Infection Prevention Interventions Research Articles

Cost of a Group Technology-Based HIV and Sexually Transmitted Infection Prevention Intervention for Black Justice-Involved Women Who Use Drugs

Cost of a Group Technology-Based HIV and Sexually Transmitted Infection Prevention Intervention for Black Justice-Involved Women Who Use Drugs

P-372. Candida auris Outbreak in a Cardiothoracic Transplant Intensive Care Unit: Implications for Infection Prevention

Abstract Background Candida auris is a yeast that causes invasive infections such as bloodstream infections (BSIs); mortality rates for C. auris BSIs may be as high as 80%. Rates have been climbing in the U.S. Exposure to skilled nursing facilities (SNFs), long-term acute care hospitals (LTACHs), or inpatient rehabilitation facilities (IRFs) represents a known risk factor for C. auris. Our institution experienced a C. auris outbreak from September 2023 - January 2024. Figure 1: C. auris Outbreak Epidemic Curve Methods C. auris cases in the outbreak were identified from clinical specimens and admission and weekly surveillance via polymerase chain reaction (PCR). Clinical characteristics were determined through chart review. A multidisciplinary team implemented infection prevention (IP) interventions to curb nosocomial spread. Infection Prevention Interventions Results There were 20 cases of C. auris identified in our CTICU between July 2023 and January 2024 (Figure 1). Whole-genome sequencing and phylogenetic analysis based on pairwise single nucleotide polymorphism (WG-SNP) distance revealed two outbreak clusters. Of the 20 patients, 13 (65%) were solid organ transplant/acute mechanical circulatory support patients and three (15%) had prior SNF, LTACH, or IRF exposure. Four (20%) patients had C. auris BSIs and seven (35%) patients died, including all patients with BSIs. The mean duration of antibiotic use in the four patients was 67 days. IP interventions addressed potential vehicles of transmission including healthcare personnel hands, shared patient equipment, and the environment (Table 1). Conclusion Only 15% of patients had prior SNF/LTACH/IRF exposure; many were admitted from home and/or outside hospitals with risk factors including recent surgery and antimicrobial use. This suggests the epidemiology of C. auris may be changing, and it may be prudent to consider routine admission and weekly surveillance on inpatient units deemed high risk for C. auris. Effective IP interventions included interventional hand hygiene auditing, increased accountability and oversight for shared patient equipment, limiting the number of rounding providers in rooms, and auditing environmental cleaning. Sustaining these efforts is crucial to keep pace with an evolving C. auris landscape. Disclosures All Authors: No reported disclosures

P-521. Assessing Infectious Disease Screening and Prevention Practices for Persons who Inject Drugs in a Large Midwestern Academic Medical Center

Abstract Background Persons who inject drugs (PWID) are at risk for infection, including HIV, hepatitis C virus (HCV), and sexually transmitted infections (STIs). Harm reduction counseling, HIV pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP), and routine STI screening are recommended to prevent infectious complications among those with substance use disorder (SUD). Hospitalizations serve as an opportunity to provide these infection prevention and screening interventions which are often difficult to access in the ambulatory or community setting for patients with active SUD. We sought to describe the frequency of infectious disease screening and preventive counseling and interventions among PWID admitted to our hospital with a serious injection related infection (SIRI). Methods We conducted a retrospective chart review of PWID > 18 years of age admitted to our large tertiary medical center in the Midwest with SIRIs in 2022. The conditions included were bacteremia, endocarditis, skin and soft tissue infection, epidural abscess, septic arthritis, osteomyelitis and other. We assessed the frequency of screening for HIV, hepatitis C, gonorrhea, chlamydia, and syphilis, and the frequency of harm reduction counseling and assessment for HIV-PrEP and PEP eligibility. We collected demographic information, discharge location and conditions, and whether infectious disease and addiction medicine were consulted. Descriptive analysis was performed. Results 45 patients with SIRIs were admitted in 2022. Of the 45, 56% underwent HIV screening, 53% HCV screening, and 16% received gonorrhea, chlamydia, and syphilis screening during the index hospitalization. Harm reduction counseling was documented for 69% of patients and was almost exclusively documented by addiction medicine. There was no documentation of PrEP consideration despite 36 patients meeting eligibility and no PrEP or PEP was prescribed. Conclusion In our institution, there were suboptimal rates of infectious disease screening, harm reduction counseling, and HIV prevention interventions among PWID admitted with SIRI in 2022. The most marked gap in care is regarding consideration for HIV-PrEP. Further work will inform barriers and facilitators to optimizing these practices in the hospital setting. Disclosures Jessica S. Tischendorf, MD, MS, Merck: Grant/Research Support

295. Methods for Cost-efficient Real-time Whole Genome Sequencing Surveillance for Enhanced Detection of Outbreaks in a Hospital Setting

Abstract Background Healthcare associated infections (HAI) are common hospital complications associated with increased length of stay, economic burden, morbidity, and mortality. Traditionally, HAI outbreaks were detected using reactive whole genome sequencing (WGS); however, with costs decreasing over time, WGS has become a practical tool for the real time detection of nosocomial outbreaks. This study describes such methods, provides a cost analysis, and reviews notable outbreaks observed while performing real time WGS surveillance of HAIs. EDS-HAT real-time genomic surveillance methodsFigure 1:EDS-HAT real-time genomic surveillance methods A) collect list generation, B) sample collection C) sample processing, D) DNA extraction, E) Library preparation, F) WGS, and G-I) Data analysis, including determining SNPs between samples and infection clusters Methods The Enhanced Detection System for Healthcare-Associated Transmission (EDS-HAT) was devised to identify potential transmitted HAIs in real time among patients admitted to the hospital for ≥ 3 days or with a previous exposure in the prior 30-days (Fig 1). We performed a cost analysis for real time genomic HAI surveillance, based on an average cutoff of 35× coverage per genome, considering personnel, reagents, supplies, and WGS platform. We also considered maximum sample counts that could be sequenced on two platforms (MiSeq or NextSeq), based on genome size (Fig 2). Bioinformatic analyses were completed following WGS, and epidemiological links were investigated for isolates that clustered with ≤ 15 pair-wise SNP differences (C. diff ≤ 2 SNPs). Maximum Sample CountsFigure 2:Maximum number of genomes that can be run on a MiSeq v3 600 cycle flow cell and NextSeq500 v2.5 300 cycle flow cell based on size (Mb). Sample counts were calculated using Illumina coverage calculator based on 80× coverage criteria. Genome size of an average run by the MiGEL lab is shown in comparison Results From November 1, 2021 to October 31, 2023, we sequenced 4,723 isolates (weekly mean N=49). The per sample cost depended on platform used and sample count, totaling $49 or $19 for MiSeq (N=32) and NextSeq (N=96), respectively (Table 1). With the inclusion of personnel costs for 1 lab technician and 1 biostatistician (salary only, based on percent effort) the average weekly cost to run EDS-HAT was $4,293 (range $3,626-$4,758). We highlight multiple outbreaks involving a common hospital unit, equipment, or location (Table 2). Following Infection Prevention (IP) intervention, no additional cases were detected for these clusters on the associated routes. Cost per sample BreakdownTable 1.Cost per sample across MiSeq, NextSeq, and commercial WGS Conclusion We describe time- and cost-efficient methods for real time outbreak surveillance and detection using WGS. These genomic methods, as described in EDS-HAT, can be utilized with traditional epidemiological methods to guide hospital IP teams to mitigate and stop the spread of deadly transmitted HAIs. Notable OutbreaksTable 2.Description of notable outbreaks detected by real-time EDS-HAT HAI surveillance Disclosures Alexander Sundermann, DrPH, CIC, FAPIC, OpGen: Honoraria Lee Harrison, MD, GSK: Advisor/Consultant|Merck: Advisor/Consultant|Pfizer: Advisor/Consultant|Sanofi: Advisor/Consultant

P-315. Safety and Effectiveness of Nasal Povidone-Iodine Decolonization Among Patients on Hemodialysis: A Multicenter Stepped-Wedge Cluster Randomized Trial

Abstract Background The SHEA/IDSA/APIC Strategies to Prevent MRSA Transmission and Infection Practice Recommendations advised that facilities consider decolonizing patients on hemodialysis. We implemented a nasal decolonization intervention in which patients self-administered povidone-iodine (PVI) at each dialysis session. We aimed to assess intervention safety and effectiveness. Methods We performed a stepped wedge cluster randomized trial at 16 outpatient hemodialysis units affiliated with 5 academic medical centers between 2020-2023. Adverse events were self-reported at 1 and 6 months. While the analysis was at the hemodialysis unit level, patients were required to give verbal informed consent for PVI use. Outcomes included National Healthcare Safety Network reportable dialysis events aggregated at hemodialysis unit level, including bloodstream infections (BSI), access-related BSI, and central venous catheter (CVC) BSI for all pathogens and for Staphylococcus aureus (SA). The primary outcome was SA BSI. A generalized linear mixed model with a negative binomial distribution, log link function, and an offset for person-months with a random intercept for each hemodialysis unit was performed. Results Overall, 1,351 patients received hemodialysis at these centers each month. Of those, 362 patients verbally consented to use PVI. Among these, 3.9% reported side effects: nasal drip, congestion or burning/stinging, unpleasant smell, headache, or minor nose bleed. A reported side effect ‘yellow tears’ was assessed via chart review and resolved by discontinuing PVI. There were no statistically significant associations between unit level randomization to the PVI intervention and infections. However, there was a non-statistically significant trend toward a protective association between unit-level randomization to PVI and SA infections, particularly SA CVC BSI.(Table) Conclusion Long-term nasal decolonization with PVI was safe with few adverse events. Unit level randomization to the PVI intervention did not significantly decrease unit-level infections. Given low patient enrollment and added infection prevention interventions due to COVID-19, the study could not determine if PVI decolonization could decrease BSI rates in the hemodialysis setting. Disclosures Marin Schweizer, PhD, 3M: Grant/Research Support Anitha Vijayan, MD, Baxter: Honoraria|NxStage: Advisor/Consultant|Qanta: Honoraria David A. Pegues, MD, DaVita/Total Renal Care: Advisor/Consultant Daniel Diekema, MD, Affinity Biosensors: Grant/Research Support|bioMerieux, Inc: Grant/Research Support Loreen Herwaldt, MD, 3M: Grant/Research Support|PDI: Grant/Research Support

P-706. Adenovirus Type 21 Outbreak among Haematology and liver transplant patients at a large tertiary care hospital in Singapore

Abstract Background Human adenoviruses (HAdVs) commonly cause acute respiratory illness, with documented outbreaks in military settings. HAdV infections frequently precipitate severe pneumonia amongst immunocompromised patients, with associated mortality risk. We report a HAdV type 21 infection cluster involving immunocompromised patients at a tertiary care hospital. Methods Hospital-onset (HO) adenoviral infection was defined as positive HAdV polymerase chain reaction (PCR) test with corresponding respiratory symptom onset six days after admission. Positive samples were typed in the National Public Health Laboratory by sequencing hexon gene variable regions. Epidemiological investigations were carried out for potential spatiotemporal linkage between these patients for targeted infection prevention interventions. Results Between 1st January to 31st March 2024, 21 HAdV-positive cases were identified, with five categorised as HO HAdV. Four patients (80%) had haematological malignancies and one had received a liver transplant 23 days prior to testing positive for HAdV. The mean age of patients was 58.6 years (SD: ± 9.7), with males comprising 60% of the cohort. The median hospital length of stay (LOS) before HAdV positivity was 21 days (range: 6 – 45). Clinical manifestations included fever, shortness of breath, cough, and acute respiratory failure. All patients required Intensive Care Unit (ICU) admission, with an average ICU LOS of 10 days (SD: ± 9.2). Respiratory samples of three patients were typed as HAdV 21, and three had adenovirus DNAemia. In the identified cluster, the four patients with haematological malignancies shared the same ward, with two overlapping in time but housed in different rooms. The liver transplant patient had overlapping stay in the critical care unit with a patient from the haematology cluster and shared the same mobile chest x-ray machine with two others from the same cluster. All four patients with haematological malignancies experienced same-admission mortality. Conclusion Timely symptom recognition and respiratory multiplex panel testing enabled detection of HAdV infection cluster in immunocompromised patients. Early cluster detection and reinforcement of infection prevention measures at risk locations can mitigate transmission of HAdV infections. Disclosures Moi Lin Ling, FRCPA, Solventum: Honoraria|Solventum: Educational grant for APSIC projects

591. The Agency for Healthcare Research and Quality (AHRQ) Safety Program for MRSA Prevention: Impact of an Educational and Implementation Project in United States (US) Hospitals

Abstract Background The AHRQ Safety Program for MRSA Prevention utilizes evidence-based infection prevention interventions and the Comprehensive Unit-based Safety Program (CUSP) framework to decrease invasive methicillin-resistant Staphylococcus aureus (MRSA) infections in intensive care units (ICUs), non-ICUs, surgical services, and long-term care facilities. We report the program's effect on hospital-onset MRSA bacteremia rates (HOB-MRSA) in 106 ICUs and 87 non-ICUs from 94 US hospitals.Table 1.Educational Toolkit Content for the AHRQ Safety Program for MRSA Prevention Methods The ICU/non-ICU Safety Program for MRSA Prevention was implemented from April 2022 to September 2023. The Safety Program aimed to decrease invasive MRSA infections through education, technical support, reinforcement of safety culture, and implementation of evidence-based infection prevention practices. Chlorhexidine bathing and nasal decolonization were major foci of the intervention, along with disinfection of the environment and practices to prevent person-based MRSA transmission and device-related infections. The project team provided 22 live webinars, supporting materials, and other tools to assist units with MRSA prevention (Table 1). Units were also assigned an implementation adviser who provided support through monthly coaching calls. Units submitted monthly data for HOB-MRSA per 10,000 patient days (PD) as well as data regarding process measures. Linear mixed effects models were employed to calculate pre-post intervention changes in HOB-MRSA events. Results 106 ICUs and 87 non-ICUs from 94 hospitals completed the Safety Program, including 31 (33%) academic medical centers (AMC), 37 (39%) non-AMC teaching hospitals, and 26 (28%) non-teaching community/other hospitals. From July-September 2021 to July-September 2023, HOB-MRSA events declined from 5.7 to 1.5 per 10,000 PD among ICUs (p< 0.001)(Figure 1) and from 3.4 to 0.2 for non-ICUs (p< 0.001) (Figure 2). Similar results were found in comparisons among other pre-program vs, end-of-program quarters. Conclusion The AHRQ Safety Program for MRSA Prevention supported implementation of evidence-based infection prevention practices, including decolonization, and was associated with reduced HOB-MRSA rates across participating ICUs and non-ICUs. Disclosures All Authors: No reported disclosures

Multimodal strategies for the implementation of infection prevention and control (IPC) interventions - update of a systematic review for the WHO guidelines on core components of IPC programmes at the facility level.

Healthcare-associated infections (HAIs) remain a significant challenge worldwide, and the use of multimodal strategies is recommended by the World Health Organization (WHO) to enhance infection prevention. To update the systematic review on facility-level infection prevention and control (IPC) interventions on the WHO Core Component of using multimodal strategies. Data Sources: Medline (via PubMed), EMBASE, CINAHL, and the Cochrane library. Randomized controlled studies (RCTs), interrupted time series (ITS), and before-after studies in acute care settings, from 24 November 2015 to 30 June 2023. Both paediatric and adult populations. IPC interventions implemented with at least three WHO multimodality elements. HAI, HAI caused by antimicrobial-resistant microorganisms, and hand hygiene (HH) compliance.Assessment of Risk of Bias: Effective practice and organisation of care (EPOC) and integrated quality criteria for review of multiple study designs (ICROMS) tools.Methods of data Synthesis: Descriptive data synthesis. Of 5678 identified titles and abstracts, 32 publications were eligible for data extraction and analysis. Five non-controlled before-after studies (NCBA) were excluded due to an insufficient ICROMS score. Of the remaining 27 studies, nine reported on the effect of multimodal strategies to reduce device-associated HAIs, four on surgical site infections, eight on infections due to AMR and six on HH compliance. Eleven were controlled studies (RCTs or controlled before-after studies (CBAs)), nine ITS and seven NCBA studies. Twenty-two of the studies originated from high-income countries and the overall quality was medium to low. Twenty studies showed either significant HAI-reductions or HH improvement. Most studies demonstrate a significant effect on HAI prevention and HH improvement after applying a multimodal strategy. However, the quality of evidence remains low to moderate with few studies from low- or middle-income countries. Future research should focus on higher quality studies in resource limited settings.

Using electronic medical records in hospital simulation for infection control intervention assessment.

Clinical trials for assessing the effects of infection prevention and control (IPC) interventions are expensive and have shown mixed results. Mathematical models can be relatively inexpensive tools for evaluating the potential of interventions. However, capturing nuances between institutions and in patient populations have adversely affected the power of computational models of nosocomial transmission. In this study, we present an agent-based model of ICUs in a tertiary care hospital, which directly uses data from the electronic medical records (EMR) to simulate pathogen transmission between patients, HCWs, and the environment. We demonstrate the application of our model to estimate the effects of IPC interventions at the local hospital level. Furthermore, we identify the most important sources of uncertainty, suggesting areas for prioritization in data collection. Our model suggests that the stochasticity in ICU infections was mainly due to the uncertainties in admission prevalence, hand hygiene compliance/efficacy, and environmental disinfection efficacy. Analysis of interventions found that improving mean HCW compliance to hand hygiene protocols to 95% from 70%, mean terminal room disinfection efficacy to 95% from 50%, and reducing post-handwashing residual contamination down to 1% from 50%, could reduce infections by an average of 36%, 31%, and 26%, respectively. In-silico models of transmission coupled to EMR data can improve the assessment of IPC interventions. However, reducing the uncertainty of the estimated effectiveness requires collecting data on unknown or lesser known epidemiological and operational parameters of transmission, particularly admission prevalence, hand hygiene compliance/efficacy, and environmental disinfection efficacy.

Rapid whole genome characterization of antimicrobial-resistant pathogens using long-read sequencing to identify potential healthcare transmission.

Whole genome sequencing (WGS) can help identify transmission of pathogens causing healthcare-associated infections (HAIs). However, the current gold standard of short-read, Illumina-based WGS is labor and time intensive. Given recent improvements in long-read Oxford Nanopore Technologies (ONT) sequencing, we sought to establish a low resource approach providing accurate WGS-pathogen comparison within a time frame allowing for infection prevention and control (IPC) interventions. WGS was prospectively performed on pathogens at increased risk of potential healthcare transmission using the ONT MinION sequencer with R10.4.1 flow cells and Dorado basecaller. Potential transmission was assessed via Ridom SeqSphere+ for core genome multilocus sequence typing and MINTyper for reference-based core genome single nucleotide polymorphisms using previously published cutoff values. The accuracy of our ONT pipeline was determined relative to Illumina. Over a six-month period, 242 bacterial isolates from 216 patients were sequenced by a single operator. Compared to the Illumina gold standard, our ONT pipeline achieved a mean identity score of Q60 for assembled genomes, even with a coverage rate as low as 40×. The mean time from initiating DNA extraction to complete analysis was 2 days (IQR 2-3.25 days). We identified five potential transmission clusters comprising 21 isolates (8.7% of sequenced strains). Integrating ONT with epidemiological data, >70% (15/21) of putative transmission cluster isolates originated from patients with potential healthcare transmission links. Via a stand-alone ONT pipeline, we detected potentially transmitted HAI pathogens rapidly and accurately, aligning closely with epidemiological data. Our low-resource method has the potential to assist in IPC efforts.

Longitudinal genomics reveals carbapenem-resistant Acinetobacter baumannii population changes with emergence of highly resistant ST164 clone

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a persistent nosocomial pathogen that poses a significant threat to global public health, particularly in intensive care units (ICUs). Here we report a three-month longitudinal genomic surveillance study conducted in a Hangzhou ICU in 2021. This followed a three-month study conducted in the same ICU in 2019, and infection prevention and control (IPC) interventions targeting patients, staff and the ICU environment. Most A. baumannii isolated in this ICU in 2021 were CRAB (80.9%; 419/518) with higher-level resistance to carbapenems. This was accompanied by the proportion of global clone 2 (GC2) isolates falling from 99.5% in 2019 to 50.8% (213/419) in 2021. The phylogenetic diversity of GC2 increased, apparently driven by regular introductions of distinct clusters in association with patients. The remaining CRAB (40.2%; 206/419) were a highly clonal population of ST164. Isolates of ST164 carried blaNDM-1 and blaOXA-23 carbapenemase genes, and exhibited higher carbapenem MIC50/MIC90 values than GC2. Comparative analysis of publicly available genomes from 26 countries (five continents) revealed that ST164 has evolved towards carbapenem resistance on multiple independent occasions. Its success in this ICU and global capacity for acquiring resistance determinants indicate that ST164 CRAB is an emerging high-risk lineage of global concern.

Transmission of Group A Streptococcus in Long-Term Care: An Outbreak Investigation

We report 2 outbreaks comprising a cluster of 18 group A Streptococcal infections across 2 nursing facilities. Point prevalence surveillance testing identified 8 of 18 cases, and whole genome sequencing validated transmission pathways. Infection prevention interventions at the facility level comprised symptomatic and asymptomatic carriage-based case finding, transmission-based precautions, and treatment to eradicate colonization.

Central Line-Associated Bloodstream Infection Reduction in Hemodialysis Patients Across 9 Hospitals and 3 States.

This quality improvement project was initiated to reduce hospital-acquired catheter-associated bloodstream infections (CLABSI) in hospitalized patients receiving dialysis. A team dedicated to reducing hospital-acquired infections led the implementation of evidence-based interventions across all the included hospitals. This innovative approach demonstrated substantial enhancements in outcomes for patients on hemodialysis. To enhance patient safety in patients receiving hemodialysis, new strategies were implemented, including (1) transitioning from a vendor model to an internal model, enabling dialysis program standardization, (2) empowering intensive care nurses with increased autonomy and ownership, (3) transitioning to a standardized dialysis machine, and (4) introducing chlorhexidine gluconate (CHG) impregnated caps and CHG pads. To reduce CLABSI in hemodialysis lines, a multidisciplinary team was formed comprising physicians, nurses, a dialysis technician, pharmacists, the dialysis director, the chief medical officer, the chief nursing officer, the assistant chief nursing officer, the infection preventionist, and the quality director. The team implemented a standardized approach to caring for hemodialysis lines, provided just-in-time education to staff, and standardized policies simultaneously at 8 hospitals. Initially, 1 facility served as the pilot facility for facility-owned dialysis services, totaling 9 facilities providing in-house standardized dialysis services. Data was reported back for monthly evaluation. Overall, there was an 88% reduction in CLABSI occurrences in hemodialysis lines from pre-intervention (n = 8) to post-intervention (n = 1), X2 (1, N = 4112) = 4.181, P = .0408. Collaboration on these initiatives improved communication and enhanced quality care and patient safety across the entire spectrum of care. Implementing innovative tracking of standardized approaches to patient care and infection prevention and evidence-based interventions resulted in decreased CLABSI rates, improving outcomes in vulnerable patients. An unintended benefit of this project was the increase in multidisciplinary collaboration.

Burden of SARS-CoV-2 infection prior to vaccine eligibility among immunocompromised children aged 1-11years at a pediatric tertiary referral hospital in Toronto, Canada.

SARS-CoV-2 seroprevalence reflects the efficacy of pandemic infection prevention and control measures. We performed anti-spike IgG serological testing on residual sera of children 1-11years old at a tertiary care referral center between October and November 2021. Immunocompromised patients had the highest SARS-CoV-2 seroprevalence, at 40.5%, compared to 19.3% in non-immunocompromised patients. Targeted infection prevention and public health interventions are warranted for pediatric immunocompromised patients in future pandemics.

Vaccines and monoclonal antibodies to prevent healthcare-associated bacterial infections.

SUMMARYHealthcare-associated infections (HAIs) represent a burden for public health with a high prevalence and high death rates associated with them. Pathogens with a high potential for antimicrobial resistance, such as ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and Clostridioides difficile, are responsible for most HAIs. Despite the implementation of infection prevention and control intervention, globally, HAIs prevalence is stable and they are mainly due to endogenous pathogens. It is undeniable that complementary to infection prevention and control measures, prophylactic approaches by active or passive immunization are needed. Specific groups at-risk (elderly people, chronic condition as immunocompromised) and also healthcare workers are key targets. Medical procedures and specific interventions are known to be at risk of HAIs, in addition to hospital environmental exposure. Vaccines or monoclonal antibodies can be seen as attractive preventive approaches for HAIs. In this review, we present an overview of the vaccines and monoclonal antibodies in clinical development for prevention of the major bacterial HAIs pathogens. Based on the current state of knowledge, we look at the challenges and future perspectives to improve prevention by these means.

Rapid Whole Genome Characterization of High-Risk Pathogens Using Long-Read Sequencing to Identify Potential Healthcare Transmission.

Routine use of whole genome sequencing (WGS) has been shown to help identify transmission of pathogens causing healthcare-associated infections (HAIs). However, the current gold standard of short-read, Illumina-based WGS is labor and time-intensive. In light of recent improvements in long-read Oxford Nanopore Technologies (ONT) sequencing, we sought to establish a low resource utilization approach capable of providing accurate WGS-based comparisons of HAI pathogens within a time frame allowing for infection prevention and control (IPC) interventions. WGS was prospectively performed on antimicrobial-resistant pathogens at increased risk of potential healthcare transmission using the ONT MinION sequencer with R10.4.1 flow cells and Dorado basecalling algorithm. Potential transmission was assessed via Ridom SeqSphere+ for core genome multilocus sequence typing and MINTyper for reference-based core genome single nucleotide polymorphisms using previously published cut-off values. The accuracy of our ONT pipeline was determined relative to Illumina-based WGS data generated from the same genomic DNA sample. Over a six-month period, 242 bacterial isolates from 216 patients were sequenced by a single operator. Compared to the Illumina gold-standard data, our ONT pipeline achieved a Q score of 60 for assembled genomes, even with a coverage rate of as low as 40X. The mean time from initiating DNA extraction to complete genetic analysis was 2 days (IQR 2-3.25 days). We identified five potential transmission clusters comprising 21 isolates (8.7% of all sequenced strains). Combining ONT WGS data with epidemiological data, >70% (15/21) of the isolates originated from patients with potential healthcare transmission links. Via a stand-alone ONT pipeline, we detected potentially transmitted HAI pathogens rapidly and accurately, aligning closely with epidemiological data. Our low-resource method has the potential to assist in the efficient detection and deployment of preventative measures against HAI transmission.

Infection prevention and control in cystic fibrosis: An update of a systematic review of interventions

Preventing transmissible infection is a priority in cystic fibrosis (CF) care. This is an update of a systematic review of the evidence for infection prevention and control interventions in CF. Our full protocol can be found on PROSPERO (CRD42018109999). We searched for studies and guidelines which included interventions for infection prevention and control in CF. We included 39 studies and 7 guidelines. Strategies included: cohort or individual segregation, hand hygiene, facemasks, equipment, enhanced adherence or a combination of these. Many studies showed a reduction in transmission with segregation. However, the certainty of evidence (using GRADE) was low or very low. Most guideline recommendations have little evidence to support them, with no updates since our original review. Undertaking RCTs in this area is ethically difficult. Large-scale registry-based studies may be the best pragmatic approach. Benefits of infection control must be balanced against the intrusion in the lives of people with CF.

Survey of Hemodialysis Patients’ Knowledge of Their Infection Risk and Acceptability of a Nasal Decolonization Intervention

Background: Patients undergoing hemodialysis are at high risk for healthcare-associated infections; they are at 100 times the risk of Staphylococcus aureus bloodstream infections (BSI) compared with U.S. adults not on hemodialysis. Prior studies found that nasal decolonization with mupirocin prevented S. aureus BSI among hemodialysis patients. We implemented a nasal decolonization intervention in which patients self-administered povidone-iodine (PVI) at each dialysis session. We aimed to assess: 1) hemodialysis patients’ knowledge of their infection risk and their willingness to take an active role in infection prevention; 2) the acceptability of the PVI nasal decolonization intervention. Methods: We performed a stepped wedge cluster randomized trial at 16 outpatient hemodialysis centers. Patients were surveyed: before starting PVI, 1 month after their center started using PVI, and ~6 months after starting PVI. We used a chi-square test to compare results. Results: 469 patients completed at least 1 survey: 400 pre-intervention, 237 at 1 month and 201 at 6 months. Overall, 56% of patients thought that their risk of infection was average or below average compared with an average person in the U.S. (Figure). Over 98% agreed with the statement “One of the most important things I can do for my health is to take an active role in my health care." In the pre-intervention survey, 73% were willing to do “a lot of effort” to prevent an infection. This proportion was similar (73%) in the 2nd survey, but decreased to 63% in the final survey (p < 0 .01). Among 106 patients who reported starting PVI, 85% reported that PVI felt neutral or pleasant, 9.4% reported a side effect, and 79% reported using it during the past 3 dialysis sessions. Among 102 patients who reported using PVI at 6 months, 87% said it felt neutral/pleasant, 3.9% reported a side effect and 75% reported using it during the past 3 dialysis sessions. Side effects included nasal dripping, congestion or burning/stinging, unpleasant smell, headache, yellow tears, and minor nose bleeding. Conclusions: Hemodialysis patients are not aware of their high risk of infection. Although many were willing to expend a lot of effort to prevent an infection, this willingness decreased during an infection prevention intervention. There were few PVI side effects and most patients stated that PVI felt neutral/pleasant, yet many patients chose to not use PVI. Future research should aim to improve patient education on their risk of infection and assess barriers to adherence with infection prevention interventions.Disclosure: Marin Schweizer: Speaker- 3M; Contracted research-3M; Anitha Vijayan: Honoraria - Quanta, Baxter, Fresenius Consulting, Astute, NxStage

Stenotrophomonas maltophilia Bloodstream Infection Outbreak in an Acute Care Hospital — Alameda County, California 2022–2023

Background: Stenotrophomonas maltophilia is an opportunistic pathogen found in healthcare settings. During April–September 2022, nine S. maltophilia bloodstream infections (BSIs) were identified among intensive care unit (ICU) patients at a hospital in Alameda County, California. Whole genome sequencing found isolates to be highly related. Despite implementation of infection prevention and control (IPC) interventions, four additional S. maltophilia BSIs were identified during June–September 2023. We investigated to identify risk factors for infection and stop transmission. Methods: We conducted a matched case-control study. A case was defined as S. maltophilia isolated from a blood culture from an ICU patient with a fever during April 2022–September 2023; control-patient subjects were patients admitted to the ICU during the same period with hospital stay greater than or equal to their matched case. Three control subjects were matched to each case. We extracted information on risk factors for infection from medical charts and observed IPC practices in hospital locations of interest. We collected environmental samples from the ICU, radiology unit, and emergency department. Results: Among 13 cases and 39 control subjects, patients exposed to iodinated contrast Omnipaque-300 (odds ratio [OR]: 5.7; 95% CI: 1.2–28.0), injectable propofol (OR: 12.2; 95% CI: 1.5–101.4), or fentanyl (OR: 9.2; 95% CI: 1.8–Inf.) were more likely to have a S. maltophilia BSI, compared with control-subjects. IPC deficiencies included improper cleaning and storage of medical equipment, including the contrast injection system, and patient care supplies. The outbreak strain of S. maltophilia was not isolated from environmental samples. Conclusions: Although a point-source was not identified, S. maltophilia was likely transmitted through improper IPC practices involving injectable contrast or anesthesia. Recommendations on proper cleaning and disinfection of the contrast injection system and proper storage, preparation, and administration of medications were made to reduce risk for contamination.

Capturing MRSA Diversity by Integrating Genomic and Epidemiological Data of Patients and their Spaces

Background: Methicillin-resistant S. aureus (MRSA) is known to cause frequent and severe infections in community living centers, potentially resulting in significant mortality for elderly patients. More research is needed to understand how to utilize genomic and epidemiological data to understand characteristics that may lead to increased transmission. We hypothesized that combining genomic and epidemiological information to sample patients and their environments during long-term stays, we will be able to capture a diverse set of MRSA strains. Method: This work included genome sequencing of patient and environmental samples from 11 patients within the VA Ann Arbor Healthcare System from May 4, 2021- November 16, 2022. All 11 patients tested positive for MRSA during their stay (mean days = 31). Patient and environmental samples were taken throughout their stays, screened for MRSA, and whole-genome sequenced. Single nucleotide variants (SNVs) were identified by mapping reads and calling variants against strain-specific reference genomes. We used ape v5.6-2 in R v4.2.2 to analyze and infer evolution, acquisition, and transmission events based on pairwise SNV distances. Genomic clusters were determined using stats v3.6.2, with a SNV distance threshold of 20. Result: Samples that were collected from patient bodily sites were able to reveal 20 distinct genomic clusters of MRSA (patient hands: n = 10, nares: n = 7, groin: n = 3). Environmental samples from patient environments also revealed distinct genomic MRSA clusters (tv remote: n = 9, toilet seat and bed rail: n = 6, table top, bed control, and call button: n = 5, bed curtain: n = 4, pulse ox = 2, cell phone, tray, pulse ox, mat, body hoist wrap, and bed: n = 1). Conclusion: The identification of various genomic clusters from patients and their environmental reservoirs suggests intrahost variation that can only be captured by using a more holistic approach of integrating epidemiology and genomic sequencing. Developing studies that incorporate genomic data, various environmental sources, and multiple isolates over time within community living centers can increase our understanding of strains that are more likely to transmit, survive on living and non-living surfaces and therefore lead to improved recommendation for infection prevention interventions and drivers of endemicity.Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix