Prior Room Occupant Research Articles

Risk of organism acquisition from prior room occupants: An updated systematic review.

Evidence from a previous systematic review indicates that patients admitted to a room where the previous occupant had a multidrug-resistant bacterial infection resulted in an increased risk of subsequent colonisation and infection with the same organism for the next room occupant. In this paper, we have sought to expand and update this review. A systematic review and meta-analysis was undertaken. A search using Medline/PubMed, Cochrane and CINHAL databases was conducted. Risk of bias was assessed by the ROB-2 tool for randomised control studies and ROBIN-I for non-randomised studies. From 5175 identified, 12 papers from 11 studies were included in the review for analysis. From 28,299 patients who were admitted into a room where the prior room occupant had any of the organisms of interest, 651 (2.3%) were shown to acquire the same species of organism. In contrast, 981,865 patients were admitted to a room where the prior occupant did not have an organism of interest, 3818 (0.39%) acquired an organism(s). The pooled acquisition odds ratio (OR) for all the organisms across all studies was 2.45 (95% CI: 1.53-3.93]. There was heterogeneity between the studies (I2 89%, P<0.001). The pooled OR for all the pathogens in this latest review has increased since the original review. Findings from our review provide some evidence to help inform a risk management approach when determining patient room allocation. The risk of pathogen acquisition appears to remain high, supporting the need for continued investment in this area.

Concerning emergence of a new vancomycin-resistant Enterococcus faecium strain ST1299/CT1903/vanA at a tertiary university centre in South Germany

vanB-carrying vancomycin-resistant Enterococcus faecium (VREfm) of the sequence types 80 (ST80) and ST117 have dominated Germany in the past. In 2020, our hospital witnessed a sharp increase in the proportion of vanA-positive VREfm. To attempt to understand these dynamics through whole-genome sequencing (WGS) and analysis of nosocomial transmissions. At our hospital, the first VREfm isolate per patient, treated during 2020, was analysed retrospectively using specific vanA/vanB PCR, WGS, multi-locus sequence typing (MLST), and core-genome (cg) MLST. Epidemiologic links between VRE-positive patients were assessed using hospital occupancy data. Isolates from 319 out of 356 VREfm patients were available for WGS, of which 181 (56.7%) fulfilled the ECDC definition for nosocomial transmission. The high load of nosocomial cases is reflected in the overall high clonality rate with only three dominating sequence (ST) and complex types (CT), respectively: the new emerging strain ST1299 (100% vanA, 77.4% CT1903), and the well-known ST80 (90.0% vanB, 81.0% CT1065) and ST117 (78.0% vanB, 65.0% CT71). The ST1299 isolates overall, and the subtype CT1903 in particular, showed high isolate clonality, which demonstrates impressively high spreading potential. Overall, 152 out of 319 isolates had an allelic cgMLST difference of ≤3 to another, including 91 (59.6%) ST1299. Occupancy data identified shared rooms (3.7%), shared departments (6.2%), and VRE-colonized prior room occupants (0.6%) within 30 days before diagnosis as solid epidemiological links. A new emerging VREfm clone, ST1299/CT1903/vanA, dominated our institution in 2020 and has been an important driver of the increasing VREfm rates.

Assessment of the effectiveness of ultraviolet-C disinfection on transmission of hospital-acquired pathogens from prior room occupants.

To evaluate the effectiveness of ultraviolet-C (UV-C) disinfection as an adjunct to standard chlorine-based disinfectant terminal room cleaning in reducing transmission of hospital-acquired multidrug-resistant organisms (MDROs) from a prior room occupant. A retrospective cohort study was conducted to compare rates of MDRO transmission by UV-C status from January 1, 2016, through December 31, 2018. Acute-care, single-patient hospital rooms at 6 hospitals within an academic healthcare system in Pennsylvania. Transmission of hospital-acquired MDRO infection was assessed in patients subsequently assigned to a single-patient room of a source occupant with carriage of 1 or more MDROs on or during admission. Acquisition of 5 pathogens was compared between exposed patients in rooms with standard-of-care chlorine-based disinfectant terminal cleaning with or without adjunct UV-C disinfection. Logistic regression analysis was used to estimate the adjusted risk of pathogen transfer with adjunctive use of UV-C disinfection. In total, 33,771 exposed patient admissions were evaluated; the source occupants carried 46,688 unique pathogens. Prior to the 33,771 patient admissions, 5,802 rooms (17.2%) were treated with adjunct UV-C disinfection. After adjustment for covariates, exposed patients in rooms treated with adjunct UV-C were at comparable risk of transfer of any pathogen (odds ratio, 1.06; 95% CI, 0.84-1.32; P = .64). Our analysis does not support the use of UV-C in addition to post-discharge cleaning with chlorine-based disinfectant to lower the risk of prior room occupant pathogen transfer.

Risk of environmental transmission of norovirus infection from prior room occupants

Environmental contamination of norovirus (NoV) is believed to be a significant source for further transmission in hospitals. To investigate the risk of acquiring NoV in a cleaned room previously occupied by a patient with NoV infection. The risk of having a roommate with recent NoV infection was also assessed. In a retrospective cohort, comprising 33,788 room stays at five infectious Disease wards in southern Sweden from 2013 to 2018, the risk of acquiring NoV infection after admission to an exposed or non-exposed room was analysed with uni- and multivariable statistical analysis, controlling for age, colonization pressure and any roommate. RNA sequencing of the NoV strains involved in suspected room transmission was also performed. Five of the 1106 patients exposed to a room with a prior occupant with NoV infection and 49 in the non-exposed group acquired NoV infection. An association between NoV acquisition was found in the univariable analysis (odds ratio (OR) 3.3, P=0.01), but not when adjusting for potential confounders (OR 1.9, P=0.2). Sequencing of the NoV samples showed that only two of the five exposed patients with acquired NoV infection were infected by identical strains to the prior room occupant, inferring a room transmission risk of 0.2% (95% confidence interval 0.05-0.78%). None of the 52 patients who shared room with a roommate with NoV symptoms resolved for ≥48 h acquired NoV infection. In absolute terms, the risk of room transmission of NoV is low. Discontinuation of isolation ≥48 h after resolution of symptoms seems adequate.

837. Contamination of Hospital Drains by Carbapenemase-Producing Enterobacterales (CPE) in Ontario, Canada

BackgroundThe hospital water environment is a CPE reservoir, and transmission of CPE from drains to patients is a risk.MethodsWe cultured sink and shower drains in patient rooms and communal shower rooms that were exposed to inpatients with CPE colonization/infection from October 2007 to December 2017 at 10 hospitals. We compared patient room drain CPE to prior room occupant CPE using Illumina and MinION whole-genome sequencing.ResultsThree-hundred and ten inpatients exposed 1,209 drains, of which 53 (4%) yielded 62 CPE isolates at 7 (70%) hospitals. Compared to room occupant CPE isolates, drain CPE isolates were more likely Enterobacter spp. (6, 10% vs. 25, 51%, p< 0.0001) or KPC-producers (9, 15% vs. 23, 47%, p=0.0002). Of the 49 CPE isolates in patient room drains, 4 (8%) were linked to a prior room occupant (Table), 24 (49%) had the same carbapenemase as a prior room occupant but isolates/carbapenemase gene-containing plasmids that were unrelated, and 21 (43%) did not share a carbapenemase with a prior room occupant. The 4 drains linked to prior room occupants were likely contaminated by these room occupants, who were CPE-colonized prior to drain exposure. Despite few links between drain and room occupant CPE, there were 10 isolates harbouring related blaNDM-1-containing IncHI2A/HI2-type plasmids in 8 rooms on two units at one hospital. Nine of these were Enterobacter hormaechei ST66 isolates that were 0 to 6 SNVs apart and one was a Klebsiella oxytoca STnovel isolate.Table. Four patient room drain CPE isolates (D1b, D4, D5, D12) and isolates from prior room occupants that they were related to by whole-genome sequencing. ConclusionIt was uncommon for drain CPE to be linked to prior patient exposure. This suggests contamination of most drains by undetected colonized patients and a need for more aggressive patient screening in our hospitals. This may also suggest retrograde (drain-to-drain) transmission, especially considering the 10 isolate drain cluster at one hospital. Reasons for the preponderance of Enterobacter spp. in drains requires further study.Disclosures Allison McGeer, MD, FRCPC, GlaxoSmithKline (Advisor or Review Panel member, Research Grant or Support)Merck (Advisor or Review Panel member, Research Grant or Support)Pfizer (Research Grant or Support)

Investigating the association of room features with healthcare-facility-onset Clostridioides difficile: An exploratory study.

To investigate hospital room and patient-level risk factors associated with increased risk of healthcare-facility-onset Clostridioides difficile infection (HO-CDI). The study used a retrospective cohort design that included patient data from the institution's electronic health record, existing surveillance data on HO-CDI, and a walk-through survey of hospital rooms to identify potential room-level risk factors. The primary outcome was HO-CDI diagnosis. A large academic medical center. All adult patients admitted between January 1, 2015, and December 31, 2016 were eligible for inclusion. Prisoners were excluded. Patients who only stayed in rooms that were not surveyed were excluded. The hospital room survey collected room-level data on 806 rooms. Included in the study were 17,034 patients without HO-CDI and 251 with HO-CDI nested within 535 unique rooms. In this exploratory study, room-level risk factors associated with the outcome in the multivariate model included wear on furniture and flooring and antibiotic use by the prior room occupant. Hand hygiene devices and fixed in-room computers were associated with reduced odds of a HO-CDI. Differences between hospital buildings were also detected. The only individual patient factors that were associated with increased odds of HO-CDI were antibiotic use and comorbidity score. Combining a hospital-room walk-through data collection survey, EHR data, and CDI surveillance data, we were able to develop a model to investigate room and patient-level risks for HO-CDI.

Carbapenemase-producing Enterobacterales in hospital drains in Southern Ontario, Canada

Hospital drains may be an important reservoir for carbapenemase-producing Enterobacterales (CPE). To determine prevalence of CPE in hospital drains exposed to inpatients with CPE, relatedness of drain and patient CPE, and risk factors for drain contamination. Sink and shower drains in patient rooms and communal shower rooms exposed to 310 inpatients with CPE colonization/infection were cultured at 10 hospitals. Using short- and long-read whole-genome sequencing, inpatient and corresponding drain CPE were compared. Risk factors for drain contamination were assessed using multi-level modelling. Of 1209 exposed patient room and communal shower room drains, 53 (4%) yielded 62 CPE isolates in seven (70%) hospitals. Of 49 CPE isolates in patient room drains, four (8%) were linked to prior room occupants. Linked drain/room occupant pairs included Citrobacter freundii ST18 isolates separated by eight single nucleotide variants (SNVs), related blaKPC-containing IncN3-type plasmids (different species), related blaKPC-3-containing IncN-type plasmids (different species), and related blaOXA-48-containing IncL/M-type plasmids (different species). In one hospital, drain isolates from eight rooms on two units were Enterobacter hormaechei separated by 0-6 SNVs. Shower drains were more likely to be CPE-contaminated than hand hygiene (odds ratio: 3.45; 95% confidence interval: 1.66-7.16) or patient-use (13.0; 4.29-39.1) sink drains. Hand hygiene sink drains were more likely to be CPE-contaminated than patient-use sink drains (3.75; 1.17-12.0). Drain contamination was uncommon but widely dispersed. Drain CPE unrelated to patient exposure suggests contamination by undetected colonized patients or retrograde (drain-to-drain) contamination. Drain types had different contamination risks.

A randomized control trial evaluating efficacy of antimicrobial impregnated hospital privacy curtains in an intensive care setting

Acquisition of pathogens into health care settings from prior room occupants has been documented. Hospital room privacy curtains are at high risk for pathogenic bacterial contamination. Antimicrobial impregnated curtains could be effective in reducing contamination. Rooms within an intensive care unit at The University of Iowa Hospitals and Clinics were randomized to 3 arms. The 2 intervention arms: (1) halamine antimicrobial curtains (BioSmart curtain [BSC]) and (2) halamine antimicrobial curtains sprayed twice weekly with a sodium hypochlorite-based disinfecting spray (BSC-pre and BSC-post) and a third control arm (standard curtain [SC]). Samples were collected twice weekly for 3 weeks to assess pathogenic bacterial contamination. The likelihood of remaining uncontaminated was 38% for SC, 37% for BSC, and 60% for the BSC-pre group. Time to event (contamination) analysis found no statistically significant difference between pathogenic contamination between the SC, BSC, and BSC-pre groups (P value = .1921). There was a decrease in average colony count for BSC curtains compared with control, however, this difference was not statistically significant. Hypochlorite spray was found to transiently decontaminate curtains, but effects dissipated after 72 hours. BSC did not show a significant reduction in pathogenic contamination compared with control. Antimicrobial curtains could have a role in reducing environmental contamination in the health care setting. Future studies should be done to determine the long-term effects of using antimicrobial curtains in health care.

Evolving Insights Into the Epidemiology and Control of Clostridium difficile in Hospitals

Typing studies suggest that most cases of hospital-onset Clostridium difficile infection (CDI) are unrelated to other cases of active disease in the hospital. New cases may instead be due to transmissions from asymptomatic carriers or progression of latent C. difficile present on admission to active infection. Direct exposure to antibiotics remains the primary risk factor for CDI but ward-level antibiotic use, antibiotic exposure of the prior room occupant, and C. difficile status of the prior room occupant increase risk for C. difficile acquisition while antibiotic exposure, gastric acid suppression, and immunosuppression increase risk for progression to infection. These insights suggest possible new approaches to prevent CDI, including screening to identify and isolate carriers, universal gloving, greater use of sporicidal cleaning methods, enhancing antibiotic and possibly proton pump inhibitor stewardship, and prescribing prophylactic vancomycin and/or probiotics to colonized patients to prevent progression from colonization to infection. We review current evidence and questions related to these interventions.

Transmission of health care-associated infections from roommates and prior room occupants: a systematic review.

Pathogens that cause health care-associated infections (HAIs) are known to survive on surfaces and equipment in health care environments despite routine cleaning. As a result, the infection status of prior room occupants and roommates may play a role in HAI transmission. We performed a systematic review of the literature evaluating the association between patients’ exposure to infected/colonized hospital roommates or prior room occupants and their risk of infection/colonization with the same organism. A PubMed search for English articles published in 1990–2014 yielded 330 studies, which were screened by three reviewers. Eighteen articles met our inclusion criteria. Multiple studies reported positive associations between infection and exposure to roommates with influenza and group A streptococcus, but no associations were found for Clostridium difficile, methicillin-resistant Staphylococcus aureus, Cryptosporidium parvum, or Pseudomonas cepacia; findings were mixed for vancomycin-resistant enterococci (VRE). Positive associations were found between infection/colonization and exposure to rooms previously occupied by patients with Pseudomonas aeruginosa and Acinetobacter baumannii, but no associations were found for resistant Gram-negative organisms; findings were mixed for C. difficile, methicillin-resistant S. aureus, and VRE. Although the majority of studies suggest a link between exposure to infected/colonized roommates and prior room occupants, methodological improvements such as increasing the statistical power and conducting universal screening for colonization would provide more definitive evidence needed to establish causality.

Transmission of Healthcare-Associated Infections From Roommates and Prior Room Occupants: A Systematic Review

Transmission of Healthcare-Associated Infections From Roommates and Prior Room Occupants: A Systematic Review

Answers linked to Mitchell BG, Dancer SJ, Anderson A, Dehn E. Risk of organism acquisition from prior room occupants: a systematic review and meta-analysis. J Hosp Infect 2015;91:211–217.

Answers linked to Mitchell BG, Dancer SJ, Anderson A, Dehn E. Risk of organism acquisition from prior room occupants: a systematic review and meta-analysis. J Hosp Infect 2015;91:211–217.

Questions linked to Mitchell BG, Dancer SJ, Anderson A, Dehn E. Risk of organism acquisition from prior room occupants: a systematic review and meta-analysis. J Hosp Infect 2015;91:211‒217.

Questions linked to Mitchell BG, Dancer SJ, Anderson A, Dehn E. Risk of organism acquisition from prior room occupants: a systematic review and meta-analysis. J Hosp Infect 2015;91:211‒217.

Frequency, Risk Factors, and Outcomes of Vancomycin-Resistant Enterococcus Colonization and Infection in Patients with Newly Diagnosed Acute Leukemia: Different Patterns in Patients with Acute Myelogenous and Acute Lymphoblastic Leukemia

OBJECTIVE To determine the frequency, risk factors, and outcomes for vancomycin-resistant Enterococcus (VRE) colonization and infection in patients with newly diagnosed acute leukemia. DESIGN Retrospective clinical study with VRE molecular strain typing. SETTING A regional referral center for acute leukemia. PATIENTS Two hundred fourteen consecutive patients with newly diagnosed acute leukemia between 2006 and 2012. METHODS All patients had a culture of first stool and weekly surveillance for VRE. Clinical data were abstracted from the Intermountain Healthcare electronic data warehouse. VRE molecular typing was performed utilizing the semi-automated DiversiLab System. RESULTS The rate of VRE colonization was directly proportional to length of stay and was higher in patients with acute lymphoblastic leukemia. Risk factors associated with colonization include administration of corticosteroids (P=0.004) and carbapenems (P=0.009). Neither a colonized prior room occupant nor an increased unit colonization pressure affected colonization risk. Colonized patients with acute myelogenous leukemia had an increased risk of VRE bloodstream infection (BSI, P=0.002). Other risk factors for VRE BSI include severe neutropenia (P=0.04) and diarrhea (P=0.008). Fifty-eight percent of BSI isolates were identical or related by molecular typing. Eighty-nine percent of bloodstream isolates were identical or related to stool isolates identified by surveillance cultures. VRE BSI was associated with increased costs (P=0.0003) and possibly mortality. CONCLUSIONS VRE colonization has important consequences for patients with acute myelogenous leukemia undergoing induction therapy. For febrile neutropenic patients with acute myelogenous leukemia, use of empirical antibiotic regimens that avoid carbapenems and include VRE coverage may be helpful in decreasing the risks associated with VRE BSI.

Prior room occupancy increases risk of methicillin-resistant Staphylococcus aureus acquisition

Abstract Background In Australia, little is known about the risk of acquiring methicillin-resistant Staphylococcus aureus (MRSA) from prior room occupants. The aims of the study are to understand the risk of MRSA acquisition from prior room occupants and to further extend the existing knowledge-base on the role of discharge cleaning in hospitals. Methods A non-concurrent cohort study was undertaken in five wards at a 250-bed general hospital in Tasmania, Australia. All admitted patients were screened for MRSA. Weekly screenings for all patients who remained in hospital were undertaken. New MRSA acquisitions were identified. The exposed group were patients whose immediate prior room occupant had MRSA, while the unexposed prior room occupant did not have MRSA. Results 6228 patients were at risk of acquiring MRSA, with 237 new MRSA acquisitions equating to an acquisition rate of 3.8% for each at-risk patient admission. The unadjusted odds ratio for acquiring MRSA when the prior room occupant had MRSA was 2.9 (95% CI 2.2–3.9). Using logistic regression, exposure to a prior occupant harbouring MRSA remained a significant predictor of subsequent acquisition, after controlling for variables, OR 2.7 (95% CI 2.0–3.6). Conclusion Admission to a room previously occupied by a person with MRSA increased the odds of acquisition forthe subsequentpatient, independent of other risk factors. It demonstrates the necessity of having effective discharge cleaning practices in place. We believe increased attention to discharge room cleaning in hospitals is required and the reconsideration of additional recommendations for discharge cleaning.

Risk of acquiring extended-spectrum β-lactamase-producing Klebsiella species and Escherichia coli from prior room occupants in the intensive care unit.

OBJECTIVE. To quantify the association between admission to an intensive care unit (ICU) room most recently occupied by a patient positive for extended-spectrum β-lactamase (EBSL)-producing gram-negative bacteria and acquisition of infection or colonization with that pathogen. DESIGN. Retrospective cohort study. SETTING AND PATIENTS. The study included patients admitted to medical and surgical ICUs of an academic medical center between September 1, 2001, and June 30, 2009. METHODS. Perianal surveillance cultures were obtained at admission to the ICU, weekly, and at discharge from the ICU. Patients were included if they had culture results that were negative for ESBL-producing gram-negative bacteria at ICU admission and had an ICU length of stay longer than 48 hours. Pulsed-field gel electrophoresis (PFGE) was performed on ESBL-positive isolates from patients who acquired the same bacterial species (eg, Klebsiella species or Escherichia coli) as the previous room occupant. RESULTS. Among 9,371 eligible admissions (7,651 unique patients), 267 (3%) involved patients who acquired an ESBL-producing pathogen in the ICU; of these patients, 32 (12%) were hospitalized in a room in which the prior occupant had been positive for ESBL. Logistic regression results suggested that the prior occupant's ESBL status was not significantly associated with acquisition of an ESBL-producing pathogen (adjusted odds ratio, 1.39 [95% confidence interval, 0.94-2.08]) after adjusting for colonization pressure and antibiotic exposure in the ICU. PFGE results suggested that 6 (18%) of 32 patients acquired a bacterial strain that was the same as or closely related to the strain obtained from the prior occupant. CONCLUSIONs. These data suggest that environmental contamination may not play a substantial role in the transmission of ESBL-producing pathogens among ICU patients. Intensifying environmental decontamination may be less effective than other interventions in preventing transmission of ESBL-producing pathogens.

Evidence that contaminated surfaces contribute to the transmission of hospital pathogens and an overview of strategies to address contaminated surfaces in hospital settings

Evidence that contaminated surfaces contribute to the transmission of hospital pathogens comes from studies modeling transmission routes, microbiologic studies, observational epidemiologic studies, intervention studies, and outbreak reports. This review presents evidence that contaminated surfaces contribute to transmission and discusses the various strategies currently available to address environmental contamination in hospitals.

Best practices in disinfection of noncritical surfaces in the health care setting: Creating a bundle for success

Because increasing evidence suggests that the environment plays a role in transmission of health care-associated infections, more attention is focusing on environmental cleaning and improving its efficacy. Creating and sustaining a successful cleaning and disinfection program should include several key components using a bundle approach and requires ongoing commitment within the institution.

How do we tackle contaminated hospital surfaces?

The role of contaminated environmental surfaces in the transmission of nosocomial pathogens has been debated for many years. Studies published in the 1970s and 1980s indicated that contaminated surfaces contributed negligibly to nosocomial transmission. However, more recent data show that bacterial endospores, vegetative bacteria and some viruses are shed into the hospital environment, can survive on dry surfaces for extended periods, usually measured in months, and can be transferred to the hands of healthcare personnel from surfaces. The most convincing evidence that contaminated environmental surfaces are important in the transmission of nosocomial pathogens comes from the finding that admission to a room previously occupied by a patient with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Clostridium difficile and certain Gram-negative rods such as Acinetobacter baumannii increased the chances of acquiring these pathogens by a factor of two or more. These data indicate that inadequate terminal disinfection is responsible for residual contamination with pathogens that increases the chances of the incoming patient acquiring a nosocomial pathogen. Thus, more needs to be done to disinfect rooms when patients are discharged (‘terminal disinfection’) in order to mitigate this increased risk. These are fever studies evaluating daily cleaning and/or disinfection during the stay of a patient. The contribution of contaminated surfaces aside from residual contamination surviving from a prior room occupant is more difficult to quantify. It seems likely that pathogens shed during the stay of a patient infected or colonised with a nosocomial pathogen will have infection control implications some of the time, for example, when acquired on the hands of healthcare personnel during patient care. Therefore, there is strong rationale for improving cleaning and disinfection both during the stay of patients and when they are discharged. A current controversy surrounds whether to improve conventional disinfection methods or to turn to ‘no-touch’ automated room disinfection (NTD) systems for terminal disinfection. The use of fluorescent markers or ATP assays to evaluate the cleaning process itself, the adoption of newer, more effective disinfectants or equipment (such a microfibre materials) can all help to improve the effectiveness of conventional methods. There is evidence that improving the efficacy of conventional cleaning and disinfection can be effective in reducing the microbial burden and transmission of nosocomial pathogens. However, there may be occasions when even optimised conventional methods do not reliably eliminate pathogens. On these occasions, an NTD system may be useful. Commonly used NTD systems include hydrogen peroxide vapour (HPV), aerosolised hydrogen peroxide (aHP) and systems based on ultraviolet C or pulsed-xenon UV. There are important differences between these systems and the choice of system will likely depend on the application. Themost studiedNTD system is HPV, which has been shown to be superior to conventional methods for the elimination of pathogens from surfaces, can help to bring outbreaks under control and can reduce the spread of pathogens in endemic settings. A recently published study from the US showed that HPV successfully mitigated the increased risk from the prior room occupant, with patients admitted to rooms disinfected using HPV being 64% less likely to acquire a multi-drug resistant organism (MDRO), particularly VRE, when the prior room occupant was infected or colonised with an MDRO. NTD systems are only useful for terminal disinfection, whereas improved conventional methods can be applied both during the stay of patients andwhen they are discharged. Thus, the most comprehensive environmental strategy would be a program of systematic improvement of conventional methods coupled with NTD disinfection of selected patient rooms. Whilst this approach would likely result in the greatest impact in terms of reduced transmissions, it would not be possible to determine the relative benefit of improved conventional methods and NTD disinfection. The ‘ultimate’ study would be a large, cluster-randomised, controlled trial to evaluate the impact of improved conventional methods and NTD disinfection individually and combined on the transmission of nosocomial pathogens. Studies of this type are likely to be performed in the future, but in themeantime, hospitals need to decide when their current methods are sufficient, when to implement improved conventional methods and when to turn toNTD systems. Iwould advocate a scenario-based approach, where the strategy chosen is dictated by the local challenges

An Evaluation of Environmental Decontamination With Hydrogen Peroxide Vapor for Reducing the Risk of Patient Acquisition of Multidrug-Resistant Organisms

Admission to a room previously occupied by a patient with certain multidrug-resistant organisms (MDROs) increases the risk of acquisition. Traditional cleaning strategies do not remove all environmental MDROs. We evaluated the environmental and clinical impact of hydrogen peroxide vapor (HPV) room disinfection. We performed a 30-month prospective cohort intervention study on 6 high-risk units in a 994-bed tertiary care hospital. Following a 12-month preintervention phase, HPV was implemented on 3 units to decontaminate the rooms of patients known to be infected or colonized with epidemiologically important MDROs, following their discharge. Monthly environmental samples for MDROs were collected on all study units for 3 preintervention and 6 intervention months. The risk of MDRO acquisition in patients admitted to rooms decontaminated using HPV was compared with rooms disinfected using standard methods. The prior room occupant was known to be infected or colonized with an MDRO in 22% of 6350 admissions. Patients admitted to rooms decontaminated using HPV were 64% less likely to acquire any MDRO (incidence rate ratio [IRR], 0.36; 95% confidence interval [CI], .19-.70; P < .001) and 80% less likely to acquire VRE (IRR, 0.20; 95% CI, .08-.52; P < .001) after adjusting for other factors. The risk of acquiring Clostridium difficile, methicillin-resistant Staphylococcus aureus, and multidrug-resistant gram-negative rods individually was reduced, but not significantly. The proportion of rooms environmentally contaminated with MDROs was reduced significantly on the HPV units (relative risk, 0.65, P = .03), but not on non-HPV units. HPV decontamination reduced environmental contamination and the risk of acquiring MDROs compared with standard cleaning protocols.