Infectious Diseases: Microbes, Cycle of Infection & Medical Asepsis PDF

Topic 2 Infectious Diseases: Microbes, Cycle of Infection & Medical Asepsis 6-Prevention-des-infections-0ctobre-2009.pdf (otimroepmq.ca) 1  Specific Objectives 1. Identify the different communicable disea...

Topic 2 Infectious Diseases: Microbes, Cycle of Infection & Medical Asepsis 6-Prevention-des-infections-0ctobre-2009.pdf (otimroepmq.ca) 1  Specific Objectives 1. Identify the different communicable diseases, modes of transmission. 2. Apply the principles of infection control related to hand hygiene, medical asepsis, surgical asepsis, isolation and sterile technique. 3. Using appropriate precautions for immunocompromised patients. 4. Apply the basic and additional precautions related to infection control. 5. Differentiate between, medical and surgical asepsis and protocols. 6. Identify the steps used in medical asepsis and how to maintain asepsis. 7. Handwashing technique 8. Donning & doffing of PPE 9. Proper disinfection of working surfaces and equipment 10. Techniques to open & set up a sterile tray/field & maintain asepsis including sterile gloves, sterile supplies 11. Distinguish between sterilization and disinfection. 12. Identify the various types of chemical disinfectants, antiseptics, and cleaning agents and their uses. 13. State the potential sources of microbial contamination. 2 Learning Outcome: Acquire knowledge to work in an environment respecting infection control, including aseptic technique and hand hygiene Elements of ministerial competency: Appliquer des mesures de prévention et de contrôle de la contagion, de la transmission des infections et de la contamination 3  MRTs have the responsibility and ability to prevent the spread of infectious organisms to their patients and the entire public sector Living Micro-organisms (microbes) are so tiny that they cannot be seen with the naked eye. There are millions in the human body. Some are beneficial, some are not Microbial flora are microorganisms that live inside or on the body and do not cause infections or diseases. Microorganisms that cause infections which can result in infectious diseases are known as pathogens https://study.com/academy/lesson/medical-asepsis-precautions-case-example.html 4  Viral infection Virus puts a lot of stress on ones body , this also allows bacterial infections to take place this happen when the body is run down (no sleep ,... ) bad diet An infection occurs when there is an invasion and multiplication of pathogenic microbes in a host (a reservoir such as a human). If the infection causes injury to the host, this will result in disease. An infection does not always result in disease To survive, a pathogen requires not only a host but must also overcome the host’s White immune responses/system and benefit from the body’s suitable environment to blood cells thrive and replicate/multiply before exiting and spreading to a new host bad diet bad sleep and ↑ If the human immune system is weakened and microbes enter a sterile part of the human body, they can cause an infection and consequently a disease Infectious Diseases - An Introduction - YouTube 5  in greek Hospital ↑ Nosocomial Infections ex: washhas Hospitals are “hot spots” for transmission of infection. Anyone with a health ↑ problem/underlying medical conditions is more susceptible to infection; therefore medical asepsis must be practised by all health care workers Nosocomial infections occur in patients who are under medical care in hospitals and health care facilities; (nosocomial = originating in a hospital) The MIT must understand what infectious diseases are, how they are spread, and how they can be controlled & reduced. Hospital Acquired Infections & How To Prevent Them | Curos - YouTube 6  Different pathogens can be transmitted in different ways: skin to skin contact contact with bodily fluids > - Saliva , blood , urine , snot , etc... airborne particles > - TB (turberculosis) very infectious , N95 masks contact with feces > - gloves are have small pores once dirty change right away touching a surface touched by an infected person ↳ virus can stay on hands aka is everything dirty Pathogens and Transmission - YouTube 7 Microorganisms can spread from other people or surfaces. This will happen when one: touches eyes, nose, and mouth with unwashed hands/nails prepares or eats food and drinks with unwashed hands/nails touches a contaminated surface or objects blows nose, coughs, or sneezes into hands and then touches other people’s hands or common objects https://www.ncbi.nlm.nih.gov/books/NBK279387/ Infectious Diseases - How do we control them? - YouTube 8  Hand washing is the best and most important practice for preventing the transfer of microorganisms and subsequently preventing the spread of nosocomial infections (WHO). world health organization Centers for Disease Control and Prevention (CDC ) recommends scrubbing (washing) hands with soap and water for at least 20 seconds. This will remove most transient organisms from the skin. Show Me the Science - How to Wash Your Hands | Handwashing | CDC https://www.cdc.gov/handwashi ng/when-how-handwashing.html Hand-washing Steps Using the WHO Technique - YouTube 9  Dissemination or spread of microbes depends on how the spread occurs and where the route of entry site is. o For example, the virus that causes the common cold, rhinovirus, enters (route of entry) the body through the eyes, mouth, or nose (upper respiratory tract). o The virus can spread through droplets/aerosols in the air when someone who is sick coughs, sneezes or talks. o The virus generally gets into the nasal passage of another person, through inhalation of particles or touching of the nose with a contaminated hand. o It is the most common viral infectious agent in humans and the predominant cause of the common cold. The Common Cold (Rhinovirus) - YouTube 10  The MIT must also understand and be able to perform all transmission-based precautions when caring for patients to guard against the spread of infection, such as: – hand hygiene > - short nails ex : – cleaning of equipment > - disinfection wipe wipe with – disposal of contaminated waste – Personal Protective Equipment (PPE) Knowledge of the principles of disinfection is fundamental. 11 It is important to remember that: A pathogen is a microorganism that has the potential to cause disease An infection is the invasion & multiplication of pathogenic microbes in an individual or population Disease is when the infection causes damage to the individual’s vital functions or systems An infection does not always result in disease 12  cycle of infection Four factors are involved in the spread of diseases & the cycle of infection: o an infectious microorganism o a reservoir o a mode of transmission o a host Each one is connected or linked to the other. If at any point during the when -You wasn infection this link is broken, yourhands the cycle is discontinued, and infection will cease to exist. Chain of infection - Ottawa Public Health 13 Infectious organisms or pathogens: microorganisms capable of causing infection include bacteria, viruses, fungi and protozoa. Resident: normally reside on the skin in stable numbers and are not harmful. Transient: o attach loosely to the skin by direct skin-to-skin contact with another (easily removed by hand washing) o These organisms can be picked up indirectly via objects, such as from grocery carts, doorknobs etc. o The life expectancy depends on the type of the infectious organism. 14 Reservoir of infection: Humans, animals, plant, food, water are suitable places where pathogens can thrive by providing moisture, nutrients and a suitable temperature Healthy people/carriers who can house pathogens without causing apparent disease to the host (HIV carrier) 15 Portal of exit: place/site of exit for the microorganism to leave. These can include the nose, mouth, fecal matter etc. Human body: any route where blood, body fluids, excretions (feces and urine) or secretions (saliva, tears, mucous) exit the body. Ex: respiratory tract (nose, mouth), GI (gastrointestinal), GU (genitourinary), infected wound, blood stream & skin. 16 Mode of transmission Direct Contact: organisms placed in direct contact with susceptible host (touch, kiss, injection or sexual intercourse) Indirect Contact: fomites (inanimate objects); an object that has been in contact with pathogenic organisms (ex; radiographic x-ray table, image receptor, sponges etc.) 17  , mosquitos Vector atics insect or animal carriers; (bites or stings from these insects can transmit diseases to humans) Droplet o contact with infectious oral secretions occurs when infectious individual coughs, sneezes, speaks in vicinity of susceptible host (droplets larger than 5 microns). o Does not remain in air, travels short distances 3 to 5 feet. o Example: meningitis (acute inflammation of the protective membranes of the brain & spinal cord) Airborne suspended residue from evaporated droplets; occurs by droplet, microorganisms that remain suspended in the air for a long time (smaller droplets < 5 microns) TB. 2 Vehicle contaminated food, water, drugs, blood; a medium that transports microorganisms o Example: contaminated food, water, blood and drugs 18 Portal of entry An opening for the microorganism to enter the host via body orifices, break in the skin, catheters, etc. Route by which pathogens gain access into the susceptible host. Enters the same way they exit (open wound, respiratory tract/nose, GI, GU tracts, eyes, and blood stream) Urinary tract Infections (UTI) are common due to the urinary catheter 19 Susceptible hosts: The host must be susceptible to the strength and numbers of the microorganisms, (patients who have reduced resistance to infection, immunosuppressed patients are at greater risk) 20 21  Medical Asepsis? Eliminating spread of microbes through facility practices Difference between resident and transient microorganisms Is Microbial flora considered a pathogen? A suitable reservoir for a pathogen to thrive should have ❖ Does not cause infections ❖ moisture, nutrients and desired temperature Pathogens → multiply → invasion → infection → may result in disease if organ ❖ A pathogen carrier may not necessarily acquire a disease function affected Portal of exit from reservoir commonly used by microorganisms Pathogen survives when... ❖ nose, mouth, fecal matter, any route where blood, body fluids, excretions ❖ host, beat immune system, suitable environment in host, multiply to spread (feces and urine) or secretions (saliva, tears, mucous). Nosocomial infections? Some Portal of entry to the host are the same as the portal of entry to the host ways that pathogens are transmitted? ❖ respiratory tract (nose, mouth), GI (gastrointestinal), GU (genitourinary), ❖ Skin to skin, body fluids & solids, Airborne, touching, infected surfaces infected wound, blood stream & skin Most effective way to avoid transmission? Direct and indirect contact with host ❖ Handwashing ❖ Fomites? Objects or materials likely to carry infection Name of virus that causes the most common infection in humans ❖ inanimate objects; an object that has been in contact with pathogenic ❖ Rhinovirus organisms Besides hand hygiene what else does the MIT do to prevent transmission of Vector microorganism? ❖ bites or stings from animals/insects ❖ cleaning equipment and accessories, proper disposal of waste and linen, apply True or False. Droplets larger than 5 microns principles of disinfection True or False. Airborne smaller than 5 microns True or False. An infection always result in disease. True or False. The host must be susceptible to the strength and numbers of the What are the 4 factors involved in the spread of microorganisms and the cycle of microorganisms, (patients who have reduced resistance to infection, infection? immunosuppressed patients are at greater risk) ❖ infectious microorganism, reservoir, mode of transmission, and host 22 Practical asepsis Stay home when you are ill Sneeze or cough into elbow or cover mouth, (wear mask if you cannot stay home) Wear a clean uniform daily and remove it BEFORE you leave the hospital Wash hands between patients Use appropriate medical aseptic technique when handling linen or contaminated items o Examples: ▪ do not shake or flap linen ▪ NEVER use any linen for more than one patient ↳ if limited flip to other side or call someone and ask for more 23 How to Prevent Transmission Hair follicles and filaments harbour microorganisms. Hair is a major source of staphylococcal bacteria contamination Microbes are most commonly spread from one person to another by human hands 24 To live, micro-organisms such as viruses and bacteria require: Food such as proteins, carbohydrates, & mineral salts taken from tissue cells Moisture Oxygen in which some bacteria require air for their O2 (aerobic), but others do not take it from air and in fact cannot live in air (anaerobic)—GI tract o Aerobic bacteria microorganisms grow in the presence of oxygen. o Anaerobic bacteria microorganisms grow in the absence of oxygen 25  Microbial growth is conducive at a certain T0 and pH value. o Most microbes that infect humans survive best at 37°C (98.6°F) without fluctuation. This results in an increase in metabolism and subsequently an increase in growth. o Once the temperature is above or below this range, the proteins or enzymes cannot perform their normal functions resulting in a blockage of growth o Most human infectious microbes grow at a neutral or slightly alkaline pH (7.0 to 7.4) level. o Some infectious microbes prefer an acidic environment and seek parts of the body that provide these conditions o Microbes are also sensitive to the presence or absence of oxygen (aerobic vs anaerobic) 26 Pathogens can multiply and: o cause an obstruction o Damage tissue o secrete organic substances called exotoxins—(proteins) that produce side effects, such as an extremely high body temperature, nausea, vomiting, or shock 27 To make a person ill, microbes must: o reach their target site in the body and not be dislodged o multiply rapidly o obtain nutrients from host o survive attacks by host’s immune system Pathogens are divided into four basic infectious agents: fungi viruses bacteria protozoan parasites 29 https://www.cdc.gov/fungal/diseases/candidiasis/pdf/Candida_auris_508.pdf Fungi Microbes that contain a nucleus and organelles, protected by a membrane and a thick cell wall; Fungi are aerobic, and require a dark and moist environment to live and reproduce There are millions of different fungi found in the environment, including on the skin and can cause infection when they overgrow Their structure can make them harder to kill and difficult to treat therefore anti-infective drugs are not effective 30  Fungi Some new strains of fungal infections have been proven to be dangerous, such as Candida Auris on inpatients Yeasts and molds are in the Fungi family o Yeasts ▪ one-celled animals that reproduce by budding (asexual)—(outgrowth and separation) ▪ some yeasts can be harmful and cause infectious diseases ❑ example: thrush also called Candida Albicans. hard to kill & ▪ Some yeasts are useful in the production of beer, wine and bread o Molds ▪ form multicellular colonies and produce spores (cells) ▪ They live almost anywhere indoors and outdoors ▪ thrive on moisture and are usually harmless in small amounts Something wicked this way comes: What health care providers need to know about Candida auris: CCDR:2018;44(11) - Canada.ca 31  Viruses Smallest microorganisms flu ↑ o examples: HIV, mumps, influenza cannot live outside a living cell and cannot reproduce itself (must invade a host cell) Viruses contain either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) but never both o DNA and RNA are the two types of nucleic acids found in cells o Nucleic acids are the biological molecules that code for genetic information and proteins They may lie dormant for many years & Ex herpees : Once infected, viruses invade host cells within the body and use the host cell components to replicate & produce more viruses * viruses love Sugar A 32  Viruses It has host cell specificity - specific for a particular host cell After the replication cycle, these newly replicated viruses are released from the host cell usually leading to destruction of the cells Some viruses can lie dormant for a period of time before multiplying again. When this happens, a person appears to have recovered from the viral infection, but years later gets ill again (e.g. shingles) Antibiotics are ineffective as a treatment because they do not kill viruses Antiviral medications can sometimes be used, depending on the virus 33  Viruses Common diseases: measles, mumps, influenza, hepatitis, AIDS Cause Theories: increased stress, excessive use of drugs, poor nutrition Some viruses can travel into the nervous system and emerge at the nerve ending, causing symptoms. They then leave the site and travel up the nerve again. This can be repeated several times and is known as a latent or dormant infection. A cold sore caused by herpes simplex virus is an example of a latent viral infection. Common viral illnesses in humans include the common cold (caused by the rhinovirus), and warts (caused by the papillomavirus). 34  Bacteria one-celled microorganisms that consist of a single prokaryotic cell (no nucleus) without organelles (mitochondria and chloroplasts) or true nucleus Contain BOTH DNA & RNA Bacteria that form protective spores are more difficult to destroy o Endospore encase the genetic material in the cell and allows the bacteria to survive for many years o They have a variety of shapes and features Some bacteria survive only in an aerobic environment and some in an anaerobic environment Many can thrive in any environment, including in & on the human bod Lactobacillus acidophilus is a probiotic type of bacteria naturally found in the intestines and vagina, where it protects against harmful bacteria 35  Bacteria A person may be more prone to bacterial infections when the immune system is compromised by a virus o The disease state caused by a virus enables normally harmless bacteria to become pathogenic Antibiotics are used to treat bacterial infections Some strains of bacteria have become resistant to antibiotics, making them difficult to treat o Some become naturally resistant while others due overuse of antibiotic medication What causes antibiotic resistance? - Kevin Wu - YouTube 36  about this on test A *1 or 2 questions Shapes of Bacteria: Spherical (cocci) o Streptococcus ▪ Occurs in chains ▪ sore throat, diarrhea o Diplococcus ▪ Occurs in Pairs (two joined cells) ▪ Pneumococcal pneumonia o Staphylococcus ▪ irregular clusters (grapelike bunch) ▪ Ie: skin infections; pneumonia o Gaffkya ▪ occurs in groups of 4 ▪ Can cause meningitis, endocarditis etc Cylindrical (bacilli) → rods shaped Helicoidol (spirillum) → corkscrew-like Bacteria - Wikipedia 37  Parasites Parasites are microorganisms that live in or on a host and feed from the host Parasitic infections although common in tropical regions, can occur anywhere; They can be spread several ways, including through the skin from contaminated soil, water, food, and blood, as well as through sexual contact and via insect bites Microbiology of Parasites - YouTube Most Painful Parasites That Infect Humans - YouTube 38  Parasites Three main types of parasites that can cause disease in humans Protozoa o complex one-celled micro-organisms that can live and multiply in the body and able to move from place to place by pseudopod (false “feet”) formation, by the action of flagella, or by cilia (hair like projections) o Diseases caused by protozoa affect the gastro-intestinal (GI) tract, the genitourinary (GU) tract, and the circulatory system Helminths o larger, multi-celled organisms known as parasitic worms can live for long periods of time in the human G.I. tract. Examples: enterobiasis (pinworm infection) o Commonly found in children which is spread by swallowing or inhaling the tiny eggs of the pinworm. Ectoparasites o multi-celled organisms that live on or feed off your skin, including some insects, such as ticks, bed bugs and mosquitos also lice 39  the ones that move Parasites: Protozoa (classification, structure, life cycle) - YouTube 40 Helminths: Cestodes and Trematodes (transmission, clinical importance, and treatment) - YouTube 41  Asepsis the state of being free from disease-causing microorganisms and infection A method used to reduce the number of microorganisms and prevent their spread to susceptible hosts or reservoirs does NOT kill Prevents the introduction of unwanted infectious organisms into an environment There are two categories of asepsis: o medical o surgical MEDICAL SURGICAL ASEPSIS - YouTube 42 Medical Asepsis again does not kill & Measures aimed at controlling by reducing the number and spread of micro-organisms to susceptible hosts. Medical Asepsis does not eliminate microbes completely but decreases the probability of infection. Their environment is altered so that growth and reproduction is not favourable. Hospitals are “hot spots” for transmission of infection. Anyone with a compromised immune system is more susceptible to infection; therefore, medical asepsis must be practised by all hospital workers How? By identifying what is considered clean and what is dirty. Hand washing with soap and water, - friction/rubbing and antiseptic agents promotes medical asepsis thatst kills 43 Surgical Asepsis or Sterilization The procedure used to prevent contamination of microbes and endospores (germination) before, during, and after surgical interventions using sterile technique The complete destruction of all organisms. The absolute killing of all life forms is termed sterilization. If proper sterilization techniques are used, the probability of infection is theoretically zero 44 Important Points Hand washing is the most important and best practice/means of preventing the spread of infection from one person to another in a hospital setting An important and effective portion of hand washing is the action of rubbing with friction the hands together 45  Soaps are effective at removing some fragile bacteria, such as pneumococci and meningococci Some microbes are even harder to remove because they are so firmly embedded An MIT comes into contact with many patients on a daily basis; hand washing and other hygiene must be performed between each patient contact Any item that touches the patient’s skin, must be cleaned and disinfected 46  All body fluids from any patient should be considered contaminated as they can be a source of infection The healthcare team and the environment can be a source of contamination for the patient Health care providers should be free from disease Patient’s environment should be as clean as possible mask , gown gloves... , - Appropriate Personal Protective Equipment (PPE) should be utilized Every case should be considered “dirty” and the same infection control precautions are taken for all patients When contamination occurs, it should be addressed immediately 47  http://publications.gc.ca/collections/collection_2016/aspc-phac/HP3-1-24-S8-eng.pdf reverse isolation : When should the MIT wash hands: ↳ immuno compromised Before contact with patient and after each patient ↳ burn victims Before and after: o participating in interventional procedures such as IV injections, and catheterizations o examinations under isolation conditions o handling food/meals o Before and after using the washroom o Before and after removing gloves ▪ wearing gloves does not remove the need to wash hands o Before and after touching face After blowing nose, coughing or sneezing in hands At the beginning and end of every shift After contact with contaminated articles and whenever hands are visibly soiled 48  Won't frequent hand hygiene dry my skin? Intact skin is the first line of defense against microorganisms; hence it is important to maintain good skin care To prevent chafing: o wet your hands with warm water before applying a mild soap o pat rather than rub hands dry o apply skin lotion liberally and frequently. o Skin lotions should not interfere with glove integrity Most alcohol-based hand rubs contain emollients to reduce the incidence of skin irritation o Frequent use of alcohol-based hand rub lessens the incidence of skin breakdown, as it does not subject hands to the friction and abrasion involved in hand washing and drying hands If skin integrity is compromised, Occupational Health Service should be consulted for assessment Hand Hygiene Resources | IPAC Canada (ipac-canada.org) 49 The medically aseptic handwashing procedure: (page 113 Torres) 1. Approach the sink. Do not lean against the sink or allow clothing to touch the sink because it is considered contaminated. Remove any jewelry except for a wedding band. 2. Turn on the tap. A sink with foot or knee control is most desirable but is not always available. If the faucet is turned on by hand, use a paper towel to touch the handles and then discard the towel. 3. Regulate the water to a comfortable warm temperature. 4. Regulate the flow of water, so that it does not splash from the sink to one’s clothing. 5. During the entire procedure, keep hands and forearms lower than the elbows. The water will drain by gravity from the area of least contamination to the area of greatest contamination. 6. Wet hands and soap them well. A liquid soap is the most convenient. 7. With a firm, circular, scrubbing motion, wash your palms, the backs of your hands, each finger, between the fingers, and finally the knuckles. Wash to at least 1 inch above the area of contamination. If hands are not contaminated, wash to 1 inch above the wrists. Fifteen seconds should be the minimum time allotted for this. 8. Rinse hands well under running water. If hands have been heavily contaminated, repeat steps 6 to 8. 9. Clean fingernails with a brush or an orange stick carefully once each day before beginning work and again if hands become heavily contaminated. Scrubbing heavily contaminated nails with a brush is recommended. 10. Rinse fingers well under running water. 11. Repeat washing procedure as described earlier after cleaning nails. 12. Turn off the water. If the handles are hand operated, use a paper towel to turn them off to avoid contaminating hands. 13. Dry arms and hands using as many paper towels as necessary to do the job well. 14. Use lotion on hands and forearms frequently. It helps to keep the skin from cracking and thereby prevents infection. 50 SoP – Infection Prevention – Hand washing Guidelines 51 52 Hand Sanitizers Washing hands with soap and water is the best way to get rid of germs in most situations. If unavailable, hand sanitizers are used hand sanitizers must contain at least 70% alcohol. Sanitizers can quickly reduce the number of germs on hands in many situations. However, they: o do not get rid of all types of germs o may not be as effective when hands are visibly dirty or greasy o might not remove harmful chemicals from hands like pesticides and heavy metals 53 How to use hand sanitizer: Apply the gel product to the palm of one hand (read the label to learn the correct amount) Rub your hands together Rub the gel over all the surfaces of your hands and fingers until your hands are dry. This should take around 20-30 seconds See video for more specific details https://www.youtube.com/watch?v=ZnSjFr6J9HI https://www.cdc.gov/handwashing/when-how-handwashing.html 54 Other important tips on hand hygiene: Do not wear jewelry, as it can harbor organisms Fingernails should be kept short, and the undersides should be cleaned frequently with soap and water o longer fingernails can harbor more dirt and bacteria than short nails, thus potentially contributing to the spread of infection Do not bite nails Use soap and lotion dispensers to prevent colonization o check compatibility between the lotion, antiseptic products and gloves 55 Use of antiseptic agents/solutions: Where there is a high level of microbial contamination (feces, infected wounds) Before an invasive procedure Before touching immunocompromised patients, burn victims With patients infected with antimicrobial resistant organisms Waterless agents are alternatives when access to water is not available at the time 20 to 30 seconds 56 handwashing videos https://www.youtube.com/watch?v=3PmVJQUCm4E https://www.youtube.com/watch?v=ZnSjFr6J9HI https://www.youtube.com/watch?v=mWe51EKbewk 57 Hands must be washed after removal of used gloves and before putting on new gloves. Gloves are not a substitute for hand washing. They only provide additional protection. Non-sterile gloves should be used when: there is a risk of contact with blood, bodily fluids, secretions, etc. exposed to feces, pus, respiratory secretions, etc. handling soiled articles such as gowns, sheets and other linen MIT’s skin is not intact an injection is given Sterile gloves are used for interventional procedures to handle and manipulate sterile instruments 58 Gloves must be changed: In between patients and handwashing If a tear is suspected and noted During care on the same patient after contact with infected matter of highly susceptible concentration of microorganisms, such as bodily fluids, feces, secretions, etc... o example: insertion of urinary catheter 59 References: Patient Care in Imaging Technology—Torres 9th edition Introduction to Radiologic and Imaging Sciences and Patient Care”, by Adler and Carleton, 7th edition https://www.ccohs.ca/oshanswers/diseases/good_hygiene.html 60