Cleaning and disinfecting are crucial for preventing or minimizing the spread of contagious and zoonotic diseases and nosocomial infections. Determining cleaning efficacy is commonly done with bacterial culture of surfaces but can be delayed and expensive. Adenosine triphosphate bioluminescence has been used but may be cost limiting. Environmental marking dyes (ie, environmental tagging) have been investigated, involving application of a fluorescent dye on a surface with subsequent evaluation after cleaning.

In this study, surfaces in a veterinary hospital and small animal referral hospital were contaminated with a fluorescent dye, and cleaning was assessed 24 hours later. Of the 563 sites, 70 could not be reevaluated (eg, equipment movement, lack of room access). Of the remaining, the dye was completely removed from 212 (43%) sites. Successful cleaning by specific locations included examination rooms (35%), wards (26%), treatment rooms (71%), operating rooms (73%), and intensive care units (64%). Site-specific successful cleaning included handles and door knobs (49%), computer keyboards and mouses (14%), medical equipment (14%), examination table tops (81%), counter tops (80%), sink taps (52%), cage handles (50%), handheld equipment (eg, bandage scissors) (18%), consumable item packages (eg, bandage materials) (16%), chair handles and backs (33%), hand sanitizer dispenser tops (20%), floors (75%), and gurneys (57%).

Often demonstrating transmission of infectious agents, GloGerm Gel ( was used to tag surfaces of the veterinary hospital. A Wood’s lamp can show the contamination, and this can be particularly powerful with respect to cross-contamination via touching and clothing. One positive outcome of the study was easy recognition of contamination and teamwork in problem solving (eg, how to better clean and disinfect). For staff, the transmission of human viral infections is of specific concern. There are many types of germ-control keyboards available, as well as washable keyboards and mouses. Minimizing staff sick days can be enhanced by investing in newer equipment, but the staff still needs to regularly wash hands and equipment.—Karen A. Moriello, DVM, DACVD

Use of fluorescent tagging for assessment of environmental cleaning and disinfection in a veterinary hospital. Weese JS, Lowe T, Walker M. VET REC 171:217, 2012.