CIC Infectious Disease Processes 2 — Questions and Answers
Question 1: Which component of the chain of infection refers to the reservoir's ability to exit and reach a susceptible host?
- Portal of entry
- Mode of transmission
- Portal of exit (Correct answer)
- Infectious dose
Correct answer: Portal of exit
The portal of exit is the pathway by which a pathogen leaves its reservoir to be transmitted to a new host.
Question 2: A patient develops fever, chills, and bacteremia 48 hours after a central line insertion. This represents which type of infection?
- Community-acquired infection
- Healthcare-associated infection (Correct answer)
- Opportunistic infection
- Endogenous infection
Correct answer: Healthcare-associated infection
An infection occurring more than 48 hours after admission that was not present on admission is classified as a healthcare-associated infection (HAI).
Question 3: Which term describes the ability of a pathogen to cause disease in a susceptible host?
- Virulence
- Pathogenicity (Correct answer)
- Infectivity
- Toxigenicity
Correct answer: Pathogenicity
Pathogenicity is the ability of an organism to cause disease, while virulence refers to the degree or severity of that disease.
Question 4: Clostridium difficile spores persist on environmental surfaces primarily because they are resistant to:
- Quaternary ammonium disinfectants
- Alcohol-based hand rubs (Correct answer)
- Heat sterilization
- Beta-lactam antibiotics
Correct answer: Alcohol-based hand rubs
C. difficile spores are not killed by alcohol-based hand rubs, which is why soap-and-water handwashing is required for C. difficile patient care.
Question 5: Which of the following best defines 'colonization' in the context of infectious disease?
- Pathogen present with host immune response and symptoms
- Pathogen present without causing signs or symptoms of infection (Correct answer)
- Pathogen present in blood causing systemic illness
- Pathogen eliminated by the host immune system
Correct answer: Pathogen present without causing signs or symptoms of infection
Colonization means a microorganism is present and may be multiplying on or in a host without producing clinical signs or symptoms of infection.
Question 6: Tuberculosis transmission most commonly occurs via which route?
- Contact transmission
- Droplet transmission
- Airborne transmission (Correct answer)
- Vehicle transmission
Correct answer: Airborne transmission
Mycobacterium tuberculosis is transmitted via airborne droplet nuclei (≤5 microns) that remain suspended in the air and can be inhaled by susceptible individuals.
Question 7: An immunocompromised patient develops Pneumocystis jirovecii pneumonia. This is best classified as:
- Primary infection
- Opportunistic infection (Correct answer)
- Nosocomial infection
- Zoonotic infection
Correct answer: Opportunistic infection
Opportunistic infections are caused by organisms that rarely cause disease in immunocompetent hosts but exploit weakened immune defenses.
CIC Infectious Disease Processes 2
Which component of the chain of infection refers to the reservoir's ability to exit and reach a susceptible host?