Infection Control and Isolation - Flashcards

Chain of Transmission

The transcript includes the heading “Chain of Transmission” but does not provide any detailed points or explanations in the excerpt provided. Future notes would expand this section to cover the typical components of transmission chains if supplied.

Susceptible Host: Risk Factors

Page 4 of the transcript poses the question: “What are some factors that would increase a patient's risk for being a susceptible host?” The excerpt does not list specific factors, so this note records the prompt without enumerating details.

Modes of Transmission

The material identifies two primary modes of transmission: Direct contact transmission and Indirect contact transmission. It shows an infection source (an infected individual) and a susceptible individual, and notes that transmission routes involving a combination of hand contact and contaminated surfaces constitute indirect contact. It also defines droplets and droplet nuclei as part of transmission: droplets with a diameter greater than >5 \ \mu m travel a short distance, and droplet nuclei with a diameter ≤5 μm\le 5 \ \mu m can travel farther.

  • Droplets: >5 \mu m diameter, travel ≤1m\le 1 \mathrm{m}.
  • Droplet nuclei: ≤5μm\le 5 \mu m diameter, travel > 1 \mathrm{m}.
  • The terms Airborne and Droplet are presented as distinct transmission categories.

Droplet and Airborne Transmission

Droplet transmission involves larger particles that travel through the air from the infectious host, typically due to actions such as sneezing, coughing, laughing, or talking. Airborne transmission involves small particles within the air that can carry infectious agents. Control measures include private rooms and negative air pressure for airborne cases.

  • Droplet transmission occurs when infectious droplets are expelled by an infected person through actions like sneezing, coughing, laughing, or talking.
  • Airborne transmission involves small particles that remain suspended and may require special room ventilation (private room and negative air pressure).
  • Control related to airborne pathogens includes using isolation rooms and engineering controls to limit dispersion.

Nonspecific vs. Specific Immunity

The transcript contrasts innate (nonspecific) immunity with adaptive (specific) immunity.

  • Innate Immunity: the first line of defense against pathogens, part of the inflammatory response, described as “barriers and general soldiers.”
  • Adaptive Immunity: a targeted, acquired defense that activates white blood cells to destroy infection, described as “trained sharpshooters with memory.”

Stages of Infection

The content outlines five stages of infection and provides a flu example to illustrate progression:

  • Incubation: A person is exposed to the flu yesterday, feels fine, but could be spreading it.
  • Prodromal: The person feels like they’re coming down with something.
  • Acute Illness: A high fever, productive cough, body aches, and chills indicate illness.
  • Period of Decline: Signs begin to improve; the patient is afebrile.
  • Period of Convalescence: The patient remains tired with a persistent dry cough but overall feels better.

Local vs. Systemic Infections

  • Local infection: Confined to one area and treated with topical and oral antibiotics, described as “Right There.”
  • Systemic infection: Spreads to the bloodstream or throughout the body, treated with IV antibiotics, described as “Everywhere.”

Medical Asepsis vs. Surgical Asepsis

  • Medical Asepsis (Clean technique): Daily care that reduces disease-causing organisms.
  • Surgical Asepsis (Sterile technique): Invasive procedures that protect the client from infection.

Sterilization vs. Disinfection

  • Sterilization: All micro-organisms, including bacterial spores, are eradicated. Methods include:
    • Thermal: autoclaving, dry steam
    • Chemical: ethylene glycol and hydrogen peroxide gas
    • Radiation: high-energy gamma rays
    • Note: The transcript lists three method categories with these examples.
    • Sterile fields aim for the smallest possible microbial presence.
  • Disinfection: Cleans so almost all micro-organisms are eradicated, but not all. Two levels:
    • High-level disinfection: some spores may remain
    • Low-level disinfection: most vegetative bacteria are destroyed, but some spores, bacteria, and fungi may remain

STANDARD PRECAUTIONS and ISOLATION PRECAUTIONS

  • Standard Precautions require the use of Personal Protective Equipment (PPE): masks, gloves, gowns, eye protection/shields, and other devices as needed. The material lists PPE items explicitly (mask, gloves, gown, goggles/face shield).
  • Contact Precautions: gown and gloves; additional PPE based on risk assessment.
  • Droplet Precautions: mask, goggles, gown, gloves; additional PPE as needed based on risk assessment.
  • Airborne Precautions: requires N95 respirator (or equivalent), goggles, gown, gloves; additional PPE per risk assessment. Door management and room type (Airborne Infection Isolation Room or single occupancy) are noted.
  • Key operational points include: post a sign for visitors to report to staff, clean hands before entering and after leaving, keep a two-meter distance between patients, and consult Infection Prevention & Control before discontinuing airborne precautions.
  • A recurring theme is the combination of standard precautions with additional precautions depending on the transmission type.

Protective Isolation

Protective isolation uses standard precautions and hand hygiene at all times and is specifically used for immunocompromised patients. The notes emphasize special room considerations such as prohibiting fresh fruits or plants in these rooms to reduce infection risk.

Health Care–Associated Infections (HAIs)

The transcript identifies common HAIs by acronym and category:

  • CLABSI: Central line-associated bloodstream infections
  • CAUTI: Catheter-associated urinary tract infections
  • SSI: Surgical-site infections
  • VAP: Ventilator-associated pneumonias