Fundamentals: Chapter 28 Flashcards
What is an infection?
the invasion of a susceptible host by pathogens or microorganisms, resulting in disease
What is colonization?
the presence and growth of microorganisms within a host but without tissue invasion or damage
What is a communicable disease?
an infectious disease that can be transmitted directly from one person to another
What is a symptomatic infection?
the pathogens multiply and cause clinical signs and symptoms
What is an asymptomatic infection?
the pathogens multiply but clinical signs and symptoms are not present
What is the chain of infection?
- An infectious agent
- A reservoir (natural habitat)
- A port of exit
- A mode of transmission
- A port of entry
- A susceptible host
What are microorganisms?
bacteria, viruses, fungi, and protozoa
What is a reservoir?
a place where microorganisms survive, multiply, and await transfer to a susceptible host
What is the ideal temperature for most human pathogens?
20° to 43° C (68° to 109° F)
What is bactericidal?
A temperature or chemical that destroys bacteria
What is bacteriostasis?
the slowing of growth and reproduction of bacteria
What pH do most microorganisms prefer?
5.0 to 7.0
List different modes of transmission:
Contact (direct or indirect)
Droplet
Airborne
Vehicles
Vector
What is droplet contamination?
Large particles that travel up to 3 feet during coughing, sneezing, or talking and come in contact with susceptible host
What is airborne contamination?
Droplet nuclei or residue or evaporated droplets suspended in air during coughing or sneezing or carried on dust particles
What are the stages of infection?
Incubation Period
Prodromal Stage
Illness Stage (Full Stage of illness)
Convalescence
Describe the incubation period of infection
Interval between entrance of pathogen into body and appearance of first symptoms (organism grows and mulitplies; time varies)
Describe the prodromol stage of infection
Interval from onset of nonspecific signs and symptoms to more specific symptoms
Describe the illness stage of infection
Interval when patient manifests signs and symptoms specific to type of infection
Describe the convalescence stage of infection
Interval when acute symptoms of infection disappear (time varies)
What is the difference between a localized infection and a systemic infection?
In a localized infection, the patient usually experiences localized symptoms such as pain, tenderness, and redness at the wound site.
In a systemic infection, the entire body instead of just a single organ or part is affected.
What is micturation?
urination
What causes a suprainfection?
develops when broad-spectrum antibiotics eliminate a wide range of normal flora organisms, not just those causing infection
What is inflammation?
The cellular response of the body to injury, infection, or irritation (brings fluid, blood products, and nutrients)
What happens during the inflammatory response?
1 Vascular and cellular responses
2 Formation of inflammatory exudates
3 Tissue repair
What are exudates?
fluid and cells that are discharged from cells or blood vessels [e.g., pus or serum]
What is phaygocytosis?
a process that involves the destruction and absorption of bacteria
What is leukocytosis?
an increase in the number of circulating WBCs
What is the normal range for serum WBC?
5,000 to 10,000/mm3
What is the range for serum WBC during inflammation?
15,000 to 20,000/mm3 and higher
What is the cause of fever during an infection?
the phagocytic release of pyrogens from bacterial cells, which causes a rise in the hypothalamic set point
What are the 3 types of exudate?
serous (clear, like plasma)
sanguineous (containing red blood cells)
purulent (containing WBCs and bacteria)
How is exudate usually cleared away?
lymphatic drainage
What are the 3 healing stages in tissue repair?
defensive, reconstructive, and maturative
What are iatrogenic infections?
a type of HAI from a diagnostic or therapeutic procedure
What are exogenous infections?
comes from microorganisms found outside the individual
What are endogenous infections?
part of the patient’s flora becomes altered and an overgrowth results
What are major sites for HAI’s?
surgical or traumatic wounds, urinary and respiratory tracts, and the bloodstream
What is the term for an age-related decline in immune system function?
immune senescence
What is the most common cause of communicable illness in young or middle-age adults
Viruses
How does a patient’s nutrition influence the susceptibility to infections?
A reduction in the intake of protein and other nutrients such as carbohydrates and fats reduces body defenses against infection and impairs wound healing
How does stress influence the susceptibility to infections?
If stress continues or becomes intense, elevated cortisone levels result in decreased resistance to infection
What is a sign of a pulmonary infection?
a productive cough with purulent sputum
What is a sign of a UTI?
cloudy, foul-smelling urine
What is aseptic technique?
practices/procedures that help reduce the risk for infection
What is medical asepsis
clean technique, includes procedures for reducing the number of organisms present and preventing the transfer of organisms
What is isolation?
the separation and restriction of movement of ill persons with contagious diseases
What is surgical asepsis?
sterile technique prevents contamination of an open wound, serves to isolate the operative area from the unsterile environment, and maintains a sterile field for surgery
What is the difference between colonization and infection?
colonization is normal and infection is an out of control growth
What is an example of communicable disease that is asymptomatic?
Hepatitis C
What is the best way to stop the chain of infection?
Break one of the links in the chain
What laboratory data indicate infection?
Elevated WBC
Increase in specific types of WBC
Elevated erythrocyte sedimentation rate
Presence of pathogen in urine blood, sputum or during cultures
What are normal floras?
microorganisms on skin surface, deep layers of skin, saliva, oral mucosa, GI & GU tracts
What are the 3 normal defenses against infection?
Normal Flora
Body System Defenses
Inflammation
What is the difference between transient and resident bacteria?
Transient are passed from person to person and do not normally reside on person. Resident bacteria are normal flora
