Epidemiology terms

Question 1

Endemic/enzootic

Answer 1

Normal amount of disease in a population at a given time

Question 2

Epidemic/epizootic

Answer 2

When a disease occurs at a level about what is normal for a given population

Question 3

Pandemic

Answer 3

A pandemic is an epidemic of an infectious disease that has spread across a large region, for instance multiple continents or worldwide, affecting a substantial number of people

Question 4

Vehicle

Answer 4

inanimate objects (food, water, blood, feces, bedding, etc.)

Question 5

Prevelance

Answer 5

total # of diseased animals / population of interest

Question 6

Incidence aka risk

Answer 6

new cases of disease / population at risk

Question 7

What is an attack rate?

Answer 7

the incidence during an active outbreak

Question 8

Crude mortality

Answer 8

total # deaths / total population

Question 9

Cause-specific mortality

Answer 9

of deaths from specific disease / total population

Question 10

Proportionate mortality

Answer 10

of deaths from specific disease / total # of deaths

Question 11

Case-fatality rate

Answer 11

of deaths from specific disease / total # of cases of specific disease

Question 12

Descriptive epidemiology

Answer 12

describe the variations in disease frequency among populations by geographical areas and over time (i.e., person, place, and time).

Question 13

Vehicle

Answer 13

A non-living thing that carries disease (ie. water, food, fomites)

Question 14

What is a point source curve

Answer 14

Persons are exposed to the same common source over a brief period of time, such as through a single meal or event attended by all cases; number of cases rise rapidly to a peak and falls off gradually; majority of cases occur within one incubation period.

Question 15

What is a continuous source curve

Answer 15

Exposure is not confined to one point in time (prolonged over a period of days, weeks or longer); as such, cases are spread over a greater period of time depending on how long the exposure persists; lasts more than one incubation period

Question 16

What is a propagated source curve

Answer 16

Does not have a common source but instead caused by spread of pathogen from one susceptible person to another; transmission may occur directly (person-to-person) or via an intermediate host; tends to have a series of irregular peaks reflecting the number of generations of infection; multiple peaks separated by approx. one incubation period; e.g., person-to-person spread of shigellosis

Question 17

What is an intermittent source curve

Answer 17

Similar to continuous but exposure is intermittent; multiple peaks – length: no relation to the incubation period (reflects intermittent times of exposure) e.g., contaminated food product sold over period of time

Question 18

Vertical transmission

Answer 18

from mother to offspring, typically transplacental, transvaginal, or transmammary

Question 19

Horizontal transmission

Answer 19

from individual to individual

Question 20

Reservoir

Answer 20

habitat where a disease agent live, grows, and multiplies

Question 21

What type of study can determine incidence?

Answer 21

Cohort

Question 22

What type of study can determine prevelance?

Answer 22

Cross-sectional

Question 23

Relative risk equation

Answer 23

(a/(a+b)) / (c/(c+d))

Question 24

Relative risk assesses…

Answer 24

risk of developing disease between exposed and non-exposed groups

Question 25

RR < 1

Answer 25

negative association, aka protective

Question 26

RR = 1

Answer 26

no association, aka null

Question 27

RR > 1

Answer 27

positive association, aka risk factor

Question 28

Odds ratio equation

Answer 28

(a * d) / (b * c)

Question 29

Odds ratio assess….

Answer 29

risk of having a disease based on exposure

Question 30

OR < 1

Answer 30

negative association, akak protective

Question 31

OR = 1

Answer 31

no association, aka null

Question 32

OR > 1

Answer 32

positive association, aka risk factor