Environmental surface contamination measured by ATP assay and attitude survey of medical and cleaning staff in the examination room

Abstract

Infectious disease is transferred through 3 main routes, contact, droplet and airborne infection. It is known commonly that contact infection causes many of health-care associated infection. Control of contact infection can be achieved by maintenance of hand hygiene and cleaning of hospital interiors. However, the effectiveness of hand hygiene maintenance depends on individual conscientiousness. High frequency contact surfaces have not been clearly defined by commonly used guidelines, nor have effective cleaning methods been established. Therefore, it is important to use scientific methods to estimate the degree of contamination on the surfaces in examination rooms in order to determine which areas should be intensively cleaned. A field measurement was conducted using an Adenosine tri-phosphate (ATP) measurement method (EnSURE® & SuperSnap™; Hygiena) in examination rooms. We set the standard values on the basis of the case study by NHS Foundation Trust as RLU (Relative Light Unit) per 100 cm2. A measurement of less than 800 RLU is considered clean, 801-1599 RLU is caution, greater than 1600 RLU is recommended for immediate re-cleaning when the measurement accuracy of the equipment was taken into consideration. The attitude survey was conducted as objects of medical and cleaning staff who are assigned to the visitor examination room. The aim of questionnaire is to establish connections between conscientiousness about surface contamination of medical and cleaning staff and the substance of surface contamination. The results of a field measurement reveal that the ATP value of the patient's chair handrail after the work occurred in a significantly higher range than those of samples before the work (p < 0.05). The handrail of the doctor's chair has a significantly greater contamination than the patient's chair (before and after the work: p < 0.01) because the doctor's chair was about twofold greater contact frequency in the mean. The handrail of the doctor's chair and the outside doorknob were evaluated as high contaminated before the start and after the end of medical service. The doctor's chair had uneven surface seems one of the reason of its high-contamination. The levels of contamination in these areas might be improved by changing the timing and/or the frequency of cleaning. The inside doorknob is susceptible to contamination greater than the outside doorknob because the inside was strongly gripped to open the door. It was suggested that not only the contact frequency but also the features of surfaces and the strength of contacting pressure make difference in contamination. The attitude survey showed that medical staff are attentive to high touching surface but cleaning staff are attentive to dust-collecting surface. Surface contamination level can be decreased by changing cleaning staff consciousness. In this study, investigation was conducted before the start and after the end of medical service but the effectiveness of a single cleaning is not clearly evaluated. However, it will be possible to discuss the change of contamination in the work time by comparison observed value between before and after work.