Chapter 28 Flashcards
why are patients in health care settings at risk for acquired infections?
because of lower resistance to pathogens; increased exposure to pathogens, some of
which may be resistant to most antibiotics; and invasive procedures
Infection
an invasion of a susceptible host by a pathogen or microorganisms resulting in disease or alteration of normal tissue function.
Colonization
the presence and growth of microorganism within a host but without tissue invasion or damage.
Communicable disease
Any disease that can be transmitted from one person or animal to another by direct or indirect contact or by vectors.
Symptomatic
pathogen that when multiply cause clinical signs and symptoms.
Asymptomatic
absence of symptoms or illness.
Chain of infection
An infectious agent or pathogen-> a reservoir or source for pathogen growth-> a port of exit from the reservoir-> a mode of transmission-> a port of entry to a host-> a susceptible host.
Virulence
ability to produce disease, and ability to enter and survive in the host, as well as the susceptibility of the host.
Immunocompromised
impaired immune system
transient microorganism
attaches to the skin when a person has contact with another person or object during normal activities.
reservoir
place where microorganism survive, multiply, and await transfer to a susceptible host.
two types of human reservoirs
- display acute or symptomatic disease
- carries that show no signs of disease
what do organism need to thrive?
proper environment, food, oxygen, water, temperature, PH, light
Aerobic
bacteria that requires oxygen for survival,
Anaerobic
needs little or no oxygen to thrive.
Port of Exit
sites such as blood, skin and mucous membranes, respiratory tract, genitourinary tract, gastrointestinal tract, and transplacental (mother to fetus)
modes of transmission
Direct- person to person (fecal, oral) physical contact between source and susceptible host (touching patient feces and then touching your inner mouth or consuming contaminated food)
Indirect- personal contact of susceptible host with contaminated inanimate object(needles or sharp object, dressings, environment)
droplet- large particles that travel up to 3 feet during coughing sneezing, or talking and come in contact with susceptible host.
airborne- droplet nuclei or residue or evaporated droplets suspended in air during coughing or sneezing or carried on dust particles.
vehicles- contaminated items, water, drugs, solutions, blood, food (improperly handled, stored, or cooked; fresh or thawed meats.)
vector- external mechanical transfer (flies) mosquitos, louse, flea, tick
course of infection
Incubation period- interval between entrance of pathogen into body and appearance of first symptoms.
Prodromal stage-interval from onset of nonspecific signs and symptoms to more specific symptoms
illness stage- interval when patient manifests signs and symptoms specific to type of infection
convalescence- interval when acute symptoms of infection disappear.
what is the major route of transmission for pathogens?
unwashed hand of health care works. other sources of transmission are equipment such as stethoscope, blood pressure cuff or bedside commode.
susceptibility
Individuals degree of Resistance to pathogens.
what are symptoms of a localized infection (wound infection)
pain, tenderness, and redness.
systemic
an infection that affects the body instead of just a single organ. fatal if undetected and untreated.
normal defenses against infection
skin,- provides barriers to microorganism and antibacterial activity
mouth,- provides mechanical barrier to microorganism.
eye,- provides mechanisms to reduce entry or assist in washing away particles containing pathogens, thus, reducing dose of organism.
respiratory tract,- traps inhales microbes and sweeps them outward in mucus to be expectorated or swallowed.
urinary tract,- washes away microorganism on lining of bladder and urethra.
gastrointestinal tract,-prevents retention of bacterial contents
vagina. -inhibit growth of many microorganism
normal floras
microorganism that normally reside on the surface and deep layers of skin, in the saliva and oral mucosa, and in the gastrointestinal and genitourinary the intestines.
