A microbiology laboratory plays a pivotal role in both endemic and epidemic epidemiology.

Multi-drug resistant (MDR) Klebsiella pneumoniae in a high-risk area like the ICU requires urgent investigation because:

It spreads rapidly via contaminated hands or equipment.

It poses a serious risk to immunocompromised patients.

An outbreak could lead to severe hospital-acquired infections (HAIs).

Why the Other Options Are Incorrect?

A. One blood isolate of Streptococcus agalactiae in the nursery – Single cases are not indicative of an outbreak.

B. Two isolates of Staphylococcus aureus in postoperative surgical sites – Common post-surgical pathogen; requires monitoring but not immediate outbreak investigation.

D. Two blood isolates of coagulase-negative staphylococci in the oncology unit – Common contaminants in blood cultures and not immediately alarming.

CBIC Infection Control Reference

APIC guidelines prioritize investigating MDR pathogens in high-risk units, such as ICU, to prevent transmission​.