Chapter 34: Infection Control

Vocabulary flashcards covering infection control, modes of transmission, asepsis techniques, and isolation precautions.

Infection

The entry and multiplication of an infectious agent in the tissues of a host.

Pathogen

An infectious agent or microorganism capable of producing a disease in a host.

Colonization

The presence and growth of microorganisms within a host without tissue invasion or disease production.

Communicable Disease

An infectious disease or process that can be transmitted directly or indirectly from one person to another.

Virulence

A measure of the severity of the disease caused by an infectious agent once infection occurs.

Infectiousness (Transmissibility)

The ease or speed with which an infectious pathogen spreads from person to person.

Chain of Infection

A continuous sequence of six interconnected links required for infection to occur: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.

Reservoir

A place where a pathogen survives and may or may not multiply, requiring food, water, proper temperature, pH, and minimal light.

Portal of Exit

The route by which a pathogen leaves the reservoir, such as body openings, broken skin, or breaks in mucous membranes.

Portal of Entry

The path through which an infectious organism enters a host, typically through the skin, respiratory tract, urinary tract, gastrointestinal tract, reproductive tract, or blood.

Susceptible Host

A person at risk of developing an infection due to a lack of immunity or decreased physiological resistance.

Direct Contact Transmission

Pathogen transmission that occurs via physical contact between the source person and a susceptible host.

Indirect Contact Transmission

Pathogen transmission occurring when a susceptible host touches a contaminated intermediary object or surface that an infected person touched.

Vehicle Transmission

The transmission of pathogens via a non-living contaminated substance or item, such as contaminated water, food, or equipment.

Vector Transmission

The transmission of pathogens by an intermediate living organism, such as a mosquito or flea.

Droplet Transmission

The spread of infection through respiratory particles larger than $5\,\mu\text{m}$ that travel approximately $1\text{ to }2\,\text{metres}$ before dropping to surfaces.

Airborne Transmission

Pathogen spread occurring via small respiratory droplet nuclei smaller than $5\,\mu\text{m}$ that remain suspended in air currents over long periods and distances.

Incubation Period

The interval between the initial entrance of a pathogen into the body and the appearance of the first symptoms.

Prodromal Stage

The interval from the onset of vague, nonspecific signs and symptoms (such as malaise, fatigue, and low-grade fever) to more specific manifestations, during which pathogens multiply.

Illness Stage

The interval when a patient manifests signs and symptoms specific to the particular type of infection.

Convalescence

The interval during which acute infection symptoms resolve and the body works to replenish resources and regain homeostasis.

Health Care–Associated Infection (HAI)

An infection acquired during healthcare delivery in a facility, with inadequate hand washing being the leading cause (also termed nosocomial infection).

Iatrogenic Infection

A type of healthcare-associated infection directly caused by an invasive diagnostic or therapeutic procedure.

Exogenous Infection

An infection originating from microorganisms outside the patient that are not part of their normal microbial flora.

Endogenous Infection

An infection that occurs when a patient's normal body flora is altered, leading to opportunistic bacterial or fungal overgrowth.

General Adaptation Syndrome (GAS)

Hans Selye's stress model describing three predictable stages of physical defense: Alarm reaction, Resistance, and Exhaustion.

Alarm Reaction

The first phase of GAS wherein the sympathetic nervous system (SNS) mobilizes bodily resources to prepare for a fight-or-flight response to a stressor.

Resistance Stage

The second phase of GAS wherein the body stabilizes and attempts to adapt to the stressor through activation of the hypothalamic-pituitary-adrenal (HPA) axis.

Exhaustion Stage

The third phase of GAS where prolonged stress depletes physiological coping reserves, leading to breakdown and diseases of adaptation.

Localized Infection

An infection restricted to a specific body location characterized by local redness, edema, warmth, pain, drainage, and functional impairment.

Systemic Infection

An infection that spreads through the bloodstream or lymphatic system, producing generalized manifestations such as fever, fatigue, malaise, and altered vital signs.

ADPIE

An acronym representing the five sequential steps of the nursing process: Assessment, Diagnosis, Planning, Implementation, and Evaluation.

Medical Asepsis

Clean technique procedures designed to reduce the overall number of pathogens and prevent their transmission (e.g., handwashing, clean barrier use).

Surgical Asepsis

Sterile technique procedures implemented to completely eliminate all microorganisms, including bacterial spores, from an area or object.

Disinfection

The elimination of virtually all pathogenic microorganisms on inanimate objects, excluding bacterial spores, using heat, chemicals, or UV light.

Sterilization

The validated process that destroys all forms of microbial life, including spores, using pressurized steam, ethylene oxide gas, or chemical plasma.

Routine Practices

Infection control measures applied during all patient care interactions involving potential contact with blood, all body fluids (except sweat), nonintact skin, or mucous membranes.

Contact Precautions

Isolation guidelines requiring gown and gloves upon entering the room and dedicated or disinfected patient-care equipment for pathogens such as MRSA, VRE, and C. difficile.

Droplet Precautions

Isolation guidelines requiring a mask and eye protection within $2\,\text{metres}$ of the patient, as well as a gown and gloves upon entry, for diseases spread by large respiratory droplets.

Airborne Precautions

Isolation guidelines requiring a negative pressure room with the door kept closed and an N95 respirator fit-tested and seal-checked prior to entry.

Reverse Isolation

Protective isolation precautions used to shield severely immunocompromised patients from environmental and personnel-borne microorganisms.

4 Moments of Hand Hygiene

The four clinical indications for hand hygiene: 1. Before initial patient/environment contact; 2. Before an aseptic procedure; 3. After body fluid exposure risk; 4. After patient/environment contact.

Donning PPE Sequence

The established protocol for putting on personal protective equipment: 1. Hand hygiene; 2. Gown; 3. Mask or N95 respirator; 4. Eye protection; 5. Gloves.

Doffing PPE Sequence

The established protocol for removing personal protective equipment to prevent self-contamination: 1. Gloves; 2. Gown; 3. Hand hygiene; 4. Eye protection; 5. Mask or N95 respirator; 6. Hand hygiene.

Open Gloving

A technique of donning sterile gloves used on general nursing units for sterile procedures without wearing a sterile gown, such as dressing changes and urinary catheterizations.

Closed Gloving

A technique of applying sterile gloves over the cuffs of a sterile gown, performed primarily in surgical operating rooms.