ch.14 Flashcards
mutualism
both organisms benefit, for example bacteria in the human colon
commensalism
one benefits and the other is indifferent, for example, mites in human hair follicles
amensalism
one is harmed and the other is indifferent, fungus secreting an antibiotic
parasitism
one benefits and the other is harmed, tuberculosis in human lung
microbiota
organisms that colonize the bodys surface without normally causing disease
resident microbiota
obtained during first month of life, in birth canal, don’t normally cause disease unless there is a immunodeficiency and they become opportunistic infection
transient microbiota
typically leaves after days
antimicrobial antagonism
resident microbiota can turn on transient microbiota by giving them no space, no nutrients, changing the pH
opportunistic pathogens
normal microbiota that causes disease under certain circumstances
reservoirs
sites where pathogens are maintained as a source of infection
contamination
the mere presence of microbes in or on the body, does not cause disease
infection
when organisms evades body external defenses, multiplies, and becomes established in the body
portals of entry and exit
sites through which pathogens enter and leave the body
the three major pathways are the skin, placenta, and mucous membranes
When does disease result?
if the invading pathogens alters normal body functions
symptoms
subjective characteristics of disease only felt by patient (pain, headache,dizziness)
signs
objective manifestations of disease observed or measured by others (fever, anemia, swelling)
syndrome
symptoms and signs that characterize a disease or an abnormal condition
incubation
contamination
organisms are growing
prodromal
vague symptoms and most infectious
illness
most severe signs and symptoms
decline
signs and symptoms start lessening
convalesence
recovery
contact transmission
direct, indirect, droplet
vehicle
airborne, waterborne, food borne
vector
mechanical and biological
incidence
number of new cases of a disease in a given area during a given period of time
prevalence
number of total cases
incidence rate
number of new cases/number of people at risk
prevalence rate
number of old and new cases/number of people at risk
endemic
normal for a specific area(malaria)
epidemic
high number of cases for a limited area, cluster
descriptive epidemiology
record location and times of cases of disease and collect patient information, try to find the index case of the disease
index case
the first case of a disease
analytical epidemiology
determines probable cause, modes of transmission, can be used when Koch’s postulates cant be applied
retrospective
investigation occurs after an outbreak has occurred
experimental epidemiology
tests a hypothesis concerning the cause of a disease, use koch’s postulates
exogenous
pathogen acquired from the health care environment
endogenous
pathogen arises from normal microbiota within the patient
iatrogenic
illness occurs after treatment or procedures
superinfections
use of antimicrobial drugs inhibits some resident microbiota, allowing other microbes to thrive
nosocomial
infections originating from the hospital
medical asepsis
good housekeeping, handwashing, bathing
surgical asepsis
cleansing of the surgical field, use of sterile instruments
