NCM-112-Lesson-II-to-IV_Immunologic-Infectious-and-Inflammatory-Response PDF

LESSON II. RESPONSES TO ALTERATION/S, PROBLEMS AND ITS PATHOPHYSIOLOGIC BASIS IN INFECTIOUS, INFLAMMATORY, AND IMMUNOLOGIC RESPONSE Issa Marie A. Apodaca, RN, MAN Subject Instructor Learning Objectives: ◦ At the end of the discussion, the students will be able...

LESSON II. RESPONSES TO ALTERATION/S, PROBLEMS AND ITS PATHOPHYSIOLOGIC BASIS IN INFECTIOUS, INFLAMMATORY, AND IMMUNOLOGIC RESPONSE Issa Marie A. Apodaca, RN, MAN Subject Instructor Learning Objectives: ◦ At the end of the discussion, the students will be able to: ◦ 1. Identify the microorganisms that cause infection, ◦ 2. Differentiate between non-specific innate immunity and specific adaptive immunity, ◦ 3. Discuss the 5 observable signs of inflammatory response, ◦ 4. Describe the 4 stages of disease, ◦ 5. Identify interventions to break the chain of infection, ◦ 6. Enumerate standard and transmission based precautions Introduction ◦An infectious disease is any disease caused by the growth of pathogenic microbes in the body. ◦Communicable or Non-communicable ◦Pathogen- an organism causing disease to its host BASIC CONCEPTS ◦ NORMAL FLORA AND MICROBIOME ◦ Normal Flora: microorganisms that occur naturally and are present everywhere in our environment. ◦ Some live on the skin, in the nasopharynx, and GI Tract. ◦ They don’t become an infection unless the host becomes susceptible. ◦ Microbiome: microorganisms that live in or on a particular part of the body, such as the skin or GI tract ◦ Individual suite of microorganisms in and on the body. ◦ A person’s microbiome is acquired at birth and evolves over their lifetime. ◦ It is different across body sites and between individuals. ◦ Plays an important role in the functioning of the human body ◦ Composed of viruses, bacteria, and fungi, residing in communities within or on the body PATHOGENS ◦Microorganisms that cause disease ◦4 common types: ◦ 1. Viruses ◦ 2. Bacteria ◦ 3. Fungi ◦ 4. Parasites  1. VIRUSES ◦ Made up of a piece of genetic code, such as DNA or RNA, and are protected by a coating of protein. ◦ After a host (i.e., the person) becomes infected by a virus, the virus invades the body’s cells and uses the components of the cell to replicate and produce more viruses. ◦ After the virus replication is complete, the new viruses are released into the body, causing damage or destruction of the host’s cells. ◦ ANTIVIRAL medications can be used to treat some viral infections. Antibiotics do not kill viruses and are ineffective as a treatment for viral infections.  2. BACTERIA ◦ Microorganisms that is made of a singe cell. ◦ Diverse, have a variety of shapes and features, and have the ability to live in any environment, including your body. ◦ However, not all bacteria cause infections. ◦ Those that cause infection are called pathogenic bacteria. ◦ A patient is susceptible to bacterial infections when their immune system is compromised by chronic diseases or certain types of medications. ◦ ANTIBIOTICS are used to treat bacterial infections. ◦ However, some strains of bacteria have become resistant to antibiotics, making them difficult to treat. ◦ (In photo: E.coli bacteria)  3. FUNGI ◦ Fungi can be found everywhere in the environment, including indoors, outdoors, and on human skin, but only about 300 species cause infection when they overgrow. ◦ Candida albicans is a type of fungus that can cause oral thrush and vaginal yeast infections, especially in susceptible patients or those taking antibiotics. ◦ Fungi cells contain a nucleus and other components protected by a membrane and a thick cell wall. ◦ This structure can make them harder to kill. ◦ Some new strains of fungal infections are proving to be especially dangerous, such as Candida auris, which is difficult to diagnose and treat, and can cause outbreaks in health care facilities.  4. PARASITES ◦ Parasites are organisms that behave like tiny animals, living in or on a host, and feeding at the expense of the host. Three main types of parasites can cause disease in humans. These include the following: Protozoa: Single-celled organisms that can live and multiply in your body (Ex: Amoeba) Helminths: Multi-celled organisms that can live inside or outside your body and are commonly known as worms Ectoparasites: Multi-celled organisms that live on or feed off skin, including ticks and mosquitos ◦ Parasites can be spread several ways, including through contaminated soil, water, food, and blood, as well as through sexual contact and insect bites. A. IMMUNOLOGIC RESPONSE  1. NON-SPECIFIC INNATE IMMUNITY 1. NON-SPECIFIC INNATE IMMUNITY ◦ Nonspecific innate immunity is a system of defenses in the body that targets invading pathogens in a non specific manner. ◦ It is called “innate” because it is present from the moment we are born. ◦ Includes physical defenses, chemical defenses, and cellular defenses and plasma protein mediators. Physical Defenses ◦ Body’s most basic form of defense against infection ◦ Physical barriers to microbes include: ◦ Skin ◦ Mucus membranes ◦ Mechanical defenses ◦ Physically remove microbes and debris from areas of the body where they might cause harm or infection. ◦ In addition, a person’s microbiome provides physical protection against disease as normal flora compete with pathogens for nutrients and cellular-binding sites. Physical Barriers to Microbes SKIN ◦ One of the body’s most important physical barriers is the skin barrier, which is composed of three layers of closely packed cells. ◦ Infections can occur when the skin barrier is broken, allowing the entry of opportunistic pathogens that infect the skin tissue surrounding the wound and possibly spread to deeper tissues.  MUCUS MEMBRANES ◦ The mucous membranes lining the nose, mouth, lungs, and urinary and digestive tracts provide another nonspecific barrier against potential pathogens. ◦ Mucous membranes consist of a layer of epithelial cells bound by tight junctions. ◦ The epithelial cells secrete a moist, sticky substance called mucous that covers and protects the fragile cell layers beneath it and also traps debris, including microbes. ◦ (In photo: Mucociliary Escalator) ENDOTHELIA ◦ Specific type of epithelial cell ◦ Thin layer of specialized cells that line the interior surface of blood vessels, and the heart. ◦ These cells form a barrier between the blood or lymph and the surrounding tissues. ◦ They act as physical barrier that prevents pathogens from entering tissues. ◦ They also help regulate the movement of immune cells like neutrophils to infection sites by releasing signaling molecules ENDOTHELIA ◦ They also produce antimicrobial substances and promote inflammation, which helps recruit immune cells to fight infections. ◦ Their role is crucial in quickly responding to pathogens as part of the body’s first line of defense. Mechanical Defenses ◦ Several mechanical defenses that physically remove pathogens from the body and prevent them from taking up residence: ◦ Examples: ◦ Flushing action of urine and tears ◦ Eyelashes and eyelids- prevent dust and airborne microorganisms from reaching the eye ◦ Any microbes or debris that make it past these physical barriers are flushed out by the mechanical action of blinking, which bathes the eye in tears, washing debris away. Chemical Defenses  Chemical Defenses ◦ The term chemical mediators encompasses a wide array of substances found in various fluids and tissues throughout the body that provide non specific antimicrobial defense mechanisms. ◦ Example: ◦ Sebaceous glands- sebum ◦ Sebum helps seal off the pores of the hair follicle and prevents bacteria on the skin surface from invading sweat glands and surrounding tissue ◦ Environmental factors can affect these chemical defenses of the skin. ◦ Example: Low humidity- dry skin & susceptible to pathogens ◦ Mgt: skin moisturizer & essential oils to prevent dry skin from being infected ◦ Other examples of chemical defenses: ◦ Enzymes ◦ Enzymes in saliva and digestive tract eliminate most pathogens that manage to survive the acidic environment of the stomach. ◦ pH Level ◦ In the urinary tract, the slight acidity of urine inhibits the growth of potential pathogens in the urinary tract. ◦ Chemical Mediators ◦ The respiratory tract also uses various chemical mediators in the nasal passages, trachea, and lungs that have antibacterial properties. Cellular Defenses  Cellular Defenses ◦ critical part of the immune system, protecting the body from infections and harmful invaders, such as bacteria, viruses, fungi, and cancerous cells. ◦ These defenses are carried out by various immune cells that either directly destroy pathogens or help coordinate an immune response. ◦ Cellular defenses are divided into two main categories: ◦ A. Innate Immune Response ◦ Phagocytes ◦ Natural Killer (NK) Cells ◦ Mast cells, Basophils, Eosinophils ◦ B. Adaptive Immune Response ◦ T lymphocytes (T cells) ◦ B lymphocytes (B cells)  Cellular Defenses ◦ A. Innate Immune Response ◦ A. Phagocytes ◦ Neutrophils: Rapidly respond to infections, especially bacterial infections, by engulfing and destroying invaders. ◦ Macrophages: These large cells consume pathogens and dead cells and also present antigens to activate adaptive immune cells. ◦ Dendritic Cells: Capture pathogens and present them to T cells, linking the innate and adaptive immune systems. ◦ Monocytes: Circulate in the blood and can differentiate into macrophages or dendritic cells when they migrate into tissues.  Cellular Defenses ◦ A. Innate Immune Response ◦ B. Natural Killer (NK) Cells ◦ NK cells patrol the body and recognize stressed or infected cells (like those infected by viruses or transformed into cancer cells). ◦ They kill these cells by releasing chemicals that induce apoptosis (programmed cell death). ◦ C. Mast Cells, Basophils, Eosinophils ◦ These cells are involved in responses to parasites and allergens. ◦ They release inflammatory chemicals, such as histamine, which help recruit other immune cells to the site of infection or injury. ◦ Eosinophils also have some phagocytic activity, especially for antibody- coated pathogens. Plasma Protein Mediators PLASMA PROTEIN MEDIATORS ◦ Proteins found in the blood plasma that play a critical role in regulating immune responses, inflammation, and blood clotting. ◦ These proteins act as signaling molecules or mediators that help coordinate various processes during an immune or inflammatory response. ◦ Three (3) Main Types: 1. Complement system help destroy pathogens by marking them for: proteins destruction (opsonization), forming pores in their membranes (lysis), and promoting inflammation. 2. Clotting factors help form blood clots to stop bleeding and provide a physical barrier to prevent the spread of infections. 3. Kinin system proteins These proteins such as bradykinin, promote inflammation by increasing blood vessel permeability and causing pain during tissue injury or infection. PLASMA PROTEIN MEDIATORS ◦ Cytokines ◦ are small signaling proteins released by cells, especially immune cells, that help regulate and coordinate the body’s immune response. ◦ They act as messengers between cells to promote or inhibit immune activities, inflammation, and cell communication during immune responses to infections, injuries, or diseases. Key Functions: 1. Regulating immune help activate or suppress immune cells, like T cells and B cells. responses: 2. Promoting inflammation Cytokines can trigger inflammation, which helps isolate and attack pathogens or damaged tissues. 3. Cell communication: allow immune cells to communicate with each other and other body systems, ensuring a coordinated response to threats. PLASMA PROTEIN MEDIATORS Some Important Types of Cytokines: Interleukins (IL) Regulate growth and activity of immune cells. Interferons (IFN) Help protect against viruses by interfering with viral replication. Tumor necrosis factors Involved in inflammation and killing tumor (TNF) cells. Chemokines Guide the movement of immune cells to the site of infection or injury. B. INFLAMMATORY RESPONSE INFLAMMATION ◦ It is a response triggered by a cascade of chemical mediators and occurs when pathogens successfully breach the nonspecific innate immune system or when an injury occurs. ◦ It is a necessary process that recruits cellular defenses needed to: ◦ 1. eliminate pathogens, ◦ 2. remove damaged and dead cells, and ◦ 3. initiate repair mechanisms. ◦ Excessive inflammation, however, can result in local tissue damage, and in severe cases, such as sepsis, it can become deadly. INFLAMMATORY RESPONSE ◦ Acute Inflammation- immediate response to tissue injury. ◦ 1. Vasoconstriction occurs to minimize blood loss if injury has occurred. ◦ 2. Vasoconstriction is followed by vasodilation with increased permeability of the blood vessels due to the release of histamine by mast cells. ◦ Histamine contributes to the five observable signs of the inflammatory response: ◦ 1. Erythema (redness), ◦ 2. Edema (swelling), ◦ 3. Heat, ◦ 4. Pain, and ◦ 5. Altered function ◦ It is also associated with an influx of phagocytes at the site of injury and/or infection. ◦ These events result in the swelling and reddening of the injured site. ◦ The increased blood flow to the injured site causes it to feel warm. ◦ Inflammation is also associated with pain due to these events stimulating nerve pain receptors in the tissue. ◦ Increasing numbers of neutrophils are then recruited to the area to fight pathogens. ◦ As the fight rages on, white blood cells are recruited to the area, and pus forms from the accumulation of neutrophils, dead cells, tissue fluids, and lymph. ◦ Typically, after a few days, macrophages clear out this pus. ◦ During injury, if this nonspecific inflammatory process does not successfully kill the pathogens, infection occurs. Fever ◦ A fever is part of the inflammatory response that extends beyond the site of infection and affects the entire body, resulting in an overall increase in body temperature. ◦ Fever enhances the nonspecific innate immune defenses by stimulating white blood cells to kill pathogens. ◦ The rise in body temperature also inhibits the growth of many pathogens. During fever, the patient’s skin may appear pale due to vasoconstriction of the blood vessels in the skin to divert blood flow away from extremities, minimize the loss of heat, and raise the body’s core temperature. ◦ The hypothalamus also stimulates the shivering of muscles to generate heat and raise the core temperature. ◦ A low-level fever is thought to help an individual overcome an illness. ◦ However, in some instances, this immune response can be too strong, causing tissue and organ damage and, in severe cases, even death. ◦ Example: Staphylococcus aureus and Streptococcus pyogenes are capable of producing superantigens that cause toxic shock syndrome and scarlet fever, respectively. ◦ Both of these conditions are associated with extremely high fevers in excess of 42 °C (108 °F) that must be managed to prevent tissue injury and death. ◦ When a fever breaks, the hypothalamus stimulates vasodilation, resulting in a return of blood flow to the skin and a subsequent release of heat from the body. The hypothalamus also stimulates sweating, which cools the skin as the sweat evaporates. 2. SPECIFIC ADAPTIVE IMMUNITY 2. SPECIFIC ADAPTIVE IMMUNITY ◦ Specific adaptive immunity is the immune response that is activated when the nonspecific innate immune response is insufficient to control an infection. ◦ There are 2 types of adaptive responses: ◦ 1. Cell-mediated immune response, which is carried out by T cells ◦ 2. Humoral immune response, which is controlled by activated B cells and antibodies. ◦ T cells- Immune cells that mature in the thymus. ◦ T cells are categorized into three classes: ◦ 1. Helper T cells ◦ 2. Regulatory T cells ◦ 3. Cytotoxic T cells. ◦ B cells- Immune cells that mature in the bone marrow and produce antibodies. ◦ The five classes of antibodies are IgG, IgM, IgA, IgD, and IgE. They also turn into memory B cells. T cells Role Function 1. Helper T Cells Activate and Coordinate and regulate the (CD4+ T Cells) Coordinate immune response by activating other immune cells. 2. Regulatory T Cells Maintain Immune Maintain immune tolerance and (Tregs) Tolerance prevent autoimmune responses by suppressing excessive immune activity. 3. 3. Cytotoxic T Direct Killing Directly kill infected or abnormal Cells (CD8+ T Cells) cells by recognizing and destroying them. ◦ Specific Adaptive Immunity also creates memory cells for each specific pathogen that provides the host with long-term protection from reinfection with that pathogen. ◦ On re-exposure, these memory cells facilitate an efficient and quick immune response. ◦ For example, when an individual recovers from chicken pox, the body develops a memory of the varicella-zoster virus that will specifically protect it from reinfection if it is exposed to the virus again.  2. SPECIFIC ADAPTIVE IMMUNITY ◦ Key Features: ◦ 1. Specificity: Targets specific antigens on pathogens. B cells and T cells have receptors designed to recognize these unique molecules, leading to a precise immune response. ◦ 2. Memory: After exposure to a pathogen, the immune system creates memory cells (both B and T cells). These cells "remember" the pathogen, allowing for a faster and stronger response upon future encounters.  2. SPECIFIC ADAPTIVE IMMUNITY ◦ 3. Clonal Expansion: Once B cells or T cells recognize an antigen, they rapidly multiply, creating clones of themselves to fight the infection more effectively. ◦ 4. Diversity: The adaptive immune system has a vast array of receptors, allowing it to recognize millions of different antigens and respond to a wide variety of pathogens. ◦ 5. Self-Tolerance: The immune system is designed to distinguish between "self" and "non-self". It usually avoids attacking the body’s own cells, preventing autoimmune reactions. Failure of self-tolerance can lead to autoimmune diseases, where the immune system mistakenly attacks healthy cells.  2. SPECIFIC ADAPTIVE IMMUNITY ◦ Two Main Branches of Adaptive Immunity: 1.Humoral Immunity (B cell-mediated immunity): 1. B cells are responsible for the humoral immune response, where they produce antibodies to target pathogens in body fluids (such as blood and lymph). 2. Antibodies bind to specific antigens on pathogens, neutralizing them and marking them for destruction by other immune cells or the complement system. 3.Effective against extracellular pathogens (bacteria, toxins, and viruses outside of cells).  2. SPECIFIC ADAPTIVE IMMUNITY ◦ 2. Cell-Mediated Immunity (T cell-mediated immunity): T cells are responsible for the cell-mediated immune response, particularly cytotoxic T cells (CD8+ T cells), which directly destroy infected, cancerous, or foreign cells. Helper T cells (CD4+ T cells) play a supporting role by releasing cytokines to activate other immune cells, including B cells and cytotoxic T cells. Effective against intracellular pathogens (viruses, bacteria, and cancer cells inside the body's own cells).  2. SPECIFIC ADAPTIVE IMMUNITY SUMMARY Feature Cell-Mediated Response Humoral Response Primary cells T cells (cytotoxic and helper T cells) B cells (with helper T cell support) involved Direct killing of infected or abnormal Antibodies neutralize and tag Main mechanism cells pathogens Target Intracellular pathogens (e.g., viruses), Extracellular pathogens (e.g., bacteria, cancer cells toxins) Role of antibodies Not involved Central to the response Example of Defense against virus-infected cells Neutralization of bacteria in the response bloodstream 2. SPECIFIC ADAPTIVE IMMUNITY STAGES OF THE ADAPTIVE IMMUNE RESPONSE 1. Recognition of B cells and T cells have unique receptors that can bind to Antigens: specific antigens presented by pathogens or infected cells. 2. Activation of Once an antigen is recognized, the specific B or T cell is Lymphocytes: activated, often with the help of helper T cells. Activated B and T cells rapidly divide to produce many clones 3. Clonal Expansion: of themselves to effectively target the pathogen. 4. Elimination of Antibodies from B cells neutralize pathogens in body fluids, Pathogens: while cytotoxic T cells kill infected or abnormal cells. 5. Memory After the infection is cleared, some B and T cells become Formation: memory cells, providing long-term protection and a faster response if the same pathogen is encountered again. 2. SPECIFIC ADAPTIVE IMMUNITY Importance of Specific Adaptive Immunity: Targeted Defense: The highly specific nature of adaptive immunity ensures that the immune system can efficiently recognize and eliminate pathogens based on their unique antigens. Long-Term Protection: The development of immunological memory allows for faster and more effective responses upon re-exposure to the same pathogen, which is the principle behind vaccination. Enhanced with Exposure: Unlike innate immunity, which remains constant, adaptive immunity becomes stronger and more effective with repeated exposure to the same pathogen. C. INFECTIOUS RESPONSE INFECTION ◦ An infection is the invasion and growth of a microorganism within the body. ◦ Infection can lead to disease that causes signs and symptoms resulting in a deviation from the normal structure or functioning of the host. ◦ Infection occurs when nonspecific innate immunity and specific adaptive immunity defenses are inadequate to protect an individual against the invasion of a pathogen. ◦ Pathogenicity- the ability of a microorganism to cause disease. ◦ Virulence- the degree to which a microorganism is likely to become a disease. ◦ Highly Virulent pathogens- will almost always lead to a disease state when introduced to the body, and some may even cause multi-organ and body system failure in healthy individuals. ◦ Less Virulent pathogens- may cause an initial infection, but may not always cause severe illness. ◦ Low Virulence- usually result in mild signs and symptoms of disease, such as a low-grade fever, headache, or muscle aches, and some individuals may even be asymptomatic. Primary Pathogens Versus Opportunistic Pathogens ◦ Pathogens can be classified as either primary pathogens or opportunistic pathogens. ◦ Primary Pathogen- A pathogen that can cause disease in a host regardless of the host’s resident microbiota or immune system. ◦ Opportunistic Pathogen- A pathogen that only causes disease in situations that compromise the host’s defenses, such as the body’s protective barriers, immune system, or normal microbiota. ◦ Individuals susceptible to opportunistic infections include the very young, the elderly, women who are pregnant, patients undergoing chemotherapy, people with immunodeficiencies (such as acquired immunodeficiency syndrome [AIDS]), patients who are recovering from surgery, and those who have nonintact skin (such as a severe wound or burn). Stages of Pathogenesis ◦ To cause disease, a pathogen must successfully achieve four stages of pathogenesis to become an infection: ◦ 1. Exposure- An encounter with a potential pathogen. ◦ 2. Adhesion (also called colonization)- Capability of pathogenic microbes to attach to the cells of the body. ◦ 3. Invasion- Means the spread of a pathogen throughout local tissues or the body. ◦ 4. Infection- Following invasion, successful multiplication of the pathogen leads to infection. Infections can be described as local, secondary, or systemic, depending on the extent of the infection. ◦ Local Infection- Infection confined to a small area of the body, typically near the portal of entry, and usually presents with signs of redness, warmth, swelling, warmth, and pain. ◦ Secondary Infection- A localized pathogen that spreads to a secondary location. ◦ Systemic Infection- An infection that becomes disseminated throughout the body. STAGES OF DISEASE Stages of Disease ◦ When a pathogen becomes an infection-causing disease, there are five stages of disease, including the incubation, prodromal, illness, decline, and convalescence periods. ◦4 STAGES OF DISEASE ◦ Incubation Period ◦ The period of a disease after the initial entry of the pathogen into the host but before symptoms develop. ◦ Prodromal Period ◦ The disease stage after the incubation period when the pathogen continues to multiply and the host begins to experience general signs and symptoms of illness that result from activation of the immune system, such as fever, pain, soreness, swelling, or inflammation. ◦ Acute Phase ◦ Following the prodromal period is the period of acute illness, during which the signs and symptoms of a specific disease become obvious and can become severe. ◦ Convalescent Period ◦ The final period of disease. Types of Infection ◦ ACUTE VS CHRONIC ◦ ACUTE, SELF-LIMITING INFECTIONS ◦ Infections that develop rapidly and generally last only 10-14 days. ◦ Colds and ear infections are considered acute, self-limiting infections. ◦ CHRONIC INFECTIONS ◦ Infections that can last up to months. ◦ Hepatitis, HIV, Tuberculosis are examples of chronic infections.  LESSON IV. PREVENTING INFECTION LINKS WITHIN THE CHAIN OF INFECTION Infectious Agent: A causative organism, such as bacteria, virus, fungi, parasite. Reservoir: A place where the organism grows, such as in blood, food, or a wound. Portal of Exit: The method by which the organism leaves the reservoir, such as through respiratory secretions, blood, urine, breast milk, or feces. Mode of Transmission: The vehicle by which the organism is transferred such as physical contact, inhalation, or injection. The most common vehicles are respiratory secretions spread by a cough, sneeze, or on the hands. A single sneeze can send thousands of virus particles into the air. Portal of Entry: The method by which the organism enters a new host, such as through mucous membranes or nonintact skin. Susceptible Host: The susceptible individual the organism has invaded. Interventions to Break the Chain of Infection ◦ Infections can be stopped from spreading by interrupting this chain at any link. ◦ Chain links can be broken by: ◦ 1. disinfecting the environment ◦ 2. sterilizing medical instruments and equipment ◦ 3. covering coughs and sneezes ◦ 4. using good hand hygiene ◦ 5. implementing standard and transmission-based precautions ◦ 6. appropriately using personal protective equipment ◦ 7. encouraging patients to stay up-to-date on vaccines (including the flu shot), ◦ 8. following safe injection practices, and ◦ 9. promoting the optimal functioning of the natural immune system with good nutrition, rest, exercise, and stress management. Disinfection and Sterilization ◦ Disinfection and Sterilization are used to kill microorganisms and remove harmful pathogens from the environment and equipment to decrease the chance of spreading infection. ◦ DISINFECTION- Removal of organisms from inanimate objects and surfaces. ◦ However, disinfection does not destroy all spores and viruses. ◦ STERILIZATION- A process used to destroy all pathogens from inanimate objects, including spores and viruses. ◦ Sterilization methods include steam, boiling water, dry heat, radiation, and chemicals. ◦ Because of the harshness of these sterilization methods, skin can only be disinfected and not sterilized.  Standard and Transmission-Based Precautions ◦ To protect patients and health care workers from the spread of pathogens, the CDC had developed precautions to use during patient care that address portals of exit, methods of transmission, and portals of entry. ◦ These precautions include STANDARD PRECAUTIONS and TRANSMISSION-BASED PRECAUTIONS. ◦ STANDARD PRECAUTIONS- The minimum infection prevention practices that apply to all patient care, regardless of suspected or confirmed infection status of the patient, in any setting where healthcare is delivered. ◦ These precautions are based on the principle that all blood, body fluids (except sweat), nonintact skin, and mucous membranes may contain transmissible infectious agents. ◦ These standards reduce the risk of exposure for the health care worker and protect the patient from potential transmission of infectious organisms. ◦ Current standard precautions according to the CDC include the following: Appropriate hand hygiene Use of personal protective equipment (e.g., gloves, gowns, masks, eyewear) whenever infectious material exposure may occur Appropriate patient placement and care using transmission-based precautions when indicated Respiratory hygiene/cough etiquette Proper handling and cleaning of environment, equipment, and devices Safe handling of laundry Sharps safety (i.e., engineering and work practice controls) Aseptic technique for invasive nursing procedures such as parenteral medication administration  HAND HYGIENE ◦ Hand hygiene, although simple, is still the best and most effective way to prevent the spread of infection. ◦ Accepted methods for hand hygiene include using either soap and water or alcohol-based hand sanitizer. ◦ 5 Moments of Hand Hygiene ◦ 1. Before touching a patient ◦ 2. Before clean/aseptic technique ◦ 3. After touching a patient ◦ 4. After body fluid exposure/ risk; ◦ 5. After touching patient surroundings  RESPIRATORY HYGIENE/COUGH ETIQUETTE ◦ Respiratory hygiene is targeted at patients, accompanying family members and friends, and staff members with undiagnosed transmissible respiratory infections. ◦ It applies to any person with signs of illness, including cough, congestion, or increased production of respiratory secretions when entering a health care facility. ◦ The elements of respiratory hygiene include the following: Education of health care facility staff, patients, and visitors Posted signs, in language(s) appropriate to the population served, with instructions to patients and accompanying family members or friends Source control measures for a coughing person (e.g., covering the mouth/nose with a tissue when coughing and prompt disposal of used tissues, or applying surgical masks on the coughing person to contain secretions) Hand hygiene after contact with one’s respiratory secretions Spatial separation, ideally greater than 3 feet, of persons with respiratory infections in common waiting areas when possible. ◦ Health care personnel are advised to wear a mask and use frequent hand hygiene when examining and caring for patients with signs and symptoms of a respiratory infection. ◦ Health care personnel who have a respiratory infection are advised to stay home or avoid direct patient contact, especially with high-risk patients. ◦ If this is not possible, then a mask should be worn while providing patient care.  PERSONAL PROTECTIVE EQUIPMENT ◦ Personal Protective Equipment ◦ Gloves, gowns, face shields, goggles, and masks used to prevent the spread of infection to and from patients and health care providers. ◦ Depending upon the anticipated exposure and type of pathogen, PPE may include the use of gloves, a fluid-resistant gown, goggles or a face shield, and a mask or respirator. Transmission-Based Precautions ◦ Transmission-based precautions are used for patients with documented or suspected infection of highly-transmissible pathogens, such as C. difficile (C-diff), Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant enterococci (VRE), Respiratory Syncytial Virus (RSV), measles, and tuberculosis (TB). ◦ For patients with these types of pathogens, standard precautions are used along with specific transmission-based precautions. ◦ Three categories of transmission-based precautions: ◦ 1. CONTACT precautions ◦ 2. DROPLET precautions ◦ 3. AIRBORNE precautions. ◦ Transmission-based precautions are used when the route(s) of transmission of a specific disease are not completely interrupted using standard precautions alone. ◦ When possible, patients with transmission-based precautions should be placed in a single occupancy room with dedicated patient care equipment (e.g., blood pressure cuffs, stethoscope, and thermometer stay in the patient’s room). ◦ A card is posted outside the door alerting staff and visitors to required precautions before entering the room. ◦ Transport of the patient and unnecessary movement outside the patient room should be limited. ◦ When transmission-based precautions are implemented, it is also important for the nurse to make efforts to counteract possible adverse effects of these precautions on patients, such as anxiety, depression, perceptions of stigma, and reduced contact with clinical staff.  TRANSMISSION BASED PRECAUTIONS PRECAUTION IMPLEMENTATION PPE AND OTHER PRECAUTIONS Gloves, Gown Known or suspected infections with increased risk Dedicated equipment for contact transmission (e.g., draining wounds, Limit patient transport out of room Contact fecal incontinence) or with epidemiologically Prioritized disinfection of the room important organisms, such as C-diff, MRSA, VRE, Note: Use only soap and water for hand or RSV hygiene in patients with C. difficile infection. Known or suspected infection with pathogens Mask, Goggles or face shield transmitted by large respiratory droplets Droplet generated by coughing, sneezing, or talking, such as influenza or pertussis Fit-tested N-95 respirator Airborne infection isolation room Known or suspected infection with pathogens Single-patient room Airborne transmitted by small respiratory droplets, such as Patient door closed measles and coronavirus Restricted susceptible personnel room entry PATIENT TRANSPORT ◦ Several principles are used to guide transport of patients requiring transmission-based precautions. In the inpatient and residential settings, these principles include the following: Limit transport for essential purposes only, such as diagnostic and therapeutic procedures that cannot be performed in the patient’s room When transporting, use appropriate barriers on the patient consistent with the route and risk of transmission (e.g., mask, gown, covering the affected areas when infectious skin lesions or drainage is present) Notify health care personnel in the receiving area of the impending arrival of the patient and of the precautions necessary to prevent transmission. ENTERIC PRECAUTIONS ◦ Enteric precautions are used when there is the presence, or suspected presence, of gastrointestinal pathogens such as Clostridium difficile (C-diff) or norovirus. These pathogens are present in feces, so health care workers should always wear a gown in the patient room to prevent inadvertent fecal contamination of their clothing from contact with contaminated surfaces. ◦ In addition to contact precautions, enteric precautions include the following: Using only soap and water for hand hygiene. Do not use hand sanitizer because it is not effective against C-diff. Using a special disinfecting process. Special disinfecting should be used after patient discharge and includes disinfection of the mattress. REVERSE ISOLATION ◦ Reverse isolation, also called neutropenic precautions, is used for patients who have compromised immune systems and low neutrophil levels. ◦ This type of isolation protects the patient from pathogens in their environment. ◦ In addition to using contact precautions to protect the patient, reverse isolation precautions include the following: Meticulous hand hygiene by all visitors, staff, and the patient Frequently monitoring for signs and symptoms of infection and sepsis Not allowing live plants, fresh flowers, fresh raw fruits or vegetables, sushi, deli foods, or cheese into the room due to bacteria and fungi Placement in a private room or a positive pressure room Limited transport and movement of the patient outside of the room Masking of the patient for transport with a surgical mask Aseptic and Sterile Techniques ◦ ASEPTIC TECHNIQUE (Medical Asepsis) ◦ The purposeful reduction of pathogens to prevent the transfer of microorganisms from one person or object to another during a medical procedure. ◦ Example: a nurse administering parenteral medication or performing urinary catheterization uses aseptic technique. ◦ When performed properly, aseptic technique prevents contamination and transfer of pathogens to the patient from caregiver hands, surfaces, and equipment during routine care or procedures. ◦ It is important to remember that potentially infectious microorganisms can be present in the environment, on instruments, in liquids, on skin surfaces, or within a wound. ◦ STERILE TECHNIQUE (Surgical Asepsis) ◦ seeks to eliminate every potential microorganism in and around a sterile field while also maintaining objects as free from microorganisms as possible. ◦ Sterile fields are implemented during surgery, as well as during nursing procedures such as the insertion of a urinary catheter, changing dressings on open wounds, and performing central line care. ◦ Sterile technique requires a combination of meticulous hand washing, creating and maintaining a sterile field, using long-lasting antimicrobial cleansing agents such as Betadine, donning sterile gloves, and using sterile devices and instruments.