NCM 103 Lecture-Infection Control in Nursing PDF

infections) and Aspergillus spp. (causes NCM 103 LECTURE respiratory infections). INFECTION CONTROL IN NURSING PARASITES: ▪ Organisms that live on o...

infections) and Aspergillus spp. (causes NCM 103 LECTURE respiratory infections). INFECTION CONTROL IN NURSING PARASITES: ▪ Organisms that live on or in a host and benefit MICROORGANISMS EXIST EVERYWHERE: at the host's expense. They can be protozoa in water, in soil, and on body surfaces such as the (single-celled) or multicellular organisms (like skin, intestinal tract, and other areas open to the worms). Examples include outside such as our mouth, upper respiratory tract, vagina, and lower urinary tract. many organisms are harmless, others are lethal, some are a normal part 2. RESERVOIR of our body. As such, the ones directly involved in Definition providing a biologically safe environment are none The reservoir is the natural habitat of the infectious other than the nurses. agent, where it lives and multiplies. This can be a human, animal, or environment. WHAT IS INFECTION? Examples A Infection is the growth of microorganisms in body HUMANS: tissue where they are not usually found. ▪ A person with a respiratory infection (common cold) K A condition characterized by the invasion and ANIMALS: multiplication of pathogenic microorganisms (such as ▪ A dog carrying rabies virus ENVIRONMENT: bacteria, viruses, fungi, or parasites) within the body, S leading to tissue damage and an immune response. ▪ Soil contaminated with Clostridium tetani Infections can manifest as localized or systemic and (causes tetanus) may result in a range of clinical signs and symptoms, E including fever, inflammation, pain, and impaired 3. PORTAL OF EXIT function of affected tissues or organs. Definition L The portal of exit is the route through which the KEY COMPONENTS infectious agent leaves the reservoir. The chain of infection is a model used to Examples understand how infections are transmitted and RESPIRATORY TRACT: spread from one individual to another. This model ▪ Coughing or sneezing (as seen with influenza) outlines six components, each of which must be SKIN: present for an infection to occur. By breaking any ▪ Cuts or abrasions (as with MRSA infections) link in this chain, healthcare providers can GASTROINTESTINAL TRACT: effectively control and prevent the spread of ▪ Diarrhea (as seen with Salmonella infections ) infections. Here’s a detailed explanation of each component along with examples: 4. MODE OF TRANSMISSION Definition 1. INFECTIOUS AGENT The mode of transmission refers to how the Definition infectious agent is spread from one host to The infectious agent is the pathogen another. (microorganism) that causes disease. This can Examples include bacteria, viruses, fungi, and parasites. DIRECT CONTACT: Examples ▪ Touching a person with an active infection BACTERIA: (e.g., a wound) ▪ Single-celled organisms that can multiply INDIRECT CONTACT: rapidly and may be pathogenic. They can be ▪ Touching contaminated surfaces or objects classified further into Gram-positive and Gram (fomites) like doorknobs or utensils negative based on their cell wall structure. DROPLET TRANSMISSION: Examples include Staphylococcus aureus ▪ Respiratory droplets expelled when an infected (causes skin infections) and Escherichia coli person coughs or sneezes (e.g., COVID-19) (causes gastrointestinal infections). AIRBORNE TRANSMISSION: VIRUSES: ▪ Infectious agents that remain suspended in ▪ Microscopic infectious agents that require a the air (e.g., tuberculosis) host cell to replicate. They are composed of VECTOR-BORNE TRANSMISSION: genetic material (DNA or RNA) surrounded by ▪ Insects or animals that carry the infectious a protein coat. Examples include the influenza agent (e.g., mosquitoes transmitting malaria) virus (causes the flu) and HIV (causes AIDS). FUNGI: ▪ Eukaryotic organisms that can be unicellular (yeasts) or multicellular (molds). Some fungi are pathogenic, causing infections, especially in immunocompromised individuals. Examples 5. PORTAL OF ENTRY include Candida albicans (causes yeast Definition  The portal of entry is the way the infectious agent A local infection is confined to a specific area of the enters a new host. This is often the same as the body, where the infectious microorganisms remain. portal of exit. The immune response is localized to the site of Examples infection, and systemic symptoms may be minimal. RESPIRATORY TRACT: Examples ▪ Inhalation of droplets (as with the flu) SKIN ABSCESS: MUCOUS MEMBRANES: ▪ A localized collection of pus caused by ▪ Through the eyes, nose, or mouth bacterial infection (e.g., Staphylococcus SKIN: aureus). It appears as a swollen, red, and ▪ Through breaks in the skin or mucous painful area on the skin. The surrounding membranes (as with MRSA) tissue may be inflamed, but the infection typically does not spread to other parts of 6. SUSCEPTIBLE HOST A the body. Definition A susceptible host is an individual who is at risk of 2. SYSTEMIC INFECTION infection due to a lack of immunity, pre-existing K A systemic infection occurs when microorganisms health conditions, or other factors that weaken spread from their original site and cause damage to their defense against pathogens. various body systems or organs. This type of S infection can lead to severe illness and may involve Examples multiple body systems. INDIVIDUALS WITH WEAKENED IMMUNE SYSTEMS: Examples E PNEUMONIA: ▪ Patients undergoing chemotherapy, individuals with HIV/AIDS ▪ When a lung infection caused by bacteria ELDERLY INDIVIDUALS: (e.g., Streptococcus pneumoniae) or L viruses spreads into the bloodstream, it can ▪ Older adults with comorbidities UNVACCINATED INDIVIDUALS: lead to systemic symptoms like fever, chills, ▪ Those not vaccinated against diseases like and fatigue. Severe cases can result in measles or influenza sepsis, a life-threatening condition. 3. BACTEREMIA BREAKING THE CHAIN OF INFECTION Bacteremia is the presence of bacteria in the By understanding the chain of infection, healthcare bloodstream. This condition can be transient and may providers can implement strategies to break this not always lead to an infection or noticeable chain at any point. Here are some interventions: symptoms. INFECTIOUS AGENT: Examples Use antimicrobial agents or appropriate DENTAL PROCEDURES: vaccinations. ▪ Following certain dental procedures, such RESERVOIR: as tooth extraction, bacteria from the mouth can enter the bloodstream, leading Maintain hygiene and sanitation; isolate infected to bacteremia. While this may resolve individuals without treatment, it poses a risk for PORTAL OF EXIT: individuals with heart valve abnormalities. Cover wounds; ensure proper waste disposal; use masks for respiratory illnesses. 4. SEPTICEMIA MODE OF TRANSMISSION: Septicemia is a more serious condition that occurs Practice hand hygiene, use personal protective when bacteremia results in a systemic infection, equipment (PPE), and follow infection control leading to sepsis. It often causes severe and protocols. widespread inflammatory responses in the body. PORTAL OF ENTRY: Examples Maintain skin integrity; use aseptic techniques SEPSIS FROM URINARY TRACT INFECTION: during procedures. ▪ If a urinary tract infection (UTI) caused by SUSCEPTIBLE HOST: Escherichia coli spreads to the Vaccinate individuals; educate on healthy bloodstream, it can lead to septicemia. lifestyles and infection prevention measures. Symptoms may include high fever, increased heart rate, and confusion. Septicemia is a medical emergency that TYPES OF INFECTION requires immediate treatment. Infection occurs when newly introduced or resident microorganisms succeed in invading a part of the body where the host’s defense 5. ACUTE INFECTION mechanisms are ineffective and the pathogen An acute infection typically appears suddenly and causes tissue dam has a short duration. The immune response is rapid, and symptoms can be intense but resolve relatively 1. LOCAL INFECTION quickly. Examples MUCOUS MEMBRANCE: INFLUENZA Mucous membranes line the respiratory, ▪ The flu is an acute viral infection gastrointestinal, and urogenital tracts. They characterized by sudden onset of symptoms secrete mucus, which traps pathogens and debris. such as fever, chills, body aches, and For instance, in the respiratory tract, mucus traps fatigue. Most cases resolve within one to two dust and microbes, which are then cleared by cilia. weeks. CILIA: Hair-like structures in the respiratory tract that help to move mucus and trapped pathogens out of the 6. CHRONIC INFECTION airways. A chronic infection develops slowly and can persist for months or years. These infections may have CHEMICAL BARRIERS periods of exacerbation and remission, leading to ANTIMICROBIAL SECRETIONS: ongoing health issues. The skin secretes antimicrobial peptides and oils Examples that inhibit microbial growth. For instance, sebum HIV/AIDS: A produced by sebaceous glands has antibacterial ▪ Human Immunodeficiency Virus (HIV) is a properties. chronic infection that can remain K ACIDIC ENVIRONMENT: asymptomatic for years before progressing The stomach produces hydrochloric acid, creating to Acquired Immunodeficiency Syndrome an acidic environment that destroys pathogens (AIDS). Ongoing replication of the virus can lead to immunosuppression, making S ingested with food individuals vulnerable to opportunistic LYSOZYME: infections and other health complications. This enzyme is found in saliva, tears, and mucus E and can break down the cell walls of bacteria, effectively killing them. L LINE OF DEFENSES SECOND LINE OF DEFENSE: Innate Immune Response NON-SPECIFIC: First Line and Second Line The second line of defense is a non-specific immune SPECIFIC: response that activates when pathogens breach the Antibody Mediated and Cell-Mediated first line of defense. This response includes various immune cells and proteins that respond to infections. The body has a series of defenses, referred to as the lines of defense, that work to protect against CELLULAR DEFENSES pathogens and maintain overall health. These PHAGOCYTES: defenses are categorized into three main lines: the Cells such as neutrophils and macrophages engulf first line (physical and chemical barriers), the second and digest pathogens. For example, when a line (innate immune response), and the third line bacterial infection occurs, neutrophils are often the (adaptive immune response). Each line plays a first responders, moving to the site of infection to crucial role in the body’s ability to fend off infections engulf and destroy bacteria. and disease. NATURAL KILLER (NK) CELLS: These cells recognize and destroy infected or cancerous cells by releasing cytotoxic substances. NON-SPECIFIC INFLAMMATORY RESPONSE FIRST LINE OF DEFENSE: INFLAMMATION Physical and Chemical Barriers This is a localized response characterized by redness, heat, swelling, and pain. Inflammation The first line of defense includes physical and occurs when tissues are injured or infected, chemical barriers that prevent pathogens from leading to the release of signaling molecules (e.g., entering the body. histamines) that increase blood flow and attract immune cells to the site of infection. For example, in response to a sprained ankle, the area becomes PHYSICAL BARRIERS inflamed as blood vessels dilate and white blood SKIN: cells move to the area. The skin is the body’s largest organ and acts as a 1ST STAGE : VASCULAR AND CELLULAR physical barrier against pathogens. Its outer layer RESPONSES (epidermis) is tough and impermeable. For There is constriction of blood vessels, dilatation of example, a cut in the skin can allow pathogens to small vessels, increased vessel permeability, enter, which is why intact skin is crucial for increased leukocytes, swelling, and pain; protection. leukocytes begin to engulf the infection.  A 2ND STAGE : EXUDATE PRODUCTION 2. ACTIVATION OF T-CELLS: This stage is characterized by exudation with fluids K Once the T cells bind to their specific antigen-MHC and dead cells; serous (clear, part of the blood), complex, they become activated. purulent (thick, pus with leukocytes), and Activated cytotoxic T cells proliferate and sanguineous (bloody). S differentiate into effector cells that can kill infected 3RD STAGE : REPARATIVE PHASE cells. The repair of tissues; examples are regeneration Helper T cells release cytokines that further (same tissues), stroma (connective tissues), E activate other immune cells, enhancing the parenchyma (functional part), and fibrous (scar). immune response. L EXAMPLES: COMPLEMENT SYSTEM COMPLEMENT PROTEINS: VIRAL INFECTIONS: A group of proteins in the blood that can be Infections like HIV or influenza lead to the activated by pathogens. They enhance activation of CD8+ T cells that destroy virus- phagocytosis, promote inflammation, and can infected cells. directly kill bacteria by forming pores in their CANCER IMMUNITY: membranes. Cytotoxic T cells can recognize and kill tumor cells by identifying specific tumor antigens. Cell-mediated and antibody-mediated defenses are two critical components of the adaptive immune response. Both mechanisms work together to protect the body from infections and diseases caused by ANTIBODY-MEDIATED IMMUNITY various pathogens. Here’s a detailed overview of (HUMORAL IMMUNITY) each type, including their functions and examples. Antibody-mediated immunity, also known as humoral immunity, is primarily mediated by B lymphocytes (B cells) and involves the production SPECIFIC of antibodies. This type of immunity is crucial for defending against extracellular pathogens, such CELL-MEDIATED IMMUNITY (CMI) as bacteria and toxins. Cell-mediated immunity is primarily mediated by T lymphocytes (T cells) and does not involve KEY COMPONENTS: antibodies. This type of immunity is crucial for the B-CELLS: defense against intracellular pathogens, such as The main players in antibody-mediated immunity viruses and some bacteria, as well as cancer cells. include: PLASMA CELLS: KEY COMPONENTS: When B cells encounter their specific antigen, they T-CELLS: differentiate into plasma cells that secrete large The main players in cell-mediated immunity include: quantities of antibodies. CYTOTOXIC T CELLS (CD8+ T CELLS): MEMORY B CELLS: These cells directly kill infected or cancerous cells. Some B cells become memory cells after When a CD8+ T cell recognizes a specific antigen activation, which provide long-term immunity and presented by infected or malignant cells, it binds a rapid response upon re-exposure to the same to the cell and induces apoptosis (cell death). antigen. HELPER T CELLS (CD4+ T CELLS): These cells help regulate the immune response by releasing cytokines that activate other immune cells, including B cells, cytotoxic T cells, and macrophages. Helper T cells play a crucial role in orchestrating the overall immune response. MECHANISM: 1. ANTIGEN RECOGNITION: B cells have surface immunoglobulin (antibodies) that recognize and bind to specific antigens. MECHANISM: 2. ACTIVATION AND PROLIFERATION: 1. ANTIGEN PRESENTATION: Upon binding to an antigen, B cells require help Pathogen-derived antigens are presented on the from CD4+ T cells (via cytokines) for full surface of antigen-presenting cells (APCs) through activation and proliferation. major histocompatibility complex (MHC) molecules. 3. ANTIBODY PRODUCTION: MCH CLASS I Activated B cells differentiate into plasma cells Presents antigens from intracellular pathogens to that produce and secrete antibodies specific to CD8+ T cells. the antigen. MCH CLASS II 4. ANTIBODY FUNCTION: Presents antigens from extracellular pathogens to NEUTRALIZATION: CD4+ T cells.  Antibodies bind to pathogens and neutralize their STERILIZATION OF INSTRUMENTS: harmful effects (e.g., blocking a virus from entering All surgical instruments and equipment must be cells). sterilized using methods such as autoclaving OPSONIZATION: (steam under pressure), ethylene oxide gas, or Antibodies coat pathogens, making them more chemical sterilants. recognizable for phagocytes (e.g., macrophages) STERILE FIELDS to engulf and destroy. Creating and maintaining a sterile field using COMPLEMENT ACTIVATION: sterile drapes and covers during surgical Antibodies can activate the complement system, procedures to ensure that only sterile items come leading to the lysis of pathogens. into contact with the surgical site. PROPER GOWNING AND GLOVING: EXAMPLES: Surgical staff must wear sterile gowns, gloves, and BACTERIAL INFECTIONS: masks to prevent contamination during Infections caused by Streptococcus pneumoniae procedures. Gowns must be worn correctly to or Staphylococcus aureus stimulate B cells to ensure that the sterile side remains produce antibodies that help neutralize and uncontaminated. eliminate these bacteria. SKIN ANTISEPSIS VACCINATION: Preparing the patient's skin before surgery using Vaccines introduce antigens that stimulate the antiseptic solutions (e.g., chlorhexidine or iodine- immune system to produce antibodies, providing based solutions) to reduce the microbial load on immunity against diseases like measles or polio. the skin. ASEPSIS IMPORTANCE OF ASEPSIS Asepsis is defined as the absence of pathogenic 1. INFECTION PREVENTION: microorganisms or their toxins in a particular Aseptic techniques are essential for preventing environment or on a specific surface. The main healthcare-associated infections (HAIs), which goal of aseptic techniques is to prevent infection can lead to serious complications, prolonged and maintain a sterile environment during hospital stays, and increased healthcare costs. medical procedures, surgeries, and the handling 2. PATIENT SAFETY: of sterile instruments and supplies. By reducing the risk of infection, asepsis contributes to improved patient outcomes and TYPES OF ASEPSIS enhances overall safety during medical 1. MEDICAL ASEPSIS (CLEAN TECHNIQUE) procedures. Medical asepsis involves practices that reduce the 3. CONTAMINATION CONTROL: number and spread of pathogens. It is aimed at Aseptic practices help maintain the integrity of preventing the transfer of microorganisms from one sterile products, such as medications and surgical person, place, or object to another. supplies, preventing contamination that could EXAMPLES: compromise their effectiveness. HAND HYGIENE: Regular handwashing with soap and water or using alcohol-based hand sanitizers to eliminate KEY PRINCIPLES OF ASEPSIS pathogens on the hands. 1. STERILITY: USE OF PERSONAL PROTECTIVE EQUIPMENT (PPE): Maintaining a sterile environment is critical. Any Wearing gloves, masks, gowns, and eye breach in sterility can lead to infection. protection when dealing with patients or 2. CLEANLINESS: contaminated materials. Regular cleaning and disinfection of surfaces and ENVIRONMENTAL CLEANING: equipment help minimize the presence of Routine cleaning and disinfecting of surfaces, pathogens. equipment, and instruments in healthcare settings 3. PERSONAL HYGIENE: to minimize the risk of infection. Healthcare workers must adhere to strict hand ISOLATION PRECAUTION: hygiene practices to prevent the transmission of Implementing measures such as droplet, contact, infections. or airborne precautions to prevent the spread of 4. ENVIRONMENTAL CONTROL: infections from infected patients to others. The healthcare environment must be designed to reduce the risk of contamination (e.g., using 2. SURGICAL ASEPSIS (STERILE TECHNIQUE) negative pressure rooms for airborne infections). Surgical asepsis involves practices that maintain a sterile environment during surgical procedures to EXAMPLES IN PRACTICE prevent contamination by pathogens. It ensures that IN SURGERY: all instruments, equipment, and the surgical field are Surgeons and their teams follow strict aseptic free from microorganisms. techniques, including wearing sterile gowns and A EXAMPLES: K  gloves, to ensure a sterile field and prevent If a private room is not available, place the client postoperative infections. with another client who is infected with the same IN INJECTION PROCEDURES microorganism. Nurses and healthcare providers use aseptic Wear an N95 respirator mask when entering the techniques when administering injections, such as room of a client who is known to have or using alcohol swabs to clean the skin before suspected of having primary tuberculosis. injection and ensuring the use of sterile needles Susceptible people should not enter the room of and syringes. a client who has rubeola (measles) or varicella IN WOUND CARE: (chicken pox). Limit movement of client outside the room to When dressing wounds, healthcare providers essential purposes; place a surgical mask on the follow aseptic principles to avoid introducing client during transport. pathogens that could lead to infection. DROPLET PRECAUTIONS STANDARD PRECAUTIONS Use standard precautions as well as the following: Place client in private room. Standard precautions are used in the care of all If a private room is not available, place the client hospitalized individuals regardless of their diagnosis with another client who is infected with the same possible infection status. microorganism. Designed for all clients in the hospital. Wear a mask if working within 1 meter (3 ft) of the These precautions apply to (a) blood; (b) all body client. fluids, excretions, and secretions except sweat; Limit movement of client outside the room to (c) nonintact broken skin; and (d) mucous essential purposes; place a surgical mask on the membranes. client during transport. Designed to reduce risk of transmission of microorganisms from recognized and unrecognized sources. CONTACT PRECAUTIONS Perform hand hygiene after contact with blood, Use standard precautions as well as the following: body fluids, excretions, secretions, and Place client in private room. contaminated objects whether or not gloves are If a private room is not available, place the client worn. with another client who is infected with the same Wear clean gloves when touching blood, body microorganism. fluids, secretions, excretions, and contaminated Wear gloves as described in standard items. precautions. Wear a mask, eye protection, or face shield if Wear a gown when entering a room if there is a splashes or sprays of blood, body fluids, possibility of contact with infected surfaces or secretions, or excretions can be expected. items, or of the client is incontinent, or has Wear a clean, non-sterile, water-resistant gown if diarrhea, a colostomy, or wound drainage not client care is likely to result in splashes or sprays contained by a dressing. of blood, body fluids, secretions, or excretions; Limit movement of client outside the room. the gown is intended to protect clothing. Dedicate the use of noncritical client care Handle client care equipment that is soiled with equipment to a single client or to clients with the blood, body fluids, secretions, or excretions same infecting microorganisms. carefully to prevent transfer of microorganisms to others and to the environment. Handle all soiled linen as little as possible. Place used needles and other “sharps” directly into puncture resistant containers as soon as PERSONAL PROTECTIVE EQUIPMENT (PPE) their use is completed. All healthcare providers must apply PPE according to the risk of exposure to potentially infective materials. Transmission-based Precautions Transmission-based precautions are used in GLOVES addition to standard precautions for clients with Gloves are worn for three reasons: first they known or suspected infections that are spread in protect the hands when the nurse is likely to one of three ways: by airborne or droplet handle any body substances; second, gloves transmission, or by contact. reduce the likelihood of nurses transmitting their own endogenous microorganisms to individuals AIRBORNE PRECAUTIONS receiving care; and third, gloves reduce the Use standard precautions as well as the following: chance that the nurses’ hands will transmit Place client in an airborne infection isolation room microorganism to from one client or object to that has negative air pressure, 6 to 12 air another client. changes per hour, and either discharge of air to In all situations, gloves are changed between the outside or a filtration system for the room air. client contacts. The hands are cleansed each time the gloves are A removed for two primary reasons: (1) the gloves K  may have imperfections or be damaged during Sterile objects may become unsterile by prolonged wearing so that they could allow microorganism exposure to airborne microorganisms. entry; and (2) the hands may become Fluids flow in the direction of gravity. contaminated during glove removal. Moisture that passes through a sterile object draws microorganisms from unsterile surfaces GOWNS above or below to the sterile surface by capillary Clean or disposable impervious (water-resistant) action. gowns or plastic aprons are worn during The edges of a sterile field are considered procedures when the nurse’s uniform is likely to unsterile. become soiled. A The skin cannot be sterilized and is unsterile. Sterile gowns may be indicated when the nurse Conscientiousness, alertness, and honesty are changes the dressings of a client with extensive essential qualities in maintaining surgical asepsis. wounds. K Single-use gown technique (using a gown only once before it is discarded or laundered) is the usual practice at hospitals. S FACE MASKS Masks are worn to reduce the risk for transmission E of microorganisms by the droplet contact or airborne routes and by splatters of body substances. L The CDC recommends that masks be worn: By those close to the client if the infection is transmitted by large particle aerosols (droplet); large particle aerosols are transmitted by close contact and generally travel short distances (about 1 m or 3 ft). By all individuals entering the room if the infection is transmitted by small particle aerosols (droplet nuclei); small-particle aerosols remain suspended in the air and thus travel great distances in the air. EYE WEAR Protective eye wear (goggles, glasses, face shields) and masks are indicated in situations where body substances may splatter the face. If the nurse wear prescription eyeglasses, goggles must still be worn over the glasses because the protection must extend around the sides of the glasses. STERILE TECHNIQUE An object is sterile only when it is free of all microorganisms. It is well known that sterile technique is practiced in operating rooms and special diagnostic areas. Sterile technique is also employed for many procedures in general care areas such as when administering injections, changing wound dressings, performing urinary catheterization, and administering intravenous therapies. In these situations, all principles of the surgical asepsis are applied as in the operating or delivery room; however, not all of the sterile techniques that follow are always required. PRINCIPLES OF SURGICAL ASEPSIS All objects used in a sterile field must be sterile. Sterile objects become unsterile when touched by unsterile objects. Sterile objects that are out of sight or below the waist or table level are considered unsterile.