Antimicrobial-resistant enteric infections may be difficult to treat, associated with severe outcomes, and costly. To determine if resistant enteric infections are more costly, we described direct hospitalization costs for hospital admissions for typhoid fever, salmonellosis, and shigellosis infections by resistance status. We included all inpatient admissions with culture-confirmed infections from approximately 300 hospitals in the Premier Healthcare database during 2012-2019. We classified typhoid fever, salmonellosis, and shigellosis infections as clinically resistant if laboratory testing found resistance to ≥1 antibiotic class recommended for treatment. We examined patient demographic characteristics and underlying chronic conditions. We used the Wilcoxon rank sum test to assess the difference in median hospitalization cost for each patient admission by resistance status. We estimated adjusted cost and length of stay (LOS) using multivariable linear regression, adjusting for host and health care provider characteristics. Among 67 inpatient admissions for typhoid fever, 3421 for salmonellosis, and 619 for shigellosis, 33% of typhoid fever, 13% of salmonellosis, and 82% of shigellosis infections were clinically resistant. The unadjusted median costs for resistant salmonellosis were higher than susceptible infection-related costs ($7,753 vs. $6,909, p = 0.002). The unadjusted costs for resistant versus susceptible typhoid fever ($13,709 vs. $9,254, p = 0.111) and shigellosis were similar ($5,365 vs. $5,777, p = 0.167). For all three pathogens, the adjusted mean hospitalization costs were not statistically different for resistant and susceptible infections. Adjusted mean LOS was significantly longer for resistant typhoid fever compared with susceptible infections (6.50 days vs. 4.35 days, p = 0.001). Although adjusted cost differences for resistant infections were not significant, we observed differences by host factors including age and comorbidities, suggesting patient demographic characteristics for resistant infections are impactful on cost. These findings support the premise that public health interventions to limit the spread of resistant infections, particularly among individuals at higher risk for severe illness, could reduce hospitalization costs.

OBJECTIVE:Inappropriate urine cultures (UCs) are common and lead to inappropriate antimicrobial use. Urinalyses (UAs) have been increasingly incorporated into diagnostic stewardship interventions, but the impact of these interventions nationally has not been assessed. We describe UA and UC utilization practices using a nationwide dataset of patients admitted to acute care hospitals. METHODS:Design, Setting and Participants: We performed a retrospective cohort study of index UCs and their associated UAs performed for adult patients (age ≥ 18 years) admitted in U.S. acute care hospitals, participating in the PINC AI™ Healthcare Database (PHD) from January 1, 2017, through December 31, 2020. A positive UA was defined as >10 leukocytes per high power field, positive leukocyte esterase, or positive nitrite. RESULTS:The overall rate of UCs in this study was 124.7 per 1000 discharges and annual UC rates decreased from 2017 (129.2) to 2020 (120.0). The proportion of UCs that had a positive UA increased from 60.5% in 2017 to 68.1% in 2020; UCs without a UA decreased from 19.3% to 10.5%, and UCs with a negative UA did not significantly change (20.2% to 21.5%). A multivariate multinomial logistic regression model identified male sex, age <65, and a diagnosis of cancer to be predictors of having a UC with a negative UA or no UA. CONCLUSIONS:UC utilization decreased over the study period. The proportion of UCs with a positive UA increased. This may suggest a positive impact of diagnostic stewardship practices at the national level although further progress is needed.

Antimicrobial resistance is a major public health problem in the US. Estimating national rates of antimicrobial-resistant infections commonly associated with health care can aid in targeted public health efforts. To determine the national incidence rates of 6 pathogens over time: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp (VRE), extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp (excluding Klebsiella aerogenes) (ESCR-EK), carbapenem-resistant Enterobacterales (CRE), carbapenem-resistant Acinetobacter spp (CRAsp), and multidrug-resistant (MDR) Pseudomonas aeruginosa. This cohort study used data from 2012 to 2022 on inpatient hospitalizations, clinical cultures, and facility-level characteristics. Hospital-months were included in the dynamic cohort if the hospital reported at least 1 culture with microbial growth accompanied by antimicrobial susceptibility testing (AST) results in the month. Data from the PINC-AI and Becton Dickinson Insights databases were used, and cases were defined as incident nonsurveillance cultures yielding an organism of interest with sufficient AST results for a phenotype of interest. Data were collected from January 2012 to December 2022 and analyzed from April 2023 to June 2024. Inpatient hospitalizations with a discharge date in an included hospital month. National annual antimicrobial-resistant cases per 10 000 hospitalizations were obtained using weights based on facility-level characteristics. Cases were defined as community-onset if collected on or before day 3 of hospitalization and hospital-onset if obtained on day 4 or later. This study cohort included 332 to 606 hospitals per year between 2012 to 2022 and 7 158 139 cultures. Antimicrobial-resistant pathogens accounted for an estimated 569 749 (95% CI, 475 949-663 548) cases and 179.6 (95% CI, 163.1-196.1) cases per 10 000 hospitalizations in 2022. Of these cases, 77% (437 657; 95% CI, 364 529-510 785) were community-onset and 23% (132 092; 95% CI, 108 241-155 943) were hospital-onset. MRSA (44% [251 854; 95% CI, 209 558-294 150]) and ESCR-EK (35% [200 884; 95% CI, 163 692-238 077]) made up the largest proportions of total infections in 2022, respectively. Rates of hospital-onset MRSA, VRE, CRE, CRAsp, and MDR P aeruginosa had periods of decline from 2012 to 2019; however, all pathogens experienced an increase in hospital-onset rates in 2020 and 2021. Community-onset ESCR-EK rates increased from 2012 to 2022, while community-onset rates of MRSA, VRE, and MDR P aeruginosa declined. While antimicrobial resistance rates have experienced uneven declines in the US from 2012 to 2022, the burden of resistance remains substantial. These findings suggest that more effective strategies to reduce antimicrobial resistance are needed.

The impact of the coronavirus disease 2019 (COVID-19) pandemic on methicillin-resistant Staphylococcus aureus (MRSA) bacteremia incidence compared with prepandemic trends is unknown. Active laboratory- and population-based surveillance identified incident MRSA blood isolates among surveillance area residents in 6 continuously reporting sites during 2005-2022. Annual incidence per 100 000 census population was stratified by epidemiologic classification (hospital-onset, community-associated, health care-associated community-onset). Joinpoint with Poisson regression was used to determine incidence trend segments and annual percent change (APC; 2005-2019) and predicted incidence (2020-2022). Recent COVID-19 was a positive severe acute respiratory syndrome coronavirus 2 viral test ≤30 days before incident MRSA culture. Overall declines in MRSA bacteremia incidence during 2005-2016 (APC, -7.1; P < .001) reversed during 2016-2019 (APC, +5.9; P < .001). Hospital-onset incidence did not change significantly during 2014-2019 (APC, -1.5; P = .32), but during 2020-2022 it was higher than during 2016-2019 and significantly higher than predicted in 2021. Health care-associated community-onset incidence increased during 2017-2019 (APC, +8.4; P < .001); 2021 incidence was the lowest observed during 2005-2022, although it was not significantly lower than predicted. Community-associated incidence was increasing prepandemic (APC, +8.4; P < .001), but during 2020-2022 it was lower than predicted. During 2020-2022, the proportion of cases with recent COVID-19 was highest among hospital-onset infections (18%-22%); 2021 hospital-onset incidence excluding these cases fell within the predicted range. Previous declines in MRSA bacteremia incidence had ended before the COVID-19 pandemic. During 2020-2022, patients with recent COVID-19 contributed substantially to increases in hospital-onset MRSA bacteremia, suggesting a need for robust infection prevention in this population. Reversal of prepandemic increases in health care-associated community-onset and community-associated infections during the pandemic could be related to COVID-19 mitigation measures.

BACKGROUND:Medicare claims are frequently used to study Clostridioides difficile infection (CDI) epidemiology. However, they lack specimen collection and diagnosis dates to assign location of onset. Algorithms to classify CDI onset location using claims data have been published, but the degree of misclassification is unknown. METHODS:We linked patients with laboratory-confirmed CDI reported to four Emerging Infections Program (EIP) sites from 2016-2021 to Medicare beneficiaries with fee-for-service Part A/B coverage. We calculated sensitivity of ICD-10-CM codes in claims within ±28 days of EIP specimen collection. CDI was categorized as hospital, long-term care facility, or community-onset using three different Medicare claims-based algorithms based on claim type, ICD-10-CM code position, duration of hospitalization, and ICD-10-CM diagnosis code presence-on-admission indicators. We assessed concordance of EIP case classifications, based on chart review and specimen collection date, with claims case classifications using Cohen's kappa statistic. RESULTS:Of 12,671 CDI cases eligible for linkage, 9,032 (71%) were linked to a single, unique Medicare beneficiary. Compared to EIP, sensitivity of CDI ICD-10-CM codes was 81%; codes were more likely to be present for hospitalized patients (93.0%) than those who were not (56.2%). Concordance between EIP and Medicare claims algorithms ranged from 68% to 75%, depending on the algorithm used (κ = 0.56-0.66). CONCLUSION:ICD-10-CM codes in Medicare claims data had high sensitivity compared to laboratory-confirmed CDI reported to EIP. Claims-based epidemiologic classification algorithms had moderate concordance with EIP classification of onset location. Misclassification of CDI onset location using Medicare algorithms may bias findings of claims-based CDI studies.

Abstract Background Microbial cultures are used in clinical care and to track trends in infectious diseases. Changes in culturing practices may affect these trends but have not been thoroughly explored. This analysis examines temporal and facility variability of clinical cultures among a cohort of acute care hospitals in the U.S. from 2012-2021. Methods We used microbiology data from a dynamic cohort of hospitals reporting data to the PINC-AI Healthcare Database from 2012-2021. Surveillance cultures and hospitals with outlier hospital-months were excluded. We defined admission cultures as those collected on or before calendar day 3 of hospitalization and post-admission cultures as those collected after calendar day 3. Admission culture rates were calculated per 1,000 discharges. Post-admission culture rates were calculated per 1,000 patient days. We calculated overall rates as well as rates stratified by specimen source (blood, respiratory, urine, other sterile sites, and other non-sterile sites). To account for multiple blood culture sets, only the first blood culture per patient per day was counted in this analysis. Results From 2012-2021, 361 hospitals were included in our cohort. Admission culture rates remained stable from 2012 through 2019. Admission culturing rates and facility variability increased in 2020 and 2021 (Fig. 1). Post-admission culture rates decreased from 2012 to 2016 and then plateaued; increases in rates and facility variability were noted in 2020 and 2021 (Fig. 2). Admission blood cultures increased over time and admission urine cultures decreased; respiratory and other non-sterile site cultures increased in 2020 and 2021 (Fig. 3). Most types of post-admission cultures declined from 2012-2016; post-admission blood cultures increased between 2016-2021 (Fig. 4). Conclusion Both admission and post-admission cultures increased during the early years of the COVID-19 pandemic, and these increases were driven by respiratory, other non-sterile, and blood cultures (which increased since 2016). Prior to 2020, culturing trends differed by specimen type and timing of culture. Assessing factors that contribute to testing tends and facility variability can inform diagnostic stewardship efforts and increase understanding of how testing changes may impact infection rates. Disclosures All Authors: No reported disclosures

Background:The impact of the coronavirus disease 2019 (COVID-19) pandemic on methicillin-resistant Staphylococcus aureus (MRSA) bacteremia incidence compared with prepandemic trends is unknown. Methods:Active laboratory- and population-based surveillance identified incident MRSA blood isolates among surveillance area residents in 6 continuously reporting sites during 2005-2022. Annual incidence per 100 000 census population was stratified by epidemiologic classification (hospital-onset, community-associated, health care-associated community-onset). Joinpoint with Poisson regression was used to determine incidence trend segments and annual percent change (APC; 2005-2019) and predicted incidence (2020-2022). Recent COVID-19 was a positive severe acute respiratory syndrome coronavirus 2 viral test ≤30 days before incident MRSA culture. Results:Overall declines in MRSA bacteremia incidence during 2005-2016 (APC, -7.1; P < .001) reversed during 2016-2019 (APC, +5.9; P < .001). Hospital-onset incidence did not change significantly during 2014-2019 (APC, -1.5; P = .32), but during 2020-2022 it was higher than during 2016-2019 and significantly higher than predicted in 2021. Health care-associated community-onset incidence increased during 2017-2019 (APC, +8.4; P < .001); 2021 incidence was the lowest observed during 2005-2022, although it was not significantly lower than predicted. Community-associated incidence was increasing prepandemic (APC, +8.4; P < .001), but during 2020-2022 it was lower than predicted. During 2020-2022, the proportion of cases with recent COVID-19 was highest among hospital-onset infections (18%-22%); 2021 hospital-onset incidence excluding these cases fell within the predicted range. Conclusions:Previous declines in MRSA bacteremia incidence had ended before the COVID-19 pandemic. During 2020-2022, patients with recent COVID-19 contributed substantially to increases in hospital-onset MRSA bacteremia, suggesting a need for robust infection prevention in this population. Reversal of prepandemic increases in health care-associated community-onset and community-associated infections during the pandemic could be related to COVID-19 mitigation measures.

Abstract Background Enterococci are common causes of both community-onset (CO) and hospital-onset (HO) infections; vancomycin-resistant enterococci (VRE) are a serious threat. We sought to describe national estimates of Enterococcus faecalis and E. faecium rates and the proportion of cases that were vancomycin-resistant from 2012-2022 Methods We identified a cohort of patients from the PINC AI and BD Research Insights databases with a clinical culture yielding an E. faecalis or E. faecium isolate with accompanying antimicrobial susceptibility testing (AST). Cultures obtained from rectal, perirectal or nasal swabs were excluded. E. faecalis or faecium isolates resistant to vancomycin were considered VRE. Isolates from patients with no culture yielding the same species and vancomycin AST phenotype in the previous 14 days were counted as an incident case. CO cultures were obtained ≤ day 3 of hospitalization; HO cultures were obtained ≥ day 4. We used a raking-procedure to determine weights for extrapolating the number of discharges included in our sample to match the national distribution of discharges, stratified by bed size, U.S. census division, urban/rural designation, and teaching status, for U.S. hospitals included in the American Hospital Association survey. Weighted rates were calculated over time as cases per 10,000 hospitalizations. The proportion of VRE (%R) was calculated as the rate of VRE cases divided by the rate of all cases of that species with an AST result. Results There were 810 unique acute care hospitals from 2012-2022. Weighted estimates resulted in 124,570 E. faecalis and 516,724 E. faecium incident cases nationally. Rates of CO and HO E. faecalis and E. faecium declined from 2012-2018 and increased from 2018-2021 (Figures 1-4). E. faecalis %R for vancomycin remained stable over the study period (CO: 4-5%, HO: 4-6%), while E. faecium %R declined over the study period from 67% to 57% among CO cases, and from 78% to 70% among HO cases. Conclusion Enterococci and VRE rates have increased recently while the proportion of resistant isolates has been stable for E. faecalis and falling for E. faecium. This suggests rate increases may be due to factors affecting all enterococci (e.g., host susceptibility or pathogen factors) rather than VRE specific factors (e.g., vancomycin exposure). Disclosures All Authors: No reported disclosures

Objectives:(1) Explore associations between county minority health social vulnerability index (MH-SVI) and total joint replacement (TJR), and (2) assess associations by individual-level race/ethnicity.Background:An expanded understanding of relevant social determinants of health is essential to inform policies and practices that promote equitable access to hip and knee TJR.Methods:Retrospective cohort study of Medicare enrollees. Centers for Medicare and Medicaid Services claims data were linked with MH-SVI. Multivariable logistic regression models were used to evaluate the odds of TJR according to the MH-SVI quartile in which enrollees resided. A total of 10,471,413 traditional Medicare enrollees in 2018 aged 67 years or older with arthritis. The main outcome was enrollee primary TJR during hospitalization. The main exposure was the MH-SVI (composite and 6 themes) for the county of enrollee residence. Results were stratified by enrollee race/ethnicity.Results:Asian American, Native Hawaiian, or Pacific Islander (AANHPI), Black or African American (Black), and Hispanic enrollees comparatively had 26%-41% lower odds of receiving TJR than White enrollees. Residing in counties within the highest quartile of composite and socioeconomic status vulnerability measures were associated with lower TJR overall and by race/ethnicity. Residing in counties with increased medical vulnerability for Black and White enrollees, housing type and transportation vulnerability for AANHPI and Hispanic enrollees, minority status and language theme for AANHPI enrollees, and household composition vulnerability for White enrollees were also associated with lower TJR.Conclusions:Higher levels of social vulnerability were associated with lower TJR. However, the association varied by individual race/ethnicity. Implementing multisectoral strategies is crucial for ensuring equitable access to care.

BackgroundThe majority of recent estimates on the direct medical cost attributable to hospital-onset infections (HOIs) has focused on device- or procedure-associated HOIs. The attributable costs of HOIs that are not associated with device use or procedures have not been extensively studied.ObjectiveWe developed simulation models of attributable cost for 16 HOIs and estimated the total direct medical cost, including nondevice-related HOIs in the USA for 2011 and 2015.Data and MethodsWe used total discharge costs associated with HOI-related hospitalization from the National Inpatient Sample and applied an analogy costing methodology to develop simulation models of the costs attributable to HOIs. The mean attributable cost estimate from the simulation analysis was then multiplied by previously published estimates of the number of HOIs for 2011 and 2015 to generate national estimates of direct medical costs.ResultsAfter adjusting all estimates to 2017 US dollars, attributable cost estimates for select nondevice-related infections attributable cost estimates ranged from $7661 for ear, eye, nose, throat, and mouth (EENTM) infections to $27,709 for cardiovascular system infections in 2011; and from $8394 for EENTM to $26,445 for central nervous system infections in 2016 (based on 2015 incidence data). The national direct medical costs for all HOIs were $14.6 billion in 2011 and $12.1 billion in 2016. Nondevice- and nonprocedure-associated HOIs comprise approximately 26-28% of total HOI costs.ConclusionResults suggest that nondevice- and nonprocedure-related HOIs result in considerable costs to the healthcare system.

Background: Medicare claims are frequently used to study Clostridioides difficile infection (CDI) epidemiology. Categorizing CDI based on location of onset and potential exposure is critical in understanding transmission patterns and prevention strategies. While claims data are well-suited for identifying prior healthcare utilization exposures, they lack specimen collection and diagnosis dates to assign likely location of onset. Algorithms to classify CDI onset and healthcare association using claims data have been published, but the degree of misclassification is unknown. Methods: We linked patients with laboratory-confirmed CDI reported to four Emerging Infections Program (EIP) sites from 2016-2020 to Medicare beneficiaries using residence, birth date, sex, and hospitalization and/or healthcare exposure dates. Uniquely linked patients with fee-for-service Medicare A/B coverage and complete EIP case report forms were included. Patients with a claims CDI diagnosis code within ±28 days of a positive CDI test reported to EIP were categorized as hospital-onset (HO), long-term care facility onset (LTCFO), or community-onset (CO, either healthcare facility-associated [COHCFA] or community-associated [CA]) using a previously published algorithm based on claim type, ICD-10-CM code position, and duration of hospitalization (if applicable). EIP classifies CDI into these categories using positive specimen collection date and other information from chart review (e.g. admit/discharge dates). We assessed concordance of EIP and claims case classifications using Cohen’s kappa. Results: Of 10,002 eligible EIP-identified CDI cases, 7,064 were linked to a unique beneficiary; 3,451 met Medicare A/B fee-for-service coverage inclusion criteria. Of these, 650 (19%) did not have a claims diagnosis code ±28 days of the EIP specimen collection date (Table); 48% (313/650) of those without a claims diagnosis code were categorized by EIP as CA CDI. Among those with a CDI diagnosis code, concurrence of claims-based and EIP CDI classification was 68% (κ=0.56). Concurrence was highest for HO and lowest for COHCFA CDI. A substantial number of EIP-classified CO CDIs (30%, Figure) were misclassified as HO using the claims-based algorithm; half of these had a primary ICD-10 diagnosis code of sepsis (226/454; 50%). Conclusions: Evidence of CDI in claims data was found for 81% of EIP-reported CDI cases. Medicare classification algorithms concurred with the EIP classification in 68% of cases. Discordance was most common for community-onset CDI patients, many of whom were hospitalized with a primary diagnosis of sepsis. Misclassification of CO-CDI as HO may bias findings of claims-based CDI studies.

In May 2023, the Food and Drug Administration (FDA) licensed Arexvy and Abrysvo vaccines for prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in adults aged >= 60 years. In prelicensure trials, Guillain-Barr & eacute; syndrome (GBS) was identified as a potential safety concern. During August 4, 2023-March 30, 2024, at least 10.6 million adults aged >= 60 years received a recommended RSV vaccine. During May 3, 2023-April 14, 2024, CDC reviewed data reported after RSV vaccination to V -safe, an active U.S. surveillance system that invites enrolled participants to complete web -based surveys, and reports to the Vaccine Adverse Event Reporting System (VAERS), a passive, voluntary surveillance system that accepts adverse event reports from the public, providers, and manufacturers. Findings from V -safe and VAERS were generally consistent with those from trials. Reporting rates of GBS after RSV vaccination in VAERS (5.0 and 1.5 reports per million doses of Abrysvo and Arexvy vaccine administered, respectively) were higher than estimated expected background rates in a vaccinated population. CDC and FDA are conducting population -based surveillance to assess risks for GBS and other adverse events. Findings from these studies will help guide development of Advisory Committee on Immunization Practices recommendations.

Background: Residents of nursing homes remain an epidemiologically important population for COVID-19 prevention efforts, including vaccination. We aim to understand effectiveness of bivalent vaccination for preventing SARS-CoV-2 infections in this population. Methods: We used a retrospective cohort of nursing home residents from November 1, 2022, through March 31, 2023, to identify new SARS-CoV-2 infections. A Cox proportional hazards model was used to estimate hazard ratios comparing residents with a bivalent vaccination compared with residents not up to date with vaccination recommendations. Vaccine effectiveness was estimated as (1 - Hazard Ratio) * 100. Results: Among 6,916 residents residing in 76 nursing homes included in our cohort, 3,211 (46%) received a bivalent vaccine 7 or more days prior to censoring. Adjusted vaccine effectiveness against laboratory confirmed SARS-CoV-2 infection comparing receipt of a bivalent vaccine versus not up to date vaccine status was 29% (95% Confidence interval 18% to 39%). Vaccine effectiveness for receipt of a bivalent vaccine against residents who were unvaccinated or vaccinated more than a year prior was 32% (95% CI: 20% to 42%,) and was 25% compared with residents who were vaccinated with a monovalent vaccine in the past 61-365 days (95% CI:10% to 37%). Conclusions: Bivalent COVID-19 vaccines provided additional protection against SARS-CoV-2 infections in nursing home residents during our study time-period, compared to both no vaccination or vaccination more than a year ago and monovalent vaccination 60 - 365 days prior. Ensuring nursing home residents stay up to date with vaccine recommendations remains a critical tool for COVID-19 prevention efforts.

Background: The 2022 Special Report: COVID-19 U.S. Impact on Antimicrobial Resistance identified continued increases in the rate of extended- spectrum beta-lactamase producing (ESBL) infections in the United States from 2017 through 2020. Using similar data sources and methodology, we examined the trends of species-specific ESBL infections from 2012-2021. Methods: We identified a cohort of patients from the PINC AI and BD Research Insights databases with a clinical culture yielding a Klebsiella pneumoniae or Escherichia coli isolate with accompanying susceptibility testing. E. coli or K. pneumoniae isolates non-susceptible to ceftriaxone, cefotaxime, ceftazidime, or cefepime were considered suggestive of ESBL production. Isolates from patients with no culture yielding the same resistance phenotype of interest in the previous 14 days were counted as an incident case. Community-onset (CO) cultures were obtained ≤ day 3 of hospitalization; hospital-onset (HO) cultures were obtained ≥ day 4. We used a raking procedure to determine weights for extrapolating the number of discharges included in our sample to match the distribution of discharges, stratified by bed size, U.S. census division, urban/rural designation, and teaching status, for U.S. hospitals included in the American Hospital Association survey. We evaluated rates over time due to the changes in number of hospitalizations during the COVID-19 pandemic. Results were stratified by HO and CO, and sterile and non-sterile specimen sources. Results: In 2021, there were 48,936 ESBL K. pneumoniae and 153,112 ESBL E. coli infections among approximately 32 million discharges. Overall, most infections were CO and from non-sterile specimens. From 2012-2021, the rate of ESBL K. pneumoniae increased from 9.54 to 15.28 per 10,000 discharges. ESBL E. coli infections increased from 2012-2020 (30.18 to 51.32 per 10,000 discharges), then declined in 2021 (47.81 per 10,000 discharges) (Table 1, Figure 1). The proportion of non-sterile ESBL E. coli declined from 88% in 2012 to 83% in 2021, and the proportion of non-sterile ESBL K. pneumoniae was 85-87% over the study period (Figure 2). Conclusion: ESBL E. coli and K. pneumoniae infections increased from 2012-2021, although the CO ESBL E. coli rate decreased between 2020 and 2021. Understanding changes in culturing practices over time may provide insights into the increased proportion of ESBL E. coli from sterile sites. Additionally, further investigation into differences in organism trends, particularly in 2021, may inform prevention strategies.

Background: Carbapenem-resistant Enterobacterales (CRE) infections are an urgent public health threat. An estimated 12,700 CRE (including E. coli, Klebsiella spp., and Enterobacter spp.) infections occurred in the United States in 2020. While the estimated incidence of CRE infections has been relatively stable between 2012 and 2020, organism-specific trends, including those for organisms not typically included in CRE surveillance definitions, have not been described. We estimated the annual rate of carbapenem-resistant Enterobacterales infections, disaggregated by organism, from 2012 to 2022. Methods: Data on inpatient hospitalizations from a dynamic cohort of short-term acute care hospitals reporting microbiology data between 2012 and 2022 were obtained from the PINC AI Database and the BD Insights Research Database. We included patients with clinical isolates of E. coli, Enterobacter spp., Klebsiella spp., Citrobacter spp., Serratia marcescens, Proteus mirabilis, and Morganella spp. and sufficient susceptibility results to identify carbapenem resistance. We limited our analysis to incident isolates, defined as a patient’s first isolate of a given organism and carbapenem resistance phenotype in a 14-day period. We calculated the annual rate of carbapenem-resistant infections per 10,000 hospitalizations for each organism. Results: There were 3,018,792 incident isolates from 55.8 million hospitalizations included in the analysis. Overall, 31,226 incident carbapenem-resistant isolates were identified. The rate of carbapenem-resistant infections varied by organism and over time (Table 1). The rate of carbapenem-resistant Klebsiella spp. infections appeared to decline from 3.94 in 2012 to 2.44 infections per 10,000 hospitalizations in 2022. The rate of carbapenem-resistant Enterobacter spp. infections appeared to increase from 1.05 in 2012 to 1.44 infections per 10,000 hospitalizations in 2022. The rate of carbapenem-resistant E. coli infections also appeared to increase, from 0.61 in 2012 to 0.85 infections per 10,000 hospitalizations in 2022. Rates of carbapenem-resistant Proteus mirabilis, Morganella spp., Citrobacter spp., or Serratia marcescens infections were similar in 2022 compared to 2012. Conclusions: Disaggregating data by organism revealed heterogeneous trends, with apparent increases in rates of carbapenem-resistant Enterobacter spp. and E. coli infections and apparent decreases in rates of carbapenem-resistant Klebsiella spp. infections. Organism-specific CRE analyses may provide additional insight into CRE epidemiology.

OBJECTIVE:The 2014 US National Strategy for Combating Antibiotic-Resistant Bacteria (CARB) aimed to reduce inappropriate inpatient antibiotic use by 20% for monitored conditions, such as community-acquired pneumonia (CAP), by 2020. We evaluated annual trends in length of therapy (LOT) in adults hospitalized with uncomplicated CAP from 2013 through 2020. METHODS:We conducted a retrospective cohort study among adults with a primary diagnosis of bacterial or unspecified pneumonia using International Classification of Diseases Ninth and Tenth Revision codes in MarketScan and the Centers for Medicare & Medicaid Services databases. We included patients with length of stay (LOS) of 2-10 days, discharged home with self-care, and not rehospitalized in the 3 days following discharge. We estimated inpatient LOT based on LOS from the PINC AI Healthcare Database. The total LOT was calculated by summing estimated inpatient LOT and actual postdischarge LOT. We examined trends from 2013 to 2020 in patients with total LOT >7 days, which was considered an indicator of likely excessive LOT. RESULTS:There were 44,976 and 400,928 uncomplicated CAP hospitalizations among patients aged 18-64 years and ≥65 years, respectively. From 2013 to 2020, the proportion of patients with total LOT >7 days decreased by 25% (68% to 51%) among patients aged 18-64 years and by 27% (68%-50%) among patients aged ≥65 years. CONCLUSIONS:Although likely excessive LOT for uncomplicated CAP patients decreased since 2013, the proportion of patients treated with LOT >7 days still exceeded 50% in 2020. Antibiotic stewardship programs should continue to pursue interventions to reduce likely excessive LOT for common infections.

Among 9196 hospitalizations involving Pneumocystis pneumonia, those without HIV had higher in-hospital mortality (24.3% vs 10.5%, P < .001) when compared with those with HIV. These findings underscore the continued importance of Pneumocystis pneumonia clinical awareness and the need for comprehensive prophylaxis guidance, particularly for certain patients without HIV who are immunosuppressed.

We conducted a retrospective study to describe antibiotic use among US adults hospitalized with a COVID-19 diagnosis. Despite a decrease in overall antibiotic use, most patients hospitalized with COVID-19 received antibiotics on admission (88.1%) regardless of critical care status, highlighting that more efforts are needed to optimize antibiotic therapy.