Chapter 2 Review Questions KEY
�2.1 NATURAL HISTORY OF DISEASE
- Susceptibility, preclinical, clinical,
recovery/disability/death
- See text.
- Primary prevention - prevent new occurrences. Secondary prevention - delay
onset or decrease severity. Tertiary prevention - minimize the progression of
disease or prevent sequelae.
- The agent multiplies within the host.
- Latency
- tuberculosis, AIDS, leprosy.
- Mammography is a form of secondary prevention because it picks up
disease after its been initiated but before it is clinically evident.
- Causal interdependence means that a disease will express itself only when
complementary components combine to create sufficiency.
- Low Ca++ diet, osteoporosis, sedation, slippery surface
- See p. 35
�2.2 SPECTRUM OF DISEASE AND THE ICEBERG
- spectrum of disease.
- Student choice . . .
- Epidemiologic iceberg
�2.3 CAUSAL CONCEPTS
- Any predecessor without which disease would not have occurred or would have occurred at a later time (all other things being equal).
- Measles virus is necessary but not sufficient to cause measles.
- (a) The agent is present in every case [necessity] (b) The agent does not
cause
any other disease [specificity] (c) The agent can be isolated in pure culture and can
initiate the disease in a susceptible host
- . . . when disease becomes inevitable.
- (E + F)
- E
- True
- Phenylkenouria is both a genetic disease and environmental disease.
The genetic disorder involves a lack of the enzyme phenylalanine hydroxylase.
The environmental component requires the presence of dietary phenylketones.
- The prevalence of phenylkenouria would be equal to the
prevalence of the genetic abnormality that determine the condition.
- Zero
- A direct cause is a causal factor that causes pathology within the
individual.
- An indirect cause is not directly related to pathologic event (in
the body) but is instead interconnected to other factors.
- Biological, physical, and chemical
- nutritive, poisons, drugs, allergens
- heat, light, radiation, noise, vibration,
and objects that cause trauma
- Infectivity = ability to infect; pathogenicity = ability to cause
disease; virulence = ability to cause severe disease
- Agent, host, and environmental factors are in ecological balancing in
a
population. Environmental factors that favor the agent lead to more disease.
Enironmental factors that harm host resistance lead to disease. See the text for
a better explanation.
- Definitions (a) = Virulence, (b) = Sufficient constellation, (c) = Cause,
(d) = Infectivity, (e) = Causal web, (f) = Pathogenicity, (g) = Necessary cause
�2.4 EPIDEMIOLOGIC VARIABLES
- what, why, when, how, where, who
- False. If there were so, there would be no point in describing their
distribution according to person, place, and time criteria.
- place, and time.
- See Table 2.3 (p. 49).
- person
- See Table 2.4 (p. 51).
- Studies show that Japanese-American women develop breast
cancer rates typical of American women after several generations of acculturation.
- (a) propagating epidemic (b) point epidemic (c) endemic (d) sporadic