CIC Infectious Agent Transmission 2 — Questions and Answers
Question 1: A patient with active pulmonary tuberculosis is placed in a negative-pressure room. What is the primary transmission route being prevented?
- Contact transmission
- Droplet transmission
- Airborne transmission (Correct answer)
- Common vehicle transmission
Correct 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.
Question 2: Which pathogen is most commonly associated with fecal-oral transmission via contaminated water supplies?
- Staphylococcus aureus
- Cryptosporidium parvum (Correct answer)
- Clostridium difficile
- Pseudomonas aeruginosa
Correct 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.
Question 3: A nurse sustains a needlestick injury from a patient with unknown HIV status. The MOST important immediate action is:
- Begin post-exposure prophylaxis immediately
- Wash the wound thoroughly with soap and water (Correct answer)
- Report the injury to occupational health
- Test the source patient for HIV
Correct 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.
Question 4: Vector-borne transmission of West Nile Virus occurs through which mechanism?
- Biological transmission via mosquito bite (Correct answer)
- Mechanical transmission via mosquito bite
- Fecal-oral transmission from bird droppings
- Direct contact with infected birds
Correct 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.
Question 5: Which factor most significantly increases the risk of healthcare-associated pathogen transmission via the contact route?
- Inadequate hand hygiene compliance among staff (Correct answer)
- Insufficient air exchanges per hour in patient rooms
- Failure to use N95 respirators
- Lack of negative-pressure isolation rooms
Correct 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.
Question 6: Norovirus outbreaks in healthcare facilities are primarily controlled by which intervention targeting its transmission route?
- Placing patients on airborne precautions
- Enhanced environmental disinfection with sporicidal agents
- Cohorting symptomatic patients and strict contact precautions (Correct answer)
- Universal masking of all staff
Correct 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.
Question 7: In the chain of infection, which element describes the portal through which a pathogen leaves the reservoir?
- Mode of transmission
- Portal of entry
- Portal of exit (Correct answer)
- Susceptible host
Correct 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.
CIC Infectious Agent Transmission 2
A patient with active pulmonary tuberculosis is placed in a negative-pressure room.
What is the primary transmission route being prevented?