In our efforts to halt transmission of harmful microbes, it is important to understand the dynamics of their transfer via hands and fomites. Previous studies have explored these dynamics in acute care and, to a lesser extent, in long-term care. While treatment in outpatient clinics is of lower acuity, it can be an important source of transmission of respiratory, gastrointestinal, and other infections. The objective of this study was to understand how organisms move through an outpatient clinic on surfaces and hands.
At the start of the clinic day, a tracer virus (bacteriophage MS2 at concentration 1 x109 plaque forming units) was inoculated onto two fomites in the outpatient clinic: the door handle exiting the patient care area and the sign in pen at the front desk. Patient care, surface cleaning practices, and hand hygiene practices continued as typical. Fomites throughout the facility (n=19), hands of clinic staff (n=4), and hands of patients (n=3-4) were sampled at 2, 3.5, and 6 hours.
At 2, 3.5, and 6 hours post-contamination, MS2 was detected on all surfaces and hands sampled. The MS2 load detected on surfaces did not significantly differ at each of the sampling times (Figure 1). Levels of MS2 collected on hands decreased over the day, detecting significantly lower numbers at 6 hours than at 2 hours (Figure 2).
Contamination spreads quickly in a high traffic outpatient clinic, reaching maximum contamination levels 2 hours after inoculation. Hands, as expected, yielded some of the highest levels of contamination. Surfaces were also serving as reservoirs of contamination, with those yielding the highest levels of contamination being door handles of exam rooms and chair arms in the nurse station. This emphasizes the importance of hand hygiene and frequent disinfection of frequently touched surfaces. Additional studies are underway evaluating the impact of targeted intervention protocols to reduce pathogen transmission.
T. Pivo, GOJO Industries: Study Sponsor , Research support
R. Leslie, GOJO Industries: Employee , Salary
A. Tamimi, GOJO Industries: Study Sponsor , Research support
C. Gerba, GOJO Industries: Study Sponsor , Research support