Active follow-up of patients identified with multidrug-resistant Gram-negative bacteria to discontinue contact precautions and isolation measures.

BACKGROUND: It is essential to refrain from unnecessary isolation measures indicated for patients identified with multidrug-resistant Gram-negative bacteria (MDR-GNB). AIM: To evaluate whether a pro-active follow-up strategy to discontinue isolation measures of patients identified with MDR-GNB (without carbapenemase production) resulted in reduced isolation days during hospitalization, compared to passive follow-up. METHODS: A comparison was made between active and passive follow-up strategies over a two-year period after first MDR-GNB identification. Patients could be declared negative after two consecutive negative screening cultures. Active follow-up patients received a questionnaire for screening cultures within six months of MDR-GNB identification. Of the 2208 patients included, 1424 patients (64.5%) underwent passive follow-up and 784 patients (35.5%) underwent active follow-up. FINDINGS: A significantly higher proportion of active follow-up patients who had sufficient (at least two) screening cultures were declared MDR-GNB negative compared to those with passive follow-up; 66.9% vs 20.6% (P < 0.001) for adult patients and 76.0% vs 17.1% (P < 0.001) for paediatric patients. A comparison between active follow-up patients with sufficient versus those with active follow-up but insufficient cultures revealed a reduction of isolation days for paediatric patients (median 10.6 vs 1.6 days; P = 0.031). Though this difference was not statistically significant for adults (median 5.3 vs 4.2 isolation days), there was a valuable decrease in the number of isolation days for both adult and paediatric patients under active follow-up with sufficient (≥2) cultures, indicating clinical relevance. CONCLUSION: We recommend an active follow-up strategy for patients identified with an MDR-GNB, to prevent further unneeded infection prevention measures.

Regional variation in the interpretation of contact precautions for multi-drug-resistant Gram-negative bacteria: a cross-sectional survey.

BACKGROUND: Contact precautions are recommended when caring for patients with carbapenemase-producing Enterobacterales (CPE), carbapenemase-producing Pseudomonas aeruginosa (CPPA), and extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E). AIM: Our aim was to determine the interpretation of contact precautions and associated infection prevention and control (IPC) measures in the non-ICU hospital setting for patients with CPE, CPPA or ESBL-E in 11 hospitals in the Southwest of the Netherlands. METHODS: A cross-sectional survey was developed to collect information on all implemented IPC measures, including use of personal protective equipment, IPC measures for visitors, cleaning and disinfection, precautions during outpatient care and follow-up strategies. All 11 hospitals were invited to participate between November 2020 and April 2021. FINDINGS: The survey was filled together with each hospital. All hospitals installed isolation precautions for patients with CPE and CPPA during inpatient care and day admissions, whereas 10 hospitals (90.9%) applied isolation precautions for patients with ESBL-E. Gloves and gowns were always used during physical contact with the patient in isolation. Large variations were identified in IPC measures for visitors, cleaning and disinfection products used, and precautions during outpatient care. Four hospitals (36.4%) actively followed up on CPE or CPPA patients with the aim of declaring them CPE- or CPPA-negative as timely as possible, and two hospitals (20.0%) actively followed up on ESBL-E patients. CONCLUSION: Contact precautions are interpreted differently between hospitals, leading to regional differences in IPC measures applied in clinical settings. Harmonizing infection-control policies between the hospitals could facilitate patient transfers and benefit collective efforts of preventing transmission of multi-drug-resistant Gram-negative bacteria.

A search strategy for detecting duodenoscope-associated infections: a retrospective observational study.

BACKGROUND: Duodenoscope-associated infections (DAIs) are exogenous infections resulting from the use of contaminated duodenoscopes. Though numerous outbreaks of DAI have involved multidrug-resistant micro-organisms (MDROs), outbreaks involving non-MDROs are also likely to occur. Detection challenges arise as these infections often resolve before culture or because causative strains are not retained for comparison with duodenoscope strains. AIM: To identify and analyse DAIs spanning a seven-year period in a tertiary care medical centre. METHODS: This was a retrospective observational study. Duodenoscope cultures positive for gastrointestinal flora between March 2015 and September 2022 were paired with duodenoscope usage data to identify patients exposed to contaminated duodenoscopes. Analysis encompassed patients treated after a positive duodenoscope culture and those treated within the interval from a negative to a positive culture. Patient identification numbers were cross-referenced with a clinical culture database to identify patients developing infections with matching micro-organisms within one year of their procedure. A 'pair' was established upon a species-level match between duodenoscope and patient cultures. Pairs were further analysed via antibiogram comparison, and by whole-genome sequencing (WGS) to determine genetic relatedness. FINDINGS: Sixty-eight pairs were identified; of these, 21 exhibited matching antibiograms which underwent WGS, uncovering two genetically closely related pairs categorized as DAIs. Infection onset occurred up to two months post procedure. Both causative agents were non-MDROs. CONCLUSION: This study provides crucial insights into DAIs caused by non-MDROs and it highlights the challenge of DAI recognition in daily practice. Importantly, the delayed manifestation of the described DAIs suggests a current underestimation of DAI risk.

Validity of self-reported compliance and behavioural determinants of observed compliance: an application of the COM-B hand hygiene questionnaire in nine Dutch hospitals.

BACKGROUND: Hand hygiene compliance (HHC) can be influenced by behavioural determinants, but knowledge on this remains scarce. The Capability, Opportunity, Motivation-Behaviour (COM-B) hand hygiene questionnaire was developed by Lydon et al. to gain insight into self-reported behavioural determinants and self-reported HHC. AIMS: To determine the validity of self-reported HHC using the COM-B questionnaire; and investigate the influence of self-reported behavioural determinants on observed HHC, taking environmental determinants into account. METHODS: This was a cross-sectional study, from September to November 2019, in nine hospitals in the Netherlands. Healthcare workers (HCWs) completed the COM-B questionnaire, and direct hand hygiene observations were performed. In addition, information on environmental determinants (workload, ward category, hospital type and ward infrastructure) was collected. Validity of self-reported HHC was determined using the intraclass correlation coefficient (ICC). Univariable and multi-variable regression analyses were performed to investigate the relationship between behavioural and environmental determinants and observed HHC. FINDINGS: The ICC showed no association between self-reported HHC and observed HHC [0.04, 95% CI -0.14 to 0.21]. In univariable regression analyses, ward category and the opportunity and motivation subscales were significantly associated with observed HHC. In multi-variable regression analysis, only ward category and the motivation subscale remained significant. CONCLUSION: Self-reported HHC is not a valid substitute for direct hand hygiene observations. Motivation (behavioural determinant) was significantly associated with HCC, while almost none of the environmental determinants had an effect on observed HHC. In further development of hand hygiene interventions, increasing the intrinsic motivation of HCWs should receive extra attention.

Higher yield in duodenoscope cultures collected with addition of neutralizing agent.

AIM: Microbiological cultures are the gold standard in the monitoring of duodenoscope reprocessing. However, many different sampling and culturing techniques are used, making it difficult to compare results. The latest Centers for Disease Control and Prevention protocol advises the use of a neutralizer to deactivate any remaining disinfectants in the samples. This study compared culturing results of duodenoscope samples collected with and without addition of a neutralizer. METHODS: Six duodenoscopes were soiled with gut bacteria in a non-clinical experimental setting and reprocessed afterwards. Samples of the tip and working channel were collected immediately after decontamination or after drying. Dey-Engley (DE) broth was added as a neutralizer to the samples of four duodenoscopes; samples for the other two duodenoscopes were collected without the addition of DE broth. RESULTS: Post-decontamination cultures were significantly more likely to be positive for growth of the applied micro-organisms in the group of samples with DE broth (88.1% vs 20.2%; P<0.0001). Post-drying samples were significantly more likely to be positive in the group of samples without DE broth (75.7% vs 33.4%; P<0.001). CONCLUSION: The addition of DE broth to samples collected from wet duodenoscopes increases the yield of those cultures. Remaining disinfectants in wet duodenoscopes can lead to false-negative results. This can be overcome by adding a neutralizer, such as DE broth, to the samples. The higher yield after drying in the group without neutralizer could be due to biofilm formation in these two duodenoscopes, but this was not investigated. Standardization of the sampling method can help to compare both clinical and study results regarding duodenoscope contamination.

Compliance with a novel hand hygiene protocol tailored to non-sterile healthcare workers in the operating theatre.

BACKGROUND: Observing hand hygiene compliance (HHC) among non-sterile healthcare workers (HCWs) in the operating theatre (OT) is challenging as there are no tailored protocols or observation tools. AIM: To develop and test a hand hygiene protocol tailored to non-sterile HCWs in the OT. METHODS: In this prospective observational study, nine hospitals in the Rotterdam-Rijnmond region provided input on a draft protocol on hand hygiene in the OT, resulting in a new consensus protocol for the region. An observation tool based on the protocol was developed and tested. HHC rates with 95% confidence intervals (CI) were calculated by type of hospital and type of HCW. FINDINGS: The protocol has three sections: (1) written general hand hygiene rules; (2) written hand hygiene rules specific for anaesthesia and surgery; and (3) visual representation of the OT, divided into four hand hygiene areas. Hand hygiene should be applied when changing area. Average HHC of 48.0% (95% CI 45.2-61.2%) was observed in OTs across all hospitals. HHC was highest in the two specialized hospitals (64.0%, 95% CI 30.6-89.8%; 76.7%, 95% CI 62.8-84.5%) and lowest in the academic teaching hospital (23.1%, 95% CI 0.0-45.8%). In terms of type of HCW, HHC was lowest among anaesthesiologists (31.6%, 95% CI 19.2-62.4%) and highest among OT assistants (57.4%, 95% CI 50.1-78.2%). CONCLUSION: This uniform way of observing HHC in the OT enables evaluation of the effectiveness of interventions in the OT and facilitates friendly competition. In the Rotterdam-Rijnmond region, HHC in the OT was below 50%; this needs to be addressed, particularly in teaching hospitals and among physicians.

Vermamoeba vermiformis resides in water-based heater-cooler units and can enhance Mycobacterium chimaera survival after chlorine exposure.

BACKGROUND: Mycobacterium chimaera colonizes water-based heater-cooler units (HCUs), from which it can spread to patients during surgery. Vermamoeba vermiformis is a free-living waterborne amoeba, which was consistently present within HCUs. AIM: To determine whether these amoebae can be involved in the persistent presence of M. chimaera. METHODS: An in-vitro disinfection model. FINDINGS: Increased survival of M. chimaera was observed after chlorine exposure in the presence of V. vermiformis. Confocal microscopy demonstrated the intracellular presence of M. chimaera in V. vermiformis. CONCLUSION: In this way, V. vermiformis can contribute to the persistent presence of M. chimaera in HCUs. Cleaning and disinfection protocols should take this phenomenon into account.

Environmental sampling of innate hospital surfaces: a survey of current practices and the need for guidelines.

BACKGROUND: Surfaces in healthcare facilities can act as reservoirs of infection. Currently, no standardized protocol on when and how to sample hospital surfaces exists. AIM: A web-based questionnaire was devised to gain insight into current sampling practices and was distributed by email to a targeted infection prevention and control (IPC) audience. METHODS: The survey consisted of 26 questions on sample collection and processing for a number of healthcare relevant bacterial species. FINDINGS: The majority of respondents were clinical microbiologists or IPC practitioners, and 57.3% were from either the Netherlands, the United Kingdom, or Ireland. Respondents had high self-reported knowledge, but this was not consistent with response to certain questions. There was no consensus on sample sites, either within or between countries. Indirect sampling methods were preferred for all target microorganisms, and cotton and flocked swabs were the most popular methods. CONCLUSION: The results of our survey highlight the inconsistencies in environmental sampling between and within countries, and the need for guidance and consensus.

Impact of sink design on bacterial transmission from hospital sink drains to the surrounding sink environment tested using a fluorescent marker.

In hospitals, sinks act as reservoirs for bacterial pathogens. To assess the extent of splashing, fluorescein dye was added to four hospital sinks previously involved in pathogen dispersal to the environment and/or transmission to patients, and one sink that was not. Applying dye to the p-trap or tailpiece did not result in any fluorescent droplets outside of the drain. When applied to the drain, droplets were found in all but one wash basin, and this was more common in the absence of a drain plug. Sink design considerations to install drain plugs, reduce dripping and offset the tap may help to prevent transmission from drains.

Incomplete surgical staging in clinical early-stage ovarian cancer: guidelines versus daily practice.

BACKGROUND: Incomplete surgical staging of patients with early-stage epithelial ovarian cancer (EOC) has been reported in up to 98% of cases, when based on the International Federation of Obstetrics and Gynecology (FIGO) staging procedure. The aim of the present retrospective study was to clarify the reasons for incomplete staging. METHODS: The PRISMA (Prevention Recovery Information System for Monitoring and Analysis) technique was used to evaluate cases with FIGO I-IIa EOC based on incomplete staging from five gynecologic oncologic center hospitals in the Netherlands in the period 2010-2014. RESULTS: Fifty cases with an incomplete surgical staging of EOC according to national guidelines were included. The most common reasons for incomplete staging were insufficient random biopsies of the peritoneum (n = 34, 68%), and less than ten lymph nodes being resected and/or found at pathology (n = 16, 32%). The most mentioned reason for not performing biopsies was, besides forgetting to do so, believing that after careful inspection and palpation, taking biopsies is irrelevant and/or already are being taken while performing a hysterectomy (peritoneum of cul-de-sac, bladder). The value of contralateral pelvic lymph node dissection in case of a unilateral ovarian malignancy was also doubted, influencing the number of lymph nodes resected. CONCLUSIONS: The most important reasons for incomplete staging in EOC are, besides omitting elements by accident, questioning the importance of obligatory elements of the staging procedure. A structured list of staging steps during surgery and more evidence-based consensus concerning these obligatory elements might increase the number of complete staging procedures in EOC.

Association of environmental surface contamination with hand hygiene and infections in nursing homes: a prospective cohort study.

BACKGROUND: Little is known about the presence of infections in nursing home residents, the causative micro-organisms, how hand hygiene (HH) influences the presence of infections in residents, and the extent to which environmental contamination is associated with the incidence of infection among residents. AIMS: To establish if environmental contamination can be used as an indicator for HH compliance, and if environmental contamination is associated with the incidence of infection. METHODS: Environmental surface samples (ESS) were collected in an exploratory study as part of a HH intervention in 60 nursing homes. ESS results from three distinct surfaces (nurses' station, communal toilet and residents' shared living area) were compared with nurses' HH compliance and the incidence of infection among residents. Real-time polymerase chain reaction assays were used to detect norovirus genogroup I and II, rhinovirus and Escherichia coli. HH compliance was measured by direct observation. The incidence of infection was registered weekly. FINDINGS: Rhinovirus (nurses' station: 41%; toilet: 14%; living area: 29%), norovirus (nurses' station: 18%; toilet: 12%; living area: 16%) and E. coli (nurses' station: 14%; toilet: 58%; living area: 54%) were detected. No significant (P<0.05) associations were found between HH compliance and the presence of micro-organisms. An association was found between E. coli contamination and the incidence of disease in general (P=0.04). No other associations were found between micro-organisms and the incidence of disease. CONCLUSION: Rhinovirus, norovirus and E. coli were detected on surfaces in nursing homes. No convincing associations were found between environmental contamination and HH compliance or the incidence of disease. This study provides reference data about surface contamination.

The effect of a hand hygiene intervention on infections in residents of nursing homes: a cluster randomized controlled trial.

BACKGROUND: The primary goal of hand hygiene is to reduce infectious disease rates. We examined if a nursing home's participation in a hand hygiene intervention resulted in residents having fewer healthcare associated infections (HAIs) when compared to nursing homes without the hand hygiene intervention. METHODS: This study is a part of a cluster randomized controlled trial (RCT) in 33 nursing homes to improve hand hygiene (HANDSOME). The incidence of five illnesses was followed over 13 months: gastroenteritis, influenza-like illness, pneumonia, urinary tract infections and infections from methicillin-resistant Staphylococcus aureus (MRSA). Incidence rates per study arm were reported for baseline (October-December 2016) and two follow-up periods (January-April 2017, May-October 2017). HAI rates were compared in a Poisson multilevel analysis, correcting for baseline differences (the baseline infection incidence and the size of the nursing home), clustering of observations within nursing homes, and period in the study. RESULTS: There was statistically significantly more gastroenteritis (p < 0.001) and statistically significantly less influenza-like illness (p < 0.01) in the intervention arm when compared to the control arm. There were no statistically significant differences or pneumonia, urinary tract infections, and MRSA infections in the intervention arm when compared to the control arm. In a sensitivity analysis, gastroenteritis was no longer statistically significantly higher in the intervention arm (p = 0.92). CONCLUSIONS: As in comparable studies, we could not conclusively demonstrate the effectiveness of an HH intervention in reducing HAIs among residents of nursing homes, despite the use of clearly defined outcome measures, a standardized reporting instrument, and directly observed HH in a multicenter cluster RCT. Trial registration Netherlands Trial Register, trial NL6049 (NTR6188). Registered October 25, 2016, https://www.trialregister.nl/trial/6049 .

The daily direct costs of isolating patients identified with highly resistant micro-organisms in a non-outbreak setting.

BACKGROUND: Isolation precautions are recommended when caring for patients identified with highly resistant micro-organisms (HRMOs). However, the direct costs of patients in isolation are largely unknown. AIM: To obtain detailed information on the daily direct costs associated with isolating patients identified with HRMOs. METHODS: This study was performed from November until December 2017 on a 12-bed surgical ward. This ward contained solely isolation rooms with anterooms. The daily direct costs of isolation were based on three cost items: (1) additional personal protective equipment (PPE), measured by counting the consumption of empty packaging materials; (2) cleaning and disinfection of the isolation room, based on the costs of an outsourced cleaning company; and (3) additional workload for healthcare workers, based on literature and multiplied by the average gross hourly salary of nurses. A distinction was made between the costs for strict isolation, contact-plus isolation, and contact isolation. FINDINGS: During the study period, 26 patients were nursed in isolation because of HRMO carriage. Time for donning and doffing of PPE was 31 min per day. The average daily direct costs of isolation were the least expensive for contact isolation (gown, gloves), €28/$31, and the most expensive for strict isolation (surgical mask, gloves, gown, cap), €41/$47. CONCLUSION: Using a novel, easy method to estimate consumption of PPE, we conclude that the daily direct costs of isolating a patient differ per type of isolation. Insight into the direct costs of isolation is of utmost importance when developing or updating infection prevention policies.

Risk factors for surgical site infections using a data-driven approach.

OBJECTIVE: The objective of this study was to identify risk factors for surgical site infection from digestive, thoracic and orthopaedic system surgeries using clinical and data-driven cut-off values. A second objective was to compare the identified risk factors in this study to risk factors identified in literature. SUMMARY BACKGROUND DATA: Retrospective data of 3 250 surgical procedures performed in large tertiary care hospital in The Netherlands during January 2013 to June 2014 were used. METHODS: Potential risk factors were identified using a literature scan and univariate analysis. A multivariate forward-step logistic regression model was used to identify risk factors. Standard medical cut-off values were compared with cut-offs determined from the data. RESULTS: For digestive, orthopaedic and thoracic system surgical procedures, the risk factors identified were preoperative temperature of ≥38°C and antibiotics used at the time of surgery. C-reactive protein and the duration of the surgery were identified as a risk factors for digestive surgical procedures. Being an adult (age ≥18) was identified as a protective effect for thoracic surgical procedures. Data-driven cut-off values were identified for temperature, age and CRP which can explain the SSI outcome up to 19.5% better than generic cut-off values. CONCLUSIONS: This study identified risk factors for digestive, orthopaedic and thoracic system surgical procedures and illustrated how data-driven cut-offs can add value in the process. Future studies should investigate if data-driven cut-offs can add value to explain the outcome being modelled and not solely rely on standard medical cut-off values to identify risk factors.

Prevalence and risk factors of inappropriate use of intravenous and urinary catheters in surgical and medical patients.

BACKGROUND: Previously, the RICAT (Reduction of Inappropriate use of intravenous and urinary CATheters) study had been conducted by ourselves to reduce inappropriate use of intravenous and urinary catheters in medical wards to prevent healthcare-associated infections. AIM: To compare surgical and medical wards, and to determine risk factors for inappropriate catheter use. METHODS: A cross-sectional study was performed from October, 2017, to May, 2018, in surgical wards of two university hospitals in the Netherlands. Patients were prospectively observed every other week for seven months. Inappropriate use was compared with non-surgical wards in the RICAT study. FINDINGS: In all, 409 surgical patients were included, and they were compared with 1781 medical patients. Inappropriate use occurred in 36 (8.5%) out of 425 peripheral intravenous catheters in 373 surgical patients, compared to 400 (22.9%) out of 1747 peripheral intravenous catheters in 1665 medical patients, a difference of 14.4% (95% confidence interval (CI): 11.1-17.8; P < 0.001). Inappropriate use of urinary catheters occurred in 14 (10.4%) out of 134 surgical patients, compared to 105 (32.4%) out of 324 medical patients, a difference of 22.0% (95% CI: 14.7-29.2; P < 0.001). Subgroup analysis in the two university hospitals confirmed these differences. The main risk factor for inappropriate use of peripheral intravenous catheters was admission in medical wards (odds ratio (OR): 3.50; 95% CI: 2.15-5.69), which was also one of the main risk factors for urinary catheters (OR: 2.75; 95% CI: 1.36-5.55). CONCLUSION: Inappropriate use of catheters is more common in medical wards compared to surgical wards. Prevention strategies to reduce healthcare-associated infections should primarily focus on sites with high prevalence of inappropriate use.

Prion disease and recommended procedures for flexible endoscope reprocessing - a review of policies worldwide and proposal for a simplified approach.

Several guidelines recommend specific treatments for endoscopes, procedures of quarantine for endoscopes, or additional treatments for the endoscope washer disinfector (EWD) in suspected or confirmed cases of Creutzfeldt-Jakob disease (CJD) or variant CJD (vCJD) but vary in many details. This study therefore reviewed guidelines on reprocessing flexible endoscopes after use in patients with suspected or confirmed prion disease. In addition, a literature search was performed in Medline on prion, CJD, vCJD, chemical inactivation, transmission healthcare, epidemiology healthcare, concentration tissue human and endoscope. Thus far, no case of CJD or vCJD transmitted by flexible endoscope has been reported. In animals it has been shown that oral uptake of 0.1-5 g of bovine spongiform encephalopathy (BSE)-infected brain homogenate is necessary for transmission. The maximum prion concentration in other tissues (e.g., terminal ileum) is at least 100-fold lower. Automated cleaning of endoscopes alone results in very low total residual protein ≤5.6 mg per duodenoscopes. Recommendations vary between countries, sometimes with additional cleaning, use of alkaline cleaners, no use of cleaners with fixative properties, use of disinfectants without fixative properties or single-use disinfectants. Sodium hydroxide (1 M) and sodium hypochlorite (10,000 and 25,000 mg/L) are very effective in preventing transmission via contaminated wires implanted into animal brains, but their relevance for endoscopes is questionable. Based on circumstantial evidence, it is proposed to consider validated reprocessing as appropriate in the case of delayed suspected prion disease when immediate bedside cleaning, routine use of alkaline cleaners, no fixative agents anywhere prior to disinfection and single use brushes and cleaning solutions can be assured.

Trends in prevalence of healthcare-associated infections and antimicrobial use in hospitals in the Netherlands: 10 years of national point-prevalence surveys.

BACKGROUND: Prevalence of healthcare-associated infections (HCAIs) and antimicrobial use in hospitals in the Netherlands has been measured using voluntary biannual national point-prevalence surveys (PPSs). AIM: To describe trends in the prevalence of patients with HCAI, risk factors, and antimicrobial use in 2007-2016. METHODS: In the PPS, patient characteristics, use of medical devices and antimicrobials, and presence of HCAI on the survey day are reported for all hospitalized patients, excluding patients in the day-care unit and psychiatric wards. Analyses were performed using linear and (multivariate) logistic regression, accounting for clustering of patients within hospitals. FINDINGS: PPS data were reported for 171,116 patients. Annual prevalence of patients with HCAI with onset during hospitalization decreased from 6.1% in 2007 to 3.6% in 2016. The adjusted odds ratio (OR) for trend was 0.97 (95% confidence interval: 0.96-0.98). Most prominent trends were seen for surgical site infections (1.6%-0.8%; OR: 0.91 (0.90-0.93)) and urinary tract infections (2.1%-0.6%; OR: 0.85 (0.83-0.87)). From 2014 on, HCAIs at admission were also registered with a stable prevalence of approximately 1.5%. The mean length of stay decreased from 10 to 7 days. The percentage of patients treated with antibiotics increased from 31% to 36% (OR: 1.03 (1.02-1.03)). CONCLUSION: Repeated PPS data from 2007 to 2016 show a decrease in the prevalence of patients with HCAI with onset during hospitalization, and a stable prevalence of patients with HCAI at admission. The adjusted OR of 0.97 for HCAI during hospitalization indicates a true reduction in prevalence of approximately 3% per year.