The interaction between an agent, a host, and the environment is ...

[lindiwe]

The interaction between an agent, a host, and the environment is called:
 
  a. natural history of disease.
  b. risk.
  c. web of causality.
  d. the epidemiologic triangle.

Question 2

A public health nurse (PHN) reports an attack rate. Which of the following has most likely been reported?
 
  a. Number of cases of cancer recorded at a medical center
  b. Number of people who died of Ebola in a given year
  c. Number of beef cattle inoculated against mad-cow disease on a farm
  d. Proportion of people becoming ill after eating at a fast-food restaurant

[asware1]

Answer to Question 1

ANS: D
The epidemiologic triangle consists of the interaction between an agent, a host, and the environ-ment. The natural history of disease is the course of the disease process from onset to resolution. Risk is the probability an event will occur within a specified period of time. The web of causality reflects the more complex interrelationship among the numerous factors interacting, sometimes in subtle ways, to increase (or decrease) risk of disease.

Answer to Question 2

ANS: D
Attack rates are often specific to exposures, such as food-specific attack rates. The number of cases of cancer, exposure to Ebola, and beef cattle are not significant without knowing the total number of people so that a proportion can be calculated.