C-8 Flashcards
epidemiology
The study of the occurrence and spread of disease and how it can be prevented or limited
etiology
The cause of disease or infection
incidence
Number of new cases of a disease in a given area/population in a given period of time; tells you what the risk of acquiring the infection is
prevalence
Total number of all individuals affected by the disease in an area at a particular time
(includes both new and old cases); tells you how widespread the disease is
morbidity
Another term for disease but not deaths (can include incidence and prevalence)
mortality
death due to disease
endemic
expected disease that normally
occurs at regular intervals at stable incidence within a given population or area (i.e. flu)
sporadic
disease with only a few scattered cases within a population or area; occurs
infrequently and irregularly (i.e. rabies)
epidemic
disease that occurs at a greater
frequency than is normal/usual for an area or population. Can be endemic!
pandemic
if an epidemic occurs
simultaneously worldwide (on multiple continents) (i.e. covid)
reservoirs
Sites where pathogens are normally maintained and act as a source of infection
portals of entry and exit (skin, mm, placenta)
skin: broken skin, natural openings, hair follicles and sweat glands, insect bites or burrowing
mm: Line the GI, respiratory, urinary, and reproductive
tracts – also line the eyes, nose, and mouth; Thinner and easier to penetrate
placenta: Barrier between fetus and mother – some pathogens can cross
direct transmission (contact)
Ex. Handshake, kissing,
intercourse, placenta,
unwashed hand to own mouth
indirect transmission (contact)
- Ex. Touching a fomite - toothbrush, drinking glass, money
- Puncture wound
droplet transmission (contact)
- Larger droplets from an
aerosol less than 1 meter away - Ex. Droplets from sneezing
mechanical transmission (vector)
don’t act as hosts for the
pathogens they transmit – only
passively carry pathogens to new hosts on feet or other body parts (flies and cockroaches)
biological transmission (vector)
transmit pathogens and serve as hosts for the multiplication of a pathogen during its life cycle (biting - mosquitos, lice, ticks, mites, etc)
airborne transmission (vehicle)
Transmitted by the air. Farther distance than droplet transmission; finer aerosolized particles. Ex. fungal spores or measles virus
waterborne transmission (vehicle)
Many GI diseases are waterborne caused by fecal
contamination of drinking water (fecal-oral infection).
Ex. cholera