Infectious Disease Processes Flashcards

An Infection Preventionist is reviewing the stages of an infectious disease with a group of new nurses. During which stage does the host begin to experience general, non-specific signs and symptoms like fatigue and low-grade fever?

Answer: Prodromal stage

The prodromal stage is the period after incubation and before the characteristic symptoms of the disease appear. During this stage, the pathogen continues to multiply, and the host's immune system is activated, leading to general and non-specific symptoms such as malaise, low-grade fever, and body aches.

A hospital is experiencing a sudden increase in cases of a specific gastrointestinal illness, significantly exceeding the expected number for this time of year within the local community. How would an Infection Preventionist BEST classify this occurrence?

Answer: Epidemic

An epidemic is defined as an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. An endemic refers to the constant presence of a disease within a geographic area. A pandemic is an epidemic that has spread over several countries or continents. Sporadic means the disease occurs infrequently and irregularly.

Which of the following terms describes the ability of a microorganism to cause disease?

Answer: Pathogenicity

Pathogenicity refers to the ability of an organism to cause disease in a host. Virulence, in contrast, is a quantitative measure of the degree of pathogenicity or the severity of the disease caused by the pathogen. Infectivity is the ability of a pathogen to establish an infection, and toxigenicity is the ability to produce toxins.

A patient with influenza sneezes, and another individual standing two feet away inhales the infectious particles. This represents which mode of transmission in the chain of infection?

Answer: Droplet transmission

Droplet transmission occurs when respiratory droplets carrying infectious pathogens are generated from a source person (e.g., through coughing or sneezing) and are propelled a short distance through the air and deposited on the mucous membranes of a nearby person. This is distinct from airborne transmission, where smaller droplet nuclei can remain suspended in the air for longer periods and travel longer distances.

In the context of the infectious disease process, what is the 'incubation period'?

Answer: The time from exposure to an infectious agent until the onset of the first signs or symptoms.

The incubation period is the time elapsed between exposure to a pathogenic organism and when the first signs and symptoms of the disease become apparent. The time from exposure until the host becomes infectious is known as the latent period.

An Infection Preventionist is educating staff on the chain of infection. Which of the following is considered a 'portal of entry'?

Answer: A break in the skin

A portal of entry is the path by which a pathogen enters a susceptible host. A break in the skin, mucous membranes, the respiratory tract, and the gastrointestinal tract are all common portals of entry. A contaminated needle is a mode of transmission (fomite), a person with a weakened immune system is a susceptible host, and coughing/sneezing represents a portal of exit.