Unit 1 Principles of Epidemiology

Question 1

A primary, or definitive, host is one in which a disease organism

Answer 1

attains its maturity and goes through its sexual or reproductive stage

Question 2

A secondary, or intermediate, host is one in which a disease organism

Answer 2

enters the larval stage

Question 3

A person or other living animal, including birds and arthropods, which are harboring a disease agent

Answer 3

host

Question 4

The person or animal that harbors a disease agent, but has no clinical signs of the disease is

Answer 4

carrier

Question 5

Are organisms that live on or in the body of a host and can produce disease or illness

Answer 5

Agent

Question 6

In a host-agent relationship, the ability of an agent to produce clinical disease in a host is its

Answer 6

pathogenicity

Question 7

In a host-agent relationship, the ability of an agent to invade and multiply, or to produce infection, in a host is its

Answer 7

infectivity

Question 8

The proportion of clinical cases resulting in severe clinical manifestations

Answer 8

virulence

Question 9

In a host-agent relationship, all of the following are types of agents except
a. fungi.
b. metazoa.
c. virulence.
d. rickettsia.

Answer 9

c. virulence

Question 10

Are multicellular organisms, often referred to as parasites

Answer 10

Metazoa

Question 11

Are single-celled, animal-like organisms. Most are free-living and found in soil and water

Answer 11

Protozoa

Question 12

Are microscopic, single-celled organisms

Answer 12

Bacteria

Question 13

What different shapes can bacteria appear in

Answer 13

bacillus (rod)
coccus (sphere)
spirillum (spiral)

Question 14

Are small bacteria. Most are obligate, intracellular parasites; that is, they must live within living cells

Answer 14

Rickettsia

Question 15

Are particles of nucleic acid
surrounded by a protein sheath; they are highly infectious

Answer 15

Viruses

Question 16

How can agents enter the body?

Answer 16

Ingestion
Inhalation
Penetration

Question 17

Diseases such as rabies are spread using this type of direct transmission mode

Answer 17

Direct contact

Question 18

Identify the three-link chain

Answer 18

Source
Mode
Host

Question 19

This is not a general health status factor for determining disease occurrence
a. Preexisting disease.
b. Physiological state.
c. Behavioral factors.
d. Nutritional status.

Answer 19

c. Behavioral factors

Question 20

In countries where pork is eaten, individuals may be at risk of trichinosis infection when the
pork is undercooked. Which intrinsic disease occurrence factor is this an example of?

Answer 20

Diet

Question 21

Using what is called night soil as a fertilizer allows the transmission of such diseases as typhoid, dysentery, amebiasis, and hepatitis. Preventing the transmission of these diseases
involves

Answer 21

proper human waste disposal

Question 22

Is one of the most important factors in the control of communicable disease

Answer 22

personal hygiene

Question 23

This environmental factor has the greatest effect on hay fever sufferers

Answer 23

Climate

Question 24

Which environmental factor is a medicinal source, such as Quinine that comes from tree bark and is used to treat malaria?

Answer 24

Biological

Question 25

Which factor contributes to the emergence of new infectious disease or the reemergence of old diseases?

Answer 25

Societal disruptions

Question 26

Which term is used to define numeric facts or data that have been assembled, classified, and tabulated to present significant information about a given subject?

Answer 26

Statistics

Question 27

Which statistical term is most commonly used as a measurement of central tendency?

Answer 27

Mean

Question 28

Which statistical term is characterized by the number occurring most often in a group or set of numbers

Answer 28

Mode

Question 29

Using statistics, the mode for numbers 6, 18, 26, 14, 12, 19, 20, and 26 is

Answer 29

26

Question 30

Which statistical term is characterized by arranging the data from the smallest number to the largest number

Answer 30

Median

Question 31

Using statistics, the median of the numbers 3, 3, 5, 7, 8, 9, and 12 is

Answer 31

7

Question 32

Public health uses rates as one of its most important statistical tools. What does the noneffectiveness rate tell you about individuals’ illnesses or injuries?

Answer 32

Temporary loss from duty

Question 33

This statistical rate is used to determine the probability of new disease cases affecting healthy people during a given time

Answer 33

Incidence rate

Question 34

If 30 out of 90 people who ate at a base picnic became ill, the attack rate per 100 persons is

Answer 34

33.30

Question 35

A method that is used to study two similar groups by administering a vaccine, special diet, or some other factor to one group while withholding it from the other group is called

Answer 35

experimental

Question 36

This method is used to study different groups under natural conditions

Answer 36

Observational

Question 37

Which disease study method traces the source of a food poisoning outbreak or examines sexually transmitted infection (STI) incidence and prevalence?

Answer 37

Uncontrolled observation.

Question 38

This is simply observing, questioning, and studying a population at one point in time in order to detect cases of a disease

Answer 38

Cross-sectional survey

Question 39

In this design, you study persons who already have the disease; you also study people who are free of the disease

Answer 39

Retrospective

Question 40

This is a plan of study in which a group under observation is divided into two groups; one having a factor believed to contribute to a disease and the other without the factor

Answer 40

Prospective

Question 41

In this step of an outbreak investigation, it is important for you to know what disease to look for and you must separate cases from noncases

Answer 41

Establish or verify the diagnosis

Question 42

In this step of an outbreak investigation, compare the current incidence and the usual, or expected, incidence

Answer 42

Establish existence of an outbreak