ANTIMICROBIAL TREATED CONSTRUCTION MATERIALS AND AIR FILTERS REDUCE FACILITY BIOBURDEN AND IMPROVE AIR QUALITY IN A HEALTHCARE ENVIRONMENT

摘要

To the authors' knowledge, this study is the first of its kind involving a healthcare setting. The purpose was to see if the total bioburden or level of microorganisms present in a healthcare environment could be reduced through antimicrobial treatment of surfaces and the air. Since the building was new and contained two identical wings, each containing 12500 square feet (1157 m~2), it offered the authors a unique opportunity to conduct a controlled 'real world' study.rnThe treatment consisted of using the well known chlorine based antimicrobial agent triclosan, either through the application of existing products or by developing special purpose products. Physical components of the treated wing included permanent and moveable fixtures, medical instruments, furniture, walls, floors, ceilings and air filters. Included were telephones, computers, filing cabinets, sinks, counters, exam tables, doors and hardware etc. Each item in the treated wing had a corresponding control item on the untreated wing that was tested for comparison. A total of 45 items were selected in each wing for testing surface bioburden. There were 10 locations selected for air sampling on each of the two wings.rnThe results of the 18-month study showed an average of 40% reduction in colony forming units (cfu) for treated surfaces and a 58% reduction of air borne microorganisms. In the case of air sampling, it was interesting to find that the air quality in the treated wing consistently improved, while that of the untreated wing got progressively worse. The antimicrobial treatment enabled the wing to maintain the level of airborne bioburden to within 16% of that found in the microbiology lab.rnUnfortunately, this study cannot be used to determine what effect the triclosan-treated reusable air filters may have had on reducing the airborne bioburden within the treated wing since the triclosan-treated filters were installed at the same time as the other surfaces were treated. Although the authors realized this at the beginning of the study, there was insufficient time and resources to conduct a comparison of the effect of different treatment applications.rnDuring the study period both wings were used for the same type of outpatient care. This was important to the validity of the study, since dissimilar use functions could have affected the test results and negated a direct comparison. Also, since hospital employees conducted all building maintenance and antimicrobial treatment, strict supervision and proper implementation of specific protocols for cleaning and treating was made possible.rnThe study had to be terminated after the 18-month period, since after one year of occupancy, renovations and functional changes were being scheduled by management. These resulted in the wings being used for very different types of patient care. Also, to reduce operating costs, all maintenance for the building was contracted out and this prevented any further study to be conducted.rnWhat impact this type of environmental treatment could have on the reduction of nosocomial infections in more critical care facilities remains to be seen. The cost of environmental treatment would have to be determined and compared against any reductions in nosocomial infection rates. However, similar treatment approaches could be integrated into infection control activities and studied within a hospital setting. If nothing else, the building and the patient environment could be maintained in a 'cleaner' state of preparedness. Additional comparison of personnel absenteeism rates before and after treatment might also prove interesting, in light of the increasing evidence of the effects of 'sick building syndromes.'