Infection (325E1) Flashcards
what is an infection
colonization of a host by a microbial species
localized infection
specific to one place
systemic infection
spread to several regions/areas of the body
common causes of an infection
virus (only DNA ot RNA, surrounded by a protein shell), needs a host or cannot (ex: covid, aids, flu, chxn pox)
bacteria causes of an infection
larger than a virus, single celled organism. it has 1 strain of dna and can replicate w/o a host and it can adapt & supress the bodies defense mechanisms (strep, uti, tb)
causes of an infection: fungal
(rare) spore forming organisms (ex: yeast infection)
causes of an infection: protozoa
(rare) typically live in water / environment (malaria)
causes of an infection: helminths
(rare) parasitic worms
causes of an infection: prions
(rarest) proteinaceocus infectious particles, only composed on protein. it is tiny misfolded DNA (mad cow)
reservoir
habitat where organism usually lives & grows (microorganism must have; can be humans, animals, infects, environment)
direct modes of transmission
kissing, sex, direct contact w/ contaminated substances (hook warms, STDs), drop
indirect modes of transmission
airborne, vehicle (through water, food or blood, ex Hep A) vector borne (mosquitos, fleas, ticks)
portal of entries
-oropharynx & nasopharynx (airways, lungs, stomach & GI *very common)
-GU tract (STDs, catheters)
-skin
what is the bodies biggest barrier
skin but is also the biggest vulnerability if you get cuts or wounds
portal of entry: translocation
movement of bacteria across the intestinal lining, occurs frequently in the peritoneal cavity from bacteria leaking from gut and also occurs in the bloodstream
portal of entry: blood
contamination blood given in a transfusion and also needle sticks
portal of entry: maternal fetal transmission
cross the placenta barrier and directly to fetus (ex: zika, listeria)
stages of infection: incubation period
time from getting into the body to when symptoms first appear (no symptoms in this stage)
stages of infection: prodromal stage
onset of non specific symptoms
stages of infection: acute stage
specific signs & symptoms of microbe (sick, can’t get out of bed)
stages of infection: convalescent stage
symptoms are improving, illness is leaving
stages of infection: resolution phase
pathogen is eliminated from the body some pathogens never get to this point (ex: chx pox)
the infectious process is also known as what
the inflammatory process (it is when your body is fighting what is going on)