Comparison of UV C Light and Chemicals for Disinfection of Surfaces in Hospital Isolation Units

Objective. To determine the bactericidal effect on surfaces of ceiling‐ and wall‐mounted UV C (UVC) light (wavelength, 254 nm) in isolation units, compared with standard hospital environmental cleaning and chemical disinfection during final disinfection after patients are treated for infections. Design. Microbial samples were obtained from surfaces in isolation units (patient room, anteroom, and bathroom) before and after irradiation with UVC, chloramine disinfection, and standard hospital environmental cleaning. Samples were tested using standard contact plates. Setting. Four identical, negative air‐pressure isolation units (patient room, anteroom, and bathroom) with a defined number of ceiling‐ and wall‐mounted UVC light units. The UVC distribution was monitored in one isolation unit after irradiation for approximately 40 minutes, corresponding to doses ranging from 160 J/m2 in a shadowed area to 19,230 J/m2 at the mostly highly exposed site (which is high enough to inactivate most bacterial organisms, ...