Service Ready Ambulance Surfaces and Emergency Medical Services Clinicians are Routinely Contaminated with Clinically Important Pathogens.

OBJECTIVES

To characterize contamination of ambulances and emergency medical services (EMS) clinicians with clinically important pathogens (CIPs) before and after a shift.

METHODS

Prospective observational study of 20 ambulances from two EMS agencies (10 nonemergency transport, 10 emergency 9-1-1) from September 2021 to March 2022. Samples were collected from patient-facing and clinician-facing surfaces, EMS uniforms, and right nostril before a shift and after a shift but prior to post-shift cleaning. Ambulance surfaces were disinfected by study staff after pre-shift sampling to establish a near-zero reference. The CIPs included methicillin-resistant and methicillin-sensitive Staphylococcus aureus (MRSA, MSSA), vancomycin-resistant Enterococcus (VRE), and Clostridioides difficile. The EMS clinicians completed surveys on hygiene behaviors and beliefs. Primary outcome was presence of ≥1 CIP at an individual sampling site.

RESULTS

Across 20 ambulances and 27 EMS clinicians, 941 samples were collected. Overall, 18.5% harbored ≥1 CIP. MSSA was most common (12.8%), followed by MRSA (4.6%) and VRE (3.0%). Clostridioides difficile was rare (0.1%). When deemed service ready, 63.1% of EMS clinicians and 60% of ambulances had ≥1 CIP. Post-shift contamination remained similar (EMS clinicians 67.6%, ambulances 60%). Emergency 9-1-1 ambulances had higher contamination than nonemergency ambulances. EMS clinicians reported high awareness of the importance of clean uniforms and vehicles.

CONCLUSIONS

EMS clinicians and ambulances harbor CIPs when deemed service ready and contamination accumulates during shifts. Pre-shift uniform contamination suggests clinicians may be sources of medical transport setting contamination. Improved uniform hygiene, rigorous terminal cleaning, and targeted interventions are needed to reduce medical transport-associated infection risk.