Infectious Agent Transmission Flashcards

A patient with active pulmonary tuberculosis is placed in a negative-pressure room. What is the primary transmission route being prevented?

Answer: Airborne transmission

TB is transmitted via airborne droplet nuclei (<5 µm) that remain suspended in air, requiring negative-pressure isolation rooms with HEPA filtration.

Which pathogen is most commonly associated with fecal-oral transmission via contaminated water supplies?

Answer: Cryptosporidium parvum

Cryptosporidium parvum is a protozoan parasite transmitted via the fecal-oral route and is highly resistant to chlorination, making it a common waterborne pathogen.

A nurse sustains a needlestick injury from a patient with unknown HIV status. The MOST important immediate action is:

Answer: Wash the wound thoroughly with soap and water

Immediate thorough washing of the wound with soap and water is the first step, reducing pathogen load before other interventions.

Vector-borne transmission of West Nile Virus occurs through which mechanism?

Answer: Biological transmission via mosquito bite

West Nile Virus undergoes biological transmission, replicating within the mosquito vector before being injected into a new host during feeding.

Which factor most significantly increases the risk of healthcare-associated pathogen transmission via the contact route?

Answer: Inadequate hand hygiene compliance among staff

Hand hygiene is the single most important measure to prevent contact transmission, as hands are the primary vector for pathogen spread between patients.

Norovirus outbreaks in healthcare facilities are primarily controlled by which intervention targeting its transmission route?

Answer: Cohorting symptomatic patients and strict contact precautions

Norovirus spreads via contact and fecal-oral routes; cohorting ill patients with strict contact precautions and enhanced hand hygiene is the primary control strategy.

In the chain of infection, which element describes the portal through which a pathogen leaves the reservoir?

Answer: Portal of exit

The portal of exit is the path through which an infectious agent leaves its reservoir, such as the respiratory tract, GI tract, or skin.