Ch 28: Infection control Flashcards
chain of infection
- Infectious agent
- Reservoir
- Portal of exit
- Mode of transmission
- portal of entry
- host
Reservoir
A place where microorganisms survive, multiply, and await transfer to a susceptible host. Common: humans, animals, insects, food, water, and organic matter on inanimate surfaces. HAIs: health care workers, hands, patients, equipment, and environment
Port of exit
After microorganisms find a site to grow and multiply they need to find a port of exit if they are to enter another host and cause disease. Ex: blood, skin, mucous membranes, respiratory tract, genitourinary tract, gastrointestinal tract, and transplacental.
Modes of transmission
transmission from one to another: hands, equipment, droplet, direct contact.
Port of Entry
same as routes used for exiting
Susceptible Host
susceptibility to an infectious agent depends on the individuals degree of resistance to pathogens.
Modes of transmission: Contact
Direct: person to person contact between source and susceptible host
Indirect: personal contact of susceptible host with contaminated inanimate object (needles, dressings)
Modes of Transmission: Droplet/Airborne
Droplet: large particles that travel up to 3 ft during coughing, sneezing, talking with suseptible host
Airborne: droplet nuclei or residue or evaporated droplets suspended in air during coughing or sneezing or carried on dust particles
Modes of Transmission: Vehicles/ Vector
Vehicles: contaminated items, water, drugs, solutions, blood, feed
Vector: flies, mosquito, flea, tick
Course of infection by stage (4)
- Incubation Period: interval between entrance and pathogen into body and appearance of first symptoms
- Prodromal Stage: interval from onset of nonspecific signs and symptoms (malaise; low grade fever) to more specific symptoms. (microorg grow and multiply. pt may be capable of spreading disease to others.
- Illness Stage: interval when patient manifests signs and symptoms specific to type of infection.
- Convalescence: interval when acute symptoms of infection disappear.
Localized vs systemic infection
Localized: patient experiences localized symptoms such as pain, tendwerness, redness. (ie wound infection)
Systemic: an infection that affects the entire body instead of just a single organ or part. Can be fatal if undetected and untreated.
Iatrogenic infections
Are a type of HAI from a diagnostic or therapeutic procedure. Ex: procedures such as a bronchoscopy and treatment with broad-spectrum antibiotics increase the risk for certain infections.
Exogenous infection
comes from microorganisms found outside the individual such as salmonella, clostridium tetani, and aspergillus. They dont exist as normal floras.
Endogenous infections
occurs when part of the pts flora becomes altered and an overgrowth results. (staphylococci, enterococci, yeasts, and streptococci) Often happens when patient receives broadspectrum antibiotics that alter the normal floras.
Airborne Precautions
Droplet nuclei smaller than 5 microns. (measles, chickenpox, varicella zoster, TB) Private room, negative pressure airflow of at least 6-12 exchanges per hour via HEPA filtration; mask or respiratory protection device, n95.
