chap 14 Flashcards
(44 cards)
infection v. disease
infection - process of getting the disease
disease - actual process of sickness
virulence v. pathogenicity
virulence - harmfulness
pathogenicity - how agent causes disease
normal microbiota
bacteria in the human body
- microbes colonize nonsterile areas/areas exposed to
environment(skin, oral and nasal cavities, lung)
comes from birth(while coming out pick up normal microbiota)
what does the presence of bacteria in sterile areas signal?
infection
transient microbiota
microorganisms that are only temporarily found in the human body
- ex pathogens
how does normal microbiota help defend against other infections?
- normal microbiota exhibit microbial antagonism/competitive exclusion
- occupy space, compete for nutrients, produce agents, modify the microenvironment
what type of relationship does host and normal microbiota have?
typically commensalism(one benefit and one is fine)
what is mutualism and paratism?
mutualism - both benefit
parasitism - one benefit one harmed
opportunistic pathogens
normally not harmful but when compromised can cause diesease
opportunistic pathogens v primary pathogens
opportunistic - normally not harmful but when compromised can cause disease
primary - not usually in body but if inside will always try to cause disease
koch’s postulates
- same pathogen present in all cases
- isolation of pathogen(pure culture)
- give pure culture to susceptible host
- re-isolate now sick host
exceptions to koch’s postulates
- healthy individual can carry and show asymptomatic
- some microbes not culturable
- similar symptoms and diseases can be from same
pathogen - same pathogen can cause different diseases
- viruses cant be cultured, some have no animal host, and
some are latent
symptoms vs. signs
symptoms - subjective (malaise, headache, dry throat)
signs - objective (measurable, fever, rash, swelling)
syndrome
group of signs and symptoms that occur together and characterize a condition
communicable disease
can directly/indirectly spread from host to host (measles, chickenpox, flu, std)
non communicable disease
can not spread from host to host (tetanus)
contagious disease
can easily spread from person to person
incidence vs. prevalence
incidence - rate of people that get disease during certain time (indicate spread)
prevalence- number people get disease in specified time period (old and new cases; indicate seriousness)
frequency of disease
- sporadic - occurs infrequently
- endemic - always present (flu)
- epidemic - rapid development in specific area
- pandemic - worldwide epidemic
severity/duration of a disease
acute disease - symptoms develop rapidly(flu)
chronic disease - disease develop slowly (tb)
subacute disease - symptoms between acute and chronic
latent disease - disease w period of no symptoms
herd immunity
immune individuals acta s barrier to spread of infections(does not work for non communicable disease)
what is the RO value
the avg number of people who will contract disease from one person w disease
different extent of infections
local - limited, confined to specific area
systemic - spread through whole body (circulatory/lymphatic)
focal - spreads from local infection to specific parts of body (teeth, tonsil)
sepsis - inflammatory condition due to presence of toxin/bacteria (ex. septicemia)
septicemia/bacteremia/sepsis
blood poisoning by bacteria