Who touched that? Interconnection of high-touch surfaces drives pathogen spread in public spaces

Abstract

Background: Surface contamination via hands plays an important role in pathogen spread in public spaces. This study aimed to identify frequently touched surfaces and evaluate the spread of a surrogate virus in a hotel lobby. Methods: In a working hotel lobby, observation was performed (30 hours) to identify the surfaces and objects touched. An entry doorknob and first floor elevator button were seeded with a bacteriophage (Phi-X174) tracer; 4 hours later 25 surfaces were swabbed to determine tracer distribution and contamination levels. Results: A total of 324 individuals performed 627 touches over 13 different fomites in the hotel lobby. The elevator button and front desk counter were the most frequently touched (32 and 22% of all touches respectively), with 55% of individuals touching the elevator button and 79% touching either the elevator button, the front desk counter, or both. More than half (56%) touched 2 or more surfaces; there were 314 interactions between surfaces. Touches from the elevator button to other surfaces (92 interactions) and from other surfaces to the elevator button (41) made up 42% of all interactions and connected the elevator button to 9 other fomites including doors, countertops, seating, a credit card reader and a hand sanitizer pump. From two seeded sites, the tracer spread to 13 surfaces over 4 hours. The most contaminated surfaces were tables, counter tops and door handles. Other contaminated objects were the luggage cart handle, sanitizer pump, and computer equipment.