Purpose: Wastewater surveillance effectively monitors pathogens. This pilot study evaluated the feasibility and utility of hospital-level wastewater surveillance by integrating wastewater and electronic health record (EHR) data. Analyses focused on hospital-acquired infections (HAI) and temporal lags between wastewater and clinical detection. Methods: From August to December 2024, wastewater autosamplers operated across five hospital pavilions at Yale New Haven Hospital, collecting samples every five minutes during a 24-hour period three times per week. Samples were analyzed by dPCR for SARS-CoV-2, Influenza (A/B), and additional pathogens. Deidentified EHR data included admissions, diagnoses, and laboratory data. The primary focus was lab-confirmed HAI SARS-CoV-2 and Influenza. HAI was defined as infections diagnosed during hospitalization without evidence at admission. Clinical and wastewater data were used to calculate the proportion of positive samples, and correlation was assessed using Spearman’s rank correlation coefficient (rho). Correlations were evaluated for lagged associations across 1–3-week lags. A sensitivity analysis was conducted by including all SARS-CoV-2 encounters. Results: Among 33,579 patient encounters, 62 SARS-CoV-2 and 74 Influenza HAI encounters were identified. This corresponded to 97 and 148 tests for SARS-CoV-2 and Influenza, respectively. Of 187 wastewater samples collected 60 (31.1%) and 1 (0.5%) were positive for SARS-CoV-2 and Influenza respectively. Due to only a single detection of Influenza in the wastewater, correlation analysis was limited to SARS-CoV-2. A correlation test of the data found no statistically significant correlation between wastewater and clinical data when aligned temporally (rho: -0.21, p: 0.51). Lagged correlations between wastewater and clinical SARS-CoV-2 positivity were evaluated across 1–3-week temporal lags. These lagged correlations were not statistically significant, but rho increased in magnitude from a 1-week lag (rho: -0.04, p: 0.89) to a 3-weeks lag (rho: 0.46, p:0.21). The sensitivity analysis found no statistically significant correlation between wastewater and clinical positivity. Conclusions: Hospital-level wastewater surveillance shows potential as an early indicator of HAI SARS-CoV-2 infections, with exploratory trends suggesting a ~3-week lead time results in stronger associations between clinical and wastewater data. Although limited by small HAI sample sizes and a short wastewater sampling period, these findings support further evaluation in larger cohorts and highlights pathogen-specific limitations as observed for Influenza. Follow-up studies should employ longer wastewater sampling windows and further refine methods to account for community-associated SARS-CoV-2 contributions to hospital wastewater, an area of active investigation by our group.

Purpose: Wastewater surveillance effectively monitors pathogens. This pilot study evaluated the feasibility and utility of hospital-level wastewater surveillance by integrating wastewater and electronic health record (EHR) data. Analyses focused on hospital-acquired infections (HAI) and temporal lags between wastewater and clinical detection. Methods: From August to December 2024, wastewater autosamplers operated across five hospital pavilions at Yale New Haven Hospital, collecting samples every five minutes during a 24-hour period three times per week. Samples were analyzed by dPCR for SARS-CoV-2, Influenza (A/B), and additional pathogens. Deidentified EHR data included admissions, diagnoses, and laboratory data. The primary focus was lab-confirmed HAI SARS-CoV-2 and Influenza. HAI was defined as infections diagnosed during hospitalization without evidence at admission. Clinical and wastewater data were used to calculate the proportion of positive samples, and correlation was assessed using Spearman’s rank correlation coefficient (rho). Correlations were evaluated for lagged associations across 1–3-week lags. A sensitivity analysis was conducted by including all SARS-CoV-2 encounters. Results: Among 33,579 patient encounters, 62 SARS-CoV-2 and 74 Influenza HAI encounters were identified. This corresponded to 97 and 148 tests for SARS-CoV-2 and Influenza, respectively. Of 187 wastewater samples collected 60 (31.1%) and 1 (0.5%) were positive for SARS-CoV-2 and Influenza respectively. Due to only a single detection of Influenza in the wastewater, correlation analysis was limited to SARS-CoV-2. A correlation test of the data found no statistically significant correlation between wastewater and clinical data when aligned temporally (rho: -0.21, p: 0.51). Lagged correlations between wastewater and clinical SARS-CoV-2 positivity were evaluated across 1–3-week temporal lags. These lagged correlations were not statistically significant, but rho increased in magnitude from a 1-week lag (rho: -0.04, p: 0.89) to a 3-weeks lag (rho: 0.46, p:0.21). The sensitivity analysis found no statistically significant correlation between wastewater and clinical positivity. Conclusions: Hospital-level wastewater surveillance shows potential as an early indicator of HAI SARS-CoV-2 infections, with exploratory trends suggesting a ~3-week lead time results in stronger associations between clinical and wastewater data. Although limited by small HAI sample sizes and a short wastewater sampling period, these findings support further evaluation in larger cohorts and highlights pathogen-specific limitations as observed for Influenza. Follow-up studies should employ longer wastewater sampling windows and further refine methods to account for community-associated SARS-CoV-2 contributions to hospital wastewater, an area of active investigation by our group.

Antimicrobial resistant pathogens and associated infections represent major public health threats affecting healthcare facilities, with sink drain biofilms serving as reservoirs for many of these bacteria. Despite attempts at sink drain biofilm disinfection and removal, drain biofilms inevitably regrow, and disinfection may shape the returning microbial communities and their resistance profiles. We applied culture-based and metagenomic approaches to study these drain disinfection effects on microbial community abundance, taxonomy, and antimicrobial resistance in operational hospital sinks. Drain biofilms regrew to baseline densities in approximately four days. Regrown biofilms contained more viable carbapenem-resistant bacteria and were dominated by Pseudomonadota, including Cupriavidus and Pseudomonas. Long-read sequencing revealed an increase in multidrug efflux pump genes after disinfection, which confer broad resistance to antibiotics and disinfectants. This work provides mechanistic insights into how disinfection influences sink drain biofilm ecology and the enrichment of antimicrobial resistance, with implications for infection prevention strategies in healthcare environments.

Wastewater surveillance (WS) has been widely adopted as a cost-effective and population-representative infectious disease monitoring tool and is increasingly being applied to bacterial and antimicrobial resistance gene (ARG) targets. However, some of these targets may persist in pipe biofilms and detach into wastewater, complicating accurate WS interpretation. To investigate biofilm contributions to wastewater pathogen and ARG signals, paired sink-drain biofilm, branch-drain-plumbing biofilm (sewer biofilm), and wastewater were collected from five hospital sites over a four-month period and analyzed using 16S rRNA gene amplicon sequencing and probe-capture metagenomics. Overall, sewer biofilm bacterial communities were as diverse as wastewater. Across sites, a mean of 9% (0.9 to 23.3%) of wastewater bacterial communities could be attributed to sewer biofilm communities. Many clinically relevant pathogens were consistently detected both in sewer biofilm and wastewater, including environmentally persistent and/or biofilm-associated taxa (e.g., Pseudomonas aeruginosa, Klebsiella pneumoniae). While many ARGs overlapped between wastewater and biofilms (e.g., tetA, sul1, blaCTX-M, vanA), others were significantly enriched in sewer biofilms (e.g., qacL, van-operon and OXA genes). Together, these findings confirm that wastewater pathogen and resistome profiles integrate inputs from both human shedding and pipe-resident communities and therefore need to be considered when selecting WS targets and interpreting signal. ### Competing Interest Statement The authors have declared no competing interest. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors

OBJECTIVE:To better understand clinicians' rationale for ordering testing for C. difficile infection (CDI) for patients receiving laxatives and the impact of the implementation of a clinical decision support (CDS) intervention. DESIGN:A mixed-methods, case series was performed from March 2, 2017 to December 31, 2018. SETTING:Yale New Haven Hospital, a 1,541 bed tertiary academic medical center. PARTICIPANTS:Hospitalized patients ≥ 18 years old, and clinicians who were alerted by the CDS. INTERVENTION:CDS was triggered in real-time when a clinician sought to order testing for CDI for a patient who received one or more doses of laxatives within the preceding 24 hours. RESULTS:A total of 3,376 CDS alerts were triggered during the 21-month study period from 2,567 unique clinician interactions. Clinicians bypassed the CDS alert 74.5% of the time, more frequent among residents (48.3% bypass vs. 39.9% accept) and advanced practice providers (APPs) (34.9% bypass vs. 30.6% accept) than attendings (11.3% bypass vs. 22.5% accept). Ordering clinicians noted increased stool frequency/output (48%), current antibiotic exposure (34%), and instructions by an attending physician to test (28%) were among the most common reasons for overriding the alert and proceeding with testing for CDI. CONCLUSIONS:Testing for CDI despite patient laxative use was associated with an increased clinician concern for CDI, patient risk for CDI, and attending physician instruction for testing. Attendings frequently accepted CDS guidance while residents and APPs often reinstated CDI test orders, suggesting a need for greater empowerment and discretion when ordering tests.

Background: Understanding healthcare personnel's (HCP) contact patterns are important to mitigate healthcare-associated infectious disease transmission. Little is known about how HCP contact patterns change over time or during outbreaks such as the COVID-19 pandemic.Methods: This study in a large United States healthcare system examined the social contact patterns of HCP via standardized social contact diaries. HCP were enrolled from October 2020 to June 2022. Participants completed monthly surveys of social contacts during a representative working day. In June 2022, participants completed a 2-day individual-level contact diary. Regression models estimated the association between contact rates and job type. We generated age-stratified contact matrices.Results: Three-hundred and sixty HCP enrolled, 157 completed one or more monthly contact diaries and 88 completed the intensive 2-day diary. In the monthly contact diaries, the median daily contacts were 15 (interquartile range (IQR) 8-20), this increased slightly during the study (slope-estimate 0.004, p-value 0.016). For individual-level contact diaries, 88 HCP reported 2,550 contacts over 2 days. HCP were 2.8 times more likely to contact other HCP (n = 1,592 contacts) than patients (n = 570 contacts). Rehabilitation/transport staff, diagnostic imaging technologists, doctors, nurses, mid-level, and laboratory personnel had higher contacts compared with the lowest contact group (Nursing aids). Contact matrices concentrated in working-age populations.Conclusions: HCP contacts concentrate in their work environment, primarily with other HCP. Their contacts remained stable over time even during large changes to societal contact patterns during the COVID-19 pandemic. This stability is critical for designing outbreak and pandemic responses.

The use of extended reality (XR) for education of healthcare personnel (HCP) is increasing. XR equipment is reusable and often shared between HCP in clinical areas; however, it may not include manufacturer's instructions for use (MIFU) in healthcare settings. Considerations for the selection of equipment and development of cleaning and disinfection protocols are described.

Background: Virtual reality (VR) headsets are increasingly used in health care settings for a variety of clinical indications, yet processes to ensure safe use between patients are not well-established. Centers vary in how these processes are performed. Most use disinfection wipes that require manual contact with VR devices for a specified dwell time to allow for sufficient pathogen killing, which may introduce manual error and device degradation over time. Ultraviolet-C light (UV-C) devices offer a no-touch, low-cost, and passive method to achieve pathogen killing without the harms of chemical contact-based disinfectants. The use of UV-C for disinfection has been studied for some medical devices but its efficacy for microbe killing on VR headsets is not well-established. Objective: This study aims to determine the bactericidal efficacy of UV-C on VR headsets through quantifying UV-C irradiance and bacterial killing of 3 commercially available UV-C devices. Methods: Three commercially available, low-cost UV-C devices were tested for UV-C energy output at multiple positions, angles, and times across the devices' zone of disinfection. The top and lens of a VR headset, the Meta Oculus Quest 2, were artificially inoculated with high quantities of 3 different strains of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis) and subjected to UV-C light according to each device's manufacturer's instructions for use. The primary outcome was the amount of bacterial killing after exposure to UV-C light. Results: All 3 UV-C devices produced a UV-C dose that ranged from 3.57 to 195.37 mJ/cm2, depending on proximity, angle, irradiance, and time the sensor received. At least 3-log10 killing of all 3 strains of bacteria was achieved for each of the tested UV-C devices; however, there was variability by organism with respect to UV-C device and VR headset location within the device, notably with the proximity of the bacteria to the bulb. S aureus and P aeruginosa were more readily killed than S epidermidis, with increased bacterial killing occurring with increased UV-C exposure doses. There was no experiment in which all bacteria were killed. Conclusions: UV-C dosage increased with exposure irradiance, time, proximity, and angle to the bulb for all 3 UV-C devices. Bacterial killing on the top and lens of a VR headset occurred in all 3 UV-C devices when run according to their manufacturer's instructions for use, although full bacterial killing did not occur in any experiment. UV-C may be an effective method for microbial killing on VR equipment with low-level contamination.

Background:Healthcare workers are at increased risk of exposure to respiratory pathogens including Streptococcus pneumoniae (pneumococcus). While little asymptomatic carriage has been reported in young-to-middle-aged adults, this may be due to nonsensitive diagnostic methods. The aim of the current study was to investigate the rates of pneumococcal carriage in a large cohort of healthcare workers, using saliva as a respiratory specimen. Methods:We evaluated pneumococcal carriage in convenience samples of saliva, self-collected from asymptomatic healthcare workers (Connecticut, USA) who were testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 30 March to 11 June 2020. DNA extracted from the culture-enriched saliva was later tested using quantitative polymerase chain reaction for piaB, lytA, and serotype. Saliva samples were considered positive for pneumococcus when the piaB cycle threshold value was <40. Results:Study participants were 22-74 years old (mean age, 38.5 years), 75% female, 75% white, and with occupations including registered nurses (48%), medical doctors (23%), and patient care assistants (5%). Overall, 138 of 1241 samples (11%) from 86 of 392 individuals (21%) tested piaB positive at some point during the 4-month study period, with 28 (33%) colonized individuals positive at multiple time points. Carriers reflected the overall study population. No significant demographic characteristics were associated with detection of pneumococcus. Colonized individuals primarily carried serotypes 19F (25.6%) and 3 (12.8%). Conclusions:During a period of mandatory masking, we identified a cumulative pneumococcal carriage prevalence of 21% among healthcare workers. This study highlights that healthcare workers may act as unrecognized reservoirs of pneumococcus in the population. Despite long-standing pediatric immunization programs, vaccine-targeted serotypes continue to be prevalent among the adult population.

Abstract Background We lack understanding of how health care workers’ (HCWs) contacts change over time or in response to pandemics. This study describes the social contact patterns of HCWs in a large United States health care system via standardized social contact diaries. Mean number of total contacts over time (Jan 2021-May 2022): The mean contacts noted with dark-blue line with 95% confidence intervals (95%CI) in dark gray. The dashed black line shows the linear regression of contacts over time. The-axis is interrupted as the study was closed in June and July 2021. Methods Inpatient and outpatient HCWs enrolled from October 2020 to June 2022. Participants completed a monthly survey of all contacts during a single representative working day selected by the participant. Direct contact was defined as being within 2 meters of another person. Indirect contact was defined as being in the same room but more than 2 meters. In June 2022, participants completed a 2-day individual-level contact diary. We generated age-stratified contact matrices. Contacts were described by contact type, duration and contact relationship. Number and duration of contacts by job were compared by chi-squared test and number of contacts over time by linear regression. Average contacts of health care worker with all individuals The individual tiles color and numeric fill denote the average number of contacts per HCW of that age range with a contact of that age range. A horizontal marginal histogram shows the age break down of HCW participants and a vertical marginal histogram shows the resulting distribution of contact’s ages. Results 360 HCWs enrolled, 95 completed 1 or more monthly contact diary and 88 completed the intensive 2-day diary. The total number of contacts was stable over time (β0.14, p 0.20, Fig.1). HCWs reported direct contacts with less than 5 patients, 5-9 patients, 10-19 patients or 20 more patients, 50%, 29%,15% or 6% of the time respectively. HCWs reported direct contact with less than 5 other HCWs, 6-10 HCWs, 11-20 or 21 or more 19%, 39%, 27 % or 15% of the time respectively. In the June 2022, a total of 2,550 contacts were reported, 1,592 (62%) were with HCWs, and 570 (22%) with patients. Social workers, rehab/transport and doctors were more likely to have contact with 20 or more patients vs. other professions. Nurses, imaging technologists and rehab/transport were more likely to spend 20 minutes or more with patients vs. other professions. Contact matrices were not age assortative with HCWs having similar contacts across all working ages (Fig. 2). HCWs’ physical contacts focused on extremes of age (Fig. 3). Contact type varied by job with nearly all groups having more contacts with colleagues than patients (Fig, 4). Average physical contacts of HCWs per day: The The individual tiles color and numeric fill denote the average number of physical contacts per HCW of that age range with a contact of that age range. A horizontal marginal histogram shows the age break down of HCW participants and a vertical marginal histogram plot the resulting distribution of contact’s ages. Conclusion HCW contacts concentrated in their work environment and most contacts were focused in the working-age population. These contacts were stable over time even in the COVID-19 pandemic response. HCWs were 2.8 time more likely to contact HCWs than patients. Number of contacts of 2 days by participant job and contact individual Grouped box plots show the number of contacts over the 2-day intensive diary by HCW job (x-axis) and the HCWs relationship with the contact (e.g. colleague, patient or other). Disclosures Lauren Pischel, MD, Auxa Health: Advisor/Consultant Amyn Malik, MBBS, MPH, PhD, Analysis Group, Inc: Former Employee. We consulted with Pharma and Biotech on different research studies Ben Lopman, PhD, Epidemiological Research and Methods, LLC: Advisor/Consultant|Hillevax, Inc: Advisor/Consultant Albert I. Ko, MD, Merck: Grant/Research Support|Regeneron: Grant/Research Support Saad Omer, MBBS MPH PhD, Meta: Advisor/Consultant|Meta: Grant/Research Support

Objective: Evidence-based central-line-associated bloodstream infection (CLABSI) prevention guidelines recommend the use of an antiseptic scrub to disinfect needleless connectors before device access. Guideline noncompliance may render disinfection ineffective. The goal of this study was to observe needleless-connector disinfection practices and to identify perceived facilitators and barriers to best practices of needleless-connector access.Methods: A human factors mixed-methods study involving nursing focus groups of perceived barriers and facilitators and clinical observations of compliance with instructions and protocols for use of 3.15% chlorhexidine gluconate/70% isopropyl alcohol (CHG/IPA) and 70% isopropyl alcohol (IPA) antisepsis products for central venous access device (CVAD) needleless-connector disinfection was conducted in intensive care units (ICUs) at 2 academic medical centers.Results: Access to the antiseptic product and lesser workload were identified as best-practice facilitators. Barriers were the time required per needleless-connector access and knowledge deficits. Of the 48 observed access events, 77% resulted in needleless-connector disinfection. The observed mean needleless-connector scrubbing times when using IPA were substantially below the recommended time. Drying time after product use was negligible.Conclusions: Lack of access to the disinfection product, emergency situations, and high workload were barriers to needleless-connector disinfection. Observed scrubbing and drying times were shorter than recommended, especially for IPA wipes. These needleless-connector disinfection deficits may increase the risk of CLABSI. Ongoing education and periodic competency evaluation of needleless-connector disinfection, improvement of supply management, and staffing workload are required to imbed and sustain best practices. Further study involving a larger sample size in diverse patient populations is warranted.

Health care–associated infections (HAIs) are a pervasive problem, and although decreased rates of HAIs have been clearly achieved during the past decades, most recent estimates by the Centers for Disease Control and Prevention show the prevalence of HAIs in U.S. hospitals to be about 3%.1 Many HAIs are preventable events and pose undue burdens on both patients and health care facilities. Hospitals' infection prevention teams are responsible for working to prevent HAIs, which includes identifying and managing outbreaks. Although there is no consensus on how to define an outbreak, outbreaks of infectious diseases are most efficiently controlled when they are identified early, so rapid identification is a key strategy.

Healthcare-associated infections (HAIs) are common and expensive complications that can occur during inpatient hospital stays. Hand hygiene (HH)—which includes hand washing with soap and water and hand rubbing with alcohol-based hand sanitizer—is the primary tool used by healthcare personnel (HCP) to prevent HAIs. Consequently, the World Health Organization (WHO) proposed guidelines for effective HH in healthcare settings. However, consistent performance of HH by HCP is still lacking. HH in healthcare requires both compliance with indications for HH and quality of HH. Integrative approaches in human factors engineering (HFE) and infection prevention can be used to promote sustainable techniques that can be implemented by HCP to improve the quality of HH techniques. This research proposes a three-phase integrative approach that uses HFE-based methods to identify why HH is often insufficiently executed by HCP in hospital settings and ultimately to help guide HCP to improve HH quality. We performed i) a tabular task analysis (TTA), constructed by HFE personnel and infection prevention specialists, ii) card sorting with infection prevention subject matter experts to prioritize HH steps and analyzed with criticality analysis and subsequent modifications to the TTA, and iii) TTA validation and verification with subject matter experts. Finally, we conducted qualitative interviews with members of hospital leadership and determined that it is feasible to implement the use of TTAs in hospital settings. This research provides enhanced HH guidance using an integrative HFE-based approach and is directed to increase the quality of HH performed by HCP, thereby reducing HAI rates and improving patient safety. Furthermore, these results can be used to support the effective implementation of the WHO's HH guidance. Our findings elucidate some of the challenges to patient safety regarding HH and clarify best practices for HH in hospital settings.

We report a cluster of 9 isolates of Parengyodontium album recovered from 4 patients who had surgical tissue specimens processed after dilution with a multiuse diluent saline solution. P album was also identified from a nonclinical sample on agar prepared with the same lot number of saline solution. Our epidemiological investigation revealed this to represent a pseudo-outbreak related to contaminated saline used to process specimens in the microbiology laboratory.

COVID-19 vaccine uptake in healthcare personnel (HCP) is poor. A cross-sectional survey study of behavioral health HCP was performed. Commonly identified reasons for vaccination were protecting others and oneself. Reasons against were a lack of perceived protection, dosing intervals, and side effects. Assessing vaccination attitudes can assist in uptake strategy.

BACKGROUND:Infection prevention (IP) behaviors such as hand hygiene (HH) and mobile device disinfection are important to reduce the risk of infection transmission from both family members and hospital staff to critically ill neonates. PURPOSE:To inform the design of educational interventions to improve both patient family and staff IP behaviors, we engaged separate groups of nurses and family members to understand perceptions about the spread of infection and barriers to implementing effective IP strategies. METHODS:This was a qualitative study using focus groups to gather data from neonatal nurses and patient family members. Data were triangulated with hospital-wide survey data and analyzed using inductive content analysis. RESULTS:Twelve nurses and 4 patient family members participated. Themes related to communication about IP between staff and family members emerged: stakeholders expressed discomfort with the timing and nature of just-in-time HH education. These communication challenges contributed to stress levels within the neonatal intensive care unit. This finding was reflected in the hospital-wide survey. IMPLICATIONS FOR PRACTICE AND RESEARCH:Steps should be taken to improve communication about IP behaviors between patient family members and frontline staff. Reducing nurse burden of providing just-in-time HH reminders to patient family members through increased IP education may decrease stress and facilitate IP behaviors. This has the potential to decrease infection spread and improve patient outcomes. The development of interventions targeting stakeholder communication is therefore warranted, but additional research is needed to understand the timing and process for delivery of the educational material.