Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

Basic epidemiology terms and definitions.


Entity necessary to cause disease in a susceptible host


The capacity to cause infection in a susceptible host


The severity of disease that the agent causes in the host


The organism that is susceptible to the effect of the agent


The conditions or influences that are not a part of the agent or host, but influence their interactions

Source for the Agent

Place where the agent originates, lives, grows, and multiples

Portal of Exit

Pathway by which the agent can leave the source

Mode of Transmission

The means of carrying the agent to the host

Direct Transmission

Transmission through contact

Indirect Transmission

Airborne, Vector borne, or Vehicle borne transmission

Portal of Entry

Pathway into the host that gives the agent access to tissue where it can multiply or act


Occurrence of more cases of disease than would normally be expected in a specific place or group of people over a given period of time


Another term for "Epidemic"


High background rate of disease


Very widespread, often global, disease

Case Definition

Set of standard criteria for deciding whether or not a person has a certain disease

Absolute Risk

The observed or calculated probability of an event under study


Statistical dependence between two or more events, characteristics, or other variables


Deviation of results or inferences from the truth, or processes leading to such deviation

Case-Control Study

Retrospective comparison of exposures of persons with disease to those of persons without the disease

Cohort Study

Prospective of exposed and non-exposed defined groups, with a comparison of disease rates during the time covered

Dose-Response Relationship

A relationship in which change in amount, intensity, or duration of exposure is associated with a change - either an increase or decrease - in risk of a specific outcome


Any definable factor that effects a change in health condition or other characteristic


The number of new cases of illness commencing, or of persons falling ill, during a specified time period in a given population

Odds Ratio

A measure of the degree of association


The proportion of persons with a particular disease within a given population at a given time


The possible outcomes of a disease or condition and the likelihood that each one will occur

Relative Risk

The ratio of the probability of developing, in a specified period of time, an outcome among those receiving treatment or exposed to a risk factor, compared with the probability of developing the outcome if the risk factor or intervention is not present

Risk Factors

Patient characteristics or factors associated with an increased probability of developing a disease or condition

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording