Patients in pediatric oncology units are highly immunocompromised, making them particularly susceptible to opportunistic fungal infections such as Aspergillus spp. HVAC systems, especially if improperly maintained or contaminated, can disseminate fungal spores into patient care areas.

According to the APIC Text (Chapter 116 – HVAC Systems), fungal spores such as Aspergillus can be transmitted via HVAC systems. These infections have been linked to contaminated air ducts, faulty air filters, and construction-related air disturbances. Outbreaks of aspergillosis are frequently associated with construction near patient care areas and are particularly dangerous for immunocompromised patients, including pediatric oncology patients.

Additional data from APIC Text (Chapter 45 – Infection Prevention in Oncology Patients) reinforces that Aspergillus spp. infections in oncology and immunocompromised patients are primarily airborne and are most often disseminated via HVAC systems.

Incorrect answer rationale:

A. MRSA – Typically spread via direct contact, not HVAC.

B. Norovirus – Spread via fecal-oral route and contaminated surfaces, not airborne HVAC.

D. Clostridioides difficile – Spread via contact with spores on surfaces, not through the air.