$$\text{Incidence} = \frac{\text{New cases in a period}}{\text{Population at risk}}$$

Question 1

Which of the following best describes the relationship between termites, protozoans, and bacteria in the termite gut?

Accepted Answer

Mutualism

Question 2

A fungus secretes an antibiotic that inhibits nearby bacteria, but the fungus is not affected. What type of symbiotic relationship is this?

Accepted Answer

Amensalism

Question 3

Which of the following is NOT a reason why transient microbiota cannot persist in the body?

Accepted Answer

They are always pathogenic

Question 4

Babies born via cesarean section are more likely to have which of the following compared to those born vaginally?

Accepted Answer

Delayed microbiome development

Question 5

Which portal of entry is most commonly used by respiratory pathogens?

Accepted Answer

Mucous membranes

Question 6

A pathogen that is deposited directly into tissues beneath the skin via a puncture wound is said to enter the host via which route?

Accepted Answer

Parenteral route

Question 7

Which of the following is an example of a sign, rather than a symptom, of disease?

Accepted Answer

Fever

Question 8

According to Koch’s postulates, which step is necessary to prove that a microorganism causes a specific disease?

Accepted Answer

The suspected agent must be isolated and grown in pure culture

Question 9

Which of the following is a virulence factor that allows bacteria to evade phagocytosis?

Accepted Answer

Capsule

Question 10

Which statement about exotoxins and endotoxins is correct?

Accepted Answer

Endotoxins are part of the bacterial cell wall and released upon cell death

Question 11

A patient develops a disease after a surgical procedure due to contamination from the hospital environment. This is best classified as:

Accepted Answer

Exogenous infection

Question 12

Which of the following equations correctly represents the calculation of disease incidence?

Accepted Answer

$$	ext{Incidence} = \frac{	ext{New cases in a period}}{	ext{Population at risk}}$$

Question 13

Which of the following is a biological vector for Lyme disease?

Accepted Answer

Ixodes tick

Question 14

A disease that is acquired in a healthcare setting is best described as:

Accepted Answer

Nosocomial

Question 15

Which of the following is a common portal of exit for pathogens?

Accepted Answer

Mouth (saliva, sputum)

Question 16

Which of the following is NOT a typical effect of pathogens crossing the placenta?

Accepted Answer

Increased immunity in the fetus

Question 17

During which stage of infectious disease are signs and symptoms most severe?

Accepted Answer

Illness

Question 18

Which of the following is an example of vehicle transmission?

Accepted Answer

Contaminated water

Question 19

Which of the following is a plausible consequence of antibiotic use on the normal microbiota?

Accepted Answer

Disruption of normal microbiota leading to opportunistic infections

Question 20

Which of the following is a correct statement about the role of public health agencies in epidemiology?

Accepted Answer

They enforce cleanliness of water and food supplies

Chapter 14: Infection, Infectious Diseases, and Epidemiology

Study Guide - Practice Questions