Healthcare Hygiene magazine October 2019

studies evaluating both environmental contamination as well as acquisition also have the potential for identifying a threshold of environmental contamination below which transmission and therefore disease risk is minimized. Identifying such a threshold for key healthcare pathogens could then facilitate additional studies using such a threshold as an acceptable ‘gold standard’ for minimizing disease risk.” As Carling, et al. (2014) emphasize, “Our findings shed further light on the challenge of defining when an apparently clean healthcare surface might reasonably be considered bacterially contaminated enough to provide evidence of poor cleaning practice or be defined as dirty. Several years ago, it was suggested that the industrial hygiene threshold for defining food preparation surfaces as clean (ACC of less than 2.5 CFU/cm2) could be used to evaluate the cleanliness of near-patient surfaces in healthcare and that surfaces con- taining heavier bacterial bioburdens be defined as cleaning failures. Although a plausible concept, logistical limitations as well as the fact that the standard has yet to be correlated with the relative risk of transmission of healthcare-associated pathogens have been noted by several authors.” The Future In the 15 years since UK microbiologist Stephanie J. Dancer first proposed a microbiological standard, she continues to emphasize the importance of a standard, akin to a CFU formula. In a paper she co-authored last year, Dancer and her colleagues had investigated if any correlation existed between environmental contamination of air and surfaces in the ICU, and any association between environmental contamination and ICU-acquired staphylococcal infection. In this study, Smith and Adams, et al. (2018) screened patients, air, and surfaces were screened on 10 sampling days in a mechanically ventilated 10-bed ICU for a 10-month period. Near-patient hand-touch sites (N = 500) and air (N = 80) were screened for total colony count and Staphylococcus aureus. Air counts were compared with surface counts ac- cording to proposed standards for air and surface bioburden. Patients were monitored for ICU-acquired staphylococcal infection throughout. The researchers found that overall, 235 of 500 (47 percent) surfaces failed the standard for aerobic counts (≤2.5 CFU/ cm2). The researchers note that, “The surface standard most likely to reflect hygiene pass/fail results compared with air was 5 CFU/cm2. Rates of ICU-acquired staphylococcal infection were associated with surface counts per bed in 72 hours encompassing sampling days.” “The standards proposed in this paper do work, but it’s for the UK,” Dancer explains. “We clean with detergent. I doubt if they equate to a hospital that douses every surface imaginable with powerful disinfectants.” Still, Dancer says that despite knowing how quickly pathogens can return to surfaces, especially given poor hand hygiene efforts, a standard of “clean” could work. “I’m a glass-half-full person,” she says. “Of course, we can define ‘clean.’ You just have to understand the risk.” References: Al-Hamad A and Maxwell S. How clean is clean? Proposed methods for hospital cleaning assessment. J Hosp Infect. 2008 Dec;70(4):328-34. Bartlett AH. How Clean Is Clean Enough -- And How Do We Get There? Medscape, Dec. 29, 2014. Campbell J, Jones C and Hill BB. Cleaning: Finding a Microbiological Standard. Int J Facility Management. Vol.5, No.1. November 2014. Carling PC, Perkins J, Ferguson J, and Thomasser A. Evaluating a New Paradigm for Comparing Surface Disinfection in Clinical Practice. In- fection Control and Hospital Epidemiol. Vol. 35, No. 11, November 2014. Carling PC. Methods for assessing the adequacy of practice and improving room disinfection. American Journal of Infection Control. Volume 41, Issue 5, Supplement, May 2013, Pages S20-S25. Carling PC, Parry MF, et a. Identifying opportunities to enhance environmental cleaning in 23 acute care hospitals. Infect Control Hosp Epidemiol, 29 (2008), pp. 1-7. Casini B, Tuvo B, et al. Evaluation of the Cleaning Procedure Efﬁcacy in Prevention of Nosocomial Infections in Healthcare Facilities Using Cultural Method Associated with High Sensitivity Luminometer for ATP Detection. Pathogens 2018, 7, 71. Chai J, Donnelly T, et al. Environmental sampling of hospital surfaces: Assessing methodological quality. Canadian J Infect Control. Vol. 33, No. 3. Pp 138-145. Fall 2018. Cloutman-Green E, et al. How clean is clean—is a new microbiology standard required? Am J Infect Control. Vol. 42, No. 9, September 2014, Pages 1002-1003. Dancer SJ. How do we assess hospital cleaning? A proposal for microbiological standards for surface hygiene in hospitals. J Hosp Infect. 2004 Jan;56(1):10-5. Dettenkofer M, et al. Does disinfection of environmental surfaces influence nosocomial infection rates? A systematic review. Am J Infect Control, 32 (2004), pp. 84-89 Doll M, Stevens M and Bearman G. Environmental cleaning and disinfection of patient areas. International Journal of Infectious Diseases. Vol. 67, February 2018, Pages 52-57. Donskey CJ. Does improving surface cleaning and disinfection reduce health care-associated infections? Am J Infect Control. 2013 May;41(5 Suppl):S12-9. Dumigan DG, Boyce JM, et al. Who is really caring for your environ- ment of care? Developing standardized cleaning procedures and effective monitoring techniques. Am J Infect Control, 38 (2010), pp. 387-392. Guh A and Carling PC. The Environmental Evaluation Workgroup. Op- tions for evaluating environmental cleaning. Atlanta: Centers for Disease Control and Prevention, 2010. Hayden MK, et al. Reduction in acquisition of vancomycin-resistant enterococcus after enforcement of routine environmental cleaning mea- sures. Clin Infect Dis, 42 (2006), pp. 1552-1560 Lewis T, Griffith C, Gallo M, Weinbren M: A modified ATP benchmark for evaluating the cleaning of some hospital environmental surfaces. J Hosp Infect 2008, 69(2):156-63. Mulvey D, et al. Finding a benchmark for monitoring hospital cleanli- ness. J Hosp Infect. Vol. 77, No. 1. Pp. 25-30. January 2011. Nante N, et al. Effectiveness of ATP bioluminescence to assess hospi- tal cleaning: a review. J Prev Med Hyg. 2017 Jun; 58(2): E177–E183. Otter JA, Yezli S and French GL. The role played by contaminated surfaces in the transmission of nosocomial pathogens. Infect Control Hosp Epidemiol, 32 (2011), pp. 687-699. Rawlinson S, Ciric L, Cloutman-Green E. How to carry out microbio- logical sampling of healthcare environment surfaces? A review of current evidence. J Hosp Infect. 2019 Jul 29. pii: S0195-6701(19)30309-3. Ryan MO, Haas CN, et al. Application of quantitative microbial risk assessment for selection of microbial reduction targets for hard surface disinfectants. Am J Infect Control. Vol. 42, No. 11, Pp. 1165-1172. November 2014. Smith J, Adams CE, et al. (2018) Is there an association between airborne and surface microbes in the critical care environment? J Hosp Infect. November 2018. Vol. 100, No. 3, Pages e123-e129. Weber DJ, Rutala WA, et al. Role of hospital surfaces in the transmission of emerging healthcare-associated pathogens: norovirus, Clostridium difficile, and Acinetobacter species. Am J Infect Control, 38 (2010), pp. S25-S33. There’s more content online! For a web exclusive on the infective dose, plus a Q&A with environmental hygiene expert Philip Carling, MD, visit: https://www.healthcarehygienemagazine.com/web-exclusives/ www.healthcarehygienemagazine.com • october 2019 27

Healthcare Hygiene magazine October 2019 | Page 27