Review Questions for Chapter 2 Last update: 03/09/2009

�2.1 NATURAL HISTORY OF DISEASE

1. List the four stages in the natural history of a disease.
2. What events marks the beginning of each stage of disease?  
3. What is the goal of primary prevention? ... of secondary prevention? of tertiary prevention?
4. What occurs during the incubation period of an infectious disease?
5. Provide a synonym for the term incubation.
6. Provide an example of an infectious disease with a long incubation period.
7. Is mammography a form of primary, secondary, or tertiary prevention?
8. What is causal interdependence? 
9. List contributing causes to hip fractures in the elderly. 
10. Discuss the natural history of HIV/AIDs. Discuss its relevance in studying the epidemiology of AIDs.

�2.2 SPECTRUM OF DISEASE AND THE ICEBERG

1. This term is used to describe "the a broad range of clinical manifestations for an ailment."
2. Provide an example of a noninfectious disease other than coronary artery disease that exhibits a broad spectrum.
3. This is the metaphor we use to say that only a small percentage of morbidity in the population is detected.

�2.3 CAUSAL CONCEPTS

1. Define "cause." 
2. Is the measles virus a necessary cause of measles? Is it sufficient?
3. List the Henle-Koch postulates. 
4. When is a causal mechanism complete? [Metaphysical, but provides insights.]
5. Suppose a disease mechanism has 3 components: D, E, and F. What is the causal complement to D?
6. Refer to the prior question. What is the causal complement to of (D+F)?
7. T/F?: Factors that work together in a given causal mechanism are said to interact.
8. Is phenylkenouria a genetic disease or an environmental disease? [Trick question.]
9. Suppose phenylketones were ubiquitous in the diet of a population. What would determine the prevalence of phenylkenouria?
10. Suppose phenylketones were absent from the environment. What would be the prevalence of phenylkenouria in the population?
11. What is a direct cause? 
12. What is an indirect cause?
13. List the three general categories of pathologic agents.
14. List four types of chemical agents.
15. List five types of physical agents.
16. Differentiate between infectivity, pathogenicity, and virulence.
17. Describe the notion of epidemiologic homeostasis.
18. Match the definition below with each of these terms: Causal-web; Component Cause; Infectivity; Necessary Causal Factor; Pathogenicity; Sufficient Causal Constellation; Virulence

Definitions:

(a) Related to the severity of disease

(b) A set of factors that makes disease inevitable in an individual.

(c) An antecedent factor that is needed for the disease to occur in a given individual.

(d) The ability of a communicable agent to enter and establish itself in a host.

(e) The causal metaphor that links direct and indirect causes of disease into a hierarchy.

(f) The ability of an agent to cause disease.

(g) A factor that is always present with a given disease; the disease cannot occur without this type of factor.

�2.4 EPIDEMIOLOGIC VARIABLES

1. Kipling kept six honest men (in the poem on p. 48). What were their names?
2. True or false? Diseases tend to distribute themselves randomly among populations. 
3. [Fill in �2] Classically, descriptive epidemiology describes the distribution of disease according to person, ________________, and ____________________ variables.
4. Provide examples of "person" variables. 
5. Is occupation a person, place, or time variable?
6. Provide an example of a host factor that is often closely tied to "place." Provide an example of an environmental factor that is closely tied to "place." 
7. How do the breast cancer studies in Japanese-American women (described in the text) prove a strong environmental component to breast cancer? 
8. Match each term with its description. 
   Terms: endemic, sporadic, point epidemic, propagating epidemic
   Descriptions:
       (a) Occurring in clear excess with continuing increases over time.
       (b) Occurring in clear excess then rapidly residing. 
       (c) Occurring predictably with minor or predictable fluctuations.
       (d) Occurring rarely and without regularity.

Key [May not be posted]