Chapter 26 Infection Control Copyright 2004 by Delmar

Chapter 26 Infection Control Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc.

Infection Control § Infection control practices are directed at controlling or eliminating sources of infection in the health care agency, home, or community. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 2

Pathogens, Infection, and Colonization § Pathogenicity is the ability of a microorganism to produce disease. § Microorganisms that cause diseases in humans are called pathogens. § Virulence is the degree of pathogenicity of an infection’s microorganism. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 3

Pathogens, Infection, and Colonization § Infection is an invasion and multiplication of microorganisms in body tissue that results in cellular injury. § These microorganisms are called infectious agents. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 4

Pathogens, Infection, and Colonization § Communicable Disease • The result of a communicable agent being transmitted to a client by direct or indirect contact, through a vehicle (or vector) or airborne route Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 5

Pathogens, Infection, and Colonization § Colonization is the multiplication of microorganisms on or within a host that does not result in cellular injury. § Flora are the vegetation of microorganisms on the human body. • Resident flora • Transient flora Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 6

Agent, Host, and Environment § Agents capable of causing disease: • Biological agents • Chemical agents • Physical agents Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 7

Agent, Host, and Environment § A host is a simple or complex organism that can be affected by an agent. • A susceptible host is a person who lacks resistance to an agent. • A compromised host is a person whose normal defense mechanisms are impaired and who is therefore susceptible to infection. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 8

Agent, Host and Environment § The environment consists of everything other than the agent and host. • • • Water, food, plants, animals Housing conditions Noise Meteorological conditions Environmental chemicals Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 9

Chain of Infection § § § Microorganism (infectious agent) Source or reservoir Portal of exit from reservoir Mode of transmission Portal of entry into host Susceptible host Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 10

Infectious Agents (Microorganisms) § Agents that produce infections can consist of bacteria, viruses, fungi, protozoa, and rickettsia Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 11

Infectious Agents § The ability of a microorganism to infect a client is related to: • Virulence of the agent • Number of microorganisms present • Ability of the agent to enter and live in the client • Susceptibility of the client Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 12

Infectious Agents § Resident Infectious Agents • Microorganisms which are always present on skin. • Can be reduced through handwashing, but not totally removed. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 13

Infectious Agents § Transient Infectious Agents • Agents that are picked up by the skin from another person or object. • Attach themselves to the skin and then may be transmitted to a susceptible host. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 14

Source or Reservoir § Required for the microorganism to survive while awaiting a host. § May allow the organism to multiply, making it more dangerous. • The human body is the most common reservoir. • Food, plants, animals, and feces are other common reservoirs. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 15

Portal of Exit § Pathway by which pathogens leave the body of a host. Accessed by: • Direct Contact • Indirect Contact • Airborne Transmission Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 16

Portal of Exit § Direct Contact • Transmission of disease from the host • Touching, kissing, and sexual intercourse § Sources of Direct Contact • Skin, mucus membranes, urine, feces, reproductive tract, blood Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 17

Portal of Exit § Indirect Contact • Occurs with the use of vehicles and vectors § Vehicles (fomites) • Toys, hospital supplies, instruments, dishes, cups, or surgical dressings, food, fluids, blood Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 18

Portal of Exit § Airborne Transmission • Transmission of infectious agents through coughing, sneezing, dust particles • Usually entry via the person’s respiratory tract Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 19

Portal of Entry § Pathway by which infectious agents gain access to the body Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 20

Susceptible Host § A person with a reduced immune response has increased susceptibility. § The immune response is the body’s natural defense against infection. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 21

Factors Influencing Production of an Infectious Disease § § § Age Heredity Stress Surgery Nutrition Health Status Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 22

Factors Influencing Production of an Infectious Disease § Age • The elderly and children under two years of age are at greatest risk. § Heredity • Conditions or diseases resulting in the absence of or inability to form immune defenses. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 23

Factors Influencing Production of an Infectious Disease § Stress • Increase in metabolic rate which results in using up stored energy • Elevation of blood cortisol, decreasing antiinflammatory responses • Continued stress produces exhaustion, further depleting ability to ward off infection. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 24

Factors Influencing Production of an Infectious Disease § Surgery • Eliminates primary barrier of infection. • Predisposes clients to surgical site infections. • Localized infection at wound site can progress to a systemic infection. • Additional risks include catheters and tubes. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 25

Factors Influencing Production of an Infectious Disease § Nutrition • Insufficient protein consumption reduces antibody production and inhibits the body’s ability to ward off infection. § Health Status • Clients with disease of their immune system are at greater risk. • Chronic diseases can predispose the client to infection. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 26

Normal Defense Mechanisms § Nonspecific and specific immune defenses work in harmony to defend the host from pathogens. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 27

Normal Defense Mechanisms § Nonspecific Immune Defenses • Protect the host from all microorganisms • Not dependent on prior exposure to the antigen Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 28

Nonspecific Immune Defenses § § § § Skin and Normal Flora Mucous Membranes Sneeze, Cough Reflexes Tearing Reflexes Elimination Acidic Environment Inflammatory Response Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 29

Nonspecific Immune Defenses § Skin • Intact skin is the body’s first line of defense against infection. • Sebum is produced by the skin and contains fatty acids that kill some bacteria. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 30

Nonspecific Immune Defenses § Normal Flora • Normal flora residing on the skin compete with pathogenic flora for food and inhibit their multiplication. • Inappropriate antibiotic use may disrupt the balance of normal flora. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 31

Nonspecific Immune Defenses § Mucous Membranes • Mucus entraps infectious agents and contains substances that inhibit bacterial growth. • Cilia trap and propel mucus and microorganisms away from the lungs. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 32

Nonspecific Immune Defenses § Sneeze and Cough Reflexes • Physically expel mucus and microorganisms from the respiratory tract and oral cavity with force § Tearing Reflex • Protects the eyes by continually flushing away microorganisms Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 33

Nonspecific Immune Defenses § Elimination Patterns and Acidic Environment • • Resident flora of the large intestines Mechanical process of defecation Flushing action of urination Acidic environment of urine and vagina Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 34

Nonspecific Immune Defenses § Inflammatory Response • Tissue injury caused by bacteria, trauma, chemicals, heat, or any other phenomenon • Release of substances that produce secondary changes in the tissue Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 35

Specific Immune Defense (The Immune Responses) § Immunity is a specific defense mechanism that creates an immune response to a specific invading antigen. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 36

Specific Immune Defense (The Immune Responses) § Immune Responses • • • Active immunity Passive immunity Acquired immunity Natural immunity Artificial immunity Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 37

Immune Responses § Active immunity results from the development within the body of antibodies that neutralize the infective agent. § Passive immunity is acquired by the introduction of preformed antibodies. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 38

Immune Responses § Acquired immunity results either from exposure to an antigen or from the passive injection of immunoglobulins. § Natural immunity refers to the genetically determined response of protection within a specific species. § Artificial immunity is produced following a vaccine. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 39

The Humoral Immune Response § B lymphocytes recognize the antigen as an enemy. § Immunoglobulins are plasma protein cells that produce five different classes of antibodies (Ig. M, Ig. G, Ig. A, Ig. D, and Ig. E). § Immunoglobulins circulate throughout the bloodstream for the purpose of destroying antigens. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 40

Cell-Mediated Immunity § Fights pathogens that survive inside cells. § Antigen stimulates the release of activated T cells. • T-helper cells • T-suppressor cells • T-cytotoxic cells Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 41

Localized Versus Systemic Infections § Infection results from tissue invasion and damage by an infectious agent. • Localized infections are limited to a defined area or single organ. • Systemic infections affect the entire body and involve multiple organs. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 42

Four Stages of Infection § § Incubation Prodromal Illness Convalescence Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 43

Nosocomial Infections § Infections acquired in a health care setting that were not present or incubating at the time of the client’s admission Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 44

Common Sites of Nosocomial Infections § Urinary tract § Surgical sites § Respiratory tract Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 45

Nosocomial Infections § Procedures identified as possible sources of infection are: • • • Inadequate handwashing Catheterization technique Improper suctioning technique Improper dressing-change technique Contamination of closed drain system Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 46

Infection Chain § Breaking the chain of infection; preventive measures follow each critical link in the chain of infection. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 47

Asepsis § Asepsis is the absence of microorganisms. § Aseptic technique is the infection control practice used to prevent the transmission of pathogens. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 48

Medical Asepsis (Clean Technique) § Practices to reduce the number, growth, and spread of microorganisms • The most common cause of nosocomial infections is contaminated hands of health care providers. • Wash hands before and after every client contact. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 49

Surgical Asepsis (Sterile Technique) § Practices that eliminate all microorganisms and spores from an object or area • • Surgical scrub Surgical attire Sterile fields Sterile instruments and equipment Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 50

Reduce or Eliminate Infectious Agents § Infection control practices to break the chain of infection • Cleansing • Disinfection • Sterilization Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 51

Reduce or Eliminate Infectious Agents § Cleansing • Removal of soil or organic material from instruments and equipment used in providing care • Water, mechanical action, detergent Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 52

Reduce or Eliminate Infectious Agents § Disinfection • Elimination of pathogens, except spores, from inanimate objects • Use of germicides and antiseptics. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 53

Reduce or Eliminate Infectious Agents § Sterilization • Methods used for total elimination of all microorganisms including spores are: - Moist heat or steam (autoclave, boiling water) Radiation Chemicals Ethylene oxide gas Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 54

Reduce or Eliminate Infectious Agents § Home Health Care Considerations • Adapting acute care infection control practice to the home care setting involves: - Cleaning and disinfecting equipment - Using clean versus sterile technique - Handling of the nursing supply bag Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 55

Reduce or Eliminate Infectious Agents § Disposal of Infectious Waste in the Home § Biological Hazard Symbol § OSHA Regulations Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 56

Guidelines for Standards Precautions § Barrier Precautions • Use of masks, gowns, and gloves to minimize the risk of exposure to blood and body fluids Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 57

Guidelines for Standards Precautions § Body Substances • • Blood All body fluids Secretions Contaminated items regardless of whether or not they contain visible blood • Nonintact skin • Mucous membranes Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 58

Role of Health Care Personnel and Health Agencies in Infection Control § § Mask and eye protection or face shield Non-sterile gown Tuberculosis masks Isolation precautions initiated when positive cultures from a draining wound are reported Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 59

Role of Health Care Personnel and Health Agencies in Infection Control § This nurse is interacting with a client who requires isolation precautions. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 60

Role of Health Care Personnel and Health Agencies in Infection Control § § Reinforce adherence to isolation. Post signs indicating type of isolation. Provide necessary supplies. Place clients in a private room with adequate ventilation. § Use disposable supplies and equipment. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 61

Role of Health Care Personnel and Health Agencies in Infection Control § Labeling of all articles leaving the room § Use of impermeable bags or double bagging § Client and family instruction § Alert to psychological discomfort Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 62

Role of Health Care Personnel and Health Agencies in Infection Control § Blood Borne Pathogen Exposure • OSHA requires that all health agencies make available the hepatitis B vaccine and vaccination series to all employees. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 63

Role of Health Care Personnel and Health Agencies in Infection Control § Exposure Control Plan • Begins with standard precautions and moves to postexposure prophylaxis • Specific follow-up for blood-borne pathogens • Postexposure prophylaxis only in cases of highest risk Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 64

Alternative Therapies Used to Treat Infections § Herbal Products • Antimicrobial action • Augment and vitalize the body’s own defenses § Client’s alternative practices should be documented. § Possible adverse reactions are possible when used with prescribed drugs. Copyright 2004 by Delmar Learning, a division of Thomson Learning, Inc. 65