Infectious Disease Processes Flashcards

Which component of the chain of infection refers to the reservoir's ability to exit and reach a susceptible host?

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.

A patient develops fever, chills, and bacteremia 48 hours after a central line insertion. This represents which type of infection?

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).

Which term describes the ability of a pathogen to cause disease in a susceptible host?

Answer: Pathogenicity

Pathogenicity is the ability of an organism to cause disease, while virulence refers to the degree or severity of that disease.

Clostridium difficile spores persist on environmental surfaces primarily because they are resistant to:

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.

Which of the following best defines 'colonization' in the context of infectious disease?

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.

Tuberculosis transmission most commonly occurs via which route?

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.

An immunocompromised patient develops Pneumocystis jirovecii pneumonia. This is best classified as:

Answer: Opportunistic infection

Opportunistic infections are caused by organisms that rarely cause disease in immunocompetent hosts but exploit weakened immune defenses.