for the longest time. First, they are cultured in the laboratory where their colony appearance may indicate the species. Microscopy of gram stained smears can also help. They can be further identified by using combinations of biochemical tests and comparing with a database or they can be identified genetically using molecular techniques. Many of the identification methods are now becoming automated. Viruses Small non-living infectious objects containing genetic information enabling them to hijack living cells in the body. They take over host cells, converting them into factories that make hundreds or thousands of copies of themselves which in turn, spread to neighboring cells and the process repeats itself. Bloodborne viruses such as Hepatitis B, C and D are a frequent risk to healthcare staff. Figure M2-19 Hepatitis B (virus 0.05 micron) Cleaning: Viruses are very small and can be difficult to remove during cleaning as they may lodge in uneven surfaces. As they are not alive, disinfection or heat does not kill them. Instead it dismantles or disrupts their chemical structure—most are susceptible to this but there are some which can be resistant. Identification: Viruses are detected and identified in a number of ways. The most usual is to culture a sample in the laboratory using tissue culture methods. Viruses are detected by the damage (cytopathic effect) they cause to healthy human or animal cells in culture. This is seen as plaques or areas of destruction. Viruses can be identified by antibody labeling or using molecular methods. Figure M2-20 Ds ing and counting infil i by 1g cell ( purple) in petri dishes. The clear areas are called plaques and each plaque is the result of one virus infecting and killing cells in the By g the one can assess the number of viruses in the original sample. Figure M2-22 Abnormal prion protein (0.01 micron) Prions Very small proteinaceous units that cause Transmissible Spongiform Encephalopathies (TSEs) when folded in an abnormal way. Abnormally folded prions can cause disease (particularly in the brain) by converting normally folded prions into abnormal ones. These then aggregate and disrupt tissue structure and function. =¥ a Figure M2-21 Normal Prion protein Cleaning: Prions are difficult to remove from reusable medical devices due to their small size and their strong adherence to surfaces. They are very difficult to inactivate using heat or disinfectants. Reusable medical devices used on prion-infected patient tissues are not used on other patients due to difficulty in decontaminating them. It is important to have a traceability system for medical devices in place to ensure these reusable medical devices are not used again. Identification: Prions are usually detected a awe ere Figure M2-23 Abnormal prions clump in aggregates by histopathology of infected tissue where misfolded prion aggregates are revealed using specific antibodies linked to dyes. Detection on reusable medical devices is very complex and time consuming and is not very successful. Other prion-like agents: Not much is known about these yet other than they are very small molecules and are transmissible. They have effects similar to prions and are thought to be equally difficult to inactivate. Microbes and CSSD Putting microbes in context in the CSSD environment Microbes are the most numerous and diverse life forms known. They have existed for over 3.5 billion years on Earth, and have adapted to and colonized the biosphere—every environment we can think of, from several kilometers deep within the earth’s crust to the upper reaches of our atmosphere. Maryam: Are all microbes dangerous? Sa) Khaled: When we think of microbes in relation to clinical environments, where cleanliness and sterility are paramount, we treat the presence of all microbes there as being potentially harmful. We try to eliminate them all and we take what are known as Standard Precautions to prevent the spread of infection. Plants, animal and humans are all dependent on microbes for their normal function and survival. Each individual has their own personal microbiome or microbe collection consisting of thousands of different species that help protect against disease, stimulate their immune system and carry out many other beneficial functions. These helpful microbes are known as commensals whereas disease causing microbes are known as pathogens. Some of the commensal species, though helpful to the person hosting them, may prove pathogenic or harmful if transferred to someone else. In a hospital or healthcare setting where patients are vulnerable to infection, we undertake many methods of infection control to prevent the transfer of pathogens or commensals. Recent research has shown that on and in the average human there are 1.3 times more microbial cells than human cells! A human can therefore add a large number of microbes to their surrounding environment in a number of different ways. Coughing, sneezing and bodily secretions can spread microbes. Your hands spread microbes when you touch your face, body parts or contaminated items and then touch other items. Dead cells flaking off at the skin surface Stratum corneum — Stratum lucidum — Stratum ___ granulosum Stratum __ spinosum & Stratum basale — ee Dermis — The top layer of the skin is the stratum corneum Figure M2-25 Diagram of skin layers Figure M2-26 High containment PPE Although, strict cleaning and decontamination procedures may be in place, the clean zone is rarely microbe-free! Keratinocytes move up as they age Skin Skin covering our bodies is multilayered; the top layer is composed of dead cells. The top layer of skin contains a large amount of commensals of our own, together with transient populations picked up from clothing, contact with others, and our environment. Our body discards this entire top layer of dead skin cells and associated microbial biofilm over a period of five or six weeks, to be replaced by a fresh layer from underneath. The forearm sheds approximately 1300 cells per cm? per hour. Figure M2-27 Bacteria on skin cells As we move around, we leave an invisible trail of microbes everywhere we go, and on everything we touch. Once we understand this, we can see how important it is to minimize the amount of contamination we bring into clean or sterile zones in the CSSD. We try to contain our dead skin cells and microbes by using hygiene procedures and appropriate PPE to prevent us from recontaminating the reusable medical devices or their environment. Very high levels of contamination prevention and PPE are used in clean rooms and sterile areas of pharmaceutical and space New Bacterial Life-Form Discovered in NASA and ESA Spacecraft Clean Rooms The previously unknown microbe was tough enough to survive stringent sterilization at two locations. Might it survive a trip to Mars? Figure M2-28 PPE Figure M2-29 News article, Scientific American assembling spacecraft. Often, two layers of clothing are worn, one to enter semi-critical . areas and then another on top of that to You must take precautions enter the critical areas. to protect yourself from Despite the highest hygiene standards and these through the use of vigorous cleaning and decontamination particular safety and hygiene regimes in these places, some microbes procedures and the use of occasionally survive (See Figure M2—29 . News article, Scientific American). This is particular PPE. also the case in the CSSD clean zones. CSSD Workwear and PPE There are three work zones within the CSSD—the Contamination zone, the Inspection, Assembly and Packaging zone and the sterile storage zone as described in module 1. These are separate zones which should each have their own entry and exit points. Staff should not be able to move between zones without passing through gowning rooms, changing PPE and undergoing hygiene procedures. When you work in the Decontamination zone in the CSSD, you are exposed to contaminated reusable medical devices and materials which were used with patients who may have been carrying pathogenic microbes in addition to their own natural commensals. Figure M2-30 PPE Decontamination Zone PPE Requirements Gown with Sleeves Wear fluid resistant gowns with long- cuffed sleeves that can be tucked inside gloves during procedures that are likely to generate splashes of blood or body fluids, or during activities that may contaminate it with infectious material. Change this gown whenever it becomes visibly soiled or wet and discard after use. Plastic Bib or Apron In some cases, you wear a bib or apron over the gown for extra protection from splashes during manual cleaning processes. Mask & Eye Protection Wear fluid repellent masks with visor eye shields to reduce the risk of microbes being transferred to the eyes, nose and mouth. These must be fitted properly and worn to cover eyes, mouth and nose, according to the manufacturer’s IFU. Do not touch the mask or eye shield with your hands while working, remove them immediately if they become moist or visibly soiled, discard them appropriately and replace with clean equipment. Further Information i ° Gloves Use gloves for environmental cleaning activities, and handling contaminated reusable medical devices and waste. Wearing gloves does not replace hand washing as gloves may have become damaged during use, or have defects that are not immediately obvious. e Wash your hands before and after using gloves. e Wear the correct size and appropriate type for the task. They should have long enough cuffs to fit over the cuffs of the gown. e Keep your nails short so you don’t puncture your gloves. e Avoid touching your mask, eyes or face with your gloves once you have started work. e Learn how to remove gloves without contaminating your hands or snapping the gloves which may spread contamination across the room. e Remove used gloves before touching anything that can be contaminated through contact such as surfaces and pens. e Discard the gloves when you are done, or when you suspect the gloves are torn or perforated. For a video, go to YouTube and look for “TwJfNfCEnKU” or “Glove Removal” from Safety Training International. Shoes or Shoe Covers Best practice suggests dedicated shoes or clogs that are worn only in the decontamination zone. Ideally, these should be washable. Disposable shoe covers could also be used to protect regular shoes from becoming wet and contaminated during cleaning procedures however, these puncture easily and may fall off. They must be replaced if there is any sign of damage and the old ones discarded properly in the waste container. Other Workwear Requirements Workwear requirements for CSSD other than the decontamination zone When you work in the IAP or sterile storage zones in CSSD, you wear different workwear. Here the emphasis is on protecting the reusable medical devices and their environment. Pay attention to general hygiene and wash your hands frequently. Uniform/Scrub Wear a freshly laundered or new, disposable, low-lint “scrub” uniform that minimizes bacterial shedding and is comfortable for you. Changed scrubs daily or whenever they become visibly soiled or wet. Head/Hair cover Wear a clean, single use, low lint surgical hat or hood that fully covers and confines your hair. Discard this head covering and replace it with a new one when re-entering the zone. Footwear Wear dedicated non-slip enclosed footwear that can protect from injury or contact with accidently dropped sharp objects. Footwear must be appropriate to the area and regularly cleaned and disinfected. Make-up/Jewelry Do not wear make-up or jewelry (except a plain wedding band) in CSSD. You may wear stud earrings that are confined within the head cover in case they come loose. Strict adherence to these work practices is important. For putting on and removing PPE, there is a correct sequence and method (Figure M2-31 Putting on and removing PPE). When it comes to working in CSSD you naturally think of protecting yourself, but in the IAP and sterile zones you also need to think of protecting the reusable medical devices from contamination by you. It is important that you are familiar with maintenance of personal hygiene appropriate to the zone of the unit you are working in. If you are ill with enteritis or have a severe respiratory tract infection causing a lot of coughing, sneezing, or skin condition, you should seek medical advice as to whether you should be handling clean or sterile goods. Handwashing and hand care are equally important in the IAP and sterile zones, to protect the reusable medical devices from contamination by you. Standard Precautions and Infectious Agent Transmission Standard Precautions are operating procedures that apply in healthcare to minimizing the risk of infection regardless of the perceived infectious risk. The approach is based on the understanding that all blood and body substances should be considered potentially infectious, therefore all surgical instruments could be potentially contaminated with microorganisms. The precautions include elements such as: e Handwashing e Use of PPE e Safe systems for handling blood and body fluid contamination e Sharps awareness and implementation of environmental controls Appropriate processing of RMD Medical condition management Education and training Aseptic technique Vaccination In the decontamination zone, Standard Precautions are relevant to handling reusable medical devices, anything associated with them or the environment they have contacted once they have been used, up to the point after decontamination has been completed. The rationale for this is that some patients may unknowingly be carriers of disease agents or they have withheld the fact from their medical history. Others may have had surgery before diagnostic tests were completed or they may only be in the early stages of a slow disease such as Creutzfeldt-Jakob (CJD). All of these unknowns could contaminate reusable medical devices, transport trays and boxes and be an unknown infection risk to the unaware decontamination staff and their environment, hence the Standard Precautions approach. Chain of Infection and Routes of Transmission The spread of microbial infection requires three factors: e Asource of infecting microorganisms at a sufficient level to cause infection e Susceptible host or hosts e Ameans for transmitting the infectious agent to the susceptible host or hosts The means of transmission may involve one or many steps and is often referred to as the chain of infection. Within the healthcare environment, much effort is invested in trying to prevent the transmission of infection. Many patients entering a hospital may have an infectious disease or may be carrying infectious microbes. Over time, a wide variety of these microbes accumulate in the healthcare environment and are spread around it in many different ways including: in the air, on cart wheels, shoes, staff and other patients. This collection of microbes is referred to as a reservoir of infection. The hospital staff constantly try to minimize this reservoir by thoroughly cleaning and disinfecting the environment and equipment and by treating the patients with antimicrobial drugs and applying various hygienic measures. Cleaning, disinfecting, drugs and other measures can kill them, but microbes can also develop resistance and become much more dangerous. Recent examples of this are Methicillin Resistant Staphylococcus aureus (MRSA), multi-drug resistant Tubercle bacillus (MDR TB) and Carbapenem-resistant Enterobacteriaceae (CRE). Infectious Agent Susceptible Host Reservoir Portal of Exit Portal of Entry Mode of Transmission Figure M2-33 Chain of infection Because patients in hospital are usually in poor health and their immune system may not be functioning very well (immunocompromisedq), they are particularly susceptible to infection. If they have surgical or other wounds, they are at even more risk. This is why we try to break the chain of infection from the various sources or reservoirs through the use of infection control at all levels. In the CSSD, we stop the transmission of microbial infection by decontaminating potentially infected reusable medical devices and ensuring that only properly decontaminated reusable medical devices are used on patients. Prompt treatment Decontamination Rapid Identification of Organism Good Health and Hygiene Environmental Sanitation Disinfection/Sterilization Treatment of Primary Disease Recognise High Risk Patients Proper Attire Hand Hygiene Trash and Waste Disposal Controls of Secretions and Excretion Aseptic Technique Wound Care Hand Hygiene Catheter Care Hand Hygiene Airflow Control Disinfection/Sterilization Proper Food Handling Isolation Precautions Figure M2-34 Breaking the chain of infection Patients who become infected by microbes while in hospital are said to have a healthcare-acquired infection (HAI). This is also known as a nosocomial infection. Staff working in the healthcare environment are also at risk from infection, however, they are healthy, they may be vaccinated against a number of diseases, they wear PPE and they are trained to use Standard Precautions. This protects them and also helps prevent them from being a reservoir of infection or a means of transmission. Maryam: Where do infection risks occur in the decontamination zone? SS) Khaled: Used reusable medical devices and materials which they have been in contact with could be sources of infection. The staff working in the CSSD could be the susceptible hosts, particularly, for example, if they are not vaccinated against hepatitis B or are immunocompromised in some way. Means of transmission could be through accidental splashes, contact or aerosols for example. Microbial infections are transmitted in the following ways: Injection — deliberate or accidental penetration of the skin or mucous membrane, for example, a needlestick, or an open wound Ingestion — swallowing into the digestive tract via a splash or droplet Inhalation — enter the respiratory tract via a droplet or aerosol Contact — transfer from a contaminated object to the skin, eye, Mucous membrane via a hand, glove, mask, droplet, or splash The role of PPE, Standard Precautions and infection control is to prevent transmission, reduce risk and break the chain of infection. Accidental Needlestick or Sharps Injury Many reusable medical devices are designed to puncture or cut skin or tissues (sharps). After use, these may be contaminated by pathogenic microbes. Some of these are designed for single use (e.g., hypodermic needles, transfusion sets, and scalpels) and will be discarded into the infectious waste stream. This is usually done in the operating room or surgery however some of these items may enter the CSSD mixed in with other reusable medical devices and can accidentally cause injury to the person handling them. If this occurs, report it immediately and seek medical attention. The main risks are from bloodborne viruses. Because of this, CSSD staff are usually vaccinated against these risks when they start work in the CSSD. Know the local policy on sharps or needlestick injury and to whom these should be reported. More importantly, be vigilant — minimize risk and avoid needlestick Aerosols or sharps injury. An aerosol is defined as being a suspension of tiny particles or droplets in the air. The size of the droplet, initial velocity and environmental conditions generally determine how long it will remain in the air and how far it will travel. An aerosol becomes a means of infection-transmission if the droplets or particles contain microbes. This may spread the infectious agent from a contaminated site or reservoir to a person or to another site which then becomes contaminated. An aerosol may form in the CSSD when handling liquids, operating an ultrasonic bath, running a tap, brushing or blowing on a wet surface or when ventilation/numidification units release contaminating microbes. Manual brushing of contaminated reusable medical devices should be carried out only while the device is submerged in the sink. Figure M2-35 Keeping the lid closed when using the Figure M2-36 Coughing, sneezing or even talking creates an aerosol of microbes ultrasonic bath prevents escape of aerosols. from your respiratory tract. 62 Microbiology and Infection Control While large droplets do not travel very far, tiny droplets (5-10 microns, true aerosol) can remain airborne for many minutes. (Figure M2-36). The size of aerosol droplets or particles also affects the extent of lung penetration if you inhale them. The smaller they are, the further they penetrate and this usually creates a higher risk of becoming infected. N ik Naso-Pharyngeal Particles = 3 Tracheo-Bronchial = Particles n 8 co J Alveolar Particles 0.1 100 Particle size (um) Figure M2-37 Deposition regions of the respiratory tract for the various particle sizes (source: Roy CJ, Milton DK. N Engl J Med. 2004; 350:1710-1712, Massachusetts Medical Society) DROPLET PRECAUTIONS AIRBORNE PRECAUTIONS Distance 1m 10m+ . Droplet nuclei Droplet size 100um 50um <Syum Zaire ry e.g., influenza A virus, coronavirus, rhinovirus ——® Figure M2—38 Droplet size and mic i issic lis : Prof lan Simple sketch of droplet and airborne virus and bacterial transmission, http://virologydownunder. blogspot.com) Further Reading Zn For further reading, go to journals.plos.org on the internet, and search for Airflow Dynamics of Human Jets: Sneezing and Breathing—Potential Sources of Infectious Aerosols, published: April 1, 2013. 63 Medical Device Reprocessing (Decontamination Specialist) Housekeeping and Infection Control The CSSD is a busy and critical location where the links in the chain of infection are broken. An important part of breaking the links is cleaning and disinfecting the CSSD itself and properly managing waste streams. Each zone within the CSSD should have its own dedicated cleaning equipment. Best practice recommends that each zone clearly labels or color codes their cleaning equipment. It is then easily identified as in the wrong zone when borrowed or misplaced. e Store the cleaning equipment (e.g., mops, buckets, and chemicals) in a dedicated storage room and clean and inspect regularly e Train staff responsible for cleaning the zone in all aspects of cleaning e Record cleaning activities and monitor the quality of the cleaning regularly Waste material are generated in the three zones of the CSSD. Use bins or containers to help receive waste and segregate it into appropriate waste streams. Wastes from the IAP and sterile storage zones are not an infectious risk. Waste generated in the decontamination zone is an infectious risk, and an important waste stream to control. Placed this waste in appropriate bags or bins, with sharps waste in a dedicated sharps bin. Seal and disinfect the exterior of the waste containers before taking them out to the waste collection point. Infection Prevention The central service significant role in the prevention of surgical site and healthcare associat- ed infection the important of this role is understood technician recognize that their work prac- tices can mean the difference between a patient successful surgery or hospital stay and nega- tive outcome that could lead to infection or possibly death Central service processes Every step or process in the cssd is carefully designed to prevent poor patient outcome poor outcome can be traced to many factors including the condition of instrument trays and other medical devices that are processed In the most simplistic terms supports infection prevention Cleaning contaminated medical devices to make them safe for handling and prepare them for biocidal process Inspecting instruments to help ensure they are safe and functional Assembling and packaging instrument in a manner that facilitates the method of sterilization chosen and provide after sterilization Selecting and properly using the sterilization or high level disinfection method for each medi- cal device Safely storing items until the are needed and delivering them using methods that protect the integrity of the sterile packages Principles of asepsis Asepsis can be defined as the absence of microorganisms that cause disease aseptic tech- nique includes any activity or procedure that prevent infection or breaks that chain of infec- tion Two types to aseptic techniques Medical asepsis clean technique procedure performed to reduce the number of microorgan- isms to minimize their spread Surgical asepsis sterile technique procedures to eliminate the presence of all microorgan- isms and or prevent the introduction of microorganisms to an area Personal hygiene and attire Hand hygiene is a term that means either hand wash or using an approved antiseptic hand rub hand hygiene is considered the single most important factor in reducing infection Attire Cssd professional must wear attire specific for the area in which they work this protects the employee and other staff members patient and the public Managing the environment to prevent the spread of bacteria Environmental concerns in central service