Objectives: The treatment of infected knee arthritis in patients with coexisting joint destruction, including superimposed advanced arthritis or chronic osteomyelitis, is challenging. We investigated the outcomes of 2-stage primary total knee arthroplasty (TKA) for evolutive infected arthritis with coexistent joint destruction. Methods: We retrospectively reviewed the cases of 50 patients from 5 hospitals who presented with infected arthritis of the knee and were treated with 2-stage TKA: debridement and antibiotic-loaded articulating cement spacer (ALCS) insertion as the first stage and TKA as the second stage. We recorded demographics, laboratory results, and radiographic findings including Kellgren-Lawrence classification (KL) for knee arthritis. Outcomes including infection eradication, knee range of motion (ROM), and patient-reported outcome measures were evaluated. Results: The patient cohort had a mean age of 71.8 years (range, 40–86); they were followed for an average of 4.1 years (range, 2.2–13.3). Also, 40 patients showed KL grade 4, whereas 10 patients showed grade 3. A pathogen was identified in 38 cases (73.1%); methicillin-resistant staphylococci infections (N = 16) and Candida spp infections (N = 7) were the 2 most common types. Constrained prostheses were used in 10 cases (20%). Stem augmentations were used in 15 cases (36.0%) and block augmentations were used in 8 cases (19.0%). One patient had recurrent infection after TKA, so the eradication rate was 98%. After 2-stage TKA, the mean knee ROM was 119.4° (range, 80°–140°) and the mean Knee Society (KS) knee score was 90.4, the average KS function score was 84.7, the average Hospital for Special Surgery (HSS) score was 87.2, and the average Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 16.7. The KS function scores (P = .029) and the WOMAC scores (P = .022) were significantly better in 17 patients who underwent ALCS insertion within 30 days of infection diagnosis compared to the other 33 patients. Conclusions: The 2-stage primary TKA for patients with infected knee arthritis with coexisting joint destruction showed satisfactory outcomes with a low infection recurrence. However, constrained prostheses or augmentation use may be necessary. Notably, some functional scores were better in the group that underwent ALCS insertion relatively early after the infection diagnosis.

Objectives: We compared rates of myopericarditis adverse events and evaluated potential risk factors of development. We compared rates of dermatological–neurological adverse events (severe and serious) with other adverse events in a specific population of deployed US military personnel who received or did not receive ACAM2000 vaccine (ie, Vaccinia smallpox live vaccine). Methods: Up to 20,000 military personnel recipients were enrolled in a prospective observational cohort study: up to 15,000 ACAM2000 recipients in cohort 1 and up to 5,000 military personnel who were eligible for ACAM2000 vaccination but were not vaccinated due to recent vaccination or characteristics of their contacts in cohort 2. Enrollment was at a 3:1 ratio, respectively. Serum specimens and data were collected at the initial visit and 10 days later (cf, window of 6–17 days). Study participants with evidence, either clinical or laboratory, of possible myopericarditis were referred to a blinded independent review committee for further evaluation and adjudication. The primary analysis was logistic regression with adjudicated myopericarditis as the dependent variable and age, sex, race, and exercise regimen as the independent variables. Results: Initial data and serum specimens were obtained from 14,667 participants (cohort 1, N = 10,825; cohort 2, N = 3,842). According to protocol, 2 visits were completed by 12,110 participants (cohort 1, N = 8,945; cohort 2, N = 3,165), and 125 participants (cohort 1, N = 111; cohort 2, N = 14) were referred for myopericarditis adjudication, of whom 1 had confirmed myocarditis, 5 had suspected myocarditis, 1 had suspected pericarditis, and 54 (cohort 1, N = 44; cohort 2, N = 10) had subclinical myopericarditis. The unadjusted myopericarditis rates were 5.7 per 1,000 (95% CI, 4.3–7.5) for cohort 1 and 3.2 per 1,000 (95% CI, 1.7–5.8) for cohort 2. The unadjusted and adjusted odds ratios for myopericarditis for cohort 1 and cohort 2 were 1.8 (95% CI, 0.9–3.6) and 1.3 (95% CI, 0.6–2.6), respectively. At least 1 serious adverse event was experienced by 117 participants (1.1%) in cohort 1 and 13 (0.3%) in cohort 2. No serious and severe neurological or dermatological adverse events were reported. Conclusions: ACAM2000 vaccination was associated with a modest but nonsignificant increase in the risk of myopericarditis in this prudently screened, young and healthy service-member population. The adjusted OR was 1.3 and the unadjusted OR was 1.8. Overall, all but 7 cases were subclinical. Citation: Faix DJ, Gordon DM, Perry LN, et al. Prospective safety surveillance study of ACAM2000 smallpox vaccine in deploying military personnel. Vaccine 2020;38:7323–7330.

Background: Surveillance and early detection of antibiotic resistance genes and multidrug-resistant organisms (MDROs), such as carbapenem-resistant Enterobacterales (CRE), are important to quell outbreaks early, as antibiotic resistance continues to be an increasing threat. Wastewater surveillance in general has gained attention in the United States, but scientific evidence demonstrating the feasibility to assess antibiotic resistance genes and MDROs is limited. In this study, wastewater effluent was used to screen a nursing home facility, which housed a population at increased risk for colonization with MDROs, for the presence of β-lactam–resistant genes.

Methods: Wastewater effluent samples (24-hour composite, n = 19; grab samples, n = 6) collected from a skilled nursing home facility from September 2021 to November 2021 in DeKalb County, Georgia, were screened for carbapenem-resistant and extended-spectrum β-lactam (ESBL)–resistant Enterobacterales using 2 selective chromogenic media: mSuperCARBA (mSC) for selection of CRE and CHROMagar ESBL for selection of gram-negative bacteria producing extended-spectrum β-lactamases. Colilert-18 (IDEXX) was applied to detect and quantify total coliforms and Escherichia coli, serving as an enrichment approach for potential gram-negative organisms (Enterobacterales) containing antibiotic resistance genes. E. coli–positive Colilert-18 (IDEXX) samples (n = 24) had a composite of 1.0 mL total from 5 positive wells or 20% per plate collected and stored at −80°C in 25% glycerol. The E. coli–positive Colilert-18 samples were later thawed and plated on mSC and CHROMagar ESBL, where a random subset of all the colonies (ie, mixture of typical and atypical colonies; n = 28) were selected for matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) to confirm identification. Additionally, a non-enrichment approach, filtered wastewater samples (10 mL, n = 23) were frozen (−80°C) until DNA extraction, followed by multiplex real-time PCR for the blaKPC, blaNDM, blaVIM, and blaOXA-48–like carbapenemase genes. Results: Among 24 E. coli–positive Colilert-18 samples, 16 (67%) of 24 contained carbapenem-resistant Klebsiella, Enterobacter, or Citrobacter (KEC), 88% contained ESBL-resistant KEC (21 of 24), 4% (1 of 24) contained carbapenem-resistant E. coli, and 67% contained ESBL-resistant E.coli (16 of 24). In the 28 colonies picked from mSC or ESBL, 10 different genera were confirmed using MALDI-TOF: Aeromonas, Citrobacter, Enterobacter, Escherichia, Klebsiella, Providencia, and Raoultella. Of 23 filtered samples, 18 (78%) were positive for the blaKPC gene, whereas all samples were negative for blaNDM, blaVIM, and blaOXA-48–like genes. In this nursing home, these findings suggest a concerning frequency of bacteria resistant to last-line antibiotics. Wastewater surveillance can potentially serve as an approach to identify antibiotic resistance and track its presence over time.

Disclosure: None

Background: Respiratory cultures are commonly obtained from patients with suspicion for ventilator-associated infections (VAIs). In the absence of specimen ordering and collection guidelines, management practices may differ. We characterized current respiratory culture collection practices and perceptions and identified potential barriers to changing practices among a national collaborative of pediatric intensive care units (PICUs). Methods: We conducted an electronic survey of PICU physicians, advanced practice providers (APPs), respiratory therapists (RTs), and nurses at 16 US academic pediatric hospitals across the United States. Positive Likert-scale responses (eg, “agree” and “strongly agree”) were grouped. To account for varying hospital representation, we analyzed the results as the median proportion of participants with that response across the hospitals. Results: After excluding incomplete responses, 568 (44%) of 1,301 invited participants responded (range, 16–107 per site); the median hospital response rate was 60% (range, 17%–83%). Roles included physicians (35%), APPs (10%), RTs (24%), and nurses (31%). Moreover, 44% of the participating units cared for cardiac surgery patients. Across hospitals, specimens are often collected by RTs, followed by nurses, typically via inline endotracheal aspirate for either endotracheal tubes or tracheostomies. Saline lavage is a common practice, but only 4% reported a standardized approach. Examining the likeliness to obtain cultures for different clinical symptoms, the widest variation in responses were for fever and inflammatory markers without respiratory symptoms (median proportion, 68%; IQR, 54%–79%), isolated change in secretion characteristics (67%; IQR, 54%–78%), isolated increased secretions (55%; IQR, 40%–65%), isolated inflammatory markers (49%; IQR, 38%–57%) or isolated fever (49%; IQR, 38%–61%). Overall, 75% (IQR, 70%–86%) of reported respiratory cultures were likely to be obtained as a “pan culture.” Most respondents (median proportion, 69%) felt confident about the indications to obtain cultures, but 60% felt that clinicians had a low threshold, and 84% reported clinical practice variation. Barriers to change included reluctance to change (70%), opinion of consultants (64%), and fear of missing a diagnosis of VAI (62%). Respondents agreed that they would find clinical decision support (CDS) tools helpful (79%). In addition, 83% expected that they would follow CDS, and 82% thought that CDS would help align ICU and/or consulting teams. Conclusions: Among 16 participating hospitals, we detected a lack of standardized respiratory-culture specimen collection and ordering practices. Most respondents agreed that CDS tools would be helpful. Diagnostic stewardship of respiratory cultures using CDS must account for potential reluctance to change and needs to address stakeholder perspectives, including fear of missing infections.

Disclosure: None

Objectives: Severe streptococcal infections are invasive, re-emerging infections that rapidly worsen and lead to death. Not only group A Streptococcus (GAS) but also group g Streptococcus (GGS) are the causative agents of this infection. Moreover, GGS produces hemolytic toxins, proteolytic toxins, and other toxins like GAS. Furthermore, drug-resistant Streptococcus spp, like other pathogenic bacteria, are on the rise worldwide. However, drug resistance has not been studied extensively in invasive GGS. Therefore, we investigated the drug susceptibility of GGS clinical isolates that are closely related to fulminant streptococcal infections. Methods: We used GGS strains isolated from sterile sites of invasive infections at a hospital in Nagoya City, Japan, from 2017 to 2021. Bacterial identification and drug-susceptibility testing were performed using a VITEK-2 system. Results: Overall, 53 strains were included in the study. The GGS strains examined in this study were resistant to 3 different antibiotics (erythromycin, clindamycin, and minocycline). Also, 18 strains (34%) were resistant to erythromycin, 9 (17%) were resistant to clindamycin, and 18 (34%) were resistant to minocycline. Moreover, there were 5 strains (9.4%) of 2-drug–resistant bacteria and 8 strains (15.1%) of 3-drug–resistant bacteria. Conclusions: Acquired resistance not only to individual antibiotics but also to multiple antibiotics suggests that GGS tends to become multidrug resistant. Continued surveillance of the drug susceptibility of GGS as a potential cause of fulminant streptococcal infections will be necessary in the future.

Objectives: SARS-CoV-2 is a novel and highly infectious virus. An effective response requires rapid training of healthcare workers (HCWs). We measured the change in knowledge related to COVID-19 and associated factors before and after training of HCWs in Vietnam. Methods: A quasi-experimental design was used to evaluate HCW knowledge related to prevention and control of SARS-CoV-2 before and after attending a 2-day training-of-trainers course. Between June and September 2020, 963 HCWs from 194 hospitals in 21 provinces received the training. HCW knowledge was assessed using a 20-item questionnaire consisting of multiple-choice questions at the beginning and closing of the training course. A participant received 1 point for each correct answer. He or she was considered to have improved knowledge the posttest score was higher than the pretest score with a score ≥15 on the posttest. We applied the McNemar test and logistic regression model to test the level of association between demographic factors and change in knowledge of COVID-19. Results: Overall, 100% of HCWs completed both the pretest and posttest. At baseline, only 14.7% scored ≥15. Following the training, 78.4% scored ≥15 and 64.3% had improved knowledge according to the predetermined definition. Questions related to the order of PPE donning and doffing and respiratory specimen collection procedures were identified as having the greatest improvement (44.6% and 60.7%, respectively). Being female (OR, 1.5; 95% CI, 1.1–2.0), having a postgraduate degree (OR, 2.5; 95% CI, 1.4–4.4), working in a nonmanager position (OR, 1.5; 95% CI, 1.1–2.1), previous contact with a COVID-19 patient (OR, 1.5; 95% CI, 1.1–2.0), and working in northern Vietnam (OR, 2.0; 95% CI, 1.4–2.6), were associated with greater knowledge improvement. Conclusions: Most HCWs demonstrated improved knowledge of COVID-19 prevention and control after attending the training. Particular groups may benefit from additional training: those who are male, leaders and managers, those who hold an undergraduate degree, and those who work in the southern provinces.

Background: Nonprescription antibiotic use includes taking an antibiotic without medical guidance (eg, leftover antibiotics, antibiotics from friends or relatives, or antibiotics purchased without a prescription). Nonprescription use contributes to antimicrobial resistance, adverse drug reactions, interactions, and superinfections such as Clostridioides difficile colitis. Qualitative studies exploring perspectives regarding nonprescription use among Hispanic patients are lacking. We used the Kilbourne Framework for Advancing Health Disparities Research to identify factors influencing Hispanic patients’ nonprescription use and to organize our findings. Methods: Our study includes Hispanic primary-care clinic patients with different types of health coverage in the Houston metroplex who endorsed nonprescription use in a previous quantitative survey. Semistructured interviews explored the factors promoting nonprescription use in Hispanic adults. Interviews were conducted remotely, in English or Spanish, between May 2020 and October 2021. We used inductive coding and thematic analysis to identify the factors and motives for nonprescription use. Results: Of the 35 Hispanic participants surveyed, 69% were female and between the ages of 27 and 66. All participants had some form of healthcare coverage (eg, Medicare or private insurance, Medicaid, or the county financial assistance program). Participants reported obtaining antibiotics from their own leftover prescriptions and through trusted persons (eg, herbalists, pharmacists, friends/relatives, and others), buying them under the counter in US markets, and purchasing them without a prescription outside the United States. Thematic analysis revealed the factors contributing to nonprescription use (Fig. 1). Themes included beliefs that the ‘doctor visit was unnecessary,’ ‘limited direct access to healthcare’ in the United States (due to limited insurance coverage, high costs of the doctor’s visits and medications, and long clinic wait times), ‘more open indirect access to healthcare’ abroad and under the counter in the United States, and communication difficulties (eg, language barriers with clinicians, perceived staff rudeness, and gaps in health literacy). Figure 2 shows representative quotes across thematic domains. Participants expressed having confidence in medical recommendations from pharmacists and trusted community members in their social networks. Conclusions: Antibiotic stewardship interventions that include pharmacist-driven patient education regarding appropriate antibiotic use may decrease nonprescription antibiotic use in Hispanic communities. Additionally, improving access to care while addressing communication barriers and cultural competency in clinics may improve primary care delivery and reduce potentially unsafe antibiotic use.

Disclosure: None

Background: Antibiotic use without a prescription (nonprescription use) leads to antibiotic overuse, with negative consequences for patient and public health. We studied whether screening patients for prior nonprescription antibiotic use in the past 12 months predicted their intentions to use them in the future. Methods: A survey asking respondents about prior and intended nonprescription antibiotic use was performed between January 2020 and June 2021 among patients in waiting rooms of 6 public clinics and 2 private emergency departments in economically and socially diverse urban and suburban areas. Respondents were classified as prior nonprescription users if they reported previously taking oral antibiotics without contacting a doctor, dentist, or nurse. Intended use was defined as answering “yes” or “maybe” to the question, “Would you use antibiotics without contacting a doctor, nurse, or dentist?” We calculated the sensitivity, specificity, and positive and negative predictive value (PPV and NPV) of prior nonprescription antibiotic use in the past 12 months for future intended nonprescription use. Bayes PPV and NPV were also calculated, considering the prevalence of nonprescription antibiotic use (24.8%) in our study. Results: Of the 564 patients surveyed, the median age was 51 years (SD, 19–92), with 72% of patients identifying as female. Most were from the public healthcare system (72.5%). Most respondents identified as Hispanic or Latino(a) (47%) or African American (33%), and 57% received Medicaid or the county financial assistance program. Prior nonprescription use was reported by 246 (43%) of 564 individuals, with 91 (16%) reporting nonprescription use within the previous 12 months. Intention to use nonprescription antibiotics was reported by 140 participants (25%). The sensitivity and specificity of prior nonprescription use in the past 12 months to predict the intention to use nonprescription antibiotics in the future were 75.9% (95% CI, 65.3–84.6) and 91.4% (95% CI, 87.8–94.2), respectively. After the Bayes’ adjustment, the PPV and NPV of prior use to predict future intention were 74.5% (95% CI, 66.7–80.9) and 92.0% (95% CI, 88.7–94.4) (Table 1). Conclusions: These results show that prior nonprescription antibiotic use in the past 12 months predicted the intention to use nonprescription antibiotics in the future (PPV of 75%). As a stewardship effort, we suggest clinicians use a simple question about prior nonprescription antibiotic use in primary-care settings as a screening question for patients at high risk for future nonprescription antibiotic use.

Financial support: HSQR-R 5R01HS026901-04

Disclosure: None

Objectives: Cryptococcus infection is one of the major human immunodeficiency virus (HIV)–related opportunistic infections, and the CD4 count falls below 100 per µL. Primary treatment for HIV-associated cutaneous cryptococcosis is amphotericin B (AmB) plus flucytosine. Methods: We present the case of a man with advanced HIV disease who developed whole-body cutaneous lesions yet improved with high-dose fluconazole alone. Results: A 33-year-old Asian man with a medical history of pulmonary tuberculosis and cryptococcal meningitis with complete treatment, injection drug use, and HIV infection with default of antiretroviral treatments (ART) 3 years earlier, presented to the emergency department with fever, oral thrush, and 30-pound weight loss over 6 weeks. He also had plaques, multiple hard papulonodules with central ulceration, and macular skin lesions all over his body of varying size. Blood cultures were negative for bacteria growth, but fungal microscopy of the blood culture showed unspecific hypha. Histopathology examination of the skin biopsy showed a classic “soap bubble” appearance, which is associated with Cryptococcus infection. Laboratory values revealed anemia (8.6 g/dL), leukopenia (2.9 ×109/L), lymphopenia (58/µL), and thrombocytopenia (145 ×109/L). The CD4 cell count was 18/µL, and the serum viral load was 638.665 copies/mL. Lumbar puncture could not be performed due to patient refusal. Treatment with high-dose fluconazole (1,200 mg) for 3 months was initiated and is planned to continue with consolidation and maintenance dose. ART was administered 4 weeks after starting antifungal therapy. His fever resolved and slow regression of the skin lesions occurred after treatment was given. Conclusions: Cutaneous cryptococcosis was assessed by biopsy of the cutaneous lesion, which is essential to confirming the diagnosis. In the case of cryptococcosis, skin infection may indicate a further progression of advanced HIV disease. In HIV-infected patients with Cryptococcus findings in any part of the body, a lumbar puncture should be considered to rule out central nervous system infection. Although neither AmB nor flucytosine was given due to unavailability in this area, the patient improved. In resource-limited settings, high-dose fluconazole alone may be useful as an alternative treatment, although it is also very challenging.

The distributions of antibiotic prescriptions by geography, antibiotic class, and prescriber specialty are similar in the US Centers for Medicare and Medicaid Services (CMS) Part D Prescriber Public Use Files and IQVIA Xponent dataset. Public health organizations and healthcare systems can use these data to track antibiotic use and guide antibiotic stewardship interventions for older adults.

Background: Detecting healthcare-associated transmission and outbreaks often relies on reactive whole-genome sequencing (WGS), which occurs after the suspected transmission has occurred. Additionally, reactive WGS frequently misidentifies transmission and misses transmission when it has occurred. We initiated weekly real-time WGS to detect bacterial transmission and direct infection prevention interventions. We describe our experience after 1 year of real-time WGS surveillance at the University of Pittsburgh Medical Center–Presbyterian Hospital, a large, tertiary-care facility. Methods: Weekly WGS surveillance was performed from November 1, 2021, to October 31, 2022. Cultured isolates of select bacterial pathogens from patients who were hospitalized for ≥3 days or had a recent healthcare exposure in the prior 30 days were collected and sequenced. Isolates that were ≤15 single-nucleotide polymorphisms (SNPs) were considered genetically related clusters except for Clostridioides difficile (≤2 SNPs). Genetically related clusters were investigated for epidemiological links and interventions to interrupt transmission were implemented at the discretion of the infection prevention team. We analyzed subsequent infections that occurred within an outbreak after an intervention was in place. Results: In total, 1,909 isolates were sequenced. Of 1,633 unique patient isolates clustered by sequence type, 74 clusters were identified comprising 210 (12.9%) patient isolates (Table 1). The median time from culture date to sequencing was 14 days (IQR, 5.25). The median cluster size was 2 (IQR, 1) (Table 2). Overall, 118 patient isolates (56.2%) had an epidemiological link to a prior isolate, indicating potential transmission. Of 74 clusters, 66 (89.2%) received infection prevention interventions after notification based upon epidemiological data. The infection prevention team performed 69 total interventions, which included unit education (n = 28), hand hygiene observations (n = 16), enhanced cleaning (n = 16), environmental cultures or removal of endoscope (n = 7), and enhanced microbiology surveillance (n = 2). The 59 subsequent infections after infection prevention notification included 17 (28.8%) with no clear epidemiological link, and 41 (69.5%) with an epidemiological link either to a new transmission route (n = 37) or the same route prior to infection prevention intervention (n = 4). Only 1 (1.7%) subsequent infection within a cluster occurred after an infection prevention intervention from the same potential route, which was a suspected unit-based transmission of vancomycin-resistant Enterococcus faecium. Conclusions: Real-time WGS was effective at detecting genetically related clusters, finding potential sources, and halting further transmission after interventions by the infection prevention team. Quick turnaround times from patient culture to sequencing and analysis were vital for successful WGS surveillance. Real-time WGS surveillance has the potential to substantially shift the infection prevention paradigm for outbreak detection.

Disclosure: None

Objectives: Medical devices and the hospital environment can be contaminated easily by multidrug-resistant bacteria. The effectiveness of cleaning practices is often suboptimal because environmental cleaning in hospitals is complex and depends on human factors, the physical and chemical characteristics of environment, and the viability of the microorganisms. Ultraviolet-C (UV-C) lamps can be used to reduce the spread of microorganisms. We evaluated the effectiveness of an ultraviolet-C (UV-C) device on terminal room cleaning and disinfection. Methods: The study was conducted at an ICU of a medical center in Taiwan. We performed a 3-stage evaluation for the effectiveness of UV-C radiation, including pre–UV-C radiation, UV-C radiation, and a bleaching procedure. The 3 stages of evaluation were implemented in the ICU rooms from which a patient had been discharged or transferred. We collected the data from adenosine triphosphate (ATP) bioluminescence testing, colonized strains, and their corresponding colony counts by sampling from the environmental surfaces and air. We tested 8 high-touch surfaces, including 2 sides of bed rails, headboards, footboards, bedside tables, monitors, pumping devices, IV stands, and oxygen flow meters. Results: In total, 1,696 environmental surfaces and 72 air samples were analyzed. The levels of ATP bioluminescence and colony counts of isolated bacteria decreased significantly after UV-C radiation and bleaching disinfection for both the environmental and air samples (P < .001). Resistant bacteria (vancomycin-resistant Enterococcus, VRE) were commonly isolated on the hard-to-clean surfaces of monitors, oxygen flow meters, and IV pumps. However, they were also eradicated (P < .001). Conclusions: UV-C can significantly reduce environmental contamination by multidrug-resistant microorganisms. UV-C is an effective device to assist staff in cleaning the hospital environment.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) are bacteria that cause healthcare-associated infections and outbreaks. Most produce carbapenemases like New Delhi metallo-β-lactamase (NDM), which are more commonly found in carbapenem-resistant Enterobacterales but rarely in CRAB. In 2018, selected laboratories began participating in a public health sentinel surveillance program by routinely submitting CRAB and other antimicrobial-resistant isolates to the AR Laboratory Network for specialized testing. In May 2020, the Antimicrobial Resistance Laboratory Network detected the first NDM-CRAB case in California, triggering an investigation. Initial whole-genome sequencing of subsequent isolates indicated high relatedness. Methods: We defined confirmed cases as patients with NDM detected in CRAB isolates and probable cases as NDM detected in a screening swab from a patient epidemiologically linked to a known case(s) with specimens collected during May 2020–September 2022. We defined outbreak facilities as having (1) 1 or more newly identified cases during a point-prevalence survey in response to a known case or (2) at least 2 cases identified within 4 weeks of each other that were epidemiologically linked. We analyzed demographic and specimen characteristics, as well as healthcare exposure history using R Studio version 1.3.959 software. Results: Of 230 total patients, 176 (77%) were confirmed and 54 (23%) were probable cases; 150 (65%) were identified through colonization screening. Among 176 NDM-CRAB isolates, the most common specimen sources were respiratory (n = 29), wound (n = 28), and urine (n = 24), and 87 (49%) of 176 isolates were nonsusceptible to all antimicrobials tested. Among patients, median age was 65 years (range, 24–97), 127 (55%) were male, 37 (15%) were Hispanic or Latino, and 100 (43%) were White. We identified 37 outbreak facilities across 13 counties, including 25 acute-care hospitals (ACHs), 6 skilled nursing facilities (SNFs), 5 ventilator-equipped SNFs (vSNFs), and 1 long-term ACH. We identified 125 cases (54%) in SNFs and vSNFs and 93 cases (40%) in ACHs; among ACH patients, 43 (46%) had been SNF or vSNF residents within the prior year. No patients reported international exposure. Conclusions: The first known case of NDM-CRAB in California was detected by sentinel surveillance. In this extensive regional outbreak, most cases were identified by screening at public health and clinical laboratories. Transmission occurred across healthcare settings connected by patient sharing, underscoring the importance of communication, active surveillance, and implementation of infection prevention and control practices to mitigate spread within and between facilities. Expanding these efforts, with support and resources from public health departments, is key to detecting, characterizing, and containing future outbreaks of antimicrobial-resistant pathogens.

Disclosure: None

Objectives: In healthcare facilities, environmental reservoirs of CPE are associated with CPE outbreaks. In the newly built NCID building, we studied the introduction of CPE in the aqueous environment. Methods: We sampled the aqueous environments (ie, sink, sink strainer, and shower drain-trap with Copan E-swabs and sink P-trap water) of 4 NCID wards (ie, 2 multidrug-resistant organism (MDRO) wards and 2 non-MDRO wards). Two sampling cycles (cycle 1, June–July 2019 and cycle 2, September–November 2019) were conducted in all 4 wards. Cycle 3 (November 2020) was conducted in 1 non-MDRO ward to investigate CPE colonization from previous cycles. Enterobacterales were identified using MALDI-TOF MS and underwent phenotypic (mCIM and eCIM) and confirmatory PCR tests for CPE. Results: We collected 448, 636, and 96 samples in cycles 1, 2, and 3, respectively. MDRO and non-MDRO wards were operational for 1 and 7 months during the first sampling cycle. The CPE prevalence rates in MDRO wards were 1.67% (95% CI, 0.46% – 4.21%) in cycle 1 and 1.76% (95% CI, 0.65% – 3.80%) in cycle 2. In the aqueous environments in MDRO wards, multiple species were detected (cycle 1: 2 K. pneumoniae, 1 E. coli, and 1 S. marcescens; cycle 2: 5 K. pneumoniae and 1 R. planticola), and multiple genotypes were detected (cycle 1: 3 blaOXA48; cycle 2: 5 blaOXA48 and 1 blaKPC). The CPE prevalence in non-MDRO wards was 1.92% (95% CI, 0.53%–4.85%) in cycle 1. The prevalence rate increased by 5.51% (95% CI, 1.99%–9.03%) to 7.43% (95% CI, 4.72%–11.04%; P = .006) in cycle 2, and by another 2.98% (95% CI, −3.82% to 9.79%) to 10.42% (95% CI, 5.11% – 18.3%; P = .353) in cycle 3. Only blaOXA48 S. marcescens were detected in all cycles (except 1 blaOXA48 K. pneumoniae in cycle 2) in the non-MDRO ward. Conclusions: CPE established rapidly in the aqueous environment of NCID wards, more so in MDRO wards than non-MDRO wards. Longitudinal studies to understand the further expansion of the CPE colonization and its impact on patients are needed.