An unusual source for an outbreak of methicillin-resistant Staphylococcus aureus on an intensive therapy unit

Area of Science:

• Infectious Diseases
• Hospital Epidemiology
• Microbiology

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat in healthcare settings, particularly intensive therapy units.
• Controlling the spread of hospital-acquired infections (HAIs) is crucial for patient safety and effective healthcare management.

Observation:

• An outbreak of MRSA, including the EMRSA 15 strain, occurred over four months in an intensive therapy unit.
• Four patients with EMRSA 15 were all nursed in the same bed prior to infection or colonization.

Findings:

• Investigation suggested the MRSA originated from exhaust ducting of an adjacent isolation room's ventilation system.
• Contaminated air entered the unit through a partially open window above the affected bed.

Implications:

• Environmental contamination, specifically ventilation systems, can be a source of MRSA transmission in hospitals.
• Interventions like repairing ventilation and sealing windows are effective in breaking MRSA transmission cycles.