Background:We described the changing epidemiology of New Delhi metallo-β-lactamase (NDM)-producing carbapenem-resistant Enterobacterales (CRE) in 10 US sites conducting population-based CRE surveillance during 2018-2023. Methods:A CRE case was defined as the first isolation of Escherichia coli, Enterobacter spp., or Klebsiella spp. resistant to ≥1 carbapenem from a sterile site or urine in a surveillance area resident within a 30-day period. Cases were classified as healthcare-associated or community-associated. Incidence rates were calculated using census data; trends were assessed using the Mann-Kendall test. Multivariable logistic regression was used to compare NDM- and Klebsiella pneumoniae carbapenemase-producing (KPC)-CRE. A subset of isolates underwent whole-genome sequencing. Results:During 2018-2023, CRE incidence increased from 5.34 to 7.65 per 100 000 population (P = .02). NDM-CRE incidence increased from 0.07 to 0.66 per 100 000 population (P = .02); no significant trend was observed for KPC-CRE. Odds of being an NDM-CRE case were increased for community-associated versus healthcare-associated cases (adjusted odds ratio [aOR], 3.2; 95% CI, 1.98-5.17) and for cases aged 0-24 years versus ≥75 years (aOR, 3.99; 95% CI, 1.59-10.02). Genomic analysis showed diversity of sequence types among NDM- versus KPC-CRE. Conclusions:Increases in CRE incidence appear to be driven by NDM-CRE, which are more likely than KPC-CRE to be community-associated. Continued surveillance is recommended to understand changes in epidemiology.

BACKGROUND:Prevalence surveys in U.S. hospitals showed that on any given day, 1 of 25 patients had a health care-associated infection in 2011, as compared with 1 of 31 patients in 2015. We repeated the survey in 2023 to assess changes in the prevalence of such infections. METHODS:Using established methods, 10 Emerging Infections Program (EIP) sites recruited up to 25 hospitals each. Hospitals selected a survey day between May 1 and September 30, 2023. EIP staff reviewed medical records of randomly selected patients to identify health care-associated infections using National Healthcare Safety Network definitions. We described patient and hospital characteristics, compared the prevalence of health care-associated infections in 2023 and 2015, and estimated the national burden of health care-associated infections in 2023. RESULTS:In 2023, of 13,653 patients in 218 hospitals, 355 (2.6%; 95% confidence interval [CI], 2.3 to 2.9) had at least one health care-associated infection, as compared with 394 of 12,299 patients (3.2%; 95% CI, 2.9 to 3.5) in 199 hospitals in 2015. Approximately 60% of the health care-associated infections were not associated with devices or procedures. Among 151 hospitals in both surveys, patients were less likely to have a health care-associated infection in 2023 than in 2015, after adjustment for other factors (risk ratio, 0.73; 95% CI, 0.63 to 0.85). We estimated that there were 518,000 health care-associated infections (95% CI, 494,500 to 542,000) in U.S. hospitals in 2023. CONCLUSIONS:The prevalence of health care-associated infections was lower in 2023 than in 2015, with 1 of 38 patients on any given day having such an infection; however, the burden of health care-associated infections in U.S. hospitals continued to be high. A majority of the health care-associated infections that were identified were not associated with a device or procedure. (Funded by the Emerging Infections Program cooperative agreement from the Centers for Disease Control and Prevention.).

Background:Prevalence surveys in U.S. hospitals in 2011 and 2015 showed that half of inpatients received antimicrobials on the survey day or day before. We repeated the survey in 2023 to assess changes in antimicrobial use (AU). Methods:Ten Emerging Infections Program (EIP) sites recruited up to 25 hospitals each, prioritizing prior participants. EIP staff reviewed medical records of randomly selected inpatients from the survey day morning census and documented AU on the survey day or day before. We compared AU and stewardship characteristics between 2023 and 2015 and used multivariable log-binomial regression to identify factors associated with AU in 2023. Results:Antimicrobial stewardship programs were present in 215/218 hospitals in 2023 (98.6%) compared with 158/199 (79.4%) in 2015. Of 13 653 patients in 2023, 6785 (49.7%) received ≥1 antimicrobial on the survey day or day before. Among 151 hospitals participating in both surveys, overall AU prevalence was similar in 2015 and 2023 (49.2% vs 49.1%), with decreases in neonatal critical care (23.4% to 17.1%) and increases in mother-baby units (24.4% to 32.8%). Fluoroquinolone use declined (9.2% to 2.8%), while third- or fourth-generation cephalosporin use increased (12.3% to 18.6%). In 2023, higher AU was associated with patient factors (medical devices, inpatient location, obesity, 4-17 day hospital stays, and suburban residence) and hospital factors (Northeast and South regions, AU audits). Conclusions:One in two inpatients received an antimicrobial in 2023, similar to 2015. However, changes in AU by inpatient location and antimicrobial class suggest evolving prescribing practices and may inform targeted surveillance and stewardship efforts.

Abstract Background Extraintestinal invasive Escherichia coli (iEC) is a leading cause of sepsis and hospitalization, but US surveillance for iEC has been frequently limited to multidrug-resistant (MDR) strains and hospitalized cohorts. To describe the incidence and clinical characteristics of MDR and non-MDR iEC and inform prevention and vaccine development, CDC’s Emerging Infections Program piloted active population- and laboratory-based surveillance in 9 US sites. Methods Among surveillance area residents ( > 7.3 million people), an incident iEC case was the first isolation of E. coli in a 30-day period from a normally sterile body site (June–August 2023). Demographic, clinical, and laboratory characteristics were assessed by chart review. Annual incidence rates by surveillance area were estimated by multiplying total case number by 4 and used 2022 US census data for denominators. Results Among 1345 iEC cases in 1334 patients, E. coli was isolated from blood in 1223 (90.9%) and from other sterile sites in 122 (9.1%). Median age was 68 years (IQR 55–79); 766 (57.0%) were female. Overall estimated annual crude incidence rate was 74.5 cases per 100,000 population (range by area 51.3–95.6) and was higher for persons aged ≥ 60 vs < 60 years (228.5 vs 30.4). Cases were most commonly community associated (554, 41.2%) or health care associated community onset (633, 47.1%). Most case-patients (1194, 88.8%) had comorbidities; diabetes was most common (457, 34.0%). Of all cases, 762 (56.7%) were associated with urinary tract infection (UTI), 192 (14.3%) with recurrent UTI, and 213 (15.8%) had a urinary catheter in the 2 days before collection of the iEC-defining specimen. Among 1160 hospitalized cases, median length of stay was 5 days (IQR 3–9), 103 (8.9%) died. Of reported E. coli susceptibilities, 144/500 (28.8%) were fluoroquinolone-resistant, 185/1345 (13.8%) were extended-spectrum β-lactamase producing, and 3/1345 (0.2%) carbapenem-resistant. Conclusion The burden of iEC disease was substantial compared to other invasive pathogens and primarily affected older adults. Over half of infections accompanied UTIs and involved hospitalization. Continued surveillance to monitor trends over time, inform vaccine development and evaluation, and advise prevention efforts are needed. Disclosures All Authors: No reported disclosures

Abstract Background Recent advancements in treating Clostridioides difficile infection (CDI) include therapeutics to prevent further recurrence in patients with recurrent CDI (rCDI). However, little is known about which patients are at increased risk for multiple recurrences (≥ 2 rCDI). We sought to identify predictors of multiple rCDI (mrCDI) in adults at the time of presentation with initial CDI (iCDI). Methods The Centers for Disease Control and Prevention’s Emerging Infections Program (EIP) conducts population-based CDI surveillance in 10 U.S. sites. We defined iCDI as a positive C. difficile test during January 2018–August 2019 in a person aged ≥ 18 years with no prior positive test reported to EIP. rCDI was defined as a positive test ≥ 14 days from the previous positive test within 180 days after iCDI. All patients with community-onset iCDI and a random sample of patients with healthcare-facility onset iCDI (i.e., hospital-onset, long-term care facility onset) had full chart reviews. Multiple imputation was performed on missing race/ethnicity. Candidate variables determined a priori to be potentially associated with mrCDI were entered into an initial multivariable logistic regression model. Patients without mrCDI who died within 180 days of their iCDI were excluded from the model. Candidate variables with a p-value < 0.1 in the initial model were included in the final model. Results Of 18,829 patients with iCDI, 882 (4.7%) had mrCDI, ranging from 2 to 5 rCDI per patient in the 180 days following iCDI. Median time between each rCDI was 43 days (interquartile range: 27–65 days). Full charts were reviewed for 435 iCDI patients with mrCDI and 7474 iCDI patients without mrCDI. Characteristics of patients with and without mrCDI are shown in Table 1. In multivariable analysis, age ≥ 65 years, recent hospitalization, chronic hemodialysis, and recent nitrofurantoin use were significantly associated with mrCDI (Table 2). Conclusion Patients with iCDI who are older, on hemodialysis, or had recent hospitalization or nitrofurantoin use may be at increased risk of mrCDI and may benefit from early use of adjunctive therapy to prevent mrCDI. If confirmed, these findings would aid in clinical decision making. Disclosures Ghinwa Dumyati, MD, Pfizer: Grant/Research Support

BACKGROUND:Understanding the epidemiology of carbapenem-resistant A. baumannii complex (CRAB) and the patients impacted is an important step toward informing better infection prevention and control practices and improving public health response. METHODS:Active, population-based surveillance was conducted for CRAB in 9 U.S. sites from January 1 to December 31, 2019. Medical records were reviewed, isolates were collected and characterized including antimicrobial susceptibility testing and whole genome sequencing. RESULTS:Among 136 incident cases in 2019, 66 isolates were collected and characterized; 56.5% were from cases who were male, 54.5% were from persons of Black or African American race with non-Hispanic ethnicity, and the median age was 63.5 years. Most isolates, 77.2%, were isolated from urine, and 50.0% were collected in the outpatient setting; 72.7% of isolates harbored an acquired carbapenemase gene (aCP), predominantly blaOXA-23 or blaOXA-24/40; however, an isolate with blaNDM was identified. The antimicrobial agent with the most in vitro activity was cefiderocol (96.9% of isolates were susceptible). CONCLUSIONS:Our surveillance found that CRAB isolates in the U.S. commonly harbor an aCP, have an antimicrobial susceptibility profile that is defined as difficult-to-treat resistance, and epidemiologically are similar regardless of the presence of an aCP.

We conducted surveillance for carbapenem-resistant Enterobacterales (CRE) during 2016-2020 at 10 US sites and extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) during 2019-2020 at 6 US sites. Among 159 CRE cases in children (median age 5 years), CRE was isolated from urine for 131 (82.4%) and blood from 20 (12.6%). Annual CRE incidence rate (cases/100,000 population) was 0.47-0.87. Among 207 ESBLE cases in children (median age 6 years), ESBL-E was isolated from urine of 196 (94.7%) and blood of 8 (3.9%). Annual ESBL-E incidence rate was 26.5 in 2019 and 19.63 in 2020. CRE and ESBL-E rates were >2-fold higher among infants than other age groups. Most CRE and ES- BL-E cases were healthcare-associated community-onset (68 [43.0%] for CRE vs. 40 [23.7%] for ESBL-E) or community-associated (43 [27.2%] for CRE vs. 109 [64.5%] for ESBL-E). Programs to detect, prevent, and treat multidrug-resistant infections must include pediatric populations (particularly the youngest) and outpatient settings.

Background: Understanding characteristics of healthcare personnel (HCP) with SARS-CoV-2 infection supports the development and prioritization of interventions to protect this important workforce. We report detailed characteristics of HCP who tested positive for SARS-CoV-2 from April 20, 2020 through December 31, 2021.Methods: CDC collaborated with Emerging Infections Program sites in 10 states to interview HCP with SARS-CoV-2 infection (case-HCP) about their demographics, underlying medical conditions, healthcare roles, exposures, personal protective equipment (PPE) use, and COVID-19 vaccination status. We grouped case-HCP by healthcare role. To describe residential social vulnerability, we merged geocoded HCP residential addresses with CDC/ATSDR Social Vulnerability Index (SVI) values at the census tract level. We defined highest and lowest SVI quartiles as high and low social vulnerability, respectively.Results: Our analysis included 7,531 case-HCP. Most case-HCP with roles as certified nursing assistant (CNA) (444, 61.3%), medical assistant (252, 65.3%), or home healthcare worker (HHW) (225, 59.5%) reported their race and ethnicity as either non-Hispanic Black or Hispanic. More than one third of HHWs (166, 45.2%), CNAs (283, 41.7%), and medical assistants (138, 37.9%) reported a residential address in the high social vulnerability category. The proportion of case-HCP who reported using recommended PPE at all times when caring for patients with COVID-19 was lowest among HHWs compared with other roles.Conclusions: To mitigate SARS-CoV-2 infection risk in healthcare settings, infection prevention, and control interventions should be specific to HCP roles and educational backgrounds. Additional interventions are needed to address high social vulnerability among HHWs, CNAs, and medical assistants.

Background: Bivalent mRNA vaccines were recommended since September 2022. However, coverage with a recent vaccine dose has been limited, and there are few robust estimates of bivalent VE against symptomatic SARS-CoV-2 infection (COVID-19). We estimated VE of a bivalent mRNA vaccine dose against COVID-19 among eligible U.S. healthcare personnel who had previously received monovalent mRNA vaccine doses. Methods: We conducted a case-control study in 22 U.S. states, and enrolled healthcare personnel with COVID-19 (case-participants) or without COVID-19 (control-participants) during September 2022-May 2023. Participants were considered eligible for a bivalent mRNA dose if they had received 2-4 monovalent (ancestral-strain) mRNA vaccine doses, and were >= 67 days after the most recent vaccine dose. We estimated VE of a bivalent mRNA dose using conditional logistic regression, accounting for matching by region and four-week calendar period. We adjusted estimates for age group, sex, race and ethnicity, educational level, underlying health conditions,

We conducted a single-center study at a free community testing site in Baltimore City to assess the accuracy of self-performed rapid antigen tests (RATs) for COVID-19. Self-administered BinaxNOW RATs were compared with clinician-performed RATs and against a reference lab molecular testing as the gold standard. Of the 953 participants, 14.9% were positive for SARS- CoV-2 as determined by RT-PCR. The sensitivity and specificity were similar for both self- and clinician-performed RATs (sensitivity: 83.9% vs 88.2%, P = 0.40; specificity: 99.8% vs 99.6%, P = 0.6). Subgroup comparisons based on age and race yielded similar results. Notably, 5.2% (95% CI: 1.5% to 9.5%) of positive results were potentially missed due to participant misinterpretation of the self-test card. However, the false-positive rate for RATs was reassuringly comparable in accuracy to clinician-administered tests. These findings hold significant implications for physicians prescribing treatment based on patient-reported, self-administered positive test results. Our study provides robust evidence supporting the reliability and utility of patient-performed RATs, underscoring their comparable accuracy to clinician-performed RATs, and endorsing their continued use in managing COVID-19. Further studies using other rapid antigen test brands are warranted.IMPORTANCEAccurate and accessible COVID-19 testing is crucial for effective disease control and management. A recent single-center study conducted in Baltimore City examined the reliability of self-performed rapid antigen tests (RATs) for COVID-19. The study found that self-administered RATs yielded similar sensitivity and specificity to clinician-performed tests, demonstrating their comparable accuracy. These findings hold significant implications for physicians relying on patient-reported positive test results for treatment decisions. The study provides robust evidence supporting the reliability and utility of patient-performed RATs, endorsing their continued use in managing COVID-19. Furthermore, the study highlights the need for further research using different rapid antigen test brands to enhance generalizability. Ensuring affordable and widespread access to self-tests is crucial, particularly in preparation for future respiratory virus seasons and potential waves of reinfection of SARS-CoV-2 variants such as the Omicron variant.

Background Protection against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (coronavirus disease 2019 [COVID-19]) can limit transmission and the risk of post-COVID conditions, and is particularly important among healthcare personnel. However, lower vaccine effectiveness (VE) has been reported since predominance of the Omicron SARS-CoV-2 variant. Methods We evaluated the VE of a monovalent messenger RNA (mRNA) booster dose against COVID-19 from October 2021 to June 2022 among US healthcare personnel. After matching case-participants with COVID-19 to control-participants by 2-week period and site, we used conditional logistic regression to estimate the VE of a booster dose compared with completing only 2 mRNA doses >150 days previously, adjusted for multiple covariates. Results Among 3279 case-participants and 3998 control-participants who had completed 2 mRNA doses, we estimated that the VE of a booster dose against COVID-19 declined from 86% (95% confidence interval, 81%-90%) during Delta predominance to 65% (58%-70%) during Omicron predominance. During Omicron predominance, VE declined from 73% (95% confidence interval, 67%-79%) 14-60 days after the booster dose, to 32% (4%-52%) ≥120 days after a booster dose. We found that VE was similar by age group, presence of underlying health conditions, and pregnancy status on the test date, as well as among immunocompromised participants. Conclusions A booster dose conferred substantial protection against COVID-19 among healthcare personnel. However, VE was lower during Omicron predominance, and waning effectiveness was observed 4 months after booster dose receipt during this period. Our findings support recommendations to stay up to date on recommended doses of COVID-19 vaccines for all those eligible.

Background: The Centers for Disease Control and Prevention’s Emerging Infections Program conducts active laboratory- and population-based surveillance for carbapenem-resistant Enterobacterales (CRE) and extended spectrum beta-lactamase-producing Enterobacterales (ESBL-E). To better understand the U.S. epidemiology of these organisms among children, we determined the incidence of pediatric CRE and ESBL-E cases and described their clinical characteristics. Methods: Surveillance was conducted among children <18 years of age for CRE from 2016–2020 in 10 sites, and for ESBL-E from 2019–2020 in 6 sites. Among catchment-area residents, an incident CRE case was defined as the first isolation of Escherichia coli, Enterobacter cloacae complex, Klebsiella aerogenes, K. oxytoca, or K. pneumoniae in a 30-day period resistant to ≥1 carbapenem from a normally sterile site or urine. An incident ESBL-E case was defined as the first isolation of E. coli, K. pneumoniae, or K. oxytoca in a 30-day period resistant to any third-generation cephalosporin and non-resistant to all carbapenems from a normally sterile site or urine. Case records were reviewed. Results: Among 159 CRE cases, 131 (82.9%) were isolated from urine and 19 (12.0%) from blood; median age was 5 years (IQR 1–10) and 94 (59.1%) were female. Combined CRE incidence rate per 100,000 population by year ranged from 0.47 to 0.87. Among 207 ESBL-E cases, 160 (94.7%) were isolated from urine and 6 (3.6%) from blood; median age was 6 years (IQR 2–15) and 165 (79.7%) were female. Annual ESBL incidence rate per 100,000 population was 26.5 in 2019 and 19.63 in 2020. Incidence rates of CRE and ESBL-E were >2-fold higher in infants (children <1 year) than other age groups. Among those with data available, CRE cases were more likely than ESBL-E cases to have underlying conditions (99/158 [62.7%] versus 59/169 [34.9%], P<0.0001), prior healthcare exposures (74/158 [46.8%] versus 38/169 [22.5%], P<0.0001), and be hospitalized for any reason around time of their culture collection (75/158 [47.5%] versus 38/169 [22.5%], P<0.0001); median duration of admission was 18 days [IQR 3–103] for CRE versus 10 days [IQR 4–43] for ESBL-E. Urinary tract infection was the most frequent infection for CRE (89/158 [56.3%]) and ESBL-E (125/169 [74.0%]) cases. Conclusion: CRE infections occurred less frequently than ESBL-infections in U.S. children but were more often associated with healthcare risk factors and hospitalization. Infants had highest incidence of CRE and ESBL-E. Continued surveillance, infection prevention and control efforts, and antibiotic stewardship outside and within pediatric care are neededDisclosure: None

Background: Carbapenem-resistant Enterobacterales (CRE) are usually healthcare-associated but are also emerging in the community. Methods: Active, population-based surveillance was conducted to identify case-patients with cultures positive for Enterobacterales not susceptible to a carbapenem (excluding ertapenem) and resistant to all thirdgeneration cephalosporins tested at 8 US sites from January 2012 to December 2015. Medical records were used to classify cases as health care-associated, or as community-associated (CA) if a patient had no known health care risk factors and a culture was collected <3 days after hospital admission. Enterobacterales isolates from selected cases were submitted to CDC for whole genome sequencing. Results: We identified 1499 CRE cases in 1194 case-patients; 149 cases (10%) in 139 case-patients were CA. The incidence of CRE cases per 100,000 population was 2.96 (95% CI: 2.81, 3.11) overall and 0.29 (95% CI: 0.25, 0.35) for CA-CRE. Most CA-CRE cases were in White persons (73%), females (84%) and identified from urine cultures (98%). Among the 12 sequenced CA-CRE isolates, 5 (42%) harbored a carbapenemase gene. Conclusions: Ten percent of CRE cases were CA; some isolates from CA-CRE cases harbored carbapenemase genes. Continued CRE surveillance in the community is critical to monitor emergence outside of traditional health care settings.

Abstract Background Preventing CRE spread is a U.S. public health priority. We described changes in 2016─2020 CRE incidence rates in 7 U.S. sites that conduct population-based CRE surveillance for the Centers for Disease Control and Prevention’s Emerging Infections Program. Methods An incident CRE case from 2016 onwards was defined as the 1st 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 to classify cases as hospital-onset (HO) if the culture was obtained >3 days after hospital admission; healthcare-associated, community-onset (HACO) if the culture was obtained in a non-hospital setting or < 3 days after hospital admission in a person with healthcare exposures in the prior year; and community-associated (CA) if there were no healthcare risk factors. 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 (RR) and 95% confidence intervals (CI). We also repeated the analysis using a pre-2016 CRE surveillance case definition that was more specific for carbapenemase-producing CRE and required carbapenem nonsusceptibility (excluding ertapenem) and third-generation cephalosporin resistance. Results Of 4996 CRE cases, 62% were HACO, 25% 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 (Figure 1). Compared to 2016, the adjusted overall CRE incidence rate declined since 2018, with a decrease of 24% (RR 0.76; 95% CI: 0.70−0.83) in 2020 (Figure 2). HACO and CA CRE rates significantly decreased in 2020, but the HO rate did not. Similar trends were seen using the other case definition, except the decline in CA CRE rate since 2016 was not significant (Figure 3).Figure 1.Crude CRE incidence rates, overall and by epidemiologic class, 2016─2020**Current CRE surveillance case definition (from 2016 onwards) applied to all yearsFigure 2.Adjusted rate ratios with 95% confidence intervals comparing annual 2017-2020 CRE incidence rates to the 2016 CRE incidence rate, using the current surveillance case definition* * Current CRE surveillance case definition (from 2016 onwards) applied to all years starting in 2016Figure 3.Adjusted rate ratios with 95% confidence intervals comparing annual 2017-2020 CRE incidence rates to the 2016 CRE incidence rate, using pre-2016 surveillance case definition* * Pre-2016 CRE surveillance case definition applied to all years starting in 2016 Conclusion Adjusted CRE incidence rates declined from 2016 to 2020 using current and prior case definitions but changes over time varied by epidemiologic class. Continued surveillance and effective control strategies are needed to prevent CRE in all settings. Disclosures Ghinwa Dumyati, MD, Pfizer: Grant/Research Support Rebecca Tsay, MPH, CDC: Grant/Research Support

Background We described changes in 20162020 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 20162020 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. From 2016 to 2020, the adjusted overall incidence rate of carbapenem-resistant Enterobacterales (CRE) across 7 US sites declined; however, changes over time varied by epidemiologic class.

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.

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.

Abstract Background Reports have shown increases in carbapenem-resistant Acinetobacter baumannii complex (CRAB) infections during the COVID-19 pandemic. To describe the effect of SARS-CoV-2 (SC2) infection on CRAB infection epidemiology, we analyzed data from the Centers for Disease Control and Prevention’s Emerging Infections Program (EIP) population-based CRAB surveillance in 9 U.S. sites. Methods: In 2020–22, among surveillance-area residents, an incident CRAB case was defined as the 1st isolation of A. baumannii complex resistant to ≥1 carbapenem (excluding ertapenem) from a normally sterile site or urine (or lower respiratory tract or wound, as of 2021) in a 30-day period. We included cases that underwent chart review. Cases with a culture collected ≥3 days after hospitalization were considered hospital-onset (HO); all others were community-onset (CO). Cases with a SC2+ test ≤14 days before the incident CRAB culture were compared to other CRAB cases. Results Of 406 CRAB cases representing 344 patients, 26 (6%) cases in 24 patients were SC2+. SC2+ case-patients were more likely to be female than other CRAB case-patients (58% vs 34%, p=0.02); there were no significant differences in race/ethnicity or age distribution. SC2+ cases were more likely to be obese (42% vs. 23%, p=0.03), have bacteremia (23% vs. 10%, p=0.05), and to have died (39% vs. 16%, p=0.003). SC2+ cases were also more likely to require hospitalization (100% vs. 75%, p=0.005) and have HO CRAB (58% vs 29%, p=0.003). Median hospital length of stay was longer in SC2+ cases (19 days, interquartile range [IQR] 8–30) than in other CRAB cases (14 days, IQR 7–26, p=0.42), but there were no significant differences in the percentages with intensive care unit stays or mechanical ventilation in the 7 days before CRAB culture. Culture sources and infection types in SC2+ cases vs. other CRAB cases are shown in the Table. Conclusion A small minority of CRAB patients were infected with SC2+ in the 14 days before CRAB infection but these patients had epidemiological and clinical features that were distinct from other CRAB patients, including higher mortality. Infection control and clinical measures are needed to protect SC2+ patients from secondary bacterial infection and mitigate poor outcomes in those with SC2 and CRAB infection. Disclosures Ghinwa Dumyati, MD, Pfizer: Grant/Research Support Rebecca Tsay, MPH, CDC: Grant/Research Support

Abstract Background While many Healthcare Associated Infection (HAI) rates increased during the pandemic, inpatient C. difficile infection (CDI) rates declined. We compared pre-pandemic (2018-2019) to interpandemic (2020-2021) data, using Maryland’s population-based surveillance data collected through the Emerging Infections Program’s CDI HAIC project, to quantify the impact of COVID-19 on decreases in CDI within different epidemiologic classes (epi classes): HCFO, CO-HCFA, CA (Tables 1 & 2).Table 1.Epidemiologic class definitions for Clostridioides difficile incident (CDI) case classifications determined by the Emerging Infection Program’s HAIC project.Table 2.Chi-square crosstabulation of Epidemiologic class Clostridioides difficile incident (CDI) case counts observed and expected pre- and interpandemic. Note: the turquoise-colored text is the expected chi-square case counts while the black text is the observed case counts. Methods Using logistic regression, we examined changes in epi class, prior antibiotic use, and basic demographics. We used crosstabulation chi-square analysis to determine proportional differences in case characteristics, pre- and interpandemic. All analyses were conducted using R version 4.2.2.Table 3.Three independent logistic regression models to determine if epidemiologic case classification is dependent on period of CDI case (Model: Interpandemic = HCFO, Interpandemic = HCFO-LTCF (HCFO-Hospital Ref.), Interpandemic = CA, Interpandemic = CO-HCFA). Results Between 2018-2021, we identified 3,822 CDI cases: 1,142 HCFO; 771 CO-HCFA; and 1,898 CA and 11 with incomplete data. Interpandemic cases were 24% less likely to be CA and 31% more likely to be CO-HCFA (Table 3, p< 0.001) than pre-pandemic cases. Though cases were 13% more likely to be classified HCFO, this increase was not significant between periods (Table 3, p=0.09). However, differences were identified between HCFO-LTCF and HCFO-Hospital where HCFO-LTCF cases were 26% less likely interpandemic than HCFO-Hospital cases (Table 4, p< 0.05; Table 3, p=0.04; respectively). Antibiotic use ≤12 weeks prior to collection did not change significantly (Table 5, p=0.7). All-cause hospital admission was 27% less likely interpandemic (p< 0.05). Though our catchment area is predominately White, Black/African American case counts increased while case counts in all other races declined and no differences were observed between sexes (Table 6, p< 0.001; Table 7, p=0.3; respectively).Table 4.Chi-square crosstabulation of HCFO Epidemiologic class Clostridioides difficile incident (CDI) case counts observed and expected pre- and interpandemic to determine where within HCFO classification between periods declines in CDI were more observed. Note: Not all HCFO designated cases are included ONLY those that were in a LTCF or Hospital 3 days prior to CDI collection date. Also, the turquoise-colored text is the expected chi-square case counts while the black text is the observed case counts.Table 5.Chi-square crosstabulation comparing CDI case counts with Antibiotic Use 12 weeks prior to C. difficile culture collection date pre-pandemic and interpandemic. Note: the turquoise-colored text is the expected chi-square case counts while the black text is the observed case counts.Table 6.Chi-square crosstabulation comparing CDI case counts of Race pre-pandemic and interpandemic. Maryland’s CDI cases are predominately White/Caucasian with the Black/African American group as the second highest racial group for our surveillance site. Comparing these two groups between these time periods is important to identify the total decline of CDI cases interpandemic. Further investigations should be conducted to better understand why this minority group’s CDI case counts increased during the COVID-19 Pandemic while all others declined. Note: the turquoise-colored text is the expected chi-square case counts while the black text is the observed case counts. Conclusion Overall CDI case counts declined during the COVID-19 pandemic across all epi classes. The rate of decline of CA was greater than the decrease in CO-HCFA cases. HCFO-LTCF cases declined more than HCFO-Hospital cases. Unexplained case rate differences between races raise health equity concerns needing exploration. Further investigation may determine whether changes in healthcare seeking behavior, changes in infection prevention methods in LTCFs, local COVID-19 restrictions, or other factors may have impacted CDI rates.Table 7.Chi-square crosstabulation comparing CDI case counts of Sex pre-pandemic and interpandemic. Note: the turquoise-colored text is the expected chi-square case counts while the black text is the observed case counts. Disclosures All Authors: No reported disclosures

Background: Healthcare facilities have experienced many challenges during the COVID-19 pandemic, including limited personal protective equipment (PPE) supplies. Healthcare personnel (HCP) rely on PPE, vaccines, and other infection control measures to prevent SARS-CoV-2 infections. We describe PPE concerns reported by HCP who had close contact with COVID-19 patients in the workplace and tested positive for SARS-CoV-2. Method: The CDC collaborated with Emerging Infections Program (EIP) sites in 10 states to conduct surveillance for SARS-CoV-2 infections in HCP. EIP staff interviewed HCP with positive SARS-CoV-2 viral tests (ie, cases) to collect data on demographics, healthcare roles, exposures, PPE use, and concerns about their PPE use during COVID-19 patient care in the 14 days before the HCP’s SARS-CoV-2 positive test. PPE concerns were qualitatively coded as being related to supply (eg, low quality, shortages); use (eg, extended use, reuse, lack of fit test); or facility policy (eg, lack of guidance). We calculated and compared the percentages of cases reporting each concern type during the initial phase of the pandemic (April–May 2020), during the first US peak of daily COVID-19 cases (June–August 2020), and during the second US peak (September 2020–January 2021). We compared percentages using mid-P or Fisher exact tests (α = 0.05). Results: Among 1,998 HCP cases occurring during April 2020–January 2021 who had close contact with COVID-19 patients, 613 (30.7%) reported ≥1 PPE concern (Table 1). The percentage of cases reporting supply or use concerns was higher during the first peak period than the second peak period (supply concerns: 12.5% vs 7.5%; use concerns: 25.5% vs 18.2%; p Conclusions: Although lower percentages of HCP cases overall reported PPE concerns after the first US peak, our results highlight the importance of developing capacity to produce and distribute PPE during times of increased demand. The difference we observed among selected groups of cases may indicate that PPE access and use were more challenging for some, such as nonphysicians and nursing home HCP. These findings underscore the need to ensure that PPE is accessible and used correctly by HCP for whom use is recommended.Funding: NoneDisclosures: None