INFECTION CONTROL

LESSON 6 INFECTION CONTROL AND ISOLATION

Learning Objectives

  • Examine the elements of the chain of infection and the body’s defenses.

  • Describe the manifestations of an inflammatory response, local and systemic infections, and related diagnostic tests.

  • Relate principles of medical and surgical asepsis and their application to client care.

  • Differentiate between standard precautions and various types of isolation precautions.

  • Identify nursing interventions that can protect against infection.

Scope of Practice

  • Differences in scope of practice between RNs and PNs.

  • Engage Fundamentals provides PN practice considerations.

  • PN scope of practice varies by state:

    • In some states, PNs can contribute directly to a plan of care.

    • In other states, PNs may only assist RNs in developing care plans.

    • Most states require PNs to be under RN supervision.

  • PNs must know and abide by state guidelines for safe practice.

Introduction

  • Focus: Elements of the chain of infection and body’s defenses.

  • The body detects foreign infectious invaders and builds defenses.

  • Discussion of:

    • Body's defense mechanisms activated through inflammatory response.

    • Manifestations of local/systemic infections and diagnostic tests related to these responses.

Infection Control Principles

  • Nurses promote infection control by implementing:

    • Standard and specific precautions.

    • Treatments and interventions to break the chain of infection.

  • Detailed principles of medical and surgical asepsis in client care.

  • Identification of types of isolation precautions in health care.

  • Nurses support body’s defenses via infection control principles.

Chain of Infection

  • Definition: A sequence of factors needed for an infection to occur.

  • Components of the chain of infection:

    • Infectious Agent: Presence of a pathogen (bacteria, virus, fungus, parasite, prion).

    • Reservoir: The habitat where the infectious agent lives, grows, and multiplies (animate or inanimate).

    • Portal of Exit: Route by which the pathogen leaves the reservoir.

    • Mode of Transmission: How the pathogen is transmitted to the host.

    • Portal of Entry: Route through which the pathogen enters a susceptible host.

    • Susceptible Host: The person who can contract the infection.

  • Breaking any link in the chain can prevent the development of an infection.

Components of the Chain of Infection

1. Infectious Agent

  • Entities that cause infection (bacteria, viruses, fungi, parasites).

  • Resident flora can become infectious agents if relocated within the body.

  • To break this link, pathogens must be destroyed through:

    • Disinfecting

    • Sterilizing

    • Cleaning

    • Antimicrobial treatment (e.g., antibiotics)

2. Reservoir

  • Definition: Habitat of the infectious agent.

  • Types of Reservoirs:

    • Animate: Humans, animals, insects.

    • Inanimate: Contaminated soil, water, food, medical equipment.

  • Nurse actions to disrupt reservoirs:

    • Hand hygiene

    • Preoperative skin preparation

    • Proper cleansing of clinical environments

3. Portal of Exit

  • Definition: Route by which a pathogen leaves its reservoir.

  • Common portals of exit include body orifices and skin.

  • Examples include blood or body fluids moving out via gastrointestinal or respiratory tracts.

  • To break this link, measures to contain body fluids should be used (e.g., drains, dressings).

4. Mode of Transmission

  • Types of Transmission:

    • Contact: Direct or indirect contact with objects or people.

    • Droplet: Infection spread via droplets expelled during actions like coughing or sneezing.

    • Airborne: Infectious agents travel through air and may remain suspended.

    • Vehicle: Transmission from contaminated items (e.g., food, water).

    • Vector-Borne: Transmission through vectors like insects.

  • Breaking this link is achieved through proper hand hygiene and barrier devices.

5. Portal of Entry

  • Definition: The route through which the pathogen enters a susceptible host.

  • Common portals include breaks in skin and mucous membranes.

  • Example: Influenza virus can enter through the respiratory tract.

6. Susceptible Host

  • An individual whose health status increases vulnerability to infection.

  • Individual resistance influenced by:

    • Immunizations

    • Nutrition

    • Hygiene

    • Medical conditions (e.g., diabetes, cancer, chronic diseases)

  • Additional risk factors include age, underlying diseases, and certain medications that suppress immunity.

Modes of Transmission Detail

Contact Transmission

  • Types:

    • Direct Contact: Pathogens transferred directly from an infected person to another.

    • Example: Blood from an infected person touching an open wound on another.

    • Indirect Contact: Pathogens transmitted via contaminated objects.

    • Example: Staph infections spread by touching contaminated surfaces.

Droplet Transmission

  • Happens when infectious droplets are inhaled by others in proximity.

  • Pathogens involved: Influenza, pertussis, norovirus.

Airborne Transmission

  • Pathogens remain suspended in air and can travel greater distances.

  • Infections: Tuberculosis, measles, chickenpox.

  • Require private rooms with negative air pressure for infected clients.

Vehicle and Vector-Borne Transmission

  • Vehicle Transmission: Contamination of items (e.g., food, water) affecting multiple individuals.

  • Vector-Borne Transmission: Pathogens carried by vectors (e.g., mosquitoes).

Body Defenses

1. Physical and Chemical Barriers

  • Skin: Largest organ and primary defense against infection.

    • Functions include preventing dehydration and blocking entry of microorganisms.

    • Maintaining skin integrity is crucial; irritants and abrasives should be avoided.

  • Mucous Membranes: Produce mucus, protecting against invaders and maintaining moisture.

2. Nonspecific Immunity

  • Involves leukocytes such as neutrophils and macrophages that perform phagocytosis to eliminate pathogens.

3. Specific Immunity

  • Involves the action of antibodies and lymphocytes that target specific pathogens.

Inflammatory Response

  • Activation occurs in response to injury or pathogens.

  • Steps include:

    1. Recognition of harmful stimuli via pattern receptors.

    2. Activation of inflammatory pathways.

    3. Release of inflammatory markers (e.g., C-reactive protein).

    4. Recruitment of inflammatory cells (e.g., leukocytes, monocytes).

  • Triggered by infections and non-infections such as trauma or irritants.

  • Can lead to protective effects but also to tissue damage if chronic.

  • Common manifestations include heat, redness, swelling, pain, and loss of function.

Stages of Infection

  1. Incubation Stage: Pathogen enters body, client asymptomatic; duration varies.

  2. Prodromal Stage: Initial nonspecific manifestations.

  3. Acute Illness Stage: Specific disease manifestations; infection severe.

  4. Period of Decline: Symptoms start to reduce; client begins recovery.

  5. Period of Convalescence: Full recovery or potential lasting effects.

Types of Infection

Local Infections

  • Confined to one area; treated with topical or oral antibiotics.

Systemic Infections

  • Start locally but spread to bloodstream; require intravenous antibiotics and monitoring.

Diagnostic Tests

  • Utilized to detect disease based on client manifestations (e.g., urinalysis, throat cultures). Each test has protocols for collection and processing to ensure accuracy.

Infection Prevention and Control Measures

Hand Hygiene

  • Critical to reduce transmission risk; involves using soap and water or alcohol-based hand sanitizers, with specific timing protocols.

Medical and Surgical Asepsis

  • Medical Asepsis: Reducing pathogens, practiced with standard precautions.

  • Surgical Asepsis: Complete elimination of pathogens, used in surgical environments.

Isolation Precautions

  • Standard Precautions: Applied to all clients; protect against body fluids and materials.

  • Contact Precautions: For pathogens requiring contact isolation (e.g., VRE, Clostridioides difficile).

  • Droplet Precautions: Prevent droplet transmission (e.g., COVID-19, influenza).

  • Airborne Precautions: Requires negative pressure rooms for infections like tuberculosis.

  • Protective Isolation: For immunocompromised patients; specific environmental conditions needed.

Nursing Interventions Against Infections

  • Health care-associated infections (HAIs): Understood as infections from a healthcare environment, with key types identified (CLABSIs, CAUTIs, SSIs, VAPs).

  • Proper aseptic techniques are vital in managing invasive devices, thus reducing infection risk.

Education and Care Bundles

  • Infection Control Bundles: Set protocols combined for effective infection prevention (e.g., CLABSI, CAUTI, SSI prevention bundles).

Multidrug-Resistant Infections (MDROs)

  • Ensure precautions are followed to prevent transmission; examples include MRSA, VRE, and new resistance patterns seen.

PPE Guidelines

  • Awareness of proper PPE usage, types required for specific situations, and protocols for donning and doffing to avoid contamination events.

Client and Environmental Handling

  • Strict measures in handling linens, waste disposal, and maintaining a clean environment to prevent pathogen spread.

Needlestick Injury Prevention

  • Recommendations to avoid needlesticks, with a focus on safe needle handling procedures.

Summary

  • Infection control requires understanding the mechanisms of infection, implementing appropriate measures to prevent infection, and maintaining client safety through rigorous standards and care protocols.