Can the adenosine triphosphate (ATP) bioluminescence assay be used as an indicator for hospital cleaning? - A pilot study

Background

In hospital cleaning, there is currently no standard for uniform monitoring of surface cleaning, either in Germany or internationally. One possibility for monitoring is the use of so-called objective methods for checking cleaning performance (e.g. fluorescence or adenosine triphosphate (ATP) method).

Aim

The aim of the study was to monitor and evaluate the implementation of the adenosine triphosphate (ATP) bioluminescence assay as a cleaning indicator in everyday hospital cleaning, in order to verify its utility and effectiveness.

Methods

In three phases, five frequently touched surfaces were examined with the ATP bioluminescence assay at different time points. 846 measurements were performed on the dermatology ward of a university hospital (phase 1), 1,350 measurements were performed on five different wards of the university hospital (phase 2), and 1,044 measurements were performed on five wards of another large hospital (phase 3). For this purpose, one structurally old and one structurally new ward as well as an intensive care unit (ICU), an outpatient clinic and a radiology department were selected for phases 2 and 3.

Results

With the ATP bioluminescence method, we were able to demonstrate a reduction in values after cleaning: before cleaning mean of ATP, 907 relative light units (RLU) (95% confidence interval [CI] 777; 1,038); after cleaning mean=286 RLU (CI=233; 495) (phase 1) and by intervention (five hours after daily cleaning mean=360 RLU (CI=303; 428); five hours after daily cleaning and two additional cleanings mean=128 RLU (CI=107; 152) (phase 3). The ATP values increased five hours after cleaning in phases 1 and 2, and eight hours after cleaning in phase 3. The structurally old wards had the highest ATP content, the ICU and the radiology department, among others, the lowest. In all phases, door handles showed both a reduction after cleaning or intervention and a subsequent increase in ATP values. Chair armrests, examination tables and door handles had high ATP values overall.

Conclusion

The study shows ward differences both for cleaning effects and for the soiling characteristics of surfaces during the course of the day. In addition, it demonstrates the benefit of intermediate cleaning twice a day. It is noteworthy that structurally old stations and older inventory were more heavily soiled and, in some cases, more difficult to clean. The results show that the ATP bioluminescence method is suitable for detecting cleaning effects and can be used in everyday clinical practice for simple cleaning monitoring. Furthermore, it enables the detection of risk surfaces and easy-to-clean surfaces with significant re-soiling.

Comparison of steam technology and a two-step cleaning (water/detergent) and disinfecting (1,000 resp. 5,000 ppm hypochlorite) method using microfiber cloth for environmental control of multidrug-resistant organisms in an intensive care unit

Aim: The aim of this prospective observational study was to evaluate the impact of two cleaning and disinfecting methods and the use of steam against methicillin-resistant Staphyl ococcus aureus, vancomycin-resistant Enterococcus faecalis, carbapenem-resistant Pseudomonas aeruginosa and multidrug-resistant (MDR) Acinetobacter baumannii in a tertiary referral hospital. Methods: McFarland 0.5 suspensions (content 1.5 x 10⁸ cfu/ml) of four challenge bacterial species were prepared and used to inoculate different sites in three ICU rooms. One of the following methods was used in each room: steam technology (Tecnovap Evo 304) resp. cleaning with microfiber cloths, soaked with detergent and water, thereafter disinfection with 1,000 ppm hypochlorite or the same procedure with 5,000 ppm hypochlorite. Qualitative microbiology and ATP bioluminescence were performed before and after cleaning with each method. The Wilcoxon test was used for paired samples to check for ordinal variables. The cost of each cleaning method was analyzed. Results: Environmental cleaning with steam technology was found to be as effective against MDR microorganisms as a two-step cleaning process (water/detergent and disinfecting with 1,000 resp. 5,000 ppm hypochlorite) in ICUs. No bacterial growth was detected after any of the three cleaning methods. Steam technology was 76% and 91% cheaper than using 5,000 ppm and 1,000 ppm hypochlorite, respectively. Conclusions: When compared to, steam technology was found to have an advantage over the 2-step procedure with cleaning and disinfection, because it avoids the use of chemicals, reduces water consumption, labor time and costs for cleaning.

Healthcare-acquired infections: prevention strategies

Healthcare-acquired infections (HAI) impact on patient care and have cost implications for the Australian healthcare system. The management of HAI is exacerbated by rising rates of antimicrobial resistance (AMR). Health-care workers and a contaminated hospital environment are increasingly implicated in the transmission and persistence of multi-resistant organisms (MRO), as well as other pathogens, such as Clostridium difficile. This has resulted in a timely focus on a range of HAI prevention actions. Core components include antimicrobial stewardship, to reduce overuse and ensure evidence-based antimicrobial use; infection prevention strategies, to control MRO - particularly methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp. (VRE) and, more recently, multi-resistant Gram-negative bacteria; enhanced institutional investment in hand hygiene; hospital cleaning and disinfection; and the development of prescribing guidelines and standards of care. AMR surveillance and comparisons of prescribing are useful feedback activities once effectively communicated to end users. Successful implementation of these strategies requires cultural shifts at local hospital level and, to tackle the serious threat posed by AMR, greater co-ordination at a national level. HAI prevention needs to be multi-modal, requires broad healthcare collaboration, and the strong support and accountability of all medical staff.

How do we assess hospital cleaning? A proposal for microbiological standards for surface hygiene in hospitals

Increasing numbers of hospital-acquired infections have generated much attention over the last decade. The public has linked the so-called 'superbugs' with their experience of dirty hospitals, but the precise role of cleaning in the control of these organisms in unknown. Hence the importance of a clean environment is likely to remain speculative unless it becomes an evidence-based science. This proposal is a call for bacteriological standards with which to assess clinical surface hygiene in hospitals, based on those used by the food industry. The first standard concerns any finding of a specific 'indicator' organism, the presence of which suggests a requirement for increased cleaning. Indicators would include Staphylococcus aureus, including methicillin-resistant S. aureus, Clostridium difficile, vancomycin-resistant enterococci and various Gram-negative bacilli. The second standard concerns a quantitative aerobic colony count of <5 cfu/cm(2) on frequent hand touch surfaces in hospitals. The principle relates to modern risk management systems such as HACCP, and reflects the fact that pathogens of concern are widespread. Further work is required to evaluate and refine these standards and define the infection risk from the hospital environment.