Chapter 14 Flashcards
Infection, Disease, and Epidemiology
Symbiosis def
to live together
microbiome def
symbiotic relationships with countless organisms
mutualism + or 0 or -
+ and +
commensalism + or - or 0
+ and 0
amensalism + or - or 0
.- and 0
parasitism 0 or - or +
+ and -
6 steps of the chain of infection
pathogen
reservoir
portal of exit
mode of transmission
portal of entry
susceptible host
reservoirs def
of infection are sites that maintains pathogens and are a source of infection
animal reservoir def
diseases that naturally spread from animal host to humans
human reservoirs def
asymptomatic carriers have the potential for more spreading
nonliving reservoirs def
soil water and food etc.
originate from contamination of feces
what are the 3 types of transmission
contact, vehicle, and vector
portals of exit ex
eyes nose mouth skin ears anus urethra
3 forms of contact transmission
direct, indirect, droplet
direct contact def
body contact btwen hosts
droplet transmission def
droplets of mucus in a close proximity
indirect contact def
spread via fomites , those are nonliving objects
vehicle transmission types
airborne, waterborne, food borne, bodily fluid
airborne ex
pathogens travel via aerosol
waterborne ex
many GI diseasesf
food borne ex
inadequate processing or storage
bodily fluid ex
blood, urine, and saliva can carry pathogens
biological vectors do what
transmit pathogens and serve as host for some stage of the pathogens life cycle
ex of a vector transmision
biological vectors which are like mosquitos
3 main portals of entry
skin
mucous membranes (respitory and GI)
placenta
pathogenicity def
ability of a microorganism to cause disease
virulence def
degree of pathogenicity
virulence factor def
strategy or product employed by pathogen to cause infection
ex of virulence factors
adhesion, extracellular enzyems, toxins, antiphagocytic factors
adhesion establishes what
colonies within the host
what do attachment proteins help in
adhesion
what do some bacterial or fugal pathogens attach to each other to form
biofilm
what are extra cellular enzymes secreted by
by the pathogen
what do extracellular enzymes help the pathogen do
invade the hose, advoid immune system , and contribute to virulence
are toxins or extracellular enzymes always proteins
extracellular enzymes
toxins harm what
tissues. or they trigger host immune responses that cause damagee
phagocytosis def
engulfment by a host cell
antiphagocytic factos def
prevent phagocytosis, therefore virulence factors
bacterial capsule do what
prevent recognition of pathogen and they are slippery and hard to engulf
antiphagocytic chemicals do what
prevent fusion of lysosome and phagocytic vesicles
and lysosome has enzymes that degrade proteins
symptoms def
subjective characteristics felt by the patient
signs def
objective manifestations of desease observed or measured by others
what are the 5 infection stages
incubation, prodromal, illness, decline, convalescenece
review each of the 5 stages of infection
no s or s, vague sympt, severs s and s, declining s and s, no signs of s or s
epidemiology def
the study of where and when disease occur, and how they are transmitted within populations
morbidity is what
of ppl getting sick/ total population %
mortality is what
of deaths/ total ppl sick %
john snow is the father of what
epidemiological studies (in london)
hospital epidemiology (HAI is what)
Healthcare associated infections
are HAI common
very common
whats the most effective way to reduce HAI
handwashing
