Question 1

Which of the following best describes a mutualistic relationship between two organisms?

Accepted Answer

Both organisms benefit from the relationship.

Question 2

A patient is prescribed antibiotics that eliminate most of her Lactobacillus bacteria. She subsequently develops a vaginal yeast infection. What is the best explanation for this outcome?

Accepted Answer

The antibiotics caused an imbalance, allowing opportunistic yeast to overgrow.

Question 3

Which of the following is NOT a function of the human microbiome?

Accepted Answer

Directly causing autoimmune diseases.

Question 4

Which of the following is an example of a sign of infectious disease?

Accepted Answer

Fever of 39°C (102°F)

Question 5

A disease that is consistently present in a population with a regular pattern is called:

Accepted Answer

Endemic

Question 6

Calculate the incidence proportion of a disease if 18 new cases occur in a population of 110 susceptible individuals during one month. Use the formula $$ 	ext{Incidence Proportion} = \frac{	ext{Number of new cases}}{	ext{Number at risk}} 	imes 100\% .$$

Accepted Answer

$$16.4\%$$

Question 7

Which of the following is a limitation of Koch’s postulates when identifying the cause of a disease?

Accepted Answer

Some pathogens cannot be cultured in laboratory media.

Question 8

Which of the following best describes herd immunity?

Accepted Answer

When a large percentage of a population is immune, protecting non-immune individuals.

Question 9

A mosquito infected with Plasmodium parasites bites a human and transmits malaria. This is an example of:

Accepted Answer

Biological vector transmission

Question 10

Which of the following is the most effective way to prevent the spread of disease via direct contact?

Accepted Answer

Hand washing

Question 11

Which of the following statements about mortality rate and case fatality rate (CFR) is true?

Accepted Answer

CFR is always higher than or equal to mortality rate if both are expressed as a percentage.

Question 12

Which of the following is NOT a factor contributing to healthcare-associated infections (HAIs)?

Accepted Answer

Some patients are allergic to certain medications.

Question 13

Which of the following best describes the difference between vertical and horizontal disease transmission?

Accepted Answer

Vertical transmission occurs between mother and baby; horizontal transmission is any other mode.

Question 14

A tick infected with Borrelia burgdorferi bites a human, causing Lyme disease. The wound made by the tick is an example of the pathogen’s:

Accepted Answer

Portal of entry

Question 15

Which of the following is NOT a reason why molecular Koch’s postulates were developed?

Accepted Answer

Pathogenic microbes cannot be cultured on laboratory medium.

Question 16

Which of the following is a true statement about zoonoses and vector-borne diseases?

Accepted Answer

A disease can be both zoonotic and vector-borne if it is transferred from an animal to a human via a vector.

Question 17

Which of the following is NOT an example of a commensal relationship?

Accepted Answer

Bacteria fixing nitrogen in the roots of some plants and the plants providing shelter for the bacteria.

Question 18

Which of the following is NOT a way in which the microbiome protects against pathogens?

Accepted Answer

Creating compounds that help us digest food.

Question 19

Which of the following best describes the prodromal period of an infectious disease?

Accepted Answer

The period of early, vague symptoms such as malaise and headache.

Question 20

Which of the following is the best example of analytical epidemiology?

Accepted Answer

Comparing the rate of lung cancer between smokers and non-smokers.

Principles of Disease and Epidemiology: Mini-Textbook Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards