Potential underreporting of treated patients using a Clostridioides difficile testing algorithm that screens with a nucleic acid amplification test

OBJECTIVE

Patients tested for Clostridioides difficile infection (CDI) using a 2-step algorithm with a nucleic acid amplification test (NAAT) followed by toxin assay are not reported to the National Healthcare Safety Network as a laboratory-identified CDI event if they are NAAT positive (+)/toxin negative (-). We compared NAAT+/toxin- and NAAT+/toxin+ patients and identified factors associated with CDI treatment among NAAT+/toxin- patients.

DESIGN

Retrospective observational study.

SETTING

The study was conducted across 36 laboratories at 5 Emerging Infections Program sites.

PATIENTS

We defined a CDI case as a positive test detected by this 2-step algorithm during 2018-2020 in a patient aged ≥1 year with no positive test in the previous 8 weeks.

METHODS

We used multivariable logistic regression to compare CDI-related complications and recurrence between NAAT+/toxin- and NAAT+/toxin+ cases. We used a mixed-effects logistic model to identify factors associated with treatment in NAAT+/toxin- cases.

RESULTS

Of 1,801 cases, 1,252 were NAAT+/toxin-, and 549 were NAAT+/toxin+. CDI treatment was given to 866 (71.5%) of 1,212 NAAT+/toxin- cases versus 510 (95.9%) of 532 NAAT+/toxin+ cases (P < .0001). NAAT+/toxin- status was protective for recurrence (adjusted odds ratio [aOR], 0.65; 95% CI, 0.55-0.77) but not CDI-related complications (aOR, 1.05; 95% CI, 0.87-1.28). Among NAAT+/toxin- cases, white blood cell count ≥15,000/µL (aOR, 1.87; 95% CI, 1.28-2.74), ≥3 unformed stools for ≥1 day (aOR, 1.90; 95% CI, 1.40-2.59), and diagnosis by a laboratory that provided no or neutral interpretive comments (aOR, 3.23; 95% CI, 2.23-4.68) were predictors of CDI treatment.

CONCLUSION

Use of this 2-step algorithm likely results in underreporting of some NAAT+/toxin- cases with clinically relevant CDI. Disease severity and laboratory interpretive comments influence treatment decisions for NAAT+/toxin- cases.

Characteristics of Patients With Initial Clostridioides difficile Infection (CDI) That Are Associated With Increased Risk of Multiple CDI Recurrences

Background

Because interventions are available to prevent further recurrence in patients with recurrent Clostridioides difficile infection (rCDI), we identified predictors of multiple rCDI (mrCDI) in adults at the time of presentation with initial CDI (iCDI).

Methods

iCDI was defined as a positive C difficile test in any clinical setting during January 2018-August 2019 in a person aged ≥18 years with no known prior positive test. rCDI was defined as a positive test ≥14 days from the previous positive test within 180 days after iCDI; mrCDI was defined as ≥2 rCDI. We performed multivariable logistic regression analysis.

Results

Of 18 829 patients with iCDI, 882 (4.7%) had mrCDI; 437 with mrCDI and 7484 without mrCDI had full chart reviews. A higher proportion of patients with mrCDI than without mrCDI were aged ≥65 years (57.2% vs 40.7%; P < .0001) and had healthcare (59.1% vs 46.9%; P < .0001) and antibiotic (77.3% vs 67.3%; P < .0001) exposures in the 12 weeks preceding iCDI. In multivariable analysis, age ≥65 years (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.55-2.35), chronic hemodialysis (aOR, 2.28; 95% CI, 1.48-3.51), hospitalization (aOR, 1.64; 95% CI, 1.33-2.01), and nitrofurantoin use (aOR, 1.95; 95% CI, 1.18-3.23) in the 12 weeks preceding iCDI were associated with mrCDI.

Conclusions

Patients with iCDI who are older, on hemodialysis, or had recent hospitalization or nitrofurantoin use had increased risk of mrCDI and may benefit from early use of adjunctive therapy to prevent mrCDI. If confirmed, these findings could aid in clinical decision making and interventional study designs.

Residential social vulnerability among healthcare personnel with and without severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection in Five US states, May-December 2020

OBJECTIVE

To characterize residential social vulnerability among healthcare personnel (HCP) and evaluate its association with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection.

DESIGN

Case-control study.

SETTING

This study analyzed data collected in May-December 2020 through sentinel and population-based surveillance in healthcare facilities in Colorado, Minnesota, New Mexico, New York, and Oregon.

PARTICIPANTS

Data from 2,168 HCP (1,571 cases and 597 controls from the same facilities) were analyzed.

METHODS

HCP residential addresses were linked to the social vulnerability index (SVI) at the census tract level, which represents a ranking of community vulnerability to emergencies based on 15 US Census variables. The primary outcome was SARS-CoV-2 infection, confirmed by positive antigen or real-time reverse-transcriptase- polymerase chain reaction (RT-PCR) test on nasopharyngeal swab. Significant differences by SVI in participant characteristics were assessed using the Fisher exact test. Adjusted odds ratios (aOR) with 95% confidence intervals (CIs) for associations between case status and SVI, controlling for HCP role and patient care activities, were estimated using logistic regression.

RESULTS

Significantly higher proportions of certified nursing assistants (48.0%) and medical assistants (44.1%) resided in high SVI census tracts, compared to registered nurses (15.9%) and physicians (11.6%). HCP cases were more likely than controls to live in high SVI census tracts (aOR, 1.76; 95% CI, 1.37-2.26).

CONCLUSIONS

These findings suggest that residing in more socially vulnerable census tracts may be associated with SARS-CoV-2 infection risk among HCP and that residential vulnerability differs by HCP role. Efforts to safeguard the US healthcare workforce and advance health equity should address the social determinants that drive racial, ethnic, and socioeconomic health disparities.

Association of Clostridioides difficile infection rates with social determinants of health in Denver area census tracts, 2016-2019

We evaluated the association between census tract measures of socioeconomic status and Clostridioides difficile infection (CDI) rates in the Denver metro area from 2016 to 2019. Social vulnerability index, poverty, and race were associated with CDI. Findings may relate to differences in chronic disease prevalence, antibiotic exposure, and access to quality care.

Trends in Incidence of Carbapenem-Resistant Enterobacterales in 7 US Sites, 2016─2020

Background

We described changes in 2016─2020 carbapenem-resistant Enterobacterales (CRE) incidence rates in 7 US sites that conduct population-based CRE surveillance.

Methods

An incident CRE case was defined as the first isolation of Escherichia coli, Klebsiella spp., or Enterobacter spp. resistant to ≥1 carbapenem from a sterile site or urine in a surveillance area resident in a 30-day period. We reviewed medical records and classified cases as hospital-onset (HO), healthcare-associated community-onset (HACO), or community-associated (CA) CRE based on healthcare exposures and location of disease onset. We calculated incidence rates using census data. We used Poisson mixed effects regression models to perform 2016─2020 trend analyses, adjusting for sex, race/ethnicity, and age. We compared adjusted incidence rates between 2016 and subsequent years using incidence rate ratios (RRs) and 95% confidence intervals (CIs).

Results

Of 4996 CRE cases, 62% were HACO, 21% CA, and 14% HO. The crude CRE incidence rate per 100 000 was 7.51 in 2016 and 6.08 in 2020 and was highest for HACO, followed by CA and HO. From 2016 to 2020, the adjusted overall CRE incidence rate decreased by 24% (RR, 0.76 [95% CI, .70-.83]). Significant decreases in incidence rates in 2020 were seen for HACO (RR, 0.75 [95% CI, .67-.84]) and CA (0.75 [.61-.92]) but not for HO CRE.

Conclusions

Adjusted CRE incidence rates declined from 2016 to 2020, but changes over time varied by epidemiologic class. Continued surveillance and effective control strategies are needed to prevent CRE in all settings.

The effects of oral contraceptives on resting autonomic function and the autonomic response to physiological stressors: a systematic review

PURPOSE

This systematic review aimed to summarize how oral contraceptives (OC) affect resting autonomic function and the autonomic response to a variety of physiological stressors.

METHODS

A search strategy was created to retrieve citations investigating physiological responses comparing OC users to non-users (NOC) in response to autonomic reflex activation.

RESULTS

A total of 6148 citations were identified across databases from inception to June 2, 2022, and 3870 citations were screened at the abstract level after deduplication. Then, 133 texts were assessed at full-text level, and only 40 studies met eligibility requirements. Included citations were grouped by the aspect of autonomic function assessed, including autonomic reflex (i.e., baroreflex, chemoreflex, mechanoreflex, metaboreflex, and venoarterial reflex), or indicators (i.e., heart rate variability, pulse wave velocity, and sympathetic electrodermal activity), and physiological stressors that may alter autonomic function (i.e., auditory, exercise, mental or orthostatic stress, altitude, cold pressor test, sweat test, and vasodilatory infusions).

CONCLUSION

OC influence the physiological responses to chemoreflex, mechanoreflex, and metaboreflex activation. In terms of autonomic indices and physiological stressors, there are more inconsistencies within the OC literature, which may be due to estrogen dosage within the OC formulation (i.e., heart rate variability) or the intensity of the stressor (exercise intensity/duration or orthostatic stress). Further research is required to elucidate the effects of OC on these aspects of autonomic function because of the relatively small amount of available research. Furthermore, researchers should more clearly define or stratify OC use by duration, dose, and/or hormone cycling to further elucidate the effects of OC.

Physiotherapy management of first nations children with bronchiectasis from remote top end communities of the northern territory: a retrospective chart audit

Background

Bronchiectasis is a chronic pulmonary disorder which is prevalent among Australian First Nations people in the Northern Territory (NT). Current guidelines recommend physiotherapy as part of multi-disciplinary management of children with bronchiectasis, however in our setting, involvement of physiotherapy remains unknown. We thus undertook a retrospective chart audit to examine physiotherapy management of First Nations children (<18 years) from remote First Nations communities in the Top End of the NT at the index bronchiectasis diagnosis and 12 months following diagnosis.

Methods

Participants were identified from a larger prospective study of children investigated for bronchiectasis at Royal Darwin Hospital, NT (2007-2016). Children were included if they were First Nations, aged <18 years, had a radiological diagnosis of bronchiectasis on high resolution computed tomography scan and lived in a remote community serviced by NT Government health clinics. The medical records from NT Government hospitals, health clinics and where possible other medical service attendance were reviewed for physiotherapy referral and management at the time of bronchiectasis diagnosis and in the following 12 months in the community.

Results

Of 143 children included, the mean age was 3.1 (standard deviation 2.4) years and 84 (58.7%) were males. At the index diagnosis, 76/122 (62.3%) children were reviewed by a physiotherapist, consisting of airway clearance techniques (83.8%), physical activity/exercise (81.7%) and caregiver education (83.3%), with only 7/127 (5.5%) having evidence of referral for community-based physiotherapy. In the following 12 months, only 11/143 (7.7%) children were reviewed by a physiotherapist, consisting of airway clearance techniques (54.5%), physical activity/exercise (45.5%) and caregiver education (36.4%).

Conclusion

This study demonstrates a significant gap in the provision of physiotherapy services in our setting and the need to develop a standardized pathway, to support the best practice management of children with bronchiectasis in remote Top End communities of the NT.

Epidemiology of Pulmonary and Extrapulmonary Nontuberculous Mycobacteria Infections at 4 US Emerging Infections Program Sites: A 6-Month Pilot

BACKGROUND

Nontuberculous mycobacteria (NTM) cause pulmonary (PNTM) and extrapulmonary (ENTM) disease. Infections are difficult to diagnose and treat, and exposures occur in healthcare and community settings. In the United States, NTM epidemiology has been described largely through analyses of microbiology data from health departments, electronic health records, and administrative data. We describe findings from a multisite pilot of active, laboratory- and population-based NTM surveillance.

METHODS

The Centers for Disease Control and Prevention's Emerging Infections Program conducted NTM surveillance at 4 sites (Colorado, 5 counties; Minnesota, 2 counties; New York, 2 counties; and Oregon, 3 counties [PNTM] and statewide [ENTM]) from 1 October 2019 through 31 March 2020. PNTM cases were defined using published microbiologic criteria. ENTM cases required NTM isolation from a nonpulmonary specimen, excluding stool and rectal swabs. Patient data were collected via medical record review.

RESULTS

Overall, 299 NTM cases were reported (PNTM: 231, 77%); Mycobacterium avium complex was the most common species group. Annualized prevalence was 7.5/100 000 population (PNTM: 6.1/100 000; ENTM: 1.4/100 000). Most patients had signs or symptoms in the 14 days before positive specimen collection (ENTM: 62, 91.2%; PNTM: 201, 87.0%). Of PNTM cases, 145 (62.8%) were female and 168 (72.7%) had underlying chronic lung disease. Among ENTM cases, 29 (42.6%) were female, 21 (30.9%) did not have documented underlying conditions, and 26 (38.2%) had infection at the site of a medical device or procedure.

CONCLUSIONS

Active, population-based NTM surveillance will provide data for monitoring the burden of disease and characterize affected populations to inform interventions.

Epidemiology of Sepsis in US Children and Young Adults

Background

Most multicenter studies of US pediatric sepsis epidemiology use administrative data or focus on pediatric intensive care units. We conducted a detailed medical record review to describe sepsis epidemiology in children and young adults.

Methods

In a convenience sample of hospitals in 10 states, patients aged 30 days-21 years, discharged during 1 October 2014-30 September 2015, with explicit diagnosis codes for severe sepsis or septic shock, were included. Medical records were reviewed for patients with documentation of sepsis, septic shock, or similar terms. We analyzed overall and age group-specific patient characteristics.

Results

Of 736 patients in 26 hospitals, 442 (60.1%) had underlying conditions. Most patients (613 [83.3%]) had community-onset sepsis, although most community-onset sepsis was healthcare associated (344 [56.1%]). Two hundred forty-one patients (32.7%) had outpatient visits 1-7 days before sepsis hospitalization, of whom 125 (51.9%) received antimicrobials ≤30 days before sepsis hospitalization. Age group-related differences included common underlying conditions (<5 years: prematurity vs 5-12 years: chronic pulmonary disease vs 13-21 years: chronic immunocompromise); medical device presence ≤30 days before sepsis hospitalization (1-4 years: 46.9% vs 30 days-11 months: 23.3%); percentage with hospital-onset sepsis (<5 years: 19.6% vs ≥5 years: 12.0%); and percentage with sepsis-associated pathogens (30 days-11 months: 65.6% vs 13-21 years: 49.3%).

Conclusions

Our data suggest potential opportunities to raise sepsis awareness among outpatient providers to facilitate prevention, early recognition, and intervention in some patients. Consideration of age-specific differences may be important as approaches are developed to improve sepsis prevention, risk prediction, recognition, and management.

1665. Potential underreporting of treated patients using a Clostridioides difficile testing algorithm that screens with a nucleic acid amplification test

Background

U.S. laboratories are increasingly using a two-step algorithm to diagnose Clostridioides difficile infection (CDI) that starts with a nucleic acid amplification test (NAAT), and if positive, reflexes to a toxin enzyme immunoassay. Here only a NAAT+/toxin+ result is reported to the Centers for Disease Control and Prevention’s (CDC) National Healthcare Safety Network (NHSN) as a CDI laboratory-identified (LabID) event, but limited data suggest that NAAT+/toxin- results may also be considered CDI by clinicians. To explore this discrepancy, we compared the characteristics and treatment of NAAT+/toxin- and NAAT+/toxin+ patients.

Methods

CDC’s Emerging Infections Program (EIP) conducts population-based CDI surveillance. A case was defined as a positive C. difficile test in a person aged ≥1 year with no positive tests in the prior 8 weeks. We included cases detected by this two-step algorithm in 5 EIP sites during 2018–2020 that underwent a full chart review. Multivariable logistic regression models adjusting for age, sex, race, comorbidities, epidemiologic classification, and CDI therapy were used to compare CDI-related complications (i.e., toxic megacolon, ileus, colectomy, or intensive-care unit stay) and recurrence between the two groups.

Results

Of 1250 NAAT+ cases, 897 (72%) were toxin- and 353 (28%) were toxin+. Lower percentages of toxin- versus toxin+ cases were aged ≥65 years (42% vs 58%; P< 0.0001), had diarrhea (779/831 [94%] vs 329/338 [97%]; P=0.01), or had white blood cell counts ≥15,000 cells/μL (183/811 [23%] vs 132/321 [42%]; P< 0.0001). CDI therapy was given to 683/882 (77%) toxin- versus 338/349 (97%) toxin+ cases (P< 0.0001). In multivariable analysis, toxin- status was protective for recurrence (adjusted odds ratio [aOR], 0.49; 95% confidence interval [CI], 0.32–0.74) but not for CDI-related complications (aOR, 1.00; 95% CI, 0.64–1.56).

Conclusion

NAAT+/toxin- cases were less likely to have recurrence but were as likely to have CDI-related complications as NAAT+/toxin+ cases. More than twice as many potentially unreported NAAT+/toxin- cases were treated than the number of reported NAAT+/toxin+ treated cases. Use of this two-step algorithm likely results in underreporting of treated CDI cases to NHSN.

Disclosures

Scott Fridkin, MD, Pfizer: Grant/Research Support Dale N. Gerding, MD, Destiny Pharma plc.: Advisor/Consultant.

Low sensitivity of ICD-10 coding for culture-confirmed candidemia cases in an active surveillance system—United States, 2019–2020

We evaluated healthcare facility use of ICD-10 codes for culture-confirmed candidemia cases detected by active public health surveillance during 2019–2020. Most cases (56%) did not receive a candidiasis code, suggesting that studies relying on ICD-10 codes likely underestimate disease burden.

Comparison of the Risk of Recurrent Clostridioides Difficile Infections Among Patients in 2018 Versus 2013

Among persons with an initial Clostridioides difficile infection (CDI) across 10 US sites in 2018 compared with 2013, 18.3% versus 21.1% had ≥1 recurrent CDI (rCDI) within 180 days. We observed a 16% lower adjusted risk of rCDI in 2018 versus 2013 (P < .0001).

Validity and Acceptability of Wearable Devices for Monitoring Step-Count and Activity Minutes Among People With Multiple Sclerosis

Multiple wearable devices that purport to measure physical activity are widely available to consumers. While they may support increases in physical activity among people with multiple sclerosis (MS) by providing feedback on their performance, there is little information about the validity and acceptability of these devices. Providing devices that are perceived as inaccurate and difficult to use may have negative consequences for people with MS, rather than supporting participation in physical activity. The aim of this study was, therefore, to assess the validity and acceptability of commercially available devices for monitoring step-count and activity time among people with MS. Nineteen ambulatory adults with MS [mean (SD) age 52.1 (11.9) years] participated in the study. Step-count was assessed using five commercially available devices (Fitbit Alta, Fitbit Zip, Garmin Vivofit 4, Yamax Digi Walker SW200, and Letscom monitor) and an activPAL3μ while completing nine everyday activities. Step-count was also manually counted. Time in light activity, moderate-to-vigorous activity, and total activity were measured during activities using an Actigraph GT3X accelerometer. Of the 19 participants who completed the validity study, fifteen of these people also wore the five commercially available devices for three consecutive days each, and participated in a semi-structured interview regarding their perception of the acceptability of the monitors. Mean percentage error for step-count ranged from 12.1% for the Yamax SW200 to −112.3% for the Letscom. Mean step-count as manually determined differed to mean step-count measured by the Fitbit Alta (p = 0.002), Garmin vivofit 4 (p < 0.001), Letscom (p < 0.001) and the research standard device, the activPAL3μ (p < 0.001). However, 95% limits of agreement were smallest for the activPAL3μ and largest for the Fitbit Alta. Median percentage error for activity minutes was 52.9% for the Letscom and 100% for the Garmin Vivofit 4 and Fitbit Alta compared to minutes in total activity. Three inductive themes were generated from participant accounts: Interaction with device; The way the device looks and feels; Functionality. In conclusion, commercially available devices demonstrated poor criterion validity when measuring step-count and activity time in people with MS. This negatively affected the acceptability of devices, with perceived inaccuracies causing distrust and frustration. Additional considerations when designing devices for people with MS include an appropriately sized and lit display and ease of attaching and charging devices.

Risk Factors for SARS-CoV-2 Infection Among US Healthcare Personnel, May-December 2020

To determine risk factors for coronavirus disease (COVID-19) among US healthcare personnel (HCP), we conducted a case-control analysis. We collected data about activities outside the workplace and COVID-19 patient care activities from HCP with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test results (cases) and from HCP with negative test results (controls) in healthcare facilities in 5 US states. We used conditional logistic regression to calculate adjusted matched odds ratios and 95% CIs for exposures. Among 345 cases and 622 controls, factors associated with risk were having close contact with persons with COVID-19 outside the workplace, having close contact with COVID-19 patients in the workplace, and assisting COVID-19 patients with activities of daily living. Protecting HCP from COVID-19 may require interventions that reduce their exposures outside the workplace and improve their ability to more safely assist COVID-19 patients with activities of daily living.

1408. Population-based Nontuberculous Mycobacteria Surveillance in Four Emerging Infections Program Sites, October 2019–March 2020

Background

Nontuberculous mycobacteria (NTM) cause pulmonary (PNTM) and extrapulmonary (ENTM) disease. NTM infections are difficult to diagnose and treat; environmental exposures occur in both healthcare and community settings. Few population-based studies describe NTM disease epidemiology. Current data indicate PNTM disease and ENTM skin and soft tissue infections are increasing. We describe findings from a multi-site pilot of population-based NTM surveillance.

Methods

CDC’s Emerging Infections Program conducted active, laboratory- and population-based surveillance for NTM cases occurring in 4 sites (Colorado [5 counties], Minnesota [2 counties], New York [2 counties], and Oregon [3 counties PNTM; statewide ENTM]) during October 1, 2019–March 31, 2020. PNTM cases were defined according to current published microbiologic criteria, based on isolation of NTM in respiratory cultures or tissue. ENTM cases required NTM isolation from a non-pulmonary specimen, excluding stool or rectal swabs. Demographic, clinical, exposure, and laboratory data were collected via medical record review. We calculated overall incidence per 100,000 population using census data and performed descriptive analyses of medical record data.

Results

Overall, 299 NTM cases were reported (231 [77%] PNTM); M. avium was the most commonly isolated species (Table). NTM incidence was 3.8 per 100,000 (PNTM 3.1/100,000; ENTM 0.7/100,000). Most patients with available data had ≥1 sign or symptom in the 14 days before culture (63 [97%] ENTM, 203 [92%] PNTM). During the surveillance period, 187 (63%) had their first infection-defining culture collected in an outpatient setting (33 [49%] ENTM, 154 [67%] PNTM). Of PNTM cases, 145 (64%) were female, and 154 (67%) had underlying pulmonary disease. Among ENTM cases, 29 (43%) were female, 9 (13%) had diabetes, 8 (12%) had HIV and 27 (40%) had infection at the site of a medical device or healthcare procedure. Common ENTM infection types were lymphadenitis (16 [24%]) and skin abscess (12 [18%]).

Table. Characteristics of persons with NTM infection identified in population-based surveillance, October 1, 2019–March 31, 2020.

Conclusion

Characterizing disease burden and affected populations with population-based NTM surveillance will provide data to inform potential interventions and monitor prevention strategy impact.

Disclosures

Christopher A. Czaja, MD, DrPH, Centers for Disease Control and Prevention (Grant/Research Support) Ruth Lynfield, MD, Nothing to disclose Ghinwa Dumyati, MD, Pfizer (Grant/Research Support)Roche Diagnostics (Advisor or Review Panel member) Emily Henkle, PhD, MPH, AN2 (Consultant, Advisor or Review Panel member)Zambon (Advisor or Review Panel member) Kevin L. Winthrop, MD, MPH, Insmed (Consultant, Grant/Research Support)Paratek (Consultant)RedHill (Consultant)Spero (Consultant) Kevin L. Winthrop, MD, MPH, Insmed (Consultant, Research Grant or Support)Paratek (Consultant)RedHill Biopharma (Consultant)Spero (Consultant)

Association between Socioeconomic Status and Incidence of Community-Associated Clostridioides difficile Infection - United States, 2014-2015

We evaluated the association between socioeconomic status (SES) and community-associated Clostridioides difficile infection (CA-CDI) incidence across 2474 census tracts in 10 states. Highly correlated community-level SES variables were transformed into distinct factors using factor analysis. We found low SES communities were associated with higher CA-CDI incidence.

Prophylactic Postoperative High Flow Nasal Oxygen Versus Conventional Oxygen Therapy in Obese Patients Undergoing Bariatric Surgery (OXYBAR Study): a Pilot Randomised Controlled Trial

BACKGROUND

Patients with obesity are predisposed to a reduction in end-expiratory lung volume (EELV) and atelectasis after anaesthesia. High flow nasal oxygen (HFNO) may increase EELV, reducing the likelihood of postoperative pulmonary complications (PPC). We conducted a pilot randomised controlled trial (RCT) of conventional oxygen therapy versus HFNO after bariatric surgery. The aim was to investigate the feasibility of using electrical impedance tomography (EIT) as a means of assessing respiratory mechanics and to inform the design of a definitive RCT.

METHODS

We performed a single-centre, parallel-group, pilot RCT. Adult patients with obesity undergoing elective bariatric surgery were eligible for inclusion. We excluded patients with a known contraindication to HFNO or with chronic lung disease.

RESULTS

Fifty patients were randomised in equal proportions. One patient crossed over from conventional O₂ to HFNO. Delta EELI was higher at 1 hour in patients receiving HFNO (mean difference = 831 Au (95% CI - 1636-3298), p = 0.5). Continuous EIT beyond 1 hour was poorly tolerated. At 6 hours, there were no differences in PaO₂/FiO₂ ratio or PaCO₂. Only one patient developed a PPC (in the HFNO group) by 6 weeks.

CONCLUSIONS

These data suggest that a large-scale RCT of HFNO after bariatric surgery in an 'all-comers' population is likely infeasible. While EIT was an effective means of assessing respiratory mechanics, it was impractical over time. Similarly, the infrequency of PPC precludes its use as a primary outcome. Future studies should focus on identifying patients at the greatest risk of PPC.

Treatment Practices for Adults with Candidemia at Nine Active Surveillance Sites - United States, 2017-2018

BACKGROUND

Candidemia is a common opportunistic infection causing substantial morbidity and mortality. Because of an increasing proportion of non-albicans Candida species and rising antifungal drug resistance, the Infectious Diseases Society of America (IDSA) changed treatment guidelines in 2016 to recommend echinocandins over fluconazole as first-line treatment for adults with candidemia. We describe candidemia treatment practices and adherence to the updated guidelines.

METHODS

During 2017-2018, the Emerging Infections Program conducted active population-based candidemia surveillance at nine U.S. sites using a standardized case definition. We assessed factors associated with initial antifungal treatment for the first candidemia case among adults using multivariable logistic regression models. To identify instances of potentially inappropriate treatment, we compared the first antifungal drug received with species and antifungal susceptibility testing (AFST) results from initial blood cultures.

RESULTS

Among 1,835 patients who received antifungal treatment, 1,258 (68.6%) received an echinocandin and 543 (29.6%) received fluconazole as initial treatment. Cirrhosis (adjusted odds ratio = 2.06, 95% confidence interval: 1.29-3.29) was the only underlying medical condition significantly associated with initial receipt of an echinocandin (versus fluconazole). Over half (n = 304, 56.0%) of patients initially treated with fluconazole grew a non-albicans species. Among 265 patients initially treated with fluconazole and with fluconazole AFST results, 28 (10.6%) had a fluconazole-resistant isolate.

CONCLUSIONS

A substantial proportion of patients with candidemia were initially treated with fluconazole, resulting in potentially inappropriate treatment for those involving non-albicans or fluconazole-resistant species. Reasons for non-adherence to IDSA guidelines should be evaluated, and clinician education is needed.

Antimicrobial Use in US Hospitals: Comparison of Results From Emerging Infections Program Prevalence Surveys, 2015 and 2011

BACKGROUND

In the 2011 US hospital prevalence survey of healthcare-associated infections and antimicrobial use 50% of patients received antimicrobial medications on the survey date or day before. More hospitals have since established antimicrobial stewardship programs. We repeated the survey in 2015 to determine antimicrobial use prevalence and describe changes since 2011.

METHODS

The Centers for Disease Control and Prevention's Emerging Infections Program sites in 10 states each recruited ≤25 general and women's and children's hospitals. Hospitals selected a survey date from May-September 2015. Medical records for a random patient sample on the survey date were reviewed to collect data on antimicrobial medications administered on the survey date or day before. Percentages of patients on antimicrobial medications were compared; multivariable log-binomial regression modeling was used to evaluate factors associated with antimicrobial use.

RESULTS

Of 12 299 patients in 199 hospitals, 6084 (49.5%; 95% CI, 48.6-50.4%) received antimicrobials. Among 148 hospitals in both surveys, overall antimicrobial use prevalence was similar in 2011 and 2015, although the percentage of neonatal critical care patients on antimicrobials was lower in 2015 (22.8% vs 32.0% [2011]; P = .006). Fluoroquinolone use was lower in 2015 (10.1% of patients vs 11.9% [2011]; P < .001). Third- or fourth-generation cephalosporin use was higher (12.2% vs 10.7% [2011]; P = .002), as was carbapenem use (3.7% vs 2.7% [2011]; P < .001).

CONCLUSIONS

Overall hospital antimicrobial use prevalence was not different in 2011 and 2015; however, differences observed in selected patient or antimicrobial groups may provide evidence of stewardship impact.

The Changing Epidemiology of Candidemia in the United States: Injection Drug Use as an Increasingly Common Risk Factor-Active Surveillance in Selected Sites, United States, 2014-2017

BACKGROUND

Injection drug use (IDU) is a known, but infrequent risk factor on candidemia; however, the opioid epidemic and increases in IDU may be changing the epidemiology of candidemia.

METHODS

Active population-based surveillance for candidemia was conducted in selected US counties. Cases of candidemia were categorized as IDU cases if IDU was indicated in the medical records in the 12 months prior to the date of initial culture.

RESULTS

During 2017, 1191 candidemia cases were identified in patients aged >12 years (incidence: 6.9 per 100 000 population); 128 (10.7%) had IDU history, and this proportion was especially high (34.6%) in patients with candidemia aged 19-44. Patients with candidemia and IDU history were younger than those without (median age, 35 vs 63 years; P < .001). Candidemia cases involving recent IDU were less likely to have typical risk factors including malignancy (7.0% vs 29.4%; relative risk [RR], 0.2 [95% confidence interval {CI}, .1-.5]), abdominal surgery (3.9% vs 17.5%; RR, 0.2 [95% CI, .09-.5]), and total parenteral nutrition (3.9% vs 22.5%; RR, 0.2 [95% CI, .07-.4]). Candidemia cases with IDU occurred more commonly in smokers (68.8% vs 18.5%; RR, 3.7 [95% CI, 3.1-4.4]), those with hepatitis C (54.7% vs 6.4%; RR, 8.5 [95% CI, 6.5-11.3]), and in people who were homeless (13.3% vs 0.8%; RR, 15.7 [95% CI, 7.1-34.5]).

CONCLUSIONS

Clinicians should consider injection drug use as a risk factor in patients with candidemia who lack typical candidemia risk factors, especially in those with who are 19-44 years of age and have community-associated candidemia.

Assessment of the Appropriateness of Antimicrobial Use in US Hospitals

IMPORTANCE

Hospital antimicrobial consumption data are widely available; however, large-scale assessments of the quality of antimicrobial use in US hospitals are limited.

OBJECTIVE

To evaluate the appropriateness of antimicrobial use for hospitalized patients treated for community-acquired pneumonia (CAP) or urinary tract infection (UTI) present at admission or for patients who had received fluoroquinolone or intravenous vancomycin treatment.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included data from a prevalence survey of hospitalized patients in 10 Emerging Infections Program sites. Random samples of inpatients on hospital survey dates from May 1 to September 30, 2015, were identified. Medical record data were collected for eligible patients with 1 or more of 4 treatment events (CAP, UTI, fluoroquinolone treatment, or vancomycin treatment), which were selected on the basis of common infection types reported and antimicrobials given to patients in the prevalence survey. Data were analyzed from August 1, 2017, to May 31, 2020.

EXPOSURE

Antimicrobial treatment for CAP or UTI or with fluoroquinolones or vancomycin.

MAIN OUTCOMES AND MEASURES

The percentage of antimicrobial use that was supported by medical record data (including infection signs and symptoms, microbiology test results, and antimicrobial treatment duration) or for which some aspect of use was unsupported. Unsupported antimicrobial use was defined as (1) use of antimicrobials to which the pathogen was not susceptible, use in the absence of documented infection signs or symptoms, or use without supporting microbiologic data; (2) use of antimicrobials that deviated from recommended guidelines; or (3) use that exceeded the recommended duration.

RESULTS

Of 12 299 patients, 1566 patients (12.7%) in 192 hospitals were included; the median age was 67 years (interquartile range, 53-79 years), and 864 (55.2%) were female. A total of 219 patients (14.0%) were included in the CAP analysis, 452 (28.9%) in the UTI analysis, 550 (35.1%) in the fluoroquinolone analysis, and 403 (25.7%) in the vancomycin analysis; 58 patients (3.7%) were included in both fluoroquinolone and vancomycin analyses. Overall, treatment was unsupported for 876 of 1566 patients (55.9%; 95% CI, 53.5%-58.4%): 110 of 403 (27.3%) who received vancomycin, 256 of 550 (46.6%) who received fluoroquinolones, 347 of 452 (76.8%) with a diagnosis of UTI, and 174 of 219 (79.5%) with a diagnosis of CAP. Among patients with unsupported treatment, common reasons included excessive duration (103 of 174 patients with CAP [59.2%]) and lack of documented infection signs or symptoms (174 of 347 patients with UTI [50.1%]).

CONCLUSIONS AND RELEVANCE

The findings suggest that standardized assessments of hospital antimicrobial prescribing quality can be used to estimate the appropriateness of antimicrobial use in large groups of hospitals. These assessments, performed over time, may inform evaluations of the effects of antimicrobial stewardship initiatives nationally.

780. How Much Does Prior Hospitalization Contribute to Readmission with Community-onset Clostridioides difficile Infection?

Background

Interventions to reduce community-onset (CO) Clostridioides difficile Infection (CDI) are not usually hospital-based due to the perception that they are often acquired outside the hospital. We determined the proportion of admitted CO CDI that might be associated with previous hospitalization.

Methods

The CDC’s Emerging Infections Program conducts population-based CDI surveillance in 10 US sites. We defined an incident case as a C. difficile-positive stool collected in 2017 from a person aged ≥ 1 year admitted to a hospital with no positive tests in the prior 8 weeks. Cases were defined as CO if stool was collected within 3 days of hospitalization. CO cases were classified into four categories: long-term care facility (LTCF)-onset if patient was admitted from an LTCF; long-term acute care hospital (LTACH)-onset if patient was admitted from an LTACH; CO-healthcare-facility associated (CO-HCFA) if patient was admitted from a private residence but had a prior healthcare-facility admission in the past 12 weeks; or community-associated (CA) if there was no admission to a healthcare facility in the prior 12 weeks. We excluded hospitals with < 10 cases among admitted catchment-area residents.

Results

Of 4724 cases in 86 hospitals, 2984 (63.2%) were CO (median per hospital: 65.8%; interquartile range [IQR]: 58.3%-70.7%). Among the CO cases, 1424 (47.7%) were CA (median per hospital: 48.1%; IQR: 40.3%-57.7%), 1201 (40.3%) were CO-HCFA (median per hospital: 41.0%; IQR: 32.9%-47.8%), 350 (11.7%) were LTCF-onset (median per hospital: 10.0%; IQR: 0.6%-14.4%), and 9 (0.3%) were LTACH-onset. Of 1201 CO-HCFA cases, 1174 (97.8%) had a prior hospitalization; among these, 978 (83.3%) (median per hospital: 83.3%; IQR: 69.2%-90.6%), which consists of 32.8% of all hospitalized CO cases, had been discharged from the same hospital (Figure), and 84.4% of the 978 cases (median per hospital: 88.2%: IQR: 76.5%-100.0%) had received antibiotics sometime in the prior 12 weeks.

Figure. Frequency of Cases Discharged in the 12 Weeks Prior to Readmission with Clostridioides difficile Infection (N=1138*)

Conclusion

A third of hospitalized CO CDI had been recently discharged from the same hospital, and most had received antibiotics during or soon after the last admission. Hospital-based and post-discharge antibiotic stewardship interventions could help reduce subsequent CDI hospitalizations.

Disclosures

Ghinwa Dumyati, MD, Roche Diagnostics (Consultant)

146. antifungal Susceptibility Patterns of candida Parapsilosis Bloodstream Isolates in the US, 2008–2018

Background

Multidrug resistant Candida is an increasing concern. C. parapsilosis in particular has decreased in vitro susceptibility to echinocandins. As a result, fluconazole had been favored for C. parapsilosis treatment. However, there is growing concern about increasing azole resistance among Candida species. We report on antifungal susceptibility patterns of C. parapsilosis in the US from 2008 through 2018.

Methods

Active, population-based surveillance for candidemia through the Centers for Disease Control and Prevention’s (CDC) Emerging Infections Program was conducted between 2008–2018, eventually encompassing 9 states (GA, MD,OR, TN, NY, CA, CO, MN, NM). Each incident isolate was sent to the CDC for species confirmation and antifungal susceptibility testing (AFST). Frequency of resistance was calculated and stratified by year and state using SAS 9.4

Results

Of the 8,704 incident candidemia isolates identified, 1,471 (15%) were C. parapsilosis; the third most common species after C. albicans and C. glabrata. AFST results were available for 1,340 C. parapsilosis isolates. No resistance was detected to caspofungin (MIC₅₀ 0.25) or micafungin (MIC₅₀ 1.00) with only one (< 1%) isolate resistant to anidulafungin (MIC₅₀ 1.00). In contrast, 84 (6.3%) isolates were resistant to fluconazole and another 44 (3.3%) isolates had dose-dependent susceptibility to fluconazole (MIC₅₀ 1.00). Fluconazole resistance increased sharply from an average of 4% during 2008–2014 to a peak of 14% in 2016 with a subsequent decline to 6% in 2018 (see figure). Regional variation is also observed with fluconazole resistance ranging from 0% (CO, MN, NM) to 42% (NY) of isolates by site.

Conclusion

The recent marked increase in fluconazole resistance among C. parapsilosis highlights this pathogen as an emerging drug resistant pathogen of concern and the need for ongoing antifungal resistance surveillance among Candida species. Our data support the empiric use of echinocandins for C. parapsilosis bloodstream infections and underscore the need to obtain AFST prior to fluconazole treatment. Furthermore, regional variation in fluconazole resistance emphasizes the importance of understanding local Candida susceptibility patterns.

Disclosures

Lee Harrison, MD, GSK (Consultant)Merck (Consultant)Pfizer (Consultant)Sanofi Pasteur (Consultant)

1424. Factors Associated with Failure to Clear Candidemia Infection: Surveillance Data from Eight States, 2017

Background

Candidemia is a bloodstream infection commonly associated with high morbidity and mortality. Failure to clear candidemia can lengthen hospitalization and treatment. Factors associated with candidemia clearance are unknown.

Methods

We analyzed 2017 candidemia surveillance data from the Centers for Disease Control and Prevention’s Emerging Infections Program. Data from eight sites (counties in California, Colorado, Georgia, Minnesota, New Mexico, New York, Oregon, and Tennessee) were included. Clearance was defined as having a blood culture negative for Candida ≤30 days after initial culture date (ICD). Cases with unknown clearance, unknown survival outcome, or death ≤30 days of ICD were excluded. Demographic and clinical factors associated with clearance were assessed with bivariate analysis using chi-square tests and multivariable logistic regression to calculate adjusted odds ratios (aOR) using backward selection (p-value&lt; 0.10).

Results

Of 1,024 candidemia cases, 737 were included and 582 (79%) demonstrated clearance, of which 79% had evidence of clearance ≤5 days after ICD. In bivariate analysis, clearance was associated with central venous catheter (CVC) ≤2 days before ICD, CVC removal ≤7 days after ICD, and systemic antifungal medication within 14 days before ICD. Clearance was inversely associated with black race and admission from another hospital. In multivariable analysis, only race and admission from another hospital were significant predictors; age, sex, and CVC presence and subsequent removal were also retained for their clinical relevance. In the final model, clearance was less likely among black patients (aOR 0.51, 95% confidence interval [CI] 0.29-0.91) and those admitted from another hospital (aOR 0.28, 95% CI 0.11-0.75).

Table 1. Bivariate associations for select variables between individuals with documented candidemia clearance and those without documented clearance in eight Emerging Infections Program surveillance sites, 2017

Conclusion

We found failure to clear candidemia infection to be associated with black race and prior hospital exposure, but not other factors previously shown to be associated (e.g., comorbidities, CVC presence). These associations could reflect illness severity, access to care, or other obstacles to effective treatment. Additional research is needed to investigate these associations further and identify other factors (e.g., treatment type and timing) to improve outcomes.

Disclosures

All Authors: No reported disclosures

Toxin Enzyme Immunoassays Detect Clostridioides difficile Infection With Greater Severity and Higher Recurrence Rates

BACKGROUND

Few data suggest that Clostridioides difficile infections (CDIs) detected by toxin enzyme immunoassay (EIA) are more severe and have worse outcomes than those detected by nucleic acid amplification tests (NAATs) only. We compared toxin- positive and NAAT-positive-only CDI across geographically diverse sites.

METHODS

A case was defined as a positive C. difficile test in a person ≥1 year old with no positive tests in the prior 8 weeks. Cases were detected during 2014-2015 by a testing algorithm (specimens initially tested by glutamate dehydrogenase and toxin EIA; if discordant results, specimens were reflexed to NAAT) and classified as toxin positive or NAAT positive only. Medical charts were reviewed. Multivariable logistic regression models were used to compare CDI-related complications, recurrence, and 30-day mortality between the 2 groups.

RESULTS

Of 4878 cases, 2160 (44.3%) were toxin positive and 2718 (55.7%) were NAAT positive only. More toxin-positive than NAAT-positive-only cases were aged ≥65 years (48.2% vs 38.0%; P < .0001), had ≥3 unformed stools for ≥1 day (43.9% vs 36.6%; P < .0001), and had white blood cell counts ≥15 000 cells/µL (31.4% vs 21.4%; P < .0001). In multivariable analysis, toxin positivity was associated with recurrence (adjusted odds ratio [aOR], 1.89; 95% confidence interval [CI], 1.61-2.23), but not with CDI-related complications (aOR, 0.91; 95% CI, .67-1.23) or 30-day mortality (aOR, 0.95; 95% CI, .73-1.24).

CONCLUSIONS

Toxin-positive CDI is more severe, but there were no differences in adjusted CDI-related complication and mortality rates between toxin-positive and NAAT-positive-only CDI that were detected by an algorithm that utilized an initial glutamate dehydrogenase screening test.

Assessment of Health Care Exposures and Outcomes in Adult Patients With Sepsis and Septic Shock

IMPORTANCE

Current information on the characteristics of patients who develop sepsis may help in identifying opportunities to improve outcomes. Most recent studies of sepsis epidemiology have focused on changes in incidence or have used administrative data sets that provided limited patient-level data.

OBJECTIVE

To describe sepsis epidemiology in adults.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study reviewed the medical records, death certificates, and hospital discharge data of adult patients with sepsis or septic shock who were discharged from the hospital between October 1, 2014, and September 30, 2015. The convenience sample was obtained from hospitals in the Centers for Disease Control and Prevention Emerging Infections Program in 10 states (California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee). Patients 18 years and older with discharge diagnosis codes for severe sepsis or septic shock were randomly selected. Data were analyzed between May 1, 2018, and January 31, 2019.

MAIN OUTCOMES AND MEASURES

The population's demographic characteristics, health care exposures, and sepsis-associated infections and pathogens were described, and risk factors for death within 30 days after sepsis diagnosis were assessed.

RESULTS

Among 1078 adult patients with sepsis (569 men [52.8%]; median age, 64 years [interquartile range, 53-75 years]), 973 patients (90.3%) were classified as having community-onset sepsis (ie, sepsis diagnosed within 3 days of hospital admission). In total, 654 patients (60.7%) had health care exposures before their hospital admission for sepsis; 260 patients (24.1%) had outpatient encounters in the 7 days before admission, and 447 patients (41.5%) received medical treatment, including antimicrobial drugs, chemotherapy, wound care, dialysis, or surgery, in the 30 days before admission. A pathogen associated with sepsis was found in 613 patients (56.9%); the most common pathogens identified were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Clostridioides difficile. After controlling for other factors, an association was found between underlying comorbidities, such as cirrhosis (odds ratio, 3.59; 95% CI, 2.03-6.32), immunosuppression (odds ratio, 2.52; 95% CI, 1.81-3.52), vascular disease (odds ratio, 1.54; 95% CI, 1.10-2.15), and 30-day mortality.

CONCLUSIONS AND RELEVANCE

Most adults experienced sepsis onset outside of the hospital and had recent encounters with the health care system. A sepsis-associated pathogen was identified in more than half of patients. Future efforts to improve sepsis outcomes may benefit from examination of health maintenance practices and recent health care exposures as potential opportunities among high-risk patients.

Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes

BACKGROUND

Efforts to prevent Clostridioides difficile infection continue to expand across the health care spectrum in the United States. Whether these efforts are reducing the national burden of C. difficile infection is unclear.

METHODS

The Emerging Infections Program identified cases of C. difficile infection (stool specimens positive for C. difficile in a person ≥1 year of age with no positive test in the previous 8 weeks) in 10 U.S. sites. We used case and census sampling weights to estimate the national burden of C. difficile infection, first recurrences, hospitalizations, and in-hospital deaths from 2011 through 2017. Health care-associated infections were defined as those with onset in a health care facility or associated with recent admission to a health care facility; all others were classified as community-associated infections. For trend analyses, we used weighted random-intercept models with negative binomial distribution and logistic-regression models to adjust for the higher sensitivity of nucleic acid amplification tests (NAATs) as compared with other test types.

RESULTS

The number of cases of C. difficile infection in the 10 U.S. sites was 15,461 in 2011 (10,177 health care-associated and 5284 community-associated cases) and 15,512 in 2017 (7973 health care-associated and 7539 community-associated cases). The estimated national burden of C. difficile infection was 476,400 cases (95% confidence interval [CI], 419,900 to 532,900) in 2011 and 462,100 cases (95% CI, 428,600 to 495,600) in 2017. With accounting for NAAT use, the adjusted estimate of the total burden of C. difficile infection decreased by 24% (95% CI, 6 to 36) from 2011 through 2017; the adjusted estimate of the national burden of health care-associated C. difficile infection decreased by 36% (95% CI, 24 to 54), whereas the adjusted estimate of the national burden of community-associated C. difficile infection was unchanged. The adjusted estimate of the burden of hospitalizations for C. difficile infection decreased by 24% (95% CI, 0 to 48), whereas the adjusted estimates of the burden of first recurrences and in-hospital deaths did not change significantly.

CONCLUSIONS

The estimated national burden of C. difficile infection and associated hospitalizations decreased from 2011 through 2017, owing to a decline in health care-associated infections. (Funded by the Centers for Disease Control and Prevention.).

111. Pediatric and Adolescent Sepsis Epidemiology and Clinical Characteristics, Emerging Infections Program, 2014–2015

Background

Sepsis is an important contributor to mortality among children and young adults. However, recent studies focused on hospital management and burden estimation do not provide critical data to inform prevention efforts. We conducted detailed medical record reviews to describe the epidemiology and clinical characteristics of children and young adults with sepsis to inform prevention and early recognition targets.

Methods

We utilized the Emerging Infections Program (EIP) to collect comprehensive data via retrospective record review for patients with severe sepsis or septic shock discharge diagnosis codes from a nonrandom sample of hospitals across 10 states. Children and young adults, aged 30 days through 21 years, discharged between September 30, 2014 and October 1, 2015, were randomly selected for inclusion. We performed a descriptive analysis of these data.

Results

Among 734 patients hospitalized with sepsis, 92% were living in a private residence 4 days before admission, 38% had an outpatient medical encounter in the 7 days before admission, 14% had sepsis onset after hospital day 3, and 11% died within 90 days of sepsis diagnosis. The most frequently identified infection was lower respiratory tract infection (14%); for 317 (43%) no infection was documented as a cause of sepsis. The most frequently identified pathogen was Staphylococcus aureus (10%); for 326 (44%) no pathogen was identified as a cause of sepsis. Among 394 (54%) patients with ≥1 chronic underlying medical condition (CUMC), the most common were pulmonary disease (35%), hematologic/oncologic disease (31%), immune compromise (24%), and cardiovascular disease (20%). Patients with CUMC had a higher percentage of their sepsis onset after hospital day 3, death within 90 days of sepsis diagnosis, and Pseudomonas aeruginosa as a cause of sepsis (table). The percentage of patients with no pathogen identified was similar between those with CUMC and those without.

Conclusion

In our large cohort of children and young adults with sepsis, most had sepsis onset outside of the hospital and over half had chronic conditions. Our data suggest that distinct approaches may be needed to develop effective prevention and early recognition strategies for children and young adults depending on the presence of chronic conditions.

Disclosures

All authors: No reported disclosures.

837. Prior Hospitalizations Among Cases of Community-Associated Clostridioides difficile Infection—10 US States, 2014–2015

Background

Despite overall progress in preventing Clostridioides difficile Infection (CDI), community-associated (CA) infections have been steadily increasing. Although the incubation period of CDI is thought to be relatively short, gastrointestinal microbial disruption from remote healthcare exposures (e.g., inpatient antibiotic use) may be associated with CA-CDI. To assess this potential association, we linked CA-CDI infections identified through CDC’s Emerging Infections Program (EIP) to Medicare claims data to describe prior healthcare utilization.

Methods

We defined an EIP CA-CDI case as a positive C. difficile test collected in 2014–2015 from an outpatient or inpatient within 3 days of hospital admission, provided there was no positive test in the prior 8 weeks and no admission to a healthcare facility in the prior 12 weeks. We linked EIP CA-CDI cases aged ≥65 years to a Medicare beneficiary using unique combinations of birthdate, sex, and zip code. Cases were included if they maintained continuous fee-for-service coverage for 1 year prior to the event date. To calculate exposure odds ratios for previous hospitalizations, each case was matched to 5 control beneficiaries on age, sex, and county of residence. We used logistic regression to calculate adjusted matched odds ratios (amOR) that controlled for chronic conditions.

Results

We successfully linked 2,287/3,367 (68%) EIP CA-CDI cases. Of these, 1,236 cases met inclusion criteria; the median age was 77 years and 63% were female. We identified 69 (5.6%) cases with misclassification of prior healthcare exposures, most of whom (48, 70%) were hospitalized in the 12 weeks prior to their event. Among the 1,167 true CA-CDI cases, 33% were hospitalized in the prior 12 weeks to 1 year. The median number of weeks from prior hospitalization to CDI was 27 (IQR 18–38, Figure 1). Cases had a higher risk of hospitalization than matched controls in the prior 3–6 months (amOR: 2.33, 95% CI: 1.87, 2.90) and 6–12 months (amOR: 1.43 95% CI: 1.18, 1.74).

Conclusion

Remote hospitalization in the previous year was a significant risk factor for CA-CDI, especially in the 3–6 months prior to CA-CDI. Long-lasting prevention strategies implemented at hospital discharge and enhanced inpatient antibiotic stewardship may prevent CA-CDI among older adults.

Disclosures

All Authors: No reported Disclosures.

1009. Measuring the quality of fluoroquinolone prescribing in hospitals: results from the Emerging Infections Program Hospital Prevalence Survey Antimicrobial Quality Assessment

Background

Improving antimicrobial use is a key component of controlling antimicrobial resistance. Multiple factors influence inpatient provider antimicrobial prescribing decisions, making it challenging to develop standard methods to evaluate prescribing quality in hospitals. In 2015, CDC’s Emerging Infections Program (EIP) conducted a hospital antimicrobial use prevalence survey and collected data to assess prescribing quality in selected scenarios, including fluoroquinolone (FQ) treatment.

Methods

EIP sites (CA, CO, CT, GA, MD, MN, NM, NY, OR, TN) each recruited up to 25 hospitals for the survey. Each hospital selected a survey date during May–September 2015. Among randomly selected inpatients on the survey date, EIP staff identified those ≥18 years old who received FQ treatment on the survey date or the day prior and reviewed medical records to gather data on underlying conditions, infections, and diagnostic tests. We used these data to update a previously developed prescribing quality assessment pathway that categorized FQ treatment as supported or unsupported based on medical record documentation.

Results

Among 12,299 patients in 199 hospitals, 1084 (8.7%) received FQ treatment; 756 (70%) were treated for a single infection type during their hospitalization and were ≥18 years old. The pathway categorized FQ treatment as supported for 646 (85.4%) and unsupported for 110 patients (14.6%) (figure). Almost half of unsupported treatment was due to a lack of compatible signs or symptoms of infection in a patient from whom an organism susceptible or likely susceptible to an FQ was identified from a nonsterile site (49/110 patients, 44.5%), suggesting colonization.

Conclusion

Utilization of a pathway that incorporates detailed clinical data enabled us to apply a standard approach to assess FQ prescribing quality in hospitals. A high percentage of FQ treatment was supported, possibly reflecting efforts in recent years to reduce inappropriate use. Our assessment approach also identified opportunities for further improvements in inpatient FQ stewardship. Incorporation of additional elements in the pathway, such as the availability of other antibiotic choices in clinical scenarios where FQ use is currently supported (e.g., pneumonia) could further enhance the pathway’s performance.

Disclosures

All authors: No reported disclosures.

1891. Invasive Group A Streptococcus Infections Among Residents of Multiple Nursing Homes—Denver, Colorado, 2017–2018

Background

Older adults residing in nursing homes (NH) are at increased risk for invasive group A Streptococcus (GAS) infections due to advanced age, presence of wounds, and comorbidities; approximately one-third of infected patients die. Beginning in 2015, increasing numbers of GAS infections in NH residents and several NH clusters were reported from the Denver metropolitan area. Colorado Department of Public Health and Environment (CDPHE) and CDC investigated to characterize cases and assess if outbreaks resulted from interfacility transmission.

Methods

We reviewed data from Active Bacterial Core surveillance (ABCs) in the 5-county Denver area from January 2017 to June 2018. We defined a case as isolation of GAS from a normally sterile site in an NH resident. GAS isolates underwent whole-genome sequencing (WGS) at CDC’s Streptococcus Laboratory to determine emm types for genotyping. Among isolates with the same emm type, pairwise single-nucleotide polymorphism (SNP) distances were calculated using Nucmer software. In October 2018, a CDPHE-CDC team assessed infection control at NHs with cases of the most common emm type.

Results

Over 18 months, among >100 NHs in the Denver area, ≥1 GAS case was identified in 29 NHs, with 6 having ≥3 cases. During this period, 68 cases in NH residents were identified. WGS identified 17 emm types among isolates from these cases; most common was emm11.10 (34%, n = 22), a rare subtype in ABCs. All emm11.10 isolates had nearly identical genomes (average pairwise SNP distance: 3.2), and were isolated from 10 NHs, with 2 NHs having ≥ 4 cases. Multiple infection control lapses were noted during site visits to 8 NHs.

Conclusion

Multiple outbreaks due to GAS were noted in 5-county Denver area NHs in 2017–2018. WGS of surveillance isolates identified a rarely seen emm subtype 11.10 from multiple facilities with temporal and genomic clustering suggesting interfacility GAS transmission.

Disclosures

All Authors: No reported Disclosures.

1836. Characteristics of Nursing Homes Associated With Self-reported Implementation of Centers for Disease Control and Prevention (CDC) Core Elements of Antibiotic Stewardship

Background

Methods

Results

Conclusion

Disclosures

490. Comparison of Clostridium difficile Infection Outcomes by Diagnostic Testing Method

Background

US laboratories are increasingly using nucleic acid amplification tests (NAAT) to diagnose Clostridium difficile infection (CDI) due to their increased sensitivity over toxin enzyme immunoassays (EIA), but NAATs may be more likely than toxin EIAs to detect colonization rather than true disease. Limited data indicate patients positive by toxin EIA (toxin+) have worse outcomes than those positive by NAAT (NAAT+) only, suggesting toxin EIA detects true infection more often than NAAT. We used multisite CDI surveillance data from the Centers for Disease Control and Prevention’s Emerging Infections Program to compare clinical course and outcomes between toxin+ and NAAT+ only patients.

Methods

A case was defined as a positive C. difficile test in a person ≥1 year old with no positive tests in the prior 8 weeks. Cases detected during 2014–2015 by a testing algorithm using toxin EIA and NAAT were classified as toxin+ or NAAT+ only. Medical charts were reviewed. Death data were obtained from state death registries. Multivariable logistic regression models were used to compare CDI recurrence and 90-day mortality between the two groups, adjusting for age, sex, race, Charlson comorbidity index, and receipt of oral vancomycin. For the outcome of recurrence, we also adjusted for history of CDI in the prior 6 months.

Results

Of 4,878 cases, 2160 (44%) were toxin+ and 2,718 (56%) were NAAT+ only. Toxin+ cases were more likely than NAAT+ only cases to be ≥65 years old (48% vs. 38%; P < 0.0001), have white blood cells ≥15,000/µL (483/1,539 [31%] vs. 423/1,978 [21%]; P < 0.0001), and have received oral vancomycin ≤3 days of diagnosis (32% vs. 29%; P = 0.03). Comparing toxin+ to NAAT+ only cases, 21% vs. 11% had a recurrence (P < 0.0001), of which 71% vs. 33% had a toxin+ recurrence (P < 0.0001), and 10% vs. 9% died ≤90 days of diagnosis (P = 0.12). In multivariable analysis, a toxin+ result was associated with recurrence (adjusted odds ratio [aOR]: 1.89, 95% CI: 1.61–2.22) but not with 90-day mortality (aOR: 0.99; 95% CI: 0.81–1.22).

Conclusion

Toxin+ CDI is more severe by some markers and more likely to recur as toxin+. However, there was no difference in adjusted mortality, which may reflect an effect on mortality in NAAT+ only cases from mild CDI, receipt of unnecessary CDI treatment, or other factors.

Disclosures

G. Dumyati, Seres: Scientific Advisor, Consulting fee.

363. National Burden of Candidemia, United States, 2017

Background

Candidemia is a common healthcare-associated bloodstream infection associated with high morbidity and mortality. No current estimates exist for understanding its burden in the United States.

Methods

In 2017, CDC’s Emerging Infections Program (EIP) performed laboratory- and active population-based candidemia surveillance in 45 counties in nine states (California, Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, Tennessee), encompassing ~17 million persons. A case was defined as Candida species isolated from blood in a surveillance area resident. EIP site staff reviewed medical records to collect demographic and clinical data. Using 2016 US census data, we created weighted estimates of national and regional incidence rates and mortality in persons with candidemia (defined as death from any cause within 7 days of incident candidemia).

Results

A total of 1,226 candidemia cases were identified in 2017. We estimated 23,000 candidemia cases (95% CI 20,000–25,000) occurred in the United States in 2017. Overall estimated incidence was 7.0/100,000 persons, with elevated rates in adults ≥65 years (20.3/100,000), males (8.0/100,000), and people of Black race (12.6/100,000) (table). Incidence was highest in the South Atlantic region (8.0/100,000) and lowest in the Pacific (6.0/100,000). Estimated number of deaths was 3,000 (1,000–5,000).

Conclusion

Our analysis highlights the substantial burden of candidemia in the US Because candidemia is only one form of invasive candidiasis, the true burden of invasive infections due to Candida species is likely higher. Ongoing surveillance can support future burden estimates and help assess the impact of prevention interventions.

Disclosures

All authors: No reported disclosures.

High flow nasal oxygen after bariatric surgery (OXYBAR), prophylactic post-operative high flow nasal oxygen versus conventional oxygen therapy in obese patients undergoing bariatric surgery: study protocol for a randomised controlled pilot trial

BACKGROUND

The incidence of obesity is increasing worldwide. In selected individuals, bariatric surgery may offer a means of achieving long-term weight loss, improved health, and healthcare cost reduction. Physiological changes that occur because of obesity and general anaesthesia predispose to respiratory complications following bariatric surgery. The aim of this study is to determine whether post-operative high flow nasal oxygen therapy (HFNO2) improves respiratory function and reduces the incidence of post-operative pulmonary complications (PPCs) in comparison to conventional oxygen therapy in these patients.

METHOD

The OXYBAR study is a prospective, un-blinded, single centre, randomised, controlled pilot study. Patients with body mass index (BMI) > 30 kg/m2, undergoing laparoscopic bariatric surgery, will be randomised to receive either standard low flow oxygen therapy or HFNO2 in the post-operative period. The primary outcome measure is the change in end expiratory lung impedance (∆EELI) as measured by electrical impedance tomography (EIT). Secondary outcome measures include change in tidal volume (∆Vt), partial arterial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio, incidence of PPCs, hospital length of stay and measures of patient comfort.

DISCUSSION

We hypothesise that the post-operative administration of HFNO2 will increase EELI and therefore end expiratory lung volume (EELV) in obese patients. To our knowledge this is the first trial designed to assess the effects of HFNO2 on EELV in this population. We anticipate that data collected during this pilot study will inform a larger multicentre trial.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12617000694314 . Registered on 15 May 2017.

Improving the quality of reconstructed X-ray CT images of polymer gel dosimeters: zero-scan coupled with adaptive mean filtering

This study evaluated the feasibility of combining the 'zero-scan' (ZS) X-ray computed tomography (CT) based polymer gel dosimeter (PGD) readout with adaptive mean (AM) filtering for improving the signal to noise ratio (SNR), and to compare these results with available average scan (AS) X-ray CT readout techniques. NIPAM PGD were manufactured, irradiated with 6 MV photons, CT imaged and processed in Matlab. AM filter for two iterations, with 3 × 3 and 5 × 5 pixels (kernel size), was used in two scenarios (a) the CT images were subjected to AM filtering (pre-processing) and these were further employed to generate AS and ZS gel images, and (b) the AS and ZS images were first reconstructed from the CT images and then AM filtering was carried out (post-processing). SNR was computed in an ROI of 30 × 30 for different pre and post processing cases. Results showed that the ZS technique combined with AM filtering resulted in improved SNR. Using the previously-recommended 25 images for reconstruction the ZS pre-processed protocol can give an increase of 44% and 80% in SNR for 3 × 3 and 5 × 5 kernel sizes respectively. However, post processing using both techniques and filter sizes introduced blur and a reduction in the spatial resolution. Based on this work, it is possible to recommend that the ZS method may be combined with pre-processed AM filtering using appropriate kernel size, to produce a large increase in the SNR of the reconstructed PGD images.

Investigation of a cluster of Clostridium difficile infections in a pediatric oncology setting

BACKGROUND

We investigated an increase in Clostridium difficile infection (CDI) among pediatric oncology patients.

METHODS

CDI cases were defined as first C difficile positive stool tests between December 1, 2010, and September 6, 2012, in pediatric oncology patients receiving inpatient or outpatient care at a single hospital. A case-control study was performed to identify CDI risk factors, infection prevention and antimicrobial prescribing practices were assessed, and environmental sampling was conducted. Available isolates were strain-typed by pulsed-field gel electrophoresis.

RESULTS

An increase in hospital-onset CDI cases was observed from June-August 2012. Independent risk factors for CDI included hospitalization in the bone marrow transplant ward and exposure to computerized tomography scanning or cefepime in the prior 12 weeks. Cefepime use increased beginning in late 2011, reflecting a practice change for patients with neutropenic fever. There were 13 distinct strain types among 22 available isolates. Hospital-onset CDI rates decreased to near-baseline levels with enhanced infection prevention measures, including environmental cleaning and prolonged contact isolation.

CONCLUSION

C difficile strain diversity associated with a cluster of CDI among pediatric oncology patients suggests a need for greater understanding of modes and sources of transmission and strategies to reduce patient susceptibility to CDI. Further research is needed on the risk of CDI with cefepime and its use as primary empirical treatment for neutropenic fever.

Dose rate properties of NIPAM-based x-ray CT polymer gel dosimeters

In this work we investigate radiation dose rate dependencies of N-isopropylacrylamide (NIPAM) based polymer gel dosimeters (PGDs) used in conjunction with x-ray computed tomography imaging for radiotherapy dose verification. We define four primary forms of dose rate variation: constant mean dose rate where beam on and beam off times both vary, variable mean dose rate where beam on time varies, variable mean dose rate where beam off time varies and machine dose rate (MU min(-1)). We utilize both small (20 mL) vials and large volume (1L) gel containers to identify and characterize dose rate dependence in NIPAM PGDs. Results indicate that all investigated constant and variable mean dose rates had negligible affect on PGD dose response with the exception of machine dose rates (100-600 MU min(-1)) which produced variations in dose response significantly lower than previously reported. Explanations of the reduced variability in dose response are given. It is also shown that NIPAM PGD dose response is not affected by variations in dose rate that may occur in modulated treatment deliveries. Finally, compositional changes in NIPAM PGDs are investigated as potential mitigating strategies for dose rate-dependent response variability.