Reducing Hospitalizations and Multidrug-Resistant Organisms via Regional Decolonization in Hospitals and Nursing Homes

Importance

Infections due to multidrug-resistant organisms (MDROs) are associated with increased morbidity, mortality, length of hospitalization, and health care costs. Regional interventions may be advantageous in mitigating MDROs and associated infections.

Objective

To evaluate whether implementation of a decolonization collaborative is associated with reduced regional MDRO prevalence, incident clinical cultures, infection-related hospitalizations, costs, and deaths.

Design, Setting, and Participants

This quality improvement study was conducted from July 1, 2017, to July 31, 2019, across 35 health care facilities in Orange County, California.

Exposures

Chlorhexidine bathing and nasal iodophor antisepsis for residents in long-term care and hospitalized patients in contact precautions (CP).

Main Outcomes and Measures

Baseline and end of intervention MDRO point prevalence among participating facilities; incident MDRO (nonscreening) clinical cultures among participating and nonparticipating facilities; and infection-related hospitalizations and associated costs and deaths among residents in participating and nonparticipating nursing homes (NHs).

Results

Thirty-five facilities (16 hospitals, 16 NHs, 3 long-term acute care hospitals [LTACHs]) adopted the intervention. Comparing decolonization with baseline periods among participating facilities, the mean (SD) MDRO prevalence decreased from 63.9% (12.2%) to 49.9% (11.3%) among NHs, from 80.0% (7.2%) to 53.3% (13.3%) among LTACHs (odds ratio [OR] for NHs and LTACHs, 0.48; 95% CI, 0.40-0.57), and from 64.1% (8.5%) to 55.4% (13.8%) (OR, 0.75; 95% CI, 0.60-0.93) among hospitalized patients in CP. When comparing decolonization with baseline among NHs, the mean (SD) monthly incident MDRO clinical cultures changed from 2.7 (1.9) to 1.7 (1.1) among participating NHs, from 1.7 (1.4) to 1.5 (1.1) among nonparticipating NHs (group × period interaction reduction, 30.4%; 95% CI, 16.4%-42.1%), from 25.5 (18.6) to 25.0 (15.9) among participating hospitals, from 12.5 (10.1) to 14.3 (10.2) among nonparticipating hospitals (group × period interaction reduction, 12.9%; 95% CI, 3.3%-21.5%), and from 14.8 (8.6) to 8.2 (6.1) among LTACHs (all facilities participating; 22.5% reduction; 95% CI, 4.4%-37.1%). For NHs, the rate of infection-related hospitalizations per 1000 resident-days changed from 2.31 during baseline to 1.94 during intervention among participating NHs, and from 1.90 to 2.03 among nonparticipating NHs (group × period interaction reduction, 26.7%; 95% CI, 19.0%-34.5%). Associated hospitalization costs per 1000 resident-days changed from $64 651 to $55 149 among participating NHs and from $55 151 to $59 327 among nonparticipating NHs (group × period interaction reduction, 26.8%; 95% CI, 26.7%-26.9%). Associated hospitalization deaths per 1000 resident-days changed from 0.29 to 0.25 among participating NHs and from 0.23 to 0.24 among nonparticipating NHs (group × period interaction reduction, 23.7%; 95% CI, 4.5%-43.0%).

Conclusions and Relevance

A regional collaborative involving universal decolonization in long-term care facilities and targeted decolonization among hospital patients in CP was associated with lower MDRO carriage, infections, hospitalizations, costs, and deaths.

Longitudinal genomic surveillance of carriage and transmission of Clostridioides difficile in an intensive care unit

Despite enhanced infection prevention efforts, Clostridioides difficile remains the leading cause of healthcare-associated infections in the United States. Current prevention strategies are limited by their failure to account for patients who carry C. difficile asymptomatically, who may act as hidden reservoirs transmitting infections to other patients. To improve the understanding of asymptomatic carriers' contribution to C. difficile spread, we conducted admission and daily longitudinal culture-based screening for C. difficile in a US-based intensive care unit over nine months and performed whole-genome sequencing on all recovered isolates. Despite a high burden of carriage, with 9.3% of admissions having toxigenic C. difficile detected in at least one sample, only 1% of patients culturing negative on admission to the unit acquired C. difficile via cross-transmission. While patients who carried toxigenic C. difficile on admission posed minimal risk to others, they themselves had a 24-times greater risk for developing a healthcare-onset C. difficile infection than noncarriers. Together, these findings suggest that current infection prevention practices can be effective in preventing nosocomial cross-transmission of C. difficile, and that decreasing C. difficile infections in hospitals further will require interventions targeting the transition from asymptomatic carriage to infection.

Impact of measurement and feedback on chlorhexidine gluconate bathing among intensive care unit patients: A multicenter study

OBJECTIVE

To assess whether measurement and feedback of chlorhexidine gluconate (CHG) skin concentrations can improve CHG bathing practice across multiple intensive care units (ICUs).

DESIGN

A before-and-after quality improvement study measuring patient CHG skin concentrations during 6 point-prevalence surveys (3 surveys each during baseline and intervention periods).

SETTING

The study was conducted across 7 geographically diverse ICUs with routine CHG bathing.

PARTICIPANTS

Adult patients in the medical ICU.

METHODS

CHG skin concentrations were measured at the neck, axilla, and inguinal region using a semiquantitative colorimetric assay. Aggregate unit-level CHG skin concentration measurements from the baseline period and each intervention period survey were reported back to ICU leadership, which then used routine education and quality improvement activities to improve CHG bathing practice. We used multilevel linear models to assess the impact of intervention on CHG skin concentrations.

RESULTS

We enrolled 681 (93%) of 736 eligible patients; 92% received a CHG bath prior to survey. At baseline, CHG skin concentrations were lowest on the neck, compared to axillary or inguinal regions (P < .001). CHG was not detected on 33% of necks, 19% of axillae, and 18% of inguinal regions (P < .001 for differences in body sites). During the intervention period, ICUs that used CHG-impregnated cloths had a 3-fold increase in patient CHG skin concentrations as compared to baseline (P < .001).

CONCLUSIONS

Routine CHG bathing performance in the ICU varied across multiple hospitals. Measurement and feedback of CHG skin concentrations can be an important tool to improve CHG bathing practice.

Impact of Mandatory Infectious Disease Specialist Approval on Hospital-Onset Clostridioides difficile Infection Rates and Testing Appropriateness

BACKGROUND

Inappropriate Clostridioides difficile testing is common in the hospital setting, leading to potential overdiagnosis of infection when single-step nucleic acid amplification testing is used. The potential role of infectious diseases (ID) specialists in enforcing appropriate C. difficile testing is unclear.

METHODS

At a single 697-bed academic hospital, we performed a retrospective study from 1 March 2012 to 31 December 2019 comparing hospital-onset C. difficile infection (HO-CDI) rates during 3 consecutive time periods: baseline 1 (37 months, no decision support), baseline 2 (32 months, computer decision support), and intervention period (25 months, mandatory ID specialist approval for all C. difficile testing on hospital day 4 or later). We used a discontinuous growth model to assess the impact of the intervention on HO-CDI rates.

RESULTS

During the study period, we evaluated C. difficile infections across 331 180 admission and 1 172 015 patient-days. During the intervention period, a median of 1 HO-CDI test approval request per day (range, 0-6 alerts/day) was observed; adherence by providers with obtaining approval was 85%. The HO-CDI rate was 10.2, 10.4, and 4.3 events per 10 000 patient-days for each consecutive time period, respectively. In adjusted analysis, the HO-CDI rate did not differ significantly between the 2 baseline periods (P = .14) but did differ between the baseline 2 period and intervention period (P < .001).

CONCLUSIONS

An ID-led C. difficile testing approval process was feasible and was associated with a >50% decrease in HO-CDI rates, due to enforcement of appropriate testing.

Candida auris in skilled nursing facilities

Candida auris is a fungal organism resistant to several classes of antifungals. Since its identification in 2009, it has gained worldwide attention in healthcare for its virulence and resistance to commonly used antifungal therapeutics. Although its origin and mechanisms of transmission are not fully elucidated, it is widely recognized as a high priority healthcare-associated pathogen. Infection control efforts in skilled nursing facilities have been very challenging due to the tendency of C. auris to persist in the environment and colonize residents. In this narrative review, we discuss the epidemiology and infection prevention of C. auris in skilled nursing facilities. We also identify challenges in the diagnosis and management of both symptomatic infections and asymptomatic colonization.

1211. Assessing the Applicability of Enhanced Barrier Precautions among Adult Hospitalized Patients

Background

In nursing homes, the CDC has endorsed an interim approach for containment of multidrug-resistant organisms called Enhanced Barrier Precautions (EBP). With an EBP approach, residents with either indwelling medical devices or chronic wounds are considered at risk for multidrug-resistant organisms; therefore, healthcare personnel are to use gown and gloves for care activities that are considered high risk for organism transmission (e.g., dressing or bathing a patient), while lower risk activities are excluded. EBP guidance currently does not apply to acute care hospitals; we aimed to assess what proportion of hospitalized patients would qualify for an EBP prevention approach.

Methods

We performed rolling single day point prevalence surveys for all adult inpatient units at Rush University Medical Center, Chicago, IL in March-April 2022. Using electronic chart review, we recorded patient unit location, multidrug-resistant organism colonization status, Contact Precautions status, presence of indwelling medical devices, and presence of wounds (pressure ulcer of stage ≥2, or open surgical wound). Patients with any indwelling device or wound qualified for EBP. We also assessed alternate definitions of EBP (device-only or wound-only). Prevalence differences were analyzed using the Chi-squared test.

Results

We assessed 353 hospitalized patients (characteristics, Table 1). Among all patients, 18% (n = 65) were in Contact Precautions, primarily for the indication of multidrug-resistant organism or C. difficile control. Under an EBP approach, a higher proportion (52%, n = 184, P = .005) would qualify. Under alternate EBP definitions, 49% (n = 172) would qualify under a device-only criterion, and 9% (n = 32) would under a wound-only criterion. Comparing intensive care unit (ICU) vs non-ICU patients, Contact Precautions rates were similar, but EBP rates would be higher in ICU patients than non-ICU patients, driven by device use (Table 2).

Conclusion

An EBP infection control approach would impact a substantially larger proportion of hospitalized patients, compared to traditional indications for Contact Precautions. To improve feasibility of an EBP approach among hospitalized patients, further refinements to the qualifying criteria are likely needed.

Disclosures

All Authors: No reported disclosures.

403. Strain Epidemiology of Clostridioides difficile across Three Geographically Distinct Medical Centers in Chicago

Background

Clostridioides difficile infections (CDI) are caused by a large and diverse group of strains with differences in prevalence and associated morbidity. Over the past 20 years the C. difficile (CD) molecular epidemiology has changed as the prevalence of the epidemic strain recognized as restriction endonuclease analysis (REA) group BI or PCR-Ribotype group (RT) 027 has decreased. The objective of this study was to determine the current epidemiology of CD in the city of Chicago.

Methods

Baseline characteristics and symptoms were compared for 81 patients who tested positive for CD by PCR (tcdB) between 9/1/2021 and 10/7/2021 at 3 hospitals in the city of Chicago. Patients were classified as having healthcare-associated CDI (HA-CDI) if symptoms began >72 hours after hospital admission, community-associated CDI (CA-CDI) if symptoms began ≤72 hours prior to admission, and community-onset healthcare-associated CDI (COHA-CDI) if they had been hospitalized ≤4 weeks prior to CDI diagnosis. Available stools were cultured and recovered CD isolates underwent REA typing. Determination of CD colonization was made by review of symptoms including chronicity of symptoms, stool frequency, and response to treatment.

Results

Among all patients, 33% (27/81) were CA-CDI, 28% (23/81) COHA-CDI, 11% (9/81) HA-CDI, and 27% (22/81) were classified as colonized. Primary CDI accounted for 66% (39/59) of the infections. Among patients with a primary CDI, 46% (18/39) of patients were classified as CA-CDI whereas COHA-CDI and HA-CDI accounted for 54% (21/39) of infections. REA group Y was the most common group strain accounting for 29% (22/75) of isolates. (Figure 1) REA group Y accounted for 26% (7/27) of CA-CDI compared to 0 REA group BI [p=0.06], and REA group Y accounted for 35% (7/20) of all colonized patients. (Figure 2) Figure 1Figure 2

Conclusion

There has been a marked change in the CD epidemiology within the city of Chicago since 2009 when REA group BI accounted for 61% of CDI (Black et al ICHE 2011; 32:897-902). REA group Y (typically identified as RT 014/020) is now the most common group strain in Chicago supplanting REA group BI (RT027). REA group Y appears to be associated primarily with CA-CDI and CD colonization. A detailed genomic analysis of REA group Y is required to determine potential reservoirs of REA group Y.

Disclosures

Mary K. Hayden, MD, Sanofi: Member, clinical adjudication panel Nicholas M. Moore, PhD, D(ABMM), Abbott Molecular: Grant/Research Support|Cepheid: Grant/Research Support Amanda Harrington, PhD, Beckman Coulter, Inc.: Clinical trial data collection funded by Beckman Coulter, Inc.|bioMeriuex/BioFire: Grant/Research Support Dale N. Gerding, MD, Destiny Pharma plc.: Advisor/Consultant Stuart Johnson, M.D., Ferring Pharmaceuticals: Membership on Ferring Publication Steering Committee|Ferring Pharmaceuticals: Employee|Summit Plc: Advisor/Consultant.

88. Increasing Bioburden of Candida auris Body Site Colonization is Associated with Environmental Contamination

Background

Environmental contamination is suspected to play a key role in transmission of Candida auris in healthcare facilities. We recently showed that environmental surfaces near C. auris-colonized patients are commonly recontaminated within hours after disinfection. Clinical factors contributing to environmental contamination are not well characterized.

Methods

We conducted a multi-regional (Chicago, IL; Irvine, CA) prospective study of environmental contamination associated with C. auris colonization at six long-term care facilities (LTCF) and 1 acute-care hospital (ACH). On day of sampling, 5 participant body sites were cultured once, followed by routine daily room cleaning by facility staff, then targeted disinfection of high-touch surfaces with hydrogen peroxide wipes by research staff. Surfaces were cultured for C. auris using pre-moistened sponge-sticks and neutralizer immediately pre- and post-disinfection, and 4, 8, and 12 hours post-disinfection. We calculated the odds of surface recontamination after disinfection as a function of body site colonization with C. auris using generalized estimating equations to account for clustering among multiple surfaces within timepoints, patients, and facilities. Models included an interaction between facility type and colonization.

Results

C. auris was cultured from ≥1 body site in 41 participants (12 ACH and 29 LTCF patients, 205 body sites) on day of sampling. Proportion of body sites colonized did not vary by facility type (Table). Although environmental contamination rates were similar prior to disinfection [ACH 38% (n=60 samples) vs LTCF 29%, (n=145 samples), p=0.209)], the proportion of surfaces recontaminated between 4–12 hours after disinfection was higher in ACH vs LTCF (n=574 samples) (Figure). Number of body sites colonized with C. auris was associated with higher odds of environmental recontamination [ACH: OR 2.16 (95% CI 1.63–2.88), p< 0.001; LTCF: OR 1.40 (95% CI 1.07–1.84), p=0.015; Interaction ACH vs LTCF p< 0.001].

Conclusion

The number of body sites colonized was associated with odds of C. auris environmental contamination. Differences in environmental recontamination by facility type may be related to greater provider-patient interactions in ACH as a driving factor.

Disclosures

Gabrielle M. Gussin, MS, Medline: Conducted studies in which hospitals and nursing homes received contributed antiseptic and/or environmental cleaning products|Stryker: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products|Xttrium Laboratories: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products Raveena D. Singh, MA, Medline: Conducted studies in which hospitals and nursing homes received contributed antiseptic and/or environmental cleaning products|Stryker: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products|Xttrium Laboratories: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products Raheeb Saavedra, AS, Medline: Conducted studies in which hospitals and nursing homes received contributed antiseptic and/or environmental cleaning products|Stryker: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products|Xttrium Laboratories: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products Nicholas M. Moore, PhD, D(ABMM), Abbott Molecular: Grant/Research Support|Cepheid: Grant/Research Support Susan S. Huang, MD, MPH, Medline: Conducted studies in which hospitals and nursing homes received contributed antiseptic and/or environmental cleaning products|Molnlyke: Conducted clinical studies in which hospitals received contributed antiseptic product|Stryker: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic products|Xttrium Laboratories: Conducted clinical studies in which hospitals and nursing homes received contributed antiseptic product Mary K. Hayden, MD, Sanofi: Member, clinical adjudication panel for an investigational SARS-CoV-2 vaccine.

Genomic Investigation to Identify Sources of Severe Acute Respiratory Syndrome Coronavirus 2 Infection Among Healthcare Personnel in an Acute Care Hospital

Background

Identifying the source of healthcare personnel (HCP) coronavirus disease 2019 (COVID-19) is important to guide occupational safety efforts. We used a combined whole genome sequencing (WGS) and epidemiologic approach to investigate the source of HCP COVID-19 at a tertiary-care center early in the COVID-19 pandemic.

Methods

Remnant nasopharyngeal swab samples from HCP and patients with polymerase chain reaction-proven COVID-19 from a period with complete sample retention (14 March 2020 to 10 April 2020) at Rush University Medical Center in Chicago, Illinois, underwent viral RNA extraction and WGS. Genomes with >90% coverage underwent cluster detection using a 2 single-nucleotide variant genetic distance cutoff. Genomic clusters were evaluated for epidemiologic linkages, with strong linkages defined by evidence of time/location overlap.

Results

We analyzed 1031 sequences, identifying 49 clusters that included ≥1 HCP (265 patients, 115 HCP). Most HCP infections were not healthcare associated (88/115 [76.5%]). We did not identify any strong epidemiologic linkages for patient-to-HCP transmission. Thirteen HCP cases (11.3%) were attributed to a potential patient source (weak evidence involving nonclinical staff that lacked location data to prove or disprove contact with patients in same cluster). Fourteen HCP cases (12.2%) were attributed to HCP source (11 with strong evidence).

Conclusions

Using genomic and epidemiologic data, we found that most HCP severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections were not healthcare associated. We did not find strong evidence of patient-to-HCP transmission of SARS-CoV-2.

[Retrospective study on clinical manifestation, thigh MRI and electrophysiology characteristics of immune-mediated necrotizing myopathy]

Objective: To summarize the clinical, thigh magnetic resonance (tMRI) and electromyographic (EMG) characteristics in patients with immune-mediated necrotizing myopathy (IMNM). Methods: A total of 32 IMNM patients who were admitted to the Department of Neurology from April 2019 to April 2021 were enrolled at the First Medical Centre of Chinese PLA General Hospital. According to the type of antibody, the patients were divided into anti-SRP antibody positive (SRP⁺) group, anti-HMGCR antibody positive (HMGCR⁺) group and seronegative (SN) group. The gender, age, course of disease, myositis antibodies, extramuscular manifestations, EMG were collected and analyzed among three groups. The characteristics of skeletal muscle were assessed by tMRI inflammatory edema and fat infiltration scores. Analysis of variance, Kruskal-Wallis test and Chi-square test were used to compare the differences in different clinical characteristics and tMRI scores among the three groups. When there was a statistical difference among the three groups, the comparison between the two groups was corrected by the Bonferroni method. Result: (1) Of the 32 patients, 20 were females (62.5%).The median age of onset was 47±14 years, 25 (78.1%) patients had an acute or subacute course.There were 17 (53.1%) with SRP⁺, 8 (25.0%) with HMGCR⁺, and 7 (21.9%) with MSAs (myositis specific antibodies) negative. Anti-Ro52 antibody was the most common combined antibody (12/32, 37.5%), among which 10 were in SRP⁺group.(2) The CK of all patients were elevated, median was 5 948 (4 229, 7 664) U/L. There was no statistical difference of MMT scores among three groups. The proximal limb score was lower than distal limb (P<0.01). The axial muscle score was lower than the distal limb score (P<0.05).(3) Extramuscular manifestations of HMGCR⁺ group were lower than those of the other two groups (12.5% vs. 71.4% and 76.5%, P<0.017). Rash (60.0% vs.14.3%, P<0.05) and interstitial pulmonary diseases (70.0% vs. 14.3%, P<0.05) were more common in patients with anti-SRP coexistence with anti-Ro52 than those with isolated anti-SRP. Connective tissue disease was more common in SN group (57.1% vs. 11.8% and 0, P<0.017).(4) tMRI showed fascial edema of SN group was more obvious than that of the other two groups (P<0.017). There was no statistical difference in the degree of fat infiltration and inflammatory edema among three groups, but SRP⁺ group had more cases of early fat infiltration.(5) Myotonic potentials (25.0% vs. 0 and 0, P<0.017) and compound repetitive discharges (CRDs) (50.0% vs. 5.9% and 0, P<0.017) were common in HMGCR⁺ group. Proteomic analysis found significantly different expressed proteins in skeletal muscle of patients with myotonic potentials or CRDs were associated with cytoskeleton, cell junction and extracellular matrix. Conclusion: IMNM with pure anti-SRP antibody positive and anti-HMGCR positive were mainly affected by skeletal muscles. Those who were co-positive for anti-SRP antibody and anti-Ro52 antibody had more extramuscular manifestations, which might be a special subtype of SRP⁺ group. This study proposed for the first time that myofascial inflammatory edema is an early sign of SN-IMNM injury. EMG of HMGCR⁺group were more prone to myotonia potential and CRDs.

Efficacy and Safety of Ensovibep for Adults Hospitalized With COVID-19 : A Randomized Controlled Trial

BACKGROUND

Ensovibep (MP0420) is a designed ankyrin repeat protein, a novel class of engineered proteins, under investigation as a treatment of SARS-CoV-2 infection.

OBJECTIVE

To investigate if ensovibep, in addition to remdesivir and other standard care, improves clinical outcomes among patients hospitalized with COVID-19 compared with standard care alone.

DESIGN

Double-blind, randomized, placebo-controlled, clinical trial. (ClinicalTrials.gov: NCT04501978).

SETTING

Multinational, multicenter trial.

PARTICIPANTS

Adults hospitalized with COVID-19.

INTERVENTION

Intravenous ensovibep, 600 mg, or placebo.

MEASUREMENTS

Ensovibep was assessed for early futility on the basis of pulmonary ordinal scores at day 5. The primary outcome was time to sustained recovery through day 90, defined as 14 consecutive days at home or place of usual residence after hospital discharge. A composite safety outcome that included death, serious adverse events, end-organ disease, and serious infections was assessed through day 90.

RESULTS

An independent data and safety monitoring board recommended that enrollment be halted for early futility after 485 patients were randomly assigned and received an infusion of ensovibep (n = 247) or placebo (n = 238). The odds ratio (OR) for a more favorable pulmonary outcome in the ensovibep (vs. placebo) group at day 5 was 0.93 (95% CI, 0.67 to 1.30; P = 0.68; OR > 1 would favor ensovibep). The 90-day cumulative incidence of sustained recovery was 82% for ensovibep and 80% for placebo (subhazard ratio [sHR], 1.06 [CI, 0.88 to 1.28]; sHR > 1 would favor ensovibep). The primary composite safety outcome at day 90 occurred in 78 ensovibep participants (32%) and 70 placebo participants (29%) (HR, 1.07 [CI, 0.77 to 1.47]; HR < 1 would favor ensovibep).

LIMITATION

The trial was prematurely stopped because of futility, limiting power for the primary outcome.

CONCLUSION

Compared with placebo, ensovibep did not improve clinical outcomes for hospitalized participants with COVID-19 receiving standard care, including remdesivir; no safety concerns were identified.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Duration of Replication-Competent Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Shedding Among Patients With Severe or Critical Coronavirus Disease 2019 (COVID-19)

BACKGROUND

Patterns of shedding replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in severe or critical COVID-19 are not well characterized. We investigated the duration of replication-competent SARS-CoV-2 shedding in upper and lower airway specimens from patients with severe or critical coronavirus disease 2019 (COVID-19).

METHODS

We enrolled patients with active or recent severe or critical COVID-19 who were admitted to a tertiary care hospital intensive care unit (ICU) or long-term acute care hospital (LTACH) because of COVID-19. Respiratory specimens were collected at predefined intervals and tested for SARS-CoV-2 using viral culture and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Clinical and epidemiologic metadata were reviewed.

RESULTS

We collected 529 respiratory specimens from 78 patients. Replication-competent virus was detected in 4 of 11 (36.3%) immunocompromised patients up to 45 days after symptom onset and in 1 of 67 (1.5%) immunocompetent patients 10 days after symptom onset (P = .001). All culture-positive patients were in the ICU cohort and had persistent or recurrent symptoms of COVID-19. Median time from symptom onset to first specimen collection was 15 days (range, 6-45) for ICU patients and 58.5 days (range, 34-139) for LTACH patients. SARS-CoV-2 RNA was detected in 40 of 50 (80%) ICU patients and 7 of 28 (25%) LTACH patients.

CONCLUSIONS

Immunocompromise and persistent or recurrent symptoms were associated with shedding of replication-competent SARS-CoV-2, supporting the need for improving respiratory symptoms in addition to time as criteria for discontinuation of transmission-based precautions. Our results suggest that the period of potential infectiousness among immunocompetent patients with severe or critical COVID-19 may be similar to that reported for patients with milder disease.

Applications and Outcomes of Extracorporeal Life Support Use in Adult Liver Transplantation: A Case Series and Review of Literature

The use of extracorporeal life support (ECLS) is increasingly reported in adult liver transplantation (LT). However, neither the role of ECLS in the perioperative setting for LT nor its outcomes has been well defined. We performed a retrospective chart review of all adult LT patients at our institution who received ECLS from 2004 to 2021. We also conducted a comprehensive literature search for adult LT cases that involved perioperative ECLS for respiratory or cardiac failure. Over the study period, 11 LT patients required ECLS at our institution, two for respiratory and nine for cardiac failure. Both patients with respiratory failure received ECLS as a bridge to LT and survived to discharge. Nine patients required ECLS for acute cardiac failure either intraoperatively or postoperatively, and two survived to discharge. In the literature, we identified 35 cases of respiratory failure in LT patients requiring perioperative ECLS. Applications included preoperative bridge to LT (n = 6) and postoperative rescue (n = 29), for which overall survival was 44%. We identified 31 cases of cardiac failure in LT patients requiring either ECLS or cardiopulmonary bypass for cardiac support or rescue for intraoperative or postoperative cardiac failure (n = 30). There is evidence for consideration of ECLS as a bridge to LT in patients with potentially reversible respiratory failure or as rescue therapy for respiratory failure in posttransplant patients. ECLS has a prohibitively high risk of futility in pretransplant patients with cardiac failure but may have a role in LT patients with a functioning graft and potentially reversible cardiac failure.

Effectiveness of mRNA Covid-19 Vaccine among U.S. Health Care Personnel

BACKGROUND

The prioritization of U.S. health care personnel for early receipt of messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), allowed for the evaluation of the effectiveness of these new vaccines in a real-world setting.

METHODS

We conducted a test-negative case-control study involving health care personnel across 25 U.S. states. Cases were defined on the basis of a positive polymerase-chain-reaction (PCR) or antigen-based test for SARS-CoV-2 and at least one Covid-19-like symptom. Controls were defined on the basis of a negative PCR test for SARS-CoV-2, regardless of symptoms, and were matched to cases according to the week of the test date and site. Using conditional logistic regression with adjustment for age, race and ethnic group, underlying conditions, and exposures to persons with Covid-19, we estimated vaccine effectiveness for partial vaccination (assessed 14 days after receipt of the first dose through 6 days after receipt of the second dose) and complete vaccination (assessed ≥7 days after receipt of the second dose).

RESULTS

The study included 1482 case participants and 3449 control participants. Vaccine effectiveness for partial vaccination was 77.6% (95% confidence interval [CI], 70.9 to 82.7) with the BNT162b2 vaccine (Pfizer-BioNTech) and 88.9% (95% CI, 78.7 to 94.2) with the mRNA-1273 vaccine (Moderna); for complete vaccination, vaccine effectiveness was 88.8% (95% CI, 84.6 to 91.8) and 96.3% (95% CI, 91.3 to 98.4), respectively. Vaccine effectiveness was similar in subgroups defined according to age (<50 years or ≥50 years), race and ethnic group, presence of underlying conditions, and level of patient contact. Estimates of vaccine effectiveness were lower during weeks 9 through 14 than during weeks 3 through 8 after receipt of the second dose, but confidence intervals overlapped widely.

CONCLUSIONS

The BNT162b2 and mRNA-1273 vaccines were highly effective under real-world conditions in preventing symptomatic Covid-19 in health care personnel, including those at risk for severe Covid-19 and those in racial and ethnic groups that have been disproportionately affected by the pandemic. (Funded by the Centers for Disease Control and Prevention.).

Transesophageal Echocardiography-Guided Aspiration of Venous Air Embolism During Liver Transplantation: A Case Report

Transesophageal echocardiography can be useful not only in diagnosing venous air embolism but also in guiding aspiration of air from the pulmonary artery. A 59-year-old man with a history of cirrhosis underwent combined kidney and liver transplantations. He developed acute hypotension after the native liver was removed due to a massive venous air embolism via a retained transjugular intrahepatic portosystemic shunt catheter. Transesophageal echocardiography revealed air in the pulmonary artery resulting in outflow obstruction. Under echocardiographic guidance, the pulmonary arterial catheter was withdrawn to the air pocket and aspirated, resulting in improved hemodynamics and successful completion of transplantations.

399. Epidemiology of Laboratory-identified Late-onset SARS-CoV-2 Positivity in Two Large, Urban, Acute-Care Hospitals: Implications for Surveillance of Hospital-Acquired COVID-19

Background

Laboratory identification (Lab-ID) of late-onset SARS-CoV-2 positive tests during a hospital stay is a potential public health surveillance approach for hospital-acquired COVID-19. However, prolonged RNA fragment shedding and intermittent detection of SARS-CoV-2 virus via PCR testing among infected patients may hamper interpretation of laboratory-identified events. We aimed to describe the epidemiology of late-onset SARS-CoV-2 laboratory events using clinical criteria, to evaluate the feasibility of a Lab-ID approach to detection of nosocomial SARS-COV-2 infection.

Methods

We evaluated all SARS-CoV-2 RT-PCR positive results recovered from patients at two acute-care hospitals in Chicago, IL, during March 1 — November 30, 2020. Each hospital maintained stringent infection control policies through-out the study period. Through chart review (WT & CS), we categorized all initial SARS-CoV-2 positive tests collected > Hospital Day 5 (defined as ‘late-onset’ based on the 5-day mean incubation period for COVID-19) into the following clinical categories: Community Acquired; Unlikely Hospital Acquired; Possible Hospital Acquired; and Probable Hospital Acquired. Categorizations were made using hospital day, symptoms, alternative diagnoses, and clinical notes (Figure 1).

Results

Of 2,671 SARS-CoV-2-positive patients, most positive tests (n=2,551; 96%) were recovered pre-admit or by Hospital Day 2; first positive tests were uncommon during Hospital Days 6 to 14 (n=40; 1.5%); and rare after Hospital Day 14 (n=15; 0.6%). By chart review, of the 55 late-onset records reviewed, categorizations in descending order were: Prior positive at outside facility (n=23); Possible Hospital Acquired (n=16); Community Acquired (n=12); Probable Hospital Acquired (n=4). Less than half of the late-onset cases were categorized as a possible or probable hospital acquisition (Figure 2).

Conclusion

Hospital-acquired SARS-CoV-2 infection was uncommon. Most late-onset episodes of SARS-CoV-2 were explained by detection at an outside healthcare facility or by delayed diagnosis of patients with symptoms at time of presentation. A Lab-ID approach to nosocomial COVID-19 surveillance would potentially misclassify a substantial number of patients.

Disclosures

All Authors: No reported disclosures

Computer Informatics for Infection Control

Computer informatics have the potential to improve infection control outcomes in surveillance, prevention, and public health. Surveillance activities include surveillance of infections, device use, and facility/ward outbreak detection and investigation. Prevention activities include awareness of multidrug-resistant organism carriage on admission, identification of high-risk individuals or populations, reducing device use, and antimicrobial stewardship. Enhanced communication with public health and other health care facilities across networks includes automated electronic communicable disease reporting, syndromic surveillance, and regional outbreak detection. Computerized public health networks may represent the next major evolution in infection control. This article reviews the use of informatics for infection control.

Regional Spread of blaNDM-1-Containing Klebsiella pneumoniae ST147 in Post-Acute Care Facilities

BACKGROUND

Carbapenem-resistant Enterobacterales (CRE) harboring blaKPC have been endemic in Chicago-area healthcare networks for more than a decade. During 2016-2019, a series of regional point-prevalence surveys identified increasing prevalence of blaNDM-containing CRE in multiple long-term acute care hospitals (LTACHs) and ventilator-capable skilled nursing facilities (vSNFs). We performed a genomic epidemiology investigation of blaNDM-producing CRE to understand their regional emergence and spread.

METHODS

We performed whole-genome sequencing on New Delhi metallo-beta-lactamase (NDM)+ CRE isolates from 4 point-prevalence surveys across 35 facilities (LTACHs, vSNFs, and acute care hospital medical intensive care units) in the Chicago area and investigated the genomic relatedness and transmission dynamics of these isolates over time.

RESULTS

Genomic analyses revealed that the rise of NDM+ CRE was due to the clonal dissemination of an sequence type (ST) 147 Klebsiella pneumoniae strain harboring blaNDM-1 on an IncF plasmid. Dated phylogenetic reconstructions indicated that ST147 was introduced into the region around 2013 and likely acquired NDM around 2015. Analyzing the relatedness of strains within and between facilities supported initial increases in prevalence due to intrafacility transmission in certain vSNFs, with evidence of subsequent interfacility spread among LTACHs and vSNFs connected by patient transfer.

CONCLUSIONS

We identified a regional outbreak of blaNDM-1 ST147 that began in and disseminated across Chicago area post-acute care facilities. Our findings highlight the importance of performing genomic surveillance at post-acute care facilities to identify emerging threats.

How to Choose Target Facilities in a Region to Implement Carbapenem-resistant Enterobacteriaceae Control Measures

BACKGROUND

When trying to control regional spread of antibiotic-resistant pathogens such as carbapenem-resistant Enterobacteriaceae (CRE), decision makers must choose the highest-yield facilities to target for interventions. The question is, with limited resources, how best to choose these facilities.

METHODS

Using our Regional Healthcare Ecosystem Analyst-generated agent-based model of all Chicago metropolitan area inpatient facilities, we simulated the spread of CRE and different ways of choosing facilities to apply a prevention bundle (screening, chlorhexidine gluconate bathing, hand hygiene, geographic separation, and patient registry) to a resource-limited 1686 inpatient beds.

RESULTS

Randomly selecting facilities did not impact prevalence, but averted 620 new carriers and 175 infections, saving $6.3 million in total costs compared to no intervention. Selecting facilities by type (eg, long-term acute care hospitals) yielded a 16.1% relative prevalence decrease, preventing 1960 cases and 558 infections, saving $62.4 million more than random selection. Choosing the largest facilities was better than random selection, but not better than by type. Selecting by considering connections to other facilities (ie, highest volume of discharge patients) yielded a 9.5% relative prevalence decrease, preventing 1580 cases and 470 infections, and saving $51.6 million more than random selection. Selecting facilities using a combination of these metrics yielded the greatest reduction (19.0% relative prevalence decrease, preventing 1840 cases and 554 infections, saving $59.6 million compared with random selection).

CONCLUSIONS

While choosing target facilities based on single metrics (eg, most inpatient beds, most connections to other facilities) achieved better control than randomly choosing facilities, more effective targeting occurred when considering how these and other factors (eg, patient length of stay, care for higher-risk patients) interacted as a system.

Regional Emergence of Candida auris in Chicago and Lessons Learned From Intensive Follow-up at 1 Ventilator-Capable Skilled Nursing Facility

BACKGROUND

Since the identification of the first 2 Candida auris cases in Chicago, Illinois, in 2016, ongoing spread has been documented in the Chicago area. We describe C. auris emergence in high-acuity, long-term healthcare facilities and present a case study of public health response to C. auris and carbapenemase-producing organisms (CPOs) at one ventilator-capable skilled nursing facility (vSNF-A).

METHODS

We performed point prevalence surveys (PPSs) to identify patients colonized with C. auris and infection-control (IC) assessments and provided ongoing support for IC improvements in Illinois acute- and long-term care facilities during August 2016-December 2018. During 2018, we initiated a focused effort at vSNF-A and conducted 7 C. auris PPSs; during 4 PPSs, we also performed CPO screening and environmental sampling.

RESULTS

During August 2016-December 2018 in Illinois, 490 individuals were found to be colonized or infected with C. auris. PPSs identified the highest prevalence of C. auris colonization in vSNF settings (prevalence, 23-71%). IC assessments in multiple vSNFs identified common challenges in core IC practices. Repeat PPSs at vSNF-A in 2018 identified increasing C. auris prevalence from 43% to 71%. Most residents screened during multiple PPSs remained persistently colonized with C. auris. Among 191 environmental samples collected, 39% were positive for C. auris, including samples from bedrails, windowsills, and shared patient-care items.

CONCLUSIONS

High burden in vSNFs along with persistent colonization of residents and environmental contamination point to the need for prioritizing IC interventions to control the spread of C. auris and CPOs.

Risk Factors Associated With SARS-CoV-2 Seropositivity Among US Health Care Personnel

IMPORTANCE

Risks for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among health care personnel (HCP) are unclear.

OBJECTIVE

To evaluate the risk factors associated with SARS-CoV-2 seropositivity among HCP with the a priori hypothesis that community exposure but not health care exposure was associated with seropositivity.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted among volunteer HCP at 4 large health care systems in 3 US states. Sites shared deidentified data sets, including previously collected serology results, questionnaire results on community and workplace exposures at the time of serology, and 3-digit residential zip code prefix of HCP. Site-specific responses were mapped to a common metadata set. Residential weekly coronavirus disease 2019 (COVID-19) cumulative incidence was calculated from state-based COVID-19 case and census data.

EXPOSURES

Model variables included demographic (age, race, sex, ethnicity), community (known COVID-19 contact, COVID-19 cumulative incidence by 3-digit zip code prefix), and health care (workplace, job role, COVID-19 patient contact) factors.

MAIN OUTCOME AND MEASURES

The main outcome was SARS-CoV-2 seropositivity. Risk factors for seropositivity were estimated using a mixed-effects logistic regression model with a random intercept to account for clustering by site.

RESULTS

Among 24 749 HCP, most were younger than 50 years (17 233 [69.6%]), were women (19 361 [78.2%]), were White individuals (15 157 [61.2%]), and reported workplace contact with patients with COVID-19 (12 413 [50.2%]). Many HCP worked in the inpatient setting (8893 [35.9%]) and were nurses (7830 [31.6%]). Cumulative incidence of COVID-19 per 10 000 in the community up to 1 week prior to serology testing ranged from 8.2 to 275.6; 20 072 HCP (81.1%) reported no COVID-19 contact in the community. Seropositivity was 4.4% (95% CI, 4.1%-4.6%; 1080 HCP) overall. In multivariable analysis, community COVID-19 contact and community COVID-19 cumulative incidence were associated with seropositivity (community contact: adjusted odds ratio [aOR], 3.5; 95% CI, 2.9-4.1; community cumulative incidence: aOR, 1.8; 95% CI, 1.3-2.6). No assessed workplace factors were associated with seropositivity, including nurse job role (aOR, 1.1; 95% CI, 0.9-1.3), working in the emergency department (aOR, 1.0; 95% CI, 0.8-1.3), or workplace contact with patients with COVID-19 (aOR, 1.1; 95% CI, 0.9-1.3).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of US HCP in 3 states, community exposures were associated with seropositivity to SARS-CoV-2, but workplace factors, including workplace role, environment, or contact with patients with known COVID-19, were not. These findings provide reassurance that current infection prevention practices in diverse health care settings are effective in preventing transmission of SARS-CoV-2 from patients to HCP.

How Long-Term Acute Care Hospitals Can Play an Important Role in Controlling Carbapenem-Resistant Enterobacteriaceae in a Region: A Simulation Modeling Study

Typically, long-term acute care hospitals (LTACHs) have less experience in and incentives to implementing aggressive infection control for drug-resistant organisms such as carbapenem-resistant Enterobacteriaceae (CRE) than acute care hospitals. Decision makers need to understand how implementing control measures in LTACHs can impact CRE spread regionwide. Using our Chicago metropolitan region agent-based model to simulate CRE spread and control, we estimated that a prevention bundle in only LTACHs decreased prevalence by a relative 4.6%-17.1%, averted 1,090-2,795 new carriers, 273-722 infections and 37-87 deaths over 3 years and saved $30.5-$69.1 million, compared with no CRE control measures. When LTACHs and intensive care units intervened, prevalence decreased by a relative 21.2%. Adding LTACHs averted an additional 1,995 carriers, 513 infections, and 62 deaths, and saved $47.6 million beyond implementation in intensive care units alone. Thus, LTACHs may be more important than other acute care settings for controlling CRE, and regional efforts to control drug-resistant organisms should start with LTACHs as a centerpiece.

919. Understanding Intermittent Detection of Multidrug-Resistant Organisms (MDROs) in Rectally Colonized Patients

Background

MDRO detection in colonized patients may be intermittent for reasons that are incompletely understood. We examined temporal patterns of gut MDRO colonization after initial MDRO detection by rectal swab screening, and determined the relationship of culture positivity to the relative abundance of corresponding MDRO operational taxonomic units (OTUs) identified by 16S rRNA gene sequence analysis.

Methods

Rectal or fecal swabs were collected daily from MICU patients 1/11/2017-1/11/2018. First MICU admissions with ≥2 swabs and MICU stays ≥3 days were studied. Samples were cultured for vancomycin-resistant enterococci (VRE), carbapenem-resistant Enterobacteriaceae (CRE) and P. aeruginosa (CRPA), and extended-spectrum β-lactamase-producing (ESBL) Enterobacteriaceae by selective media. Resistance mechanisms were confirmed by phenotypic methods and/or PCR. Limit of detection was similar for different MDROs (24-52 CFU/sample). OTU categories corresponding to MDRO species were identified by taxonomy and BLAST. Multilevel regression models estimated the association between MDRO detection and relative abundance of the corresponding OTU.

Results

796 unique patients with 3519 swabs were studied. Median (IQR) age was 64 (51-74) years, MICU length of stay was 5 (3-8) days, and number of samples-per-patient was 3 (2-5). Following initial MDRO detection, the probability of subsequent detection varied by MDRO type, and was highest for VRE and lowest for CRPA [Figure 1]. Within each sample, we found a significant association between MDRO detection and relative abundance of the corresponding OTU [Table 1]. In contrast, relative OTU abundance in the first sample with MDRO detection was not predictive of odds of future MDRO detection (p >0.05 for all comparisons). Carriage of >1 MDRO did not affect the odds of MDRO detection in later samples.

Figure 1. Probability of Subsequent MDRO Detection after First Positive Varies by MDRO Type

Table 1. Higher Mean Corresponding OTU Relative Abundance Within Each Sample is Associated with MDRO Detection

Conclusion

MDRO culture positivity in rectally colonized patients was correlated with relative abundance of the corresponding OTU in the same sample. Serial detection of different MDRO types was variable, possibly due to distinct microbial community dynamics of different MDRO types. Intermittent failure to detect MDROs could result in misattribution of MDRO acquisition, resulting in inappropriate investigation or intervention.

Disclosures

All Authors: No reported disclosures

How Introducing a Registry With Automated Alerts for Carbapenem-resistant Enterobacteriaceae (CRE) May Help Control CRE Spread in a Region

BACKGROUND

Regions are considering the use of electronic registries to track patients who carry antibiotic-resistant bacteria, including carbapenem-resistant Enterobacteriaceae (CRE). Implementing such a registry can be challenging and requires time, effort, and resources; therefore, there is a need to better understand the potential impact.

METHODS

We developed an agent-based model of all inpatient healthcare facilities (90 acute care hospitals, 9 long-term acute care hospitals, 351 skilled nursing facilities, and 12 ventilator-capable skilled nursing facilities) in the Chicago metropolitan area, surrounding communities, and patient flow using our Regional Healthcare Ecosystem Analyst software platform. Scenarios explored the impact of a registry that tracked patients carrying CRE to help guide infection prevention and control.

RESULTS

When all Illinois facilities participated (n = 402), the registry reduced the number of new carriers by 11.7% and CRE prevalence by 7.6% over a 3-year period. When 75% of the largest Illinois facilities participated (n = 304), registry use resulted in a 11.6% relative reduction in new carriers (16.9% and 1.2% in participating and nonparticipating facilities, respectively) and 5.0% relative reduction in prevalence. When 50% participated (n = 201), there were 10.7% and 5.6% relative reductions in incident carriers and prevalence, respectively. When 25% participated (n = 101), there was a 9.1% relative reduction in incident carriers (20.4% and 1.6% in participating and nonparticipating facilities, respectively) and 2.8% relative reduction in prevalence.

CONCLUSIONS

Implementing an extensively drug-resistant organism registry reduced CRE spread, even when only 25% of the largest Illinois facilities participated due to patient sharing. Nonparticipating facilities garnered benefits, with reductions in new carriers.

Predicting Carbapenem-Resistant Enterobacteriaceae Carriage at the Time of Admission Using a Statewide Hospital Discharge Database

BACKGROUND

Timely identification of patients likely to harbor carbapenem-resistant Enterobacteriaceae (CRE) can help health care facilities provide effective infection control and treatment. We evaluated whether a model utilizing prior health care information from a state hospital discharge database could predict a patient's probability of CRE colonization at the time of hospital admission.

METHODS

We performed a case-control study using the Illinois hospital discharge database. From a 2014-2015 patient cohort, we defined cases as index adult patient hospital encounters with a positive CRE culture collected within the first 3 days of hospitalization, as reported to the Illinois XDRO registry; controls were all patient admissions from the same hospital and month. We split the data into training (~60%) and validation (~40%) sets and developed a logistic regression model to estimate coefficients for predictors of interest.

RESULTS

We identified 486 index cases and 340 005 controls. Independent risk factors for CRE at the time of admission were age, number of short-term acute care hospital (STACH) hospitalizations in the prior 365 days, mean STACH length of stay, number of long-term acute care hospital (LTACH) hospitalizations in the prior 365 days, mean LTACH length of stay, current admission to LTACH, and prior hospital admission with an infection diagnosis code. When applying the model to the validation data set, the area under the receiver operating characteristic curve was 0.84.

CONCLUSIONS

A prediction model utilizing prior health care exposure information could discriminate patients who were likely to harbor CRE at the time of hospital admission.

Regional Spread of an Outbreak of Carbapenem-Resistant Enterobacteriaceae Through an Ego Network of Healthcare Facilities

Background

In 2013, New Delhi metallo-β-lactamase (NDM)-producing Escherichia coli, a type of carbapenem-resistant Enterobacteriaceae uncommon in the United States, was identified in a tertiary care hospital (hospital A) in northeastern Illinois. The outbreak was traced to a contaminated duodenoscope. Patient-sharing patterns can be described through social network analysis and ego networks, which could be used to identify hospitals most likely to accept patients from a hospital with an outbreak.

Methods

Using Illinois' hospital discharge data and the Illinois extensively drug-resistant organism (XDRO) registry, we constructed an ego network around hospital A. We identified which facilities NDM outbreak patients subsequently visited and whether the facilities reported NDM cases.

Results

Of the 31 outbreak cases entered into the XDRO registry who visited hospital A, 19 (61%) were subsequently admitted to 13 other hospitals during the following 12 months. Of the 13 hospitals, the majority (n = 9; 69%) were in our defined ego network, and 5 of those 9 hospitals consequently reported at least 1 additional NDM case. Ego network facilities were more likely to identify cases compared to a geographically defined group of facilities (9/22 vs 10/66; P = .01); only 1 reported case fell outside of the ego network.

Conclusions

The outbreak hospital's ego network accurately predicted which hospitals the outbreak patients would visit. Many of these hospitals reported additional NDM cases. Prior knowledge of this ego network could have efficiently focused public health resources on these high-risk facilities.

82. First 5 Years of Experience with the Illinois Extensively Drug-Resistant Organism (XDRO) Registry and Implementation of Automated Alerting

Background

The Illinois XDRO Registry was created in November 2013 as an information system for XDROs; currently, the registry includes carbapenem-resistant Enterobacteriaceae (CRE), carbapenemase-producing Pseudomonas aeruginosa, and Candida auris. All Illinois healthcare facilities can manually query the registry at the time of admission to assess patients’ prior colonization status. A subset of facilities, mainly hospitals, participate in the registry’s automated querying process; alerts are generated automatically and sent via email, page, or text to infection preventionists at the time of patient admission.

Methods

We assessed counts of XDRO report submissions and total queries (manual and automated) over time, by organism. Facilities achieved automated alerts by sending a near-real-time feed of inpatient admission data (patient name and date of birth) to Illinois Department of Public Health (IDPH) via one of the three connection types: direct (data sent directly to IDPH), vendor (data sent via vendor software), and syndromic surveillance (existing syndromic surveillance data adapted for registry).

Results

In total, 6,445 unique patients (11,258 total reports) from 213 facilities have been reported to the XDRO registry (counts by organism type, Table). The registry has been manually queried 39,678 times by 232 facilities. Seventy-five facilities have achieved automation of alerting; the types of data connections used were direct (N = 56), vendor (N = 18), and syndromic surveillance (N = 1). In total, 5,344 automated alerts have been sent for 1,555 unique patients. Automated alerts per month have increased over time (P < 0.001, Figure). Infection preventionists reported feedback on 3,008 CRE alerts via a website questionnaire; among 1176 first alerts/patient/facility, 49% of patients’ XDRO status were previously unknown to the facility, and 33% were not in contact precautions at the time of alert.

Conclusion

The XDRO registry, originally focused on CRE, successfully expanded to include emerging XDRO threats such as Candida auris and is poised for rapid response to emerging threats. The registry’s adaptable reporting structure and expanding automation have enabled it to deliver an increasing number of actionable infection-control alerts over time.

Disclosures

All Authors: No reported Disclosures.

572. Relationship Between Chlorhexidine Gluconate (CHG) Skin Concentrations and Microbial Skin Colonization among Medical Intensive Care Unit (MICU) Patients

Background

CHG bathing is used to suppress patients’ microbial skin colonization, in order to prevent infections and transmission of multidrug-resistant organisms. Prior work has suggested that microbial growth is inhibited when CHG skin concentrations exceed threshold levels.

Methods

We conducted 6 single-day surveys from January 2018 to February 2019 in 7 academic hospital MICUs with established CHG patient bathing. Adult patients were eligible to have skin swabbed from adjacent 25 cm2 areas on the neck, axilla, and inguinal region for culture and CHG concentration determination. CHG skin concentrations were measured by a semi-quantitative colorimetric assay. Selective media were used to isolate targeted microorganisms (Table 1). Species were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry; antibiotic susceptibility was determined by MicroScan (Beckman Coulter). We modeled the relationship between CHG skin concentrations (log2-transformed) and microorganism recovery (yes/no as primary outcome) using multilevel models controlling for clustering of body sites within patients and within ICUs, assessing slope and threshold effects.

Results

We enrolled 736/759 (97%) patients and sampled 2176 skin sites. Gram-positive bacteria were detected most frequently (Table 1). The adjusted odds of identifying gram-positive organisms decreased linearly as CHG skin levels increased (Figure 1a), without evidence of a threshold effect. We also found significant negative linear slopes without evidence of threshold effects for other pathogens tested (Table 2; Figure 1), with the exception of gram-negative bacteria and vancomycin-resistant enterococci. When modeling quantitative culture results (colony-forming units) for gram-positive organisms as a continuous outcome variable, a similar relationship was found.

Conclusion

Higher concentrations of CHG were associated with less frequent recovery of gram-positive bacteria and Candida species on the skin of MICU patients who were bathed routinely with CHG. For microbial inhibition, we did not identify a threshold concentration of CHG on the skin; rather, increasing CHG skin concentrations led to additional gains in inhibition. For infection prevention, aiming for high CHG skin levels may be beneficial.

Disclosures

All authors: No reported disclosures.

897. Prevalence of Candida auris at Body Sites, Characterization of Skin Microbiota, and Relation of Chlorhexidine Gluconate (CHG) Skin Concentration to C. auris Detection Among Patients at a High-Prevalence Ventilator-Capable Skilled Nursing Facility (vSNF) with Established CHG Bathing

Background

vSNF patients are at high risk of colonization and infection with C. auris. CHG bathing has been used as an intervention to reduce nosocomial transmission of multi-drug-resistant organisms, but its effect on C. auris is unclear.

Methods

We studied a 70-bed ventilator ward in a 300-bed vSNF in Chicago, IL with a high prevalence of C. auris and established CHG bathing. Swab samples were collected from patients for culture, microbiome analysis, and CHG skin concentration testing (Table 1).

Results

We collected 2,467 samples (950 culture, 950 microbiome, 567 CHG) from 57 patients during 2 surveys conducted January–March 2019. Forty-six (81%) patients had C. auris cultured from ≥1 body site. Mean (±SD) age was 59 (±14) years, 40% were women, 70% were African American, mean (±SD) Charlson score was 3 (±2). Patients colonized with C. auris were more likely to be mechanically ventilated (50% vs. 0%, P < 0.001), have a gastrostomy tube (78% vs. 27%, P < 0.001) or have urinary catheter (72% vs. 23%, P = 0.01) than noncolonized patients. Frequency of C. auris isolation varied among 10 body sites tested (P < 0.001); colonization of anterior nares (41%) and hands (40%) was detected most often (Figure 1). By ITS1 analysis, all isolates were members of the C. auris South American clade. Skin microbiome sequencing confirmed culture Results. While Malassezia is the dominant genera observed in healthy volunteers and patients in this vSNF, C. auris was observed to dominate the fungal community of multiple skin sites, including nares, hands, inguinal, toe web (Figure 2). Other Candida spp. were also identified on the skin of patients in the current study, but at lower relative abundance. CHG was detected on skin of 52 (91%) patients (median CHG concentration 19.5 µg/mL; IQR 4.9–78.1 µg/mL). In a mixed-effects model controlling for body site and multiple measurements per patient, odds of C. auris detection by culture were less at CHG concentrations ≥625 µg/mL than at lower concentrations (Figure 3; OR 0.25, 95% CI: 0.10–0.66; P = 0.005).

Conclusion

Frequent C. auris colonization of vSNF patients’ anterior nares and hands suggests that nasal decolonization and patient hand hygiene are potential options to reduce C. auris transmission. High concentrations of CHG may be needed to suppress C. auris on skin.

Disclosures

All Authors: No reported Disclosures.

895. Impact of Measurement and Results Feedback of Chlorhexidine Gluconate (CHG) Skin Concentrations in Medical Intensive Care Unit (MICU) Patients Receiving CHG Bathing

Background

Higher CHG skin levels may be needed to adequately control infection and transmission of pathogens in the ICU. We assessed whether measurement and feedback of patient CHG skin concentrations could improve CHG bathing quality and identified factors associated with higher CHG skin concentrations.

Methods

We conducted 6 one-day surveys from January 2018 to February 2019 in 7 academic hospital MICUs with established daily CHG bathing. Adults admitted >1 day were assessed for CHG skin levels with a semi-quantitative colorimetric assay using swabbed 25 cm² areas of anterior neck, axilla, and inguinal skin. Prior to survey 4, results from the first 3 surveys (baseline) were reported to ICU leadership and front-line staff to retrain and reeducate on bathing technique. Feedback of results from prior surveys also occurred before surveys 5 and 6. For statistical analysis, mixed-effects models accounted for clustering of CHG measurements within patients and ICUs. We categorized CHG product type as “cloth” for no-rinse 2% CHG-impregnated cloth and “liquid” for 4% CHG liquid or foam.

Results

In total, 681 of 704 (97%) patients were enrolled. Three ICUs used CHG cloth, 3 ICUs used CHG liquid, and 1 ICU switched from liquid to cloth after the second survey. Median CHG skin concentrations were higher in both the baseline and feedback period for institutions using CHG cloth, as compared with liquid (table). Across all time points, axillary and inguinal regions had higher skin CHG concentrations than the neck (median 39.1, 78.1, 19.5 µg/mL, respectively, P < 0.001). After controlling for age, mechanical ventilation, presence of a central venous catheter, body site, and hours since last CHG bath, institutions that used CHG cloth had a 3-fold increase in adjusted CHG skin concentrations in the feedback period compared with the baseline period (P = 0.001, Figure). There was no significant change in CHG skin concentrations from baseline to feedback period for institutions that used liquid CHG.

Conclusion

CHG skin concentrations on MICU patients receiving daily CHG bathing varied by body site and CHG product type. The use of CHG cloth was associated with higher CHG skin levels, compared with CHG liquid. For ICUs using CHG cloth, feedback of CHG skin concentration results to ICU staff improved CHG bathing quality.

Disclosures

All Authors: No reported Disclosures.

2849. Gut Microbiota Differences at the Time of Medical Intensive Care Unit (MICU) Admission Are Associated with Acquisition of Multi-drug-Resistant Organisms (MDROs) Among Patients Not Already Colonized with an MDRO

Background

Among hospitalized patients, underlying variation in gut microbiota may confer differential risk for gut MDRO acquisition.

Methods

Rectal swab samples were collected from patients ≤2 days of MICU admission and then daily in the 27-bed MICU of an acute care hospital in Chicago, IL over 1 year. Patients were screened for MDRO colonization by selective culture (see Figure 1 for MDRO types); those with ≥2 swabs and MICU stays ≥3 days were studied. Bacterial 16S rRNA gene amplicon sequences were used for microbiota analysis. Medical records were reviewed.

Results

In preliminary analysis, 2,480 samples were collected from 627 patients who acquired 170 MDROs (Figure 1). Debilitation, co-morbidities, and certain medical devices were associated with MDRO acquisition, though admission MDRO status was not (table). While no interactions were detected between admission MDRO status and clinical predictors of MDRO acquisition, there were significant differences in gut microbiota composition at the time of MICU admission between patients colonized with an MDRO on admission and those not colonized (P < 0.001, using analysis of molecular variance (AMOVA) on distances). Therefore, we stratified our analysis by admission MDRO colonization status. For patients MDRO-colonized at admission, there were no significant differences in microbiota of patients who later did or did not acquire a new MDRO (AMOVA P-value = 0.32). For patients not MDRO-colonized on admission, there was a significant difference in microbiota of patients who later acquired an MDRO and those who did not (AMOVA P-value: 0.026). Differentially abundant operational taxonomic units (OTUs, based on 3% sequence difference) included OTUs classified as Anaerococcus and as other Clostridiales (higher in patients who remained uncolonized) and as Enterococcus (higher in patients who acquired an MDRO) (Figure 2). Diversity was also higher in patients who remained uncolonized (Wilcoxon test P-value: 0.035) (Figure 3).

Conclusion

Among patients not already colonized with an MDRO on admission, we identified gut microbiota differences associated with MDRO acquisition that could help explain patient-level variation in MDRO colonization resistance.

Disclosures

All Authors: No reported Disclosures.

2852. Epidemiology of Emerging Carbapenemase-Producing Organisms (CPO) in Chicago, Illinois, 2013–2018

Background

Emerging CPO in the Chicago area poses clinical and infection control challenges across the spectrum of care. Since November 2013, CPO are reportable to the Illinois’ Extensively Drug-resistant Organism (XDRO) registry. We examined trends in mechanism of resistance (MOR) among CPO reported through December 2018.

Methods

MOR reported into the XDRO registry were identified by clinical laboratories performing molecular methods on routine clinical cultures, by public health laboratories during point prevalence surveys (PPS) in response to clusters and as part of a project to assess CPO prevalence in high-risk Chicago area healthcare settings. Chicago patients with known MOR other than Klebsiella pneumoniae carbapenemase (KPC) are investigated by Chicago Department of Public Health (CDPH) to implement containment strategies and identify risk factors within 6 months of culture date.

Results

MOR was identified in 40% (1,216/3,587) of CPO-positive specimens collected from unique Chicago patients; 87% were KPC, 7% New Delhi metallo-β-lactamase (NDM), 5% Verona integron-mediated metallo-β-lactamase (VIM), 0.6% OXA-48-type carbapenemases, and 0.01% Imipenemase metallo-β-lactamase (IMP) (figure). Since 2017, 15 patients with CPO expressed more than one MOR; 14 were identified during PPS at ventilator capable skilled nursing facilities (vSNF) or long-term acute care hospitals (LTACH), and one was hospitalized in India. Among 156 patients with non-KPC CPO, the median age was 64 years (range, 20–97), 107 (69%) were identified from rectal screening and 49 (31%) were from clinical specimens, most of which were urine 23 (47%) or blood 6 (12%). Among 134 patients with risk factor history, 64% had history of tracheostomy (Table 1). Among 113 patients without documented travel outside of the United States, all stayed overnight at an Illinois healthcare facility; 62% stayed in a vSNF and 24% in an LTACH within 6 months of identification (Table 2).

Conclusion

We have increasingly detected non-KPC CPO in Chicago; however, estimates of prevalence are limited by lack of systematic surveillance and molecular testing. The high proportion of CPO patients without travel who stayed in vSNF or LTACH underscores the need for infection control training and surveillance in these settings.

Disclosures

All Authors: No reported Disclosures.

Increased Relative Abundance of Klebsiella pneumoniae Carbapenemase-producing Klebsiella pneumoniae Within the Gut Microbiota Is Associated With Risk of Bloodstream Infection in Long-term Acute Care Hospital Patients

BACKGROUND

An association between increased relative abundance of specific bacterial taxa in the intestinal microbiota and bacteremia has been reported in some high-risk patient populations.

METHODS

We collected weekly rectal swab samples from patients at 1 long-term acute care hospital (LTACH) in Chicago from May 2015 to May 2016. Samples positive for Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) by polymerase chain reaction and culture underwent 16S rRNA gene sequence analysis; relative abundance of the operational taxonomic unit containing KPC-Kp was determined. Receiver operator characteristic (ROC) curves were constructed using results from the sample with highest relative abundance of KPC-Kp from each patient admission, excluding samples collected after KPC-Kp bacteremia. Cox regression analysis was performed to evaluate risk factors associated with time to achieve KPC-Kp relative abundance thresholds calculated by ROC curve analysis.

RESULTS

We collected 2319 samples from 562 admissions (506 patients); KPC-Kp colonization was detected in 255 (45.4%) admissions and KPC-Kp bacteremia in 11 (4.3%). A relative abundance cutoff of 22% predicted KPC-Kp bacteremia with sensitivity 73%, specificity 72%, and relative risk 4.2 (P = .01). In a multivariable Cox regression model adjusted for age, Charlson comorbidity index, and medical devices, carbapenem receipt was associated with achieving the 22% relative abundance threshold (P = .044).

CONCLUSION

Carbapenem receipt was associated with increased hazard for high relative abundance of KPC-Kp in the gut microbiota. Increased relative abundance of KPC-Kp was associated with KPC-Kp bacteremia. Whether bacteremia arose directly from bacterial translocation or indirectly from skin contamination followed by bloodstream invasion remains to be determined.

974. Impact of Mandatory Infectious Disease (ID) Specialist Approval on Hospital-Onset Clostridium difficile (HO-CDI) Testing and Infection Rates: Results of a Pilot Study

Background

The 2017 IDSA C. difficile guidelines recommend the use of nucleic acid amplification testing alone for detection of HO-CDI if appropriate stool specimens are collected (e.g., patients not receiving laxatives and ≥3 unformed stools in 24 hours). The potential role of ID specialists in enforcing appropriate C. difficile testing is unclear.

Methods

At a single academic hospital, we performed a pilot study of an ID specialist-led approval process for C. difficile testing. During the baseline period (January 2016 and November 2017), HO-CDI testing appropriateness was enforced using a computerized decision support tool that discouraged inappropriate testing based on detected laxative use and stool frequency criteria; however, clinicians frequently ignored the computer alerts. During the intervention period (December 2017 and March 2018), all HO-CDI testing on hospital day 4 or later triggered a computer alert requesting mandatory testing approval by an ID specialist. Approvals were provided via telephone consultation 7 days a week between 8 a.m. and 5 p.m. (in both periods, CDI testing was not performed overnight). We analyzed differences HO-CDI testing and infection rates (defined by CDC’s LabID event) per 10,000 patient days using Poisson models. We also analyzed the number of approval pager calls, rates of C. difficile testing approval, and time burden.

Results

Two infectious diseases specialists (M.Y.L.; J.S.) primarily answered C. difficile pager approval requests; the remainder of approvals were provided by ID specialists already consulted on the patients. During the intervention period, ordering providers made 159 calls to the approval pager; 119 (75%) received approval. HO-CDI testing and infection rates declined between the baseline and intervention periods (figure). There was a mean of 1.3 pager approval requests per day (range, 0–4) with an average of 3 minutes of time spent per request.

Conclusion

An ID specialist-led C. difficile testing approval process was feasible and associated with a significant decrease in HO-CDI testing and infection rates, due to enforcement of appropriate testing. ID specialists can provide a key role in enforcing appropriate C. difficile testing, but more experience is needed with respect to sustainability.

Disclosures

M. Y. Lin, Stryker (Sage Products): Research support in the form of contributed product, Research support. OpGen, Inc: Research support in the form of contributed products, Research support. CareFusion Foundation (now BD): Grant Investigator, Research grant.

1764. The Gut: A Veiled Reservoir for Multidrug-resistant Organisms (MDROs) Below the Tip of the Iceberg

Background

Clinical culture results are sometimes used to estimate the burden of multidrug-resistant organisms (MDROs) in hospitals. The association between positive clinical culture results and prevalence of MDROs in the gut is incompletely understood.

Methods

Rectal swab or stool samples were collected daily from adult medical intensive care unit (MICU) patients and cultured for target MDROs using selective media between January 2017 and January 2018 at Rush University Medical Center, a 676-bed tertiary-care center in Chicago. Resistance mechanisms were confirmed by phenotypic methods and/or polymerase chain reaction. Clinical culture results during MICU stay were extracted from the hospital information system. Target MDROs included vancomycin-resistant Enterococci (VRE), carbapenem-resistant Enterobacteriaceae (CRE), extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Acinetobacter baumannii (CRAB). Patients with either a study or clinical culture positive for a target MDRO were analyzed.

Results

We collected 5,086 study samples from 1,661 unique admissions (1,419 patients) and included here data from 413 unique admissions (397 patients) with completed microbiologic analysis. Median (IQR) patient age was 65 (51–75) years and length of MICU stay was 3 (3–4) days. A total of 156 (37.8%) patients had a target MDRO detected from a study sample at any point; 57 (36.5%) patients had >1 MDRO detected. Overall prevalence of these MDROs was found to be 22.5% VRE, 6.5% CRE, 19.8% ESBL, 4.4% CRPA, and 0.7% CRAB. New MDRO acquisition was observed in 58 (14.6%) patients (figure). Once a target MDRO was detected in a study sample, 82.2% of subsequent study samples were positive for that MDRO. Only 13 (5.8%) patients had a positive clinical culture for any target MDRO during their MICU stay (table).

Conclusion

Clinical cultures capture only the tip of the resistance iceberg and alone are insufficient to guide MDRO-targeted prevention strategies. Universal infection prevention measures are an alternative that may be preferred in settings where overall prevalence of MDROs is moderate or high and patients may be colonized with >1 MDRO.

Disclosures

All authors: No reported disclosures.

2167. Predicting Carbapenem-Resistant Enterobacteriaceae (CRE) Carriage on Admission using Updated Statewide Hospital Discharge Data

Background

We previously built a patient-level prediction model to assess an individual’s risk of Carbapenem-resistant Enterobacteriaceae (CRE) carriage upon hospital admission based on the following factors: past hospital visits (short- and long-term acute care (STACHs and LTACHs)), endoscopic procedures, infection-related diagnosis codes, and patient age and sex. Our model discriminated CRE cases relatively well (c-statistic = 0.86). In the hopes of operationalizing our results, we evaluated the distribution of predicted probabilities on an updated dataset using existing model parameters.

Methods

We used Illinois Hospital discharge data (CYs 2015–2016) with ICD-10 diagnosis and procedure codes to establish baseline exposure history (2015) and to generate predicted probabilities (2016). We calculated the number of hospital visits and the average number of hospital days in the past year (STACH and LTACH). We identified infection-related diagnosis codes using prior knowledge, and included procedure codes for endoscopic retrograde cholangiopancreatography (ERCP). We then used the model parameters from our previous work to generate predicted probabilities corresponding to each hospital visit.

Results

Our study year (2016) included 1,229,158 visits by 816,500 unique adult patients. Sixty-two percent of patients had no inpatient visits in the previous year. Among those with a prior hospitalization, the median STACH length of stay was 4 days (IQR: 2–6). Three thousand five hundred and sixty-six patients (0.4%) had previous LTACH exposure upon admission, with a median length of stay of 25 days (IQR: 13–40). Thirty-two percent of hospital visits had an infection-related diagnosis code, and 0.5% had an ERCP procedure code. Of the more than 1.2 million visits, our model predicted 10,614 visits associated with a CRE risk of over 1%, 946 visits of over 10%, and 96 visits by 63 unique patients with over a 50% risk. On average, highest risk patients were exposed to (median) 15 (7–97) STACH, 104 LTACH (37–174) days; 83% had infection codes.

Conclusion

Using a large, de-identified statewide dataset, we were able to identify a small number of extremely high-risk individuals. Selective screening of these individuals upon admission could prove to be a valuable way to identify CRE-colonized patients in order to take proper precautions.

Disclosures

All authors: No reported disclosures.

The β-adrenoceptor blocker propranolol ameliorates compulsive-like gambling behaviour in a rodent slot machine task: implications for iatrogenic gambling disorder

Previous work has shown that chronic administration of the dopamine D_2/3 receptor agonist ropinirole invigorates performance on a rodent slot machine task (rSMT). This behavioural change appears superficially similar to the iatrogenic gambling disorder (GD) observed in a sub-set of patients with Parkinson's disease (PD), and has been associated with increased activation of the intra-cellular signalling proteins GSK3β and CREB in the striatum. Here, we wanted to determine whether this response to ropinirole could be attenuated by targeting these signalling proteins, and if the loss of dopaminergic innervation characteristic of PD would alter ropinirole's effects on the rSMT. Male Long Evans rats were trained on the rSMT. Dopaminergic terminals innervating the dorsolateral striatum were then lesioned bilaterally using the neurotoxin 6-hydroxydopamine hydrochloride (6-OHDA). Subsequently animals were implanted with osmotic mini-pumps delivering ropinirole. Lastly, animals were given dietary lithium (Li⁺ ), to inhibit the activation of GSK3β, or injections of the ß-adrenoceptor antagonist propranolol, which potently inhibits CREB as a secondary mechanism of action, and any changes in ropinirole-induced increases in compulsive-like engagement in the rSMT evaluated. Chronic ropinirole increased the number of trials animals completed, reproducing our original finding. This increase in task engagement was not altered in animals with 6-OHDA lesions, a putative model of early PD. In addition, the effects of ropinirole were not attenuated by administration of Li⁺ , but were ameliorated by propranolol. These data suggest that propranolol may represent a potential pharmacotherapy for the treatment of iatrogenic gambling.

Gut Microbiota and Clinical Features Distinguish Colonization With Klebsiella pneumoniae Carbapenemase-Producing Klebsiella pneumoniae at the Time of Admission to a Long-term Acute Care Hospital

Background

Identification of gut microbiota features associated with antibiotic-resistant bacterial colonization may reveal new infection prevention targets.

Methods

We conducted a matched, case–control study of long-term acute care hospital (LTACH) patients to identify gut microbiota and clinical features associated with colonization by Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp), an urgent antibiotic resistance threat. Fecal or rectal swab specimens were collected and tested for KPC-Kp; 16S rRNA gene-based sequencing was performed. Comparisons were made between cases and controls in calibration and validation subsamples using microbiota similarity indices, logistic regression, and unit-weighted predictive models.

Results

Case (n = 32) and control (n = 99) patients had distinct fecal microbiota communities, but neither microbiota diversity nor inherent clustering into community types distinguished case and control specimens. Comparison of differentially abundant operational taxonomic units (OTUs) revealed 1 OTU associated with case status in both calibration (n = 51) and validation (n = 80) subsamples that matched the canonical KPC-Kp strain ST258. Permutation analysis using the presence or absence of OTUs and hierarchical logistic regression identified 2 OTUs (belonging to genus Desulfovibrio and family Ruminococcaceae) associated with KPC-Kp colonization. Among clinical variables, the presence of a decubitus ulcer alone was independently and consistently associated with case status. Combining the presence of the OTUs Desulfovibrio and Ruminococcaceae with decubitus ulcer increased the likelihood of KPC-Kp colonization to >38% in a unit-weighted predictive model.

Conclusions

We identified microbiota and clinical features that distinguished KPC-Kp gut colonization in LTACH patients, a population particularly susceptible to KPC-Kp infection. These features may warrant further investigation as markers of risk for KPC-Kp colonization.

Regional Epidemiology of Methicillin-Resistant Staphylococcus aureus Among Adult Intensive Care Unit Patients Following State-Mandated Active Surveillance

Background

In 2007, Illinois became the first state in the United States to mandate active surveillance of methicillin-resistant Staphylococcus aureus (MRSA). The Illinois law applies to intensive care unit (ICU) patients; contact precautions are required for patients found to be MRSA colonized. However, the effectiveness of a legislated "search and isolate" approach to reduce MRSA burden among critically ill patients is uncertain. We evaluated whether the prevalence of MRSA colonization declined in the 5 years after the start of mandatory active surveillance.

Methods

All hospitals with an ICU having ≥10 beds in Chicago, Illinois, were eligible to participate in single-day serial point prevalence surveys. We assessed MRSA colonization among adult ICU patients present at time of survey using nasal and inguinal swab cultures. The primary outcome was region-wide MRSA colonization prevalence over time.

Results

All 25 eligible hospitals (51 ICUs) participated in serial point prevalence surveys over 8 survey periods (2008-2013). A total of 3909 adult ICU patients participated in the point prevalence surveys, with 432 (11.1%) found to be colonized with MRSA (95% confidence interval [CI], 10.1%-12.0%). The MRSA colonization prevalence among patients was unchanged during the study period; year-over-year relative risk for MRSA colonization was 0.97 (95% CI, .89-1.05; P = .48).

Conclusions

MRSA colonization prevalence among critically ill adult patients did not decline during the time period following legislatively mandated MRSA active surveillance. Our findings highlight the limits of legislated MRSA active surveillance as a strategy to reduce MRSA colonization burden among ICU patients.

Assessing the Ability of Hospital Diagnosis Codes to Detect Inpatient Exposure to Antibacterial Agents

OBJECTIVE Because antibacterial history is difficult to obtain, especially when the exposure occurred at an outside hospital, we assessed whether infection-related diagnostic billing codes, which are more readily available through hospital discharge databases, could infer prior antibacterial receipt. DESIGN Retrospective cohort study. PARTICIPANTS This study included 121,916 hospitalizations representing 78,094 patients across the 3 hospitals. METHODS We obtained hospital inpatient data from 3 Chicago-area hospitals. Encounters were categorized as "infection" if at least 1 International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) code indicated a bacterial infection. From medication administration records, we categorized antibacterial agents and calculated total therapy days using Centers for Disease Control and Prevention (CDC) definitions. We evaluated bivariate associations between infection encounters and 3 categories of antibacterial exposure: any, broad spectrum, or surgical prophylaxis. We constructed multivariable models to evaluate adjusted risk ratios for antibacterial receipt. RESULTS Of the 121,916 inpatient encounters (78,094 patients) across the 3 hospitals, 24% had an associated infection code, 47% received an antibacterial, and 13% received a broad-spectrum antibacterial. Infection-related ICD-9-CM codes were associated with a 2-fold increase in antibacterial administration compared to those lacking such codes (RR, 2.29; 95% confidence interval [CI], 2.27-2.31) and a 5-fold increased risk for broad-spectrum antibacterial administration (RR, 5.52; 95% CI, 5.37-5.67). Encounters with infection codes had 3 times the number of antibacterial days. CONCLUSIONS Infection diagnostic billing codes are strong surrogate markers for prior antibacterial exposure, especially to broad-spectrum antibacterial agents; such an association can be used to enhance early identification of patients at risk of multidrug-resistant organism (MDRO) carriage at the time of admission. Infect Control Hosp Epidemiol 2018;39:377-382.

Evaluating biomechanics of user-selected sitting and standing computer workstation

A standing computer workstation has now become a popular modern work place intervention to reduce sedentary behavior at work. However, user's interaction related to a standing computer workstation and its differences with a sitting workstation need to be understood to assist in developing recommendations for use and set up. The study compared the differences in upper extremity posture and muscle activity between user-selected sitting and standing workstation setups. Twenty participants (10 females, 10 males) volunteered for the study. 3-D posture, surface electromyography, and user-reported discomfort were measured while completing simulated tasks with each participant's self-selected workstation setups. Sitting computer workstation associated with more non-neutral shoulder postures and greater shoulder muscle activity, while standing computer workstation induced greater wrist adduction angle and greater extensor carpi radialis muscle activity. Sitting computer workstation also associated with greater shoulder abduction postural variation (90th-10th percentile) while standing computer workstation associated with greater variation for should rotation and wrist extension. Users reported similar overall discomfort levels within the first 10 min of work but had more than twice as much discomfort while standing than sitting after 45 min; with most discomfort reported in the low back for standing and shoulder for sitting. These different measures provide understanding in users' different interactions with sitting and standing and by alternating between the two configurations in short bouts may be a way of changing the loading pattern on the upper extremity.

Longitudinal Comparison of the Microbiota During Klebsiella pneumoniae Carbapenemase-Producing Klebsiella pneumoniae (KPC-Kp) Acquisition in Long-Term Acute Care Hospital (LTACH) patients

Background

Colonization with KPC-Kp precedes infection and represents a potential target for intervention. To identify microbial signatures associated with KPC-Kp acquisition, we conducted a prospective, longitudinal study of the fecal microbiota in LTACH patients at risk of acquiring KPC-Kp.

Methods

We collected admission and weekly rectal swab samples from patients admitted to one LTACH from May 2015 to May 2016. Patients were screened for KPC-Kp by PCR at each sampling time. KPC acquisition was confirmed by culture of KPC-Kp. To assess changes in the microbiota related to acquisition, we sequenced the 16S rRNA gene (V4 region) from collected rectal swabs. Diversity, intra-individual changes, and the relative abundance of the operational taxonomic unit (OTU) that contains KPC-Kp were compared in patients who were KPC-Kp negative upon admission and who had at least one additional swab sample collected.

Results

318 patients (1247 samples) were eligible for analysis; 3.7 samples (mean) were collected per patient. Sixty-two patients (19.5%) acquired KPC-Kp (cases) and 256 patients remained negative for all carbapenem-resistant Enterobacteriaceae throughout their stay (controls). Median length of stay before KPC-Kp detection was 14.5 days. At time of KPC-Kp acquisition, levels of an Enterobacteriaceae OTU increased significantly compared with pre-acquisition samples and to samples from control patients (Wilcoxon test, P < 0.0001). Similarly, we observed a decrease in total diversity of the fecal microbiota at time of acquisition in cases (P < 0.01). Compared with controls, cases exhibited decreased intra-individual fecal microbiota similarity immediately prior to acquisition of KPC-Kp (P < 0.01). Comparison of microbial features at time of admission using random forest revealed a higher abundance of Enterococcus and Escherichia OTUs in controls vs cases.

Conclusion

We observed intra-individual changes in the fecal microbiota of case patients prior to acquisition of KPC-Kp. Compared with patients who did not acquire KPC-Kp, cases exhibited significant changes in microbiota diversity and increased abundance of potential KPC-Kp at acquisition. Our results suggest that shifts in the microbiota may precede colonization by KPC-Kp.

Disclosures

N. M. Moore, Cepheid: Research Contractor, Funded and provided reagents for associated research projects; R. A. Weinstein, OpGen: Receipt of donated laboratory services for project, Research support; CLorox: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; Molnlycke: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; Sage Products: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; M. Y. Lin, Sage, Inc.: receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; OpGen, Inc.: receipt of in-kind laboratory services, Conducting studies in healthcare facilities that are receiving contributed product; M. K. Hayden, OpGen, Inc.: Receipt of donated laboratory services for project, Research support; Clorox: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; Molnlycke: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product; Sage Products: Receipt of contributed product, Conducting studies in healthcare facilities that are receiving contributed product.

Regional Epidemiology of Methicillin-Resistant Staphylococcus aureus Among Critically Ill Children in a State With Mandated Active Surveillance

BACKGROUND

In theory, active surveillance of methicillin-resistant Staphylococcus aureus (MRSA) reduces MRSA spread by identifying all MRSA-colonized patients and placing them under contact precautions. In October 2007, Illinois mandated active MRSA surveillance in all intensive care units, including neonatal intensive care units (NICUs) and pediatric intensive care units (PICUs). We evaluated MRSA trends in a large metropolitan region in the wake of this law.

METHODS

Chicago hospitals with a NICU or PICU were recruited for 8 single-day point prevalence surveys that occurred twice-yearly between June 2008 and July 2011 and then yearly in 2012 to 2013. Samples from all patients were cultured for MRSA (nose and umbilicus for neonates, nose and groin for pediatric patients). Hospital-reported admission MRSA-screening results also were obtained. Point prevalence cultures were screened for MRSA by using broth enrichment, chromogenic agar, and standard confirmatory methods.

RESULTS

All eligible hospitals (N = 10) participated (10 NICUs, 6 PICUs). Hospital-reported adherence to state-mandated MRSA screening at admission was high (95% for NICUs, 94% for PICUs). From serial point prevalence surveys, overall MRSA prevalences in the NICUs and PICUs were 4.2% (89 of 2101) and 5.7% (36 of 632), respectively. MRSA colonization prevalences were unchanged in the NICUs (year-over-year risk ratio [RR], 0.93 [95% confidence interval (CI), 0.78-1.12]; P = .45) and trended toward an increase in the PICUs (RR, 1.25 [95% CI, 0.72-2.12]; P = .053). We estimated that 81% and 40% of MRSA-positive patients in the NICUs and PICUs, respectively, had newly acquired MRSA.

CONCLUSIONS

In a region with mandated active MRSA surveillance, we found ongoing unchanged rates of MRSA colonization and acquisition among NICU and PICU patients.