Background: The Colorado Department of Public Health and Environment (CDPHE) detected an increase in Klebsiella pneumoniae carbapenemase-producing carbapenem-resistant Enterobacterales (KPC-CRE) infections in October 2022. We investigated patient epidemiological links and isolate relatedness to characterize interfacility transmission of KPC-CRE in the Denver metro area and inform regional prevention strategies. Methods: We defined a case as polymerase chain reaction detection of KPC from clinical or screening specimens collected during January 2022 – January 2023. Cases were identified through statewide CRE surveillance and carbapenemase testing at the CDPHE laboratory and counted once within a 30-day period. Medical records were reviewed to identify healthcare facility admissions and patient facility overlap in the 12 months prior to sample collection. Whole genome sequencing (WGS) was performed for 34 patients with available KPC-CRE isolates using short- and long-read sequencing techniques. We performed multi-locus sequence typing, generated genome phylogenetic trees, and compared plasmid contig sequences to identify relatedness between KPC-CRE isolates. Clusters were defined as ≥2 genetically related isolates of the same organism or carbapenemase plasmid, from different patients. Results: We identified 48 cases (34 clinical and 14 screening) among 39 patients (figure). Patients had a mean age of 52 years (range 16-86) and median of three healthcare facility admissions (range 1-14). Twenty-eight patients (72%) were male. We identified 16 (41%) patients with epidemiological links to one acute care hospital (ACH), 11 (28.2%) patients to one long-term acute care hospital (LTACH), and four (10.2%) patients to each of two ventilator-capable skilled nursing facilities (vSNF). Five distinct clusters of KPC-CRE were identified by WGS among 23 patients (E. hormaechei, two distinct E. cloacae clusters, K. pneumoniae, and K. oxytoca) with linkages to ten healthcare facilities, including two vSNFs, two LTACHs, and six ACHs. Three distinct KPC genes were identified among the clusters: KPC-2, KPC-3, and KPC-4. Genomes assembled from long reads identified identical or similar KPC-gene-containing plasmids across different species or sequence types, suggesting horizontal gene transfer of KPC. Conclusions: Multiple KPC-CRE strains co-circulated and were associated with patient movement between acute and post-acute care settings. WGS allowed us to identify multi-facility clusters. Time and location of carbapenemase acquisition were challenging to determine for genetically related isolates when epidemiologic links could not be determined from medical records. This could be due to undetected cases. We notified healthcare facilities of their shared transmission risk and advocated for improved attention to infection control, carbapenemase screening, and communication upon patient transfer.

Background: Stenotrophomonas maltophilia (SM) is a non-fermenting, Gram-negative bacillus. Its intrinsic resistance to many beta-lactams makes for challenging treatment decisions. A preprint of the latest Infectious Diseases Society of America (IDSA) guidance on managing SM infections was published in December 2022 providing a recommendation for combination therapy including trimethoprim/sulfamethoxazole (TMP/SMX) and a second agent. An evaluation of the impact on SM treatment practices following this guidance was conducted at our institution. Methods: A list of 130 patients with non-urine SM cultures from December 2021-August 2023 was generated using a pharmacovigilance platform. Patients were excluded if on comfort measures or discharged to hospice prior to therapy completion, no directed antibiotics were given, or any history of prior SM infection. Twenty-five patients were randomly selected from the pre- and post-guidance periods (before and one month after December 1, 2022) for a total of 50 patients. Data was collected via manual chart review. The primary endpoint was frequency of combination antibiotic therapy in each time period. Secondary endpoints included treatment success (defined as resolution of infection symptoms and lack of infection recurrence), in-hospital mortality, 30-day mortality, and 30-day infection recurrence. Results: Overall, baseline characteristics were similar between groups, the median age was 65 years, 64% of patients were male, 20% were immunocompromised based on prespecified criteria, the median Charlson comorbidity index was 5 (21% estimated 10-Year survival), and 76% of SM cultures were pulmonary isolates. Displayed in figure 1, combination therapy was given in 6 of 25 cases (24%) in the post-guidance group and zero patients in the pre-guidance group. Secondary endpoints of treatment success and all-cause mortality were similar between groups. Duration of therapy was similar between combination and non-combination therapy regimens (median 9 vs 10 days). Among patients who received combination therapy, all had ID consultation, 4 (66.7%) were admitted to the ICU, and 2 (33.3%) had treatment success. Conclusions: Patients treated for SM infection at our institution in the post-IDSA guidance period were more likely to receive combination therapy. A higher rate of treatment success was not observed in the post-IDSA guidance arm for SM infections. Limitations of this study include its small sample size and retrospective design, leading to inability to distinguish colonization from true infection. Additional studies are needed to evaluate the impact of combination antibiotic therapy on outcomes.

Background: Early identification of patients colonized with MDROs can help healthcare facilities improve infection control and treatment. We evaluated whether a model previously validated to predict carbapenem-resistant Enterobacterales (CRE) carriage on hospital admission (area under the curve [AUC]=0.86, Lin et al. OFID 2019) would generalize to predict a patient’s likelihood of CRE and non-CRE MDRO colonization at the time of medical intensive care unit (MICU) admission. Methods: We analyzed data collected previously in a retrospective observational cohort study of patients admitted to Rush University Medical Center’s MICU from 1/2017-1/2018 and screened within the first two days for rectal MDRO colonization. Organisms of interest included CRE, carbapenem-resistant Pseudomonas aeruginosa (CRPA), vancomycin-resistant enterococci (VRE), and third-generation cephalosporin-resistant Enterobacterales (3GCR-E). Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization at admission was determined by routine clinical screening. Each patient’s first MICU admission during the study period was linked to Illinois’ hospital discharge database and assigned a CRE colonization risk probability using the existing model. Model covariates were age, and during the prior 365 days, number of short-term acute care hospitalizations (STACH) and mean STACH length of stay, number of long-term acute care hospitalizations (LTACH) and mean LTACH length of stay, prior hospital admission with an ICD-10 diagnosis code indicating bacterial infection, and current admission to LTACH. Predictive value of the model was evaluated by receiver operating characteristic (ROC) curves. Results: We analyzed 1237 MICU admissions. MDRO admission prevalence is shown in the Table. The model performed well to predict carriage of healthcare-associated MDROs, including CRE, CRPA, composite CR-MDROs (CRE & CRPA), and VRE. However, the model performed poorly for MDROs with known community reservoirs, including 3GCR-E and MRSA (Table). In general, MDRO admission prevalence increased in parallel with predicted CRE colonization risk (Figure). The number needed to screen (NNS) to detect one healthcare-associated MDRO carrier was inversely related to the CRE colonization risk score. For example, NNS in the total cohort compared to those with CRE risk score of >0.5% was: CRE 111 vs 32 patients, CRPA 333 vs 42 patients, composite CR-MDRO 83 vs 18 patients, and VRE 12 vs 4 patients. However, higher CRE risk score cutoff was inversely related to screening sensitivity. Conclusion: A prediction model using prior healthcare exposure information successfully discriminated patients likely to harbor healthcare-associated MDROs upon MICU admission. Prediction scores generated by a public-health accessible database could be used to target screening/isolation or enact protective measures for high-risk patients.

Background: Taurolidine exhibits broad antimicrobial activity and is a component of a recently FDA approved catheter lock solution (DefenCath®, taurolidine 13,500 μg/mL and heparin 1000 Units/mL) indicated for reducing the risk of catheter-related bloodstream infections (CRBSI) in adult patients receiving chronic hemodialysis through a central venous catheter (HD-CVC). FDA approval was based on a Phase 3 randomized trial (LOCK-IT-100) in which DefenCath showed a 71% reduction in CRBSI risk among HD-CVC patients as compared with heparin alone. Although individual isolates from the clinical program were not available for testing, this study evaluated the in vitro antimicrobial activity of taurolidine against a set of recent clinical isolates representative of those recovered from the LOCK-IT-100 trial and/or those commonly associated with CRBSI. Methods: 420 bacterial and 50 yeast isolates were selected from the SENTRY Antimicrobial Surveillance Program. All isolates were collected from the bloodstream of patients in the U.S. between 2018-2023. Isolates were tested for susceptibility to taurolidine and comparators using Clinical and Laboratory Standards Institute (CLSI) broth microdilution guidelines. JMI Laboratories produced susceptibility test panels for testing. CLSI-recommended quality control strains were also tested concurrently. MIC values were determined after 24 hours. Results: Taurolidine exhibited broad antimicrobial activity against all isolates tested (see table). Against gram-positive bacteria, taurolidine MIC50/90 values ranged from 256-512/512-1,024 μg/mL for S. aureus, Coagulase-negative Staphylococcus, Enterococcus species, and Viridans group streptococci. This activity was maintained regardless of methicillin susceptibility for Staphylococcal isolates or vancomycin resistance among Enterococcal species. Against gram-negative bacteria, taurolidine MIC50/90 values ranged from 256-1,024/512-2,048 μg/mL for Enterobacterales, P. aeruginosa, S. maltophilia, A. baumannii-calcoaceticus, and B. cepacia. This activity was maintained in both multidrug resistant Enterobacterales and P. aeruginosa isolates. Among Candida isolates, taurolidine MIC50/90 values ranged from 256-512/512 μg/mL for C. glabrata and C. parapsilosis while taurolidine MIC50/90 values of 4,096/4,096 μg/mL were observed for C. albicans. Conclusions: Taurolidine activity was very similar among a large collection of gram-positive, gram-negative, and yeast organisms. MIC90 values for all species/groups were ≤2,048 μg/mL, except C. albicans where an MIC90 of 4,096 μg/mL was observed. The activity of taurolidine was unaffected by resistance to antibiotics (i.e. methicillin, vancomycin, or multi-drug resistance) among gram-positive or gram-negative organisms. Based on these data, catheter lock solutions containing the broad-spectrum antimicrobial taurolidine at 13,500 μg/mL have the potential to prevent CRBSI caused by a variety of species, including those observed in the recent LOCK-IT-100 clinical trial and other common bloodstream pathogens

Background: Candida auris is often identified in healthcare settings through bilateral composite of axilla/groin skin swabs screening. Re-screening the same patient has demonstrated inconsistent results over time, complicating the understanding of longitudinal colonization and limiting confidence in negative Results: Previous studies have described identification of colonized patients using other anatomical sites. Here, we compare bilateral composite of nares/hands with bilateral composite of axilla/groin screenings in a cohort of hospitalized patients in Miami, Florida, to assess the use of screening other body sites for C. auris surveillance. Methods: This study took place in a 560-bed academic acute-care facility and included patients previously colonized with C. auris who were cohorted on a 30-bed unit. Bilateral composite samples from both the axilla/groin and nares/hands were obtained simultaneously. Swabs were collected at six different time points at biweekly intervals between March and May 2023 (Figure 1) and sent to the Centers for Disease Control and Prevention for testing with culture and Real-time PCR-based methods. Results: A total of 102 swabs (51 from each swab type) were collected from 19 patients who were each sampled a median of twice (IQR: 1-5). Among the 102 swabs, 35 of 51 (69%) axilla/groin swabs were positive compared with 45 of 51 (88%) nares/hands swabs using culture (Figure 2). Furthermore, 48 of 51 (94%) swabs were positive by culture for both methods, with 15 positive from the nares/hands and one positive from the axilla/groin (Figure 3). Among 11 patients who were tested ≥2 times with nares/hands swabs, 9/11 (81%) tested positive on all sequential swabs via culture and 10/11 (90%) tested positive via PCR (Ct threshold < 3 6.9). Among the same 11 patients but using the axilla/groin swabs, 3/11 (27%) patients tested positive on all sequential swabs using culture, and 5/11 (45%) tested positive using PCR (Figures 2-4). On average, samples collected from nares/hands swabs had lower Ct values (mean=27) compared to axilla/groin swabs (mean=31) (p-value=< 0.001) (Figure 5). Discussion: Identifying the swab site with most consistent C. auris detection is important for surveillance purposes. In our study, there were more positives and consistent positivity for nares/hands by both culture and PCR-based methods, as well as lower Ct values, suggesting that these swabs provide more reliable detection of C. auris colonization. Alternative screening methods deserve consideration as CDC continues to explore whether swabbing of other body sites (e.g., nares, hands) would improve accuracy and consistency when identifying colonized patients.

Background: Detection of outbreaks traditionally relies on passive surveillance, and often misidentify or miss outbreaks. Whole genome sequencing (WGS) surveillance has emerged as a proactive measure, enabling early detection of outbreaks and facilitating rapid intervention strategies. WGS surveillance has not been widely studied due to infrastructure, cost, and evidence barriers regarding its impact on reducing healthcare-associated infections (HAIs). This study represents findings from two years of a real-time WGS surveillance program called the Enhanced Detection System for Healthcare-associated Transmission (EDS-HAT). Methods: The study was conducted at UPMC Presbyterian hospital, a 694-bed tertiary care center. Patient isolates of select bacterial pathogens were collected and underwent WGS weekly from November 2021 to November 2023. Potential transmission was defined using single-nucleotide polymorphism thresholds (≤15 for all organisms except Clostridioides difficile). Genetically related clusters were reviewed weekly for epidemiological linkages (unit, personnel, or procedural commonalities) and appropriate interventions were initiated by the infection prevention and control team. We described the frequency of genetic relatedness and nature of epidemiological linkages. Results: Of 7,051 eligible unique patient organism isolates, 4,723 were deemed healthcare-associated and underwent WGS. EDS-HAT identified 478 (12.2%) isolates genetically related to ≥1 other isolate across 173 clusters. Epidemiological links were found in 278 (58.2%) isolates in 114 clusters, with the majority being unit-based (205 isolates, 71.9%); other epidemiological links included equipment or healthcare workers (32 isolates, 11.5%), external facilities (24 isolates, 8.6%), and shared endoscopes (17 isolates, 6.1%); all endoscope outbreaks were effectively contained at two patients. No epidemiological links could be identified for 200 (41.8%) isolates. Infection prevention initiated 134 interventions in 114 clusters, including 74 (55.2%) general staff notification and education, 25 (18.7%) enhanced cleaning efforts, 23 (17.2%) hand hygiene/personal-protective equipment compliance observations, 9 (6.7%) environmental cultures, and 3 (2.2%) enhanced microbiological surveillance. Following the detection of an epidemiological link and intervention, 94/101 (94.1%) outbreaks were effectively halted on the intervened route (Figure). Conclusion: This study demonstrates the feasibility and efficacy of EDS-HAT as an infection prevention tool. Early detection and intervention of outbreaks significantly enhance the capability of healthcare facilities to control and prevent the spread of HAIs. Investment in infrastructure and implementation costs will result in reducing pathogen transmission and improving patient safety in acute care settings.

Disclosure: Alexander Sundermann: Honoraria - Opgen

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of procedure-related, skin, and soft-tissue infections. Hospitalized patients who are colonized with MRSA are at a higher risk of developing invasive infections after discharge. Chlorhexidine, an antiseptic/disinfectant, has been used to reduce carriage and prevent infections in these patients. Studies have shown chlorhexidine resistance among MRSA strains. Chlorhexidine resistance is associated with qac genes, which encode multidrug efflux pumps that increase bacterial tolerance to disinfectant agents. The global distribution and prevalence of qacA and qacB genes are highly variable. One study reported that qacA and qacB genes could be found in 0.9% - 83.3% of clinical MRSA isolates worldwide. The goal of this study was to determine the prevalence of chlorhexidine resistance and identify the resistance-associated genes from our MRSA samples using whole genome sequencing (WGS). Methods: 474 MRSA samples were obtained from hospitals in Detroit, MI (287) and Cleveland, OH (187). Whole genome sequencing was performed using the NextSeq (Illumina Inc., CA) platform. The sequencing data was analyzed using ResFinder 4.1, a publicly available database that can be used to identify acquired genes and chromosomal mutations mediating antimicrobial resistance. The output was organized into a data sheet to visualize the presence of the genes of interest. Results: The qacA gene was present in only one MRSA sample from the Cleveland area hospital. In the samples from Detroit, 14 out of 287 showed disinfectant resistance genes. The qacA, qacB, and qacD were present in 1, 6, and 7 samples, respectively. The prevalence of any qac gene in the Cleveland area samples was 0.5%. Meanwhile, the prevalence of any qac gene in Detroit area samples was 4.9%. Among the 7 samples that have qacD gene, 6 samples have more than one copy of qacD. Conclusions: The prevalence of the “qac” gene varied widely based on the origin of the samples. Detroit area samples had more qac genes prevalence than Cleveland area samples. Chlorhexidine is a widely used antiseptic/disinfectant, and it plays a vital role in reducing carriage and preventing infection among hospitalized patients colonized with MRSA. Monitoring and addressing MRSA-reduced susceptibility to chlorhexidine is imperative for maintaining the effectiveness of infection control practices such as decolonization.

Background: Most healthcare facilities in the US apply contact precautions (CP) for patients with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) infection and/or colonization. Most individuals with MRSA or VRE colonization will clear over time; however, frontline clinicians rarely evaluate for discontinuation of CP, resulting in increased burden on infection preventionists (IPs). Automation of time- and test-based evaluation using clinical decision support systems (CDSS) embedded in electronic health records (EHR) may increase evaluation and discontinuation of CP when appropriate, while preserving IP resources. Methods: This quality improvement initiative was implemented at Mass General Brigham (MGB), an integrated healthcare system, where patients with MRSA or VRE infection/colonization are identified in the EHR with a corresponding “infection status” and CP applied. Following MGB policy (Figure 1), CDSS features included: 1) automated time-based resolution from 2/15/2023-11/13/2023 and 2) automated ordering of screening assays for patients eligible for test-based evaluation from 6/20/2023-11/14/2023 (Figure 2). Counts of CP discontinuation and automated ordering were performed. IPs at one MGB facility performing manual review of patients self-recorded the time spent evaluating for CP discontinuation. Using these time reports, the average time to complete these tasks and the projected time savings were calculated over the implementation period. Results: Four IPs recorded the time to review patients for CP discontinuation, including reviewing recent antimicrobial administration, microbiology results, ordering screening test(s), and contacting the primary team. Twenty-five patient encounters were timed with a mean of 4.7 minutes documented per encounter. Over a 9-month period after initiation of the automated time-based resolution, the monthly mean number of patients with CP for MRSA and VRE which were automatically discontinued was 247 and 100, respectively. Projected IP time savings over the same 9-month period for MRSA and VRE were 174.1 and 70.5 hours, respectively. Over a 5-month period after initiation of automated ordering of MRSA polymerase chain reaction (PCR)/culture, as well as VRE culture for test-based evaluation, the monthly mean number of MRSA culture, MRSA PCR, and VRE culture automatically ordered for patients on CP for MRSA and VRE were 176, 24, and 145, respectively. Projected IP time savings over the same 5-month period for MRSA and VRE were 78.3 and 56.8 hours, respectively.

Conclusion: Healthcare systems that enhance their EHR with CDSS to automate CP evaluations may improve frontline clinician workflow, patient flow and bed capacity, while optimizing use of IP resources.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen responsible for nosocomial and community-acquired infections with high morbidity and mortality1. MRSA nasal colonization is a major risk factor for developing infection in the hospital setting2,3. Decolonization of MRSA carriers is a strategy to decrease recurrence or to prevent new MRSA infections3,4. Decolonization with nasal mupirocin 2% and chlorhexidine baths has been shown to decrease the risk of MRSA infection after hospital discharge3. Mupirocin is an RNA synthetase inhibitor with activity against MRSA5. Resistance of MRSA isolates to mupirocin has been described previously6. As topical disinfectants play a crucial role in prevention of MRSA infection in a variety of settings, it is important to monitor the emergence of resistance. The goal of this study was to determine the prevalence of mupirocin resistance among MRSA samples isolated from two different regions in the United States (U.S). Methods: Our study had a total of 474 MRSA samples that were obtained from hospitals in Detroit, MI (287 samples) and Cleveland, OH (187 samples). After whole genome sequencing using NextSeq (Illumina Inc., CA) platform the data was analyzed using ResFinder 4.1, to identify antimicrobial resistance which can be either acquired or chromosomally mediated mutations. To visualize the presence of genes of interest the resistance genes were tallied on a spread sheet. Results: Mupirocin resistance gene was detected in five of 287 (1.74%) MRSA samples from the Detroit hospitals, all of which were associated with the mupA gene. Samples collected from the Cleveland area hospital demonstrated mupirocin resistance in seven samples of 187 (3.74%), all associated again with the mupA gene. One sample from the Detroit group showed resistance to both mupirocin and chlorhexidine. Conclusions: Prevalence of mupirocin resistance gene varied between the two hospital locations. Resistance to mupirocin has been documented in association with mutations in the mupA gene as well as chromosomal point mutations that can lead to either low or high-level resistance7,8. Although the mechanisms are not fully clear, mupA gene has been associated with high-level resistance9. Mupirocin resistance among MRSA isolates has increased over time9. MRSA infections remain an important etiology of nosocomial and community-acquired infections and common practice to combat this issue is universal decolonization with mupirocin10. It is critical to understand and monitor for development of mupirocin resistance as mupirocin remains one of the most effective tools to prevent invasive infection with MRSA in many patient populations.

Background: Invasive Staphylococcus aureus infections cause significant morbidity and mortality in neonatal intensive care unit (NICU) infants.1 Colonization (asymptomatic carriage in the nose, skin, or gut) is a risk factor for subsequent invasive infection (e.g., pneumonia, bone infections, bloodstream infections, etc.). Active surveillance and decolonization measures for S. aureus-colonized infants have been associated with decreased invasive infection rates. 2-4 Methods: A methicillin-resistant S. aureus (MRSA) surveillance and decolonization program, consisting of admission and weekly MRSA nasal cultures followed by intranasal mupirocin plus chlorhexidine baths for colonized infants, was implemented in our level IV NICU with 150 beds in 2006.5 Due to poor compliance with decolonization protocols5, existing practices were reviewed and multiple interventions to increase compliance were implemented in 2018. These renewed efforts included revision of the existing MRSA decolonization protocol, updating the associated electronic medical record order set, re-education of unit staff, and weekly review by the Infection Prevention (IP) and NICU leadership teams to ensure the decolonization protocol was followed for newly colonized infants. Mean MRSA bloodstream infection (BSI) rates were calculated quarterly pre- (January 2014-December 2017) and post- (January 2018-December 2023) implementation of renewed efforts and compared via unpaired t-test. In July 2020 a similar methicillin-susceptible S. aureus (MSSA) surveillance and decolonization program was implemented with an associated revision of existing documents, education campaign, and weekly review of infants with new MSSA colonization. Mean MSSA BSI rates pre- (July 2018-June 2020) and post- (July 2020-December 2023) implementation were compared via unpaired t-test. Results: Renewed implementation of MRSA surveillance and decolonization was associated with a sustained decrease in the mean MRSA BSI rate (Figure 1): 0.10 per 1000 patient-days pre-implementation, 0.03 post-implementation (p=0.02). Following implementation of MSSA surveillance and decolonization, there was no statistically significant change in the mean MSSA BSI rate (Figure 2): 0.20 per 1000 patient-days pre-implementation, 0.15 post-implementation (p=0.32). Conclusions: Implementation of a robust MRSA surveillance and decolonization program in the NICU was associated with a sustained decrease in invasive MRSA infections. No change in invasive MSSA infection rates was observed following implementation of a similar protocol for MSSA. Additional research is needed to better understand the role of MSSA surveillance and decolonization in the NICU.

References: 1. Ericson, J.E., et al., JAMA Pediatr, 2015. 2. Popoola, V.O., et al., ICHE, 2016. 3. Kotloff, K.L., et al., Pediatrics, 2019. 4. Voskertchian, A., et al., ICHE, 2018. 5. Reich, P.J., et al. Clin Microbiol Infect, 2016.

Background: Whole genome sequencing (WGS) is a relatively new method for analyzing outbreaks and modes of transmission, particularly for multidrug resistant bacteria. This study sought to investigate clusters of patients with genetically related Vancomycin-Resistant Enterococcus spp. (VRE) bacteremia for shared hospital environmental exposures. Methods: All VRE blood culture isolates from patients from July 1, 2021 to June 30, 2022 underwent Illumina WGS. Core single nucleotide polymorphisms (SNPs) were identified, and multi-locus sequence typing (MLST) was performed across the VRE isolates. Clusters were defined as isolates with 15 or fewer core genome SNPs and were investigated for potential transmission routes. For each cluster, patients were evaluated in the 12 weeks before and after the first VRE isolate for shared hospital environmental exposures (hospital unit, patient rooms, procedural rooms, and radiology suites). Hospital units were comprised of patient rooms located geographically together on the same floor of the hospital. Results: A total of 82 VRE isolates underwent WGS. Thirty-eight (46%) clustered genetically with at least one other isolate. Clusters included 2 to 15 patients per group and represented 10 distinct MLST subgroups (Figure 1). Nine hundred and thirty-nine hospital environmental exposures were identified across the 38 patients. For each cluster, there was a total of 341 (36.3%) shared exposures. Shared environmental exposures occurred in radiology suites (35, 38.5%), patient rooms (32, 35.6%) and procedural rooms (23, 25.6%). Of the patients who shared the same hospital unit, 10 (31.3%) had the same patient room with 7 (70%) of them being in the emergency department (ED). Overall, the ED represented 7 (21.9%) of the shared hospital units. Each cluster had at least one shared hospital environmental exposure found. Conclusions: Use of WGS can help investigate outbreak clusters of resistant organisms such as VRE. In this study, nearly half of all VRE blood isolates were able to be segregated into clusters with at least one other isolate. Although VRE colonization of hospital rooms is well described, patient rooms represented the smallest proportion of shared hospital environmental exposures. This study thus suggests other environmental transmission routes such as radiology suites and procedural rooms warrant closer investigation.

Background: Nursing homes (NHs) have high prevalence of multi-drug resistant organisms (MDROs) with rates exceeding those in hospitals. This study proposes quantifying patients’ risk of MDRO colonization and creating a risk profile for the NH patient populations to assist in reducing MDRO burden in health care facilities. Methods: We assessed a risk classification model using data from a prospective cohort study (2018 Pathways study). Patient sample included 783 newly admitted patients followed for up to 180 days and 9,587 samples collected from patients during 2,089 visits. Individual risk factors of MDRO colonization were assessed using unadjusted logistic regression, and patients were risk classified based on number of risk factors. Multivariate regression was performed to obtain odds of MDRO colonization for patient risk groups adjusting for patient age, sex, race, and length of NH stay (LOS). The risk classification tool developed using Pathways data was also tested among a sample of NH residents from Veterans Administration (N=190). Results: The patient sample (Pathways data) was 43.2% male, 37.2% Black with a mean age 74 years. 69.3% were colonized with a MDRO during the study. In unadjusted regression, recent antibiotic use (p<.001), open wounds (p<.05), use of urinary catheter or feeding tube (p<.001), functional disability (p<.001), diabetes (p<.01), and preadmission hospital stay over 14 days (p<.001) were associated with colonization, while Charlson comorbidity score, age, sex, and race were not. In adjusted analysis (c-statistic=0.75), a patient’s colonization risk increased with the number of risk factors (Figure 1), with 47.2% expected colonization among patients with none of the risk factors and 86.7% expected colonization among patients with four or more risk factors. The risk classification model had similar performance among male and female patients, and among Black and White patients (Figure 2). Secondary analysis using data obtained from separate, Veterans Administration facilities provided preliminary validation of the risk scoring tool. The model had acceptable fit (c-statistic=0.71). Veterans with four or more risk factors had 87.8% expected probability of MDRO colonization compared with 39.6% colonization among those without any risk factors. Veterans with less than four risk factors also had higher colonization, but these differences were not statistically significant. Conclusions. Despite system-wide efforts to reduce MDRO burden, prevalence of MDRO colonization remains high in NHs. The risk classification tool can assist in early identification of most vulnerable NH patients to direct targeted interventions such as education, enhanced environmental cleaning, and active surveillance.

Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix

Background: All dental professionals face the risk of occupational percutaneous injuries and exposures. Previous studies have reported high incidents of percutaneous injuries among dentists. This study examined injury data over six years at a large teaching institution for trends to increase awareness and to design appropriate interventions to reduce injury rates. Method: Study injury data was collected for the department of employee and occupational health. The data was entered into an electronic incident reporting system from 2017-2023. Statistical analysis was performed with Openepi to determine injury trend by year and overall association by activity type. Result: There was a total of 168 injuries reported between 2017 and 2023. A majority of the injuries (54%) were caused by a needle or sutures followed by instruments at 41%. Most of the injuries (44%) occurred during treatment and while cleaning the surgical spaces at 15%. Only 13% of the injuries were attributed to handling or recapping needles. Chi-square test 0.2618 (p>.05) indicated there was no significant difference between years and number of injuries. Overall chi-square p ( < 0 .001) by activity type was significant indicating risk was not equal across all activities. Conclusion: Injuries declined during COVID-19 but soared back up in 2023. Needles, sutures, and instruments were the predominant source of injuries. Injuries occurred during treatment (43%), while cleaning the surgical space (15%) and while recapping or handling needles (13%). This study is the first step in understanding the trend and factors attributing to injuries to implement appropriate corrective actions. Further analysis should be conducted to identify specific procedures or clinical activities exposing employees to Occupational percutaneous injuries.

Background: A vital role of hospital employee health is the management, characterization, and targeted prevention of bloodborne pathogen exposures (BPPE) among healthcare workers. A comprehensive review of a health center’s BPPE over time was conducted to identify areas for improvement and target education and training, given changes in BBPE standard operating procedures (SOPs) over time. Methods: A retrospective descriptive analysis was conducted on deidentified BBPE cases reported to employee health at VA Connecticut Healthcare System from 1995-2023 (N=296) using R statistical software. Results: The highest number of BBPE occurred among trainee physicians (N=103, 34.8%, especially surgery and internal medicine), registered nurses (N=60, 20.3%), and non-trainee physicians (N=45, 15.2%). The most frequently implicated devices were hollow-bore (N=103, 34.8%) and suture needles (N=60, 20.3%). Most BBPE occurred during surgical procedures (N=114, 38.5%) or medication administration (N=52, 17.6%). Over half of BBPE occurred during afternoons/nights (N=172, 58.1%). Over half occurred with use of personal protective equipment (PPE) (N=181, 61.1%). The majority of BBPE implicated finger injuries (N=220, 74.3%). Blood was the most frequently reported exposure (N=127, 42.9%), a similar percentage of records did not specifically name a body fluid type (N=121) or whether PPE was used (N=110). In most cases, the source patient was identified (N=282, 95.3%) and tested (N=272, 91.9%). Forty-three sources (14.5%) had positive BBP testing, which included HIV (N=14, 4.7%), hepatitis C (N=23, 7.8%), and hepatitis B (N=6, 2.0%). Most employees presented to employee health for initial evaluation (N=231, 78%) and underwent post-exposure testing (N=266, 89.9%); most had evidence of immunity to hepatitis B (N=246, 83.1%). Eighty-three employees (28%) received HIV PEP (average=1.9 days). Most records did not indicate if this was a first-time BBPE (N=250, 84.5%). No employee records indicated seroconversion for a bloodborne pathogen. Conclusions: Physicians and RNs, those performing surgical procedures and administering medications, and those on second and third shifts are at highest risk and may benefit from additional interventions such as exposure assessment or education. Required recordkeeping has been variable over time. Updated national SOPs have been adapted to employee health, though additional details could be considered for quality improvement purposes, such as duration of employment, level of training, and prior BBPE prevention education. It is unclear if some information such as history of BBPE or PPE use was elicited but not documented – this information could be helpful in management of BBPEs.

Background: Although various difficulties and self-contamination concerns have been continuously reported regarding the use of personnel protective equipment (PPE) among healthcare personnel (HCP), better PPE options are unavailable in healthcare settings. This study aimed to thoroughly examine HCP’s PPE experience to develop improved PPE. Method: By sending cooperation requests to eight academic societies (e.g., Korean Society of Infectious Disease, Korean Society of Critical Care Nursing), four hospitals (e.g., National Medical Center), and Korea Disease Control and Prevention Agency, 250 HCP who had direct patient contact with emerging infectious diseases were recruited. The questionnaire with 65 main questions (211 maximum including sub-questions and 19 open-ended questions) was developed in detail (e.g., use frequency, priority check among the options) based on literature reviews and verified by an expert panel. Through an online survey link, participants completed the questionnaire between December 6-11, 2023, and received a $53 incentive. Descriptive statistics were performed for data analysis. Results: Among 250 participants, most were female (80%), in their thirties (46.4), nurses (78%,), working at general hospitals (56%), and averaged 121.1 months of clinical experience (Table 1). Among 6 PPE sets (Figure 1), 29% of participants used Set #2 (i.e., disposable water-proof gown, gloves, goggles/face shield, hair cap, and N95 mask) and 26% used Set #3 (i.e., Level D, gloves, goggles/face shield, shoe cover, N95 mask, and hair cap). 64% of HCP preferred Set #2 due to practical aspects (e.g., simple, convenient, safer than Set #1, and easy donning/doffing). Most PPE sets were largely used for 30 minutes to 1 hour (except level D, to 2 hours). Most prioritized difficulties of PPE use were: disposable mask dampness; pressure pain on the wearing area for N95 masks; powered air purifying respirator (PAPR) wear takes a long time; sweating for gloves, waterproof gowns, and level D/C coveralls; skin exposed through torn gloves; blurry visibility for goggles/face shield; hearing difficulty for hoods; and a slippery bottom for shoe covers. Moments for self-contamination concerns were: adjusting PPE that has slipped down (e.g., masks, gowns, gloves, goggles/face shield, and hoods); doffing hood procedure (e.g., PAPR); and skin contact of shoe cover surfaces during doffing. Most difficulties when using PPE combinations were unfamiliarity with donning/doffing procedures. Participants wish to develop various PPE sizes which can be easily donned/doffed intuitively (e.g., well-ventilated integral PPE). Conclusion: Collaboration with manufacturers based on our results is necessary to develop better PPE options for HCP’s safety and satisfaction.

Background: Although self-contamination has been identified through relevant studies on the safe utilization of personal protective equipment (PPE) by healthcare personnel and the prevention of healthcare-associated infection transmission, there is a lack of in-depth understanding of self-contamination. This study aimed to review previous research on self-contamination and clarify the concept. By understanding this concept, healthcare personnel can improve their conscientiousness regarding self-contamination and gain a foundation for the requisite interventions to reduce self-contamination in healthcare settings. Method: MeSH terms such as “Health Personnel,” “Students, Health Occupations,” and keywords related to PPE combined with “contaminat*” and “self-contamination” to retrieve literature in OVID, EMBASE, Cochrane, CINAHL, and PsycINFO databases without time limits through December 2023 (Figure 1). The concept of self-contamination’s antecedents, attributes, and consequences were explained based on Rodgers’ evolutionary Results: After eliminating duplicates from the 2,195 studies that were initially searched, the authors reviewed the articles and determined eligibility independently. A total of 25 articles, published between 2006 and 2023, were included and analyzed. Antecedents to self-contamination were classified into three groups for each component (Figure 2). First, PPE factors included 1) types of PPE and/or ensemble choices, and 2) problems with PPE designs and/or their functions. Second, user factors involved 1) mistakes (errors of intent), 2) violations (deviations from recommendations), and 3) slips (natural flaws in humans). Third, organizational factors covered 1) unstandardized PPE protocol, 2) suboptimal and inconsistent PPE training, and 3) inadequate clinical environment. In total, five major concept attributes were the conveyance of organisms, unintentional behavior, preventable action, incidental contact, and difficulty discerning. Consequences were categorized into: 1) raising concerns about occupationally acquired infections, and 2) the potential transmission of the infection to the environment or other people (cross-contamination). Conclusion: While studies have raised questions about whether self-contamination causes infection, self-contamination was obvious among healthcare personnel when dealing with PPE. Considering the wide range of causes and potential results of self-contamination, multifaceted interventions, including improvement of the PPE design, tailoring protocols, and training for specific ensembles, should be implemented over an extended time period with suitable intervals to optimize interventions’ effectiveness.

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.

Background: Since 2009, the CDC has invested in nationwide outbreak response capacity through Healthcare-associated Infections and Antimicrobial Resistance (HAI/AR) Programs in public health departments. The unpredictable nature of outbreaks requires public health programs to be able to scale operations and adapt strategies to effectively respond to emerging challenges, as demonstrated by the COVID-19 pandemic. This analysis characterizes HAI/AR Programs response capacity in scalability, adaptability, and technical expertise. Method: We reviewed data from HAI/AR Programs in 50 state, 6 local, and 2 territorial health departments (August 2019–December 2022). HAI/AR responses were defined as specific public health actions to assess an acute risk and prevent further harm in the context of a confirmed or possible healthcare outbreak; responses were categorized as involving novel or targeted multi-drug resistant organisms (nMDROs), COVID-19, and HAIs or infection control breaches. Descriptive statistics were used to analyze reported responses in three domains: scalability (number of responses per year), adaptability (number of pathogens and healthcare facility types involved in responses), and technical expertise (number of responses involving onsite or remote infection control assessments). The annual number of responses conducted in 2019 was estimated based on five months of data (Aug–Dec); all other results were calculated directly. Results: From August 2019 to December 2022, 58 HAI/AR Programs reported 141,445 responses (87% COVID-19, 11% nMDROs, 2% other HAIs or infection control breaches). Annually, programs conducted an estimated 5,546 responses in 2019, and this figure rose to 42,359 in 2020, 49,124 in 2021, and 47,651 in 2022. Outbreak responses involved 110 different pathogens, including emerging infectious diseases (e.g., SARS-CoV-2, mpox), nMDRO (e.g., carbapenemase-producing organisms, Candida auris), and other pathogens (e.g., hepatitis viruses, Mycobacterium abscessus) across >20 setting types (e.g., acute care hospitals, skilled nursing facilities, ambulatory surgery centers, assisted living facilities). Additionally, programs responded to infection control breaches in the absence of identified patient infections, including drug diversion, medical device reprocessing, and injection safety breaches. Programs conducted 50,245 infection control assessments during reported responses. Conclusion: From 2019–2022, as the COVID-19 pandemic took hold, HAI/AR Programs effectively utilized CDC funding to scale their response operations with an 8-fold increase in annual response activity, including a 24% increase for non-COVID-19 responses. Programs adapted responses to various pathogens, including emerging infectious diseases, across various setting types. Health department staff utilized technical expertise to conduct infection control assessments. This analysis provides valuable insights into the resilience and impact of HAI/AR Programs nationwide.

Background: An unprecedented burden of morbidity and mortality has been reported in patients admitted to healthcare facilities with SARS-COV-2 infection globally since March 2020. A higher incidence of ICU-acquired bloodstream infection has been described with the cumulative risk increased with the length of ICU stay, use of steroids, anti-inflammatory agents, and indwelling catheters. Additionally, SARS-COV-2 infection may increase the risk of bacteremia from gastrointestinal flora such as Enterococcus species by disrupting the gastrointestinal barrier and microbiome. Methods: We aimed to investigate the outbreaks of Enterococcus bacteremia in patients with SARS-COV-2 infection and included patients aged>18 years admitted to the ICU at the Oklahoma City Veterans Affairs Medical Center who were infected with SARS-COV-2 and were identified as having positive blood cultures for Enterococcus faecalis, Enterococcus faecium including vancomycin-resistant species and other bacterial or candida species between March 1, 2020, to March 9, 2022. We collected the following data: duration of hospitalization including ICU stay, unit and room location during the hospital stay, blood culture collection date and results, duration, and site of central line placement, duration of ventilation, administration of antimicrobials and COVID-19 directed therapeutics using computerized patient record system (CPRS). We sent 10 E. faecalis and 12 E. Faecium isolates for genetic analysis. DNA was sequestered from each isolate and multi-locus sequence typing (MLST) was performed by amplifying 7 regions of the E. faecalis genome and 7 regions of the E. faecium genome by polymerase chain reaction (PCR). Resulting amplicons were sequenced and allele type for each gene region and overall sequence type was determined using MLST database (http://pubmlst.org). Results: There were 22 episodes of enterococcal bacteremia in a 3-month duration in the ICU in 20 patients of which 17 were associated with another episode with the same strain (Figure-1-2). Central line placement was noted in 18/22 episodes. Genetic analysis by multi-locus sequence typing of enterococcal bacterial strains was performed by the Public Health Reference Laboratory, Palo Alto. Similar strains were localized to patients in the same geographical region in the ICU (Figure 3). The isolates from 2 other patients who presented with the same strain of Enterococcus but were never hospitalized at the same time during the COVID-19 pandemic were localized to another hospital where both had received care at different times. Conclusion: Higher rates of enterococcal bacteremia were reported during the SARS-COV-2 pandemic. Geographical proximity with strained infection control measures accounted for ICU outbreaks seen in our tertiary care setup.

Background: While Streptococcus agalactiae (Group B Streptococcus [GBS]) infections in infants usually result from maternal transmission, healthcare-associated cases, particularly in the neonatal intensive care unit (NICU), can occur. Whole genome sequencing (WGS) can aid in investigating GBS outbreaks among infants in hospital settings. The aim of the study is to describe the investigation of GBS infections in NICU using WGS. Methods: Infection prevention and control (IPAC) at our hospital monitors the occurrence of late-onset GBS disease (LOD) in our 57-bed NICU, which consists of all private rooms. The occurrence of 2 cases of LOD within 2 weeks triggered an investigation, including WGS of the two isolates and isolates causing invasive GBS during the last 6 months in the unit. GBS isolates underwent WGS using Illumina at Canada’s National Microbiology Laboratory. All affected patients underwent chart-review. Outbreak description and investigation: In August 2023, two NICU neonates (patients 2,3) experienced LOD two weeks apart, one with bacteremic meningitis and the other with two bacteremic episodes three weeks apart. While WGS was pending two additional cases of late-onset GBS bacteremia (patients 4,5) occurred. Isolates from Pts 2,3 and 5 were indistinguishable from each other and from an isolate from an infant admitted to the NICU with early onset bacteremia on July 27, 2023 (day 1 of life) (patient 1). Weekly point prevalence for throat and rectal colonization over 3 weeks identified five infants colonized with unrelated strains. An additional long-stay infant (patient 6) developed GBS conjunctivitis due to a strain indistinguishable from (patient 4) by pulse field gel electrophoresis, WGS for the second cluster is pending. IPAC interventions: Lapses in IPAC practices were observed, with no commonalities among cases other than similar geographic location within the unit. We hypothesized transmission was due to horizontal transmission between babies due to these lapses. Basic IPAC measures, including hand hygiene and environmental cleaning, were reinforced; Additional Precautions were not used due to private rooms’ unit structure. No environmental samples were taken due to lack of an obvious environmental point or common source. Point prevalence monitoring persisted until no new cases related to the outbreak strains were further identified in three consecutive weekly point prevalence. Conclusions: Increased awareness of healthcare-associated transmission is crucial in NICU as LOD GBS emerges. WGS plays a key role in identifying transmission. Detecting a multi-strain outbreak can appropriately redirect investigations. Legend: Figure 1: Timeline of stay at NICU and infection timing for patients 1-6