Epidemiology
Large numbers of people over a wide geographical area are affected.
Epidemic
Compares sick people to healthy people to find exposures
case-control study
(Sick People ÷ total population) × 100
attack rate
A sharp rise and gradual fall suggests this type of outbreak
point-source outbreak
Disease spread by coughing or sneezing at close range
droplet transmission
The total number of existing cases in a population at a given time.
prevalence
Follows exposed and unexposed groups over time
cohort study
(Deaths ÷ cases) × 100
case fatality rate
A plateau-shaped curve suggests
continuous common source
Disease spread through contaminated objects
fomite transmission
A person who has the disease being studied
a case
Measures exposure and disease at one point in time
cross-sectional study
A measure that compares risk between two groups
relative risk
Successive peaks one incubation period apart indicate
propagated outbreak
A living organism that transmits disease (ex: mosquito)
vector
The time between exposure and symptom onset
incubation period
Researchers assign exposure (ex: vaccine trials)
experimental study
Odds of exposure in cases ÷ odds in controls
odds ratio
The highest point on an epi curve represents
peak number of cases
Removing sick individuals from the population
isolation
A person who spreads disease without showing symptoms
asymptomatic carrier
Looks back in time using existing records
retrospective study
If RR = 1, this means
there is no association between exposure and disease
Used to estimate incubation period from a point source
time from exposure to peak/range of onset dates
Separating exposed but not yet sick individuals
quarantine