Exam 2 — terminology

Question 1

Define endemic

Answer 1

Infection is maintained in the population without the need for external inputs

E.g. influenza

Question 2

Define epidemic

Answer 2

A disease that appears as new cases in the population in a period of time at a rate that substantially exceeds what is “expected,” based on recent experience.

E.g. bubonic plague in the 1300s in Europe

Question 3

Define outbreak

Answer 3

Small, localized epidemic

Question 4

Define pandemic

Answer 4

Global epidemic of infectious disease that affects people or animals over an extensive geographical area

E.g. AIDS is pandemic

Question 5

Define herd immunity

Answer 5

Immune people act as a sort of “firebreak” in the spread of the disease, slowing or preventing the further transmission of the disease to others.

If the number of immune individuals drop, the greater likelihood of disease

Question 6

Incubation period

Answer 6

Time elapsed between exposure to a pathogenic organism and when symptoms and signs are first apparent

Question 7

Define epidemiology

Answer 7

Study of the distribution and determinants of health related states or events in specified populations, and the application of this study to control health problems.

Question 8

Define morbidity

Answer 8

Measurement of the incidence of a disease.

How many new cases have developed over time.

Question 9

What is the equation for measuring morbidity?

Answer 9

new cases in 1 year/mid year population X 1000

Just remember that its a measurement of NEW cases in a population.

Question 10

Define prevalence

Answer 10

Number of individuals affected at a specific time

Question 11

Equation for prevalence

Answer 11

of cases at specific time/population at that time X 1000

Just a snapshot of all cases no matter how old or new they are.

Question 12

Define the attack rate

Answer 12

Number of people who got exposed to the disease during the outbreak who actually get sick

E.g. the number of people who get sick from a dinner party

Question 13

Equation for the attack rate

Answer 13

Ie. 65 people are exposed, 51 develop symptoms, the attack rate is 51/65 = 78%

Question 14

Define mortality

Answer 14

Death rate

Question 15

Define zoonosis

Answer 15

Any infectious disease that can be transmitted from animals (wild and domestic) to humans

E.g. arthropod-borne diseases

Question 16

Define eutrophication

Answer 16

Aging of a body of water

High biological oxygen demand (BOD) results in the aging of a body of water

Question 17

High BOD rating means what

Answer 17

Lot of critters living in the water

Question 18

Translate ‘eutrophication’

Answer 18

well-nourished

Question 19

Define eutrophication

Answer 19

How body of water ages over time

“Liquid waste or sewage discharged into a river or the sea.”

Question 20

Define incidence

Answer 20

The occurrence rate

Question 21

Define coliform

Answer 21

Gram negative, lactose fermenting, facultative microbes that produce gas

Question 22

Define etiology

Answer 22

Study of why things occur, the study of causation

Question 23

Define droplet nuclei

Answer 23

Particles 1-10 um in diameter, implicated in spread of airborne infection

E.g. when someone sneezes in your face, you get their droplet nucleis

Question 24

Clinical vs subclinical transmission

Answer 24

Clinical is symptomatic, subclinical is mild symptoms, not yet clinical

E.g. clinical carrier is an individual that does not exhibit symptoms, but harbors organism causing disease

Question 25

Vector transmission examples

Answer 25

Insects (mosquitos, flies) and arachnids (ticks)