Dante Cicchetti’s earliest work, his studies of social-emotional development in infants and children with Down syndrome, set the stage for the emergence of the larger field of developmental psychopathology. By applying basic developmental principles, methodologies, and questions to the study of persons with Down syndrome, Dante took on the challenge of searching for patterns in atypical development. In doing so, he extended traditional developmental theory and introduced a more “liberal” approach that both continues to guide developmentally based research with persons with neurodevelopmental conditions (NDCs), including Down syndrome. We highlight five themes from Dante’s work: (1) appreciating the importance of developmental level; (2) prioritizing the organization of development; (3) examining whether developmental factors work similarly in those with known genetic conditions; (4) rethinking narratives about ways of being; and (5) examining the influence of multiple levels of the environment on the individual’s functioning. We highlight ways that these essential lessons anticipated present-day research with persons with a variety of NDCs, including Down syndrome, other genetic syndromes associated with intellectual disability, and autism. We conclude with visions to the future for research with these populations as well as for the field of developmental psychopathology more generally.

The role of memory in supporting adolescents' sense of place and past is not well understood, but older adults offer a wealth of life stories and wisdom that they can share with younger generations. This in-depth pilot study positioned Australian high school students as oral historians to interview older Australians about their lives. Oral historian training and materials were provided, and pre- and post-intervention measures of adolescents' sense of everyday Australian history, well-being, and social connection were collected for an intervention school group (n = 17) and a waitlist control school group (n = 12). In-depth supplementary memory and well-being data were also collected for six participating older adults. In the intervention condition, scaffolded memory interviews took place during weekly aged care visits across one school term and were followed by an intergenerational celebration and memory book presentation. As hypothesised, older adults imbued their stories with life lessons for adolescents. Although no quantitative changes in participants' well-being emerged, qualitative data revealed the emergence of rich interpersonal relationships and bonding between adolescents and older adults. There were also benefits of the programme for older adults' reports of generativity and adolescents' understanding of everyday Australian history. The findings demonstrate the social and academic benefits of scaffolded intergenerational memory conversations and represent a scalable educational model and materials with downstream community benefits.

The trend of global cooling across the Cenozoic transformed the North American landscape from closed forest to more open grasslands, resulting in dietary adaptations in herbivores in response to shifting resources. In contrast, the material properties of the predator food source (muscle, skin, and bone) have remained constant over this transition, suggesting a corresponding lack of change in predator dietary adaptations. We investigated the North American mammalian predator fossil record using a tooth-shape metric and body mass, predicting that the former would exhibit stability. Instead, we found that mean molar morphology became more blade-like, with our tooth-shape metric sharply increasing in the late Eocene and remaining high from the Oligocene onward. Subsequent tests in extant carnivorans reveal taxa with more bladelike teeth are prevalent in more open environments. Our results reveal an unexpected functional shift among North American predators in response to large-scale environmental changes across the Cenozoic.

On October 7, 2023, somewhere around 1,500-3,000 terrorists invaded southern Israel killing 1,200 people, injuring 1,455, and taking 239 as hostages resulting in the largest mass-casualty event (MCE) in the country’s history. Most of the victims were civilians who suffered from complex injuries including high-velocity gunshot wounds, blast injuries from rocket-propelled grenades, and burns. Many would later require complex surgeries by all disciplines including general surgeons, vascular surgeons, orthopedists, neurosurgeons, cardiothoracic surgeons, otolaryngologists, oral maxillofacial surgeons, and plastic surgeons. Magen David Adom (MDA) is Israel’s National Emergency Prehospital Medical Organization and a member of the International Red Cross. While there are also private and non-profit ambulance services in Israel, the Ministry of Health has mandated MDA with the charge of managing an MCE. For this event, MDA incorporated a five-part strategy in this mega MCE: (1) extricating victims from areas under fire by bulletproof ambulances, (2) establishing casualty treatment stations in safe areas, (3) ambulance transport from the casualty treatment stations to hospitals, (4) ambulance transport of casualties from safe areas to hospitals, and (5) helicopter transport of victims to hospitals. This is the first time that MDA has responded to a mega MCE of this magnitude and lessons are continually being learned.

Background: Methicillin-resistant S. aureus (MRSA) is known to cause frequent and severe infections in community living centers, potentially resulting in significant mortality for elderly patients. More research is needed to understand how to utilize genomic and epidemiological data to understand characteristics that may lead to increased transmission. We hypothesized that combining genomic and epidemiological information to sample patients and their environments during long-term stays, we will be able to capture a diverse set of MRSA strains. Method: This work included genome sequencing of patient and environmental samples from 11 patients within the VA Ann Arbor Healthcare System from May 4, 2021- November 16, 2022. All 11 patients tested positive for MRSA during their stay (mean days = 31). Patient and environmental samples were taken throughout their stays, screened for MRSA, and whole-genome sequenced. Single nucleotide variants (SNVs) were identified by mapping reads and calling variants against strain-specific reference genomes. We used ape v5.6-2 in R v4.2.2 to analyze and infer evolution, acquisition, and transmission events based on pairwise SNV distances. Genomic clusters were determined using stats v3.6.2, with a SNV distance threshold of 20. Result: Samples that were collected from patient bodily sites were able to reveal 20 distinct genomic clusters of MRSA (patient hands: n = 10, nares: n = 7, groin: n = 3). Environmental samples from patient environments also revealed distinct genomic MRSA clusters (tv remote: n = 9, toilet seat and bed rail: n = 6, table top, bed control, and call button: n = 5, bed curtain: n = 4, pulse ox = 2, cell phone, tray, pulse ox, mat, body hoist wrap, and bed: n = 1). Conclusion: The identification of various genomic clusters from patients and their environmental reservoirs suggests intrahost variation that can only be captured by using a more holistic approach of integrating epidemiology and genomic sequencing. Developing studies that incorporate genomic data, various environmental sources, and multiple isolates over time within community living centers can increase our understanding of strains that are more likely to transmit, survive on living and non-living surfaces and therefore lead to improved recommendation for infection prevention interventions and drivers of endemicity.

Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix

Background: The molecular and epidemiological landscape of C. difficile infection (CDI) has evolved markedly in the last decade; however, limited information is available contrasting differences between adult and pediatric populations. We describe a multicenter study evaluating healthcare-associated (HA) and community-associated (CA) adult and pediatric-CDI identified in the Canadian Nosocomial Infection Surveillance Program (CNISP) network from 2015 to 2022. Methods: Hospitalized patients with CDI were identified from up to 84 hospitals between 2015–2022 using standardized case definitions. Cases were confirmed by PCR, cultured, and further characterized using ribotyping and E-test. We used two-tailed tests for significance (p≤0.05). Results: Of 30,817 cases reported, 29,245 were adult cases [HA-CDI (73.2%), CA-CDI (26.8%)] and 1,572 were pediatric cases [HA-CDI (77.7%), CA-CDI (22.3%)]. From 2015 to 2022, HA-CDI rates decreased 19.7% (p=0.007) and 29.4% (p=0.004) in adult and pediatric populations, respectively (Figure 1). CA-CDI rates remained relatively stable in the adult population (p=0.797), while decreasing 60.7% in the pediatric population (p=0.013). Median ages of adult and pediatric patients were 70 (interquartile range (IQR), 58–80) and seven (IQR, 3–13) years, respectively. Thirty-day all-cause mortality was significantly higher among adult vs. Pediatric CDI patients (11.0% vs 1.4%, p < 0.0001). No significant differences in other severe outcomes were found. Ribotyping and susceptibility data were available for 4,620 samples: 3,558 adult (77.0%) and 1,062 pediatric (23.0%). The predominant adult and pediatric ribotypes (RT) were 106 (12.2/16.2%), 027 (11.4/3.2%), and 014 (8.8/8.2%). Overall, RT027 prevalence significantly decreased from 17.9% in 2015 to 3.2% in 2022 (p=0.003), while RT106 increased from 8.5% to 14.4%. Resistance rates among adult and pediatric isolates were similar for all antimicrobials tested except moxifloxacin (16.2% vs. 6.2%, p < 0.0001, respectively). Adult moxifloxacin resistance decreased from 30% to 6.3% from 2015 to 2022 (p=0.006). Adults with moxifloxacin-resistant CDI were older (median: 74 vs. 69 years, p < 0.001) and had higher thirty-day all-cause mortality (13% vs. 9.8%, p=0.041) and recurrence (10% vs. 5.7%, p < 0.001) compared to those with moxifloxacin non-resistant CDI, while these trends were not observed in pediatric patients. Among RT027 strains, moxifloxacin resistance decreased from 91.0% in 2015 to 7.1% in 2022. There was one metronidazole-resistant pediatric sample in 2018 and no resistance to vancomycin or tigecycline in either population. Conclusion: We have found differences in the epidemiological and molecular characteristics of adult and pediatric CDI, with higher thirty-day all-cause mortality among adults. Overall, RT106 has replaced RT027 as the predominant ribotype with a concomitant decrease in fluoroquinolone resistance.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) and Pseudomonas aeruginosa (CRPA) are drug-resistant pathogens causing high mortality rates with limited treatment options. Understanding the incidence of these organisms and laboratory knowledge of testing protocols is important for controlling their spread in healthcare settings. This project assessed how often Veterans Affairs (VA) healthcare facilities identify CRAB and CRPA and testing practices used. Method: An electronic survey was distributed to 126 VA acute care facilities September-October 2023. The survey focused on CRAB and CRPA incidence, testing and identification, and availability of testing resources. Responses were analyzed by complexity of patients treated at VA facilities (High, Medium, Low) using Fisher’s exact tests. Result: 77 (61.1%) facilities responded, most in urban settings (85.4%). Most respondents were lead or supervisory laboratory technologists (84.2%) from high complexity facilities (69.0%). Few facilities detected CRAB ≥ once/month (4.4%), with most reporting that they have not seen CRAB at their facility (55.0%). CRPA was detected more frequently: 19% of facilities with isolates ≥ once/month, 29.2% a few times per year, and 26.9% reporting had not seen the organism. No differences in CRAB or CRPA incidence was found by facility complexity. Nearly all facilities, regardless of complexity, utilize the recommended methods of MIC or disk diffusion to identify CRAB or CRPA (91.9%) with remaining facilities reporting that testing is done off-site (7.8%). More high complexity facilities perform on-site testing compared to low complexity facilities (32.0% vs 2.7%, p=0.04). 83% of laboratories test for Carbapenemase production, with one-fourth using off-site reference labs. One-fourth of facilities perform additional antibiotic susceptibility testing for CRAB and CRPA isolates, most of which test for susceptibility to combination antibiotics; no differences between complexities were found. Agreement that sufficient laboratory and equipment resources were available was higher in high complexity than in medium complexity facilities (70.7% vs 33.3%, p=0.01), but not low complexity facilities (43.8%). Conclusion: Having timely and accurate testing protocols for CRAB and CRPA are important to quickly control spread and reduce associated mortality. This study shows that most VA protocols follow recommended testing and identification guidelines. Interestingly, there was no difference in CRAB or CRPA incidence for facilities providing higher vs lower complexity of care. While high and low complexity facilities generally reported sufficient resources for CRAB and CRPA evaluation, some medium-complexity labs, who may feel more compelled than low-complexity labs to bring testing in house, reported that additional resources would be required.

Background: Incorporating diversity, equity, inclusion, and justice into healthcare ensures equitable opportunity to achieve optimal health. Infectious diseases, antimicrobial stewardship, and infection prevention teams rely on consultative recommendations to improve patient care which may be influenced by implicit and explicit biases of the recipient treatment teams. Little is known about how race, ethnicity, and other characteristics impact stewardship and infection control recommendations. Methods: A survey of infectious diseases, antimicrobial stewardship, and infection prevention practitioners was developed through the Society of Healthcare Epidemiology of America (SHEA) Antimicrobial Stewardship Committee. The survey was sent electronically to members of the SHEA Research Network and was promoted to attendees of two sessions at IDWeek 2022 and SHEA Spring 2023. Survey questions included demographics, awareness of (and participation in) unconscious bias and microaggression training at their institutions, antibiotic prescribing bias observations, and perceptions of how race, ethnicity, and other characteristics have influenced participants' antimicrobial stewardship and infection prevention recommendations. Descriptive statistics were performed using SAS V.9.4 . Results: Among 175 survey respondents, 75% (n=129) were White, 16% (n=27) were Asian, 4% (n=7) were Black, 85% (n=150) were non-Hispanic, 5% (n=8) were Hispanic, and 3% (n=5) reported ethnicity as multiethnic. 76% of respondents identified as female, and 2% as non-binary or gender-fluid. 29% of respondents had a medical degree, 12% had a nursing degree, 7% had a pharmacy degree, and 52% had a degree listed as other (7% had a PhD, 23% had an MPH/MSPH degree, and 15% had an MS degree). 65% and 49% of respondents had participated in unconscious bias and microaggression training, respectively. 18% (n=22) of White respondents, 43% (n=3) of Black respondents, and 30% (n=8) of Asian respondents reported witnessing antimicrobial prescribing influenced by race, ethnicity, or other characteristics. 17% and 15% of respondents felt that their antimicrobial stewardship and infection prevention recommendations, respectively, had not been accepted due to their race, ethnicity, gender identity, or other personal identifiers. Conclusion: This survey showed demographic characteristics of professionals working in infectious diseases and their perceptions of how certain aspects of their identity have influenced their recommendations. Differences between racial groups were observed in how frequently respondents witnessed inequities in antimicrobial prescribing, and many respondents felt their recommendations had not been accepted due to their identity. A limitation of this analysis is that few Black individuals completed the survey, which makes comparisons by race difficult; however, the respondents were consistent with SHEA membership demographics.

Background: Infectious Diseases Society of America guidelines recommend antibiotic prescribing for urinary tract infections (UTIs) when there is a positive culture and signs and symptoms of infection. Despite these guidelines, prescribing for asymptomatic bacteriuria remains prevalent. We conducted a chart review of UTI outpatient encounters to determine the prevalence of antibiotic prescribing as well as patient and provider factors associated with inappropriate prescribing for UTIs. Methods: Patients who were seen at any Department of Veterans Affairs (VA) outpatient clinic with a positive urine culture from 1/1/2019-12/31/2022 were evaluated for inclusion. Exclusion criteria were pregnancy, neutropenia, neurogenic bladder, spinal cord injury/disorder, chronic kidney disease stage III and above, and those undergoing urologic surgical procedures within 7 days. Inappropriate prescribing was defined as an antibiotic prescription given for UTI treatment when no signs or symptoms of infection were recorded during the patient encounter. Chi-square, Fisher’s exact and t-tests were used to evaluate the association between patient and provider characteristics and antibiotic prescribing. Results: Among 341 visits, most patients were male (70%), White (40%), older (mean age of 65.8 ± 15.9 years) and treated at an urban facility (57%). Antibiotics were prescribed for 67% (229/341) of visits. Of the 229 antibiotic courses prescribed, 119 (52%) were appropriate; issued to patients with > = 1 sign or symptom consistent with a urinary tract infection. The most common symptom recorded was dysuria, followed by frequency, urgency, and hematuria (Figure 1). The remaining 110 (48%) antibiotic prescriptions were inappropriate; given to patients without documented UTI-related signs or symptoms. The proportion of inappropriate prescribing was higher among advanced practice practitioners (39/56; 69%) compared to physicians (68/113; 60%; P < 0 .0001). Prescribing of an antibiotic did not differ by gender (p-value=0.3779), race (p-value=0.3972), age (p-value=0.7461) or urban versus rural geography (p-value=0.3647). Discussion: In outpatient clinics, nearly half of antibiotics prescribed to patients with a positive urine culture occurred in the absence of documented of signs or symptoms of a UTI. These results suggest that interventions to improve antibiotic use for UTI-related concerns in the outpatient setting should address UTI-related signs and symptoms as well as asymptomatic bacteriuria. Advanced practice practitioners were more likely to prescribe without documentation of relevant signs or symptoms than physicians. Improving meaningful documentation about the presence or absence of signs and symptoms of a UTI may help reduce inappropriate antibiotic prescriptions in the outpatient setting.

Disclosure: Robin Jump: Research support to my institution from Merck and Pfizer; Advisory boards for Pfizer

Background: The Clinical & Laboratory Standards Institute (CLSI) recommends use of annual antibiograms to help guide empiric antibiotic therapy. Because CLSI periodically updates minimum inhibitory concentration (MIC) breakpoints, we assessed the impact of these updates on longitudinal trends in antibiotic susceptibility rates for Escherichia coli and Klebsiella pneumoniae at a single academic medical center in Atlanta, GA. Methods: Susceptibilities for cefepime, ceftazidime, and levofloxacin in E. coli and K. pneumoniae were extracted from hospital antibiograms from 1988 to 2022. Starting in 1995, intensive care units (ICUs) and wards had separate annual antibiograms, which we combined using weighted averages to create annual overall hospital antibiograms. After summarizing the frequency of isolates tested and susceptibilities using medians and interquartile ranges (IQR), we conducted an interrupted time series analysis using linear segmented regression models, to evaluate the level changes and trends in susceptibility, before and after CLSI MIC breakpoints were updated for ceftazidime (2010 and 2017), cefepime (2014 and 2017), and levofloxacin (2013). Results: Among 21,214 E. coli, there was a median of 291 [IQR: 104, 555] isolates tested annually. Similarly, among 8,686 K. pneumoniae isolates, the median was 125 per year (IQR: 76, 178). Prior to the MIC breakpoint changes, baseline susceptibility trends of both organisms to all 3 antibiotics significantly declined at a rate between 0.2% to 2.4% per year (Table 1). For cefepime (Figure 1), susceptibility decreased annually during 1988 – 2013 for both E. coli (-0.5%) and K. pneumoniae (-1.2%). There were no significant level changes but there were trend changes after 2018, for E. coli (+2.1%) and K. pneumoniae (– 5.5%). For ceftazidime (Figure 2), significant level changes occurred after 2010 for both organisms (E. coli: -5.7%; K. pneumoniae: -5.2%). For levofloxacin (Figure 3), the breakpoint update in 2013 lead to significant level change in susceptibility (E. coli: +8.4%; K. pneumoniae: +11.4%). Conclusion: Overall, we observed a consistent decrease in antibiotic susceptibility in E. coli and K. pneumoniae over three decades, with immediate increases in the level change of susceptibility when MIC breakpoints were changed, followed by a decreasing trend. These findings highlight the importance of longitudinal surveillance and MIC breakpoint changes to inform antimicrobial stewardship strategies.

The capture of wild-living animals can provide valuable information that is critical in developing and implementing effective conservation actions. These capture procedures, however, often require direct handling of individuals by researchers, and conservationists should constantly seek to improve capture methods so that the impacts on animal welfare are minimised. The ngwayir (western ringtail possum; Pseudocheirus occidentalis) is a critically endangered arboreal marsupial in need of effective conservation. It is, however, not amenable to conventional trapping, leading to the use of methods such as nest robbing and tranquilisation using dart guns or pole syringes, which involve potentially serious animal welfare risks and longer exposure of animals to humans as compared to conventional trapping. In pursuit of an improved capture method, we investigated opportunistically whether placing traps above the ground would increase the capture success rate of the species, using wire cage traps baited with universal bait and fruit. Between 2010 and 2019, we deployed trapping grids in Locke Nature Reserve and adjacent campsites near Busselton, WA, Australia, with traps placed on the ground for 1,985 trap nights and traps placed on horizontal tree branches, fallen trees or fences, 1–2 m above ground for 694 trap nights. With the above ground traps we trapped 82 ngwayirs out of 694 trap nights, 27 in autumn and 55 in spring. We also captured eleven common brushtail possums (Trichosurus vulpecula; 1.6% trap success rate), 12 King’s skinks (Egernia kingii; 1.7%) and five black rats (Rattus rattus; 0.7%). Trapping success rate was higher in elevated traps (up to 18.3%) compared to traps on the ground (0.5%) and using fruit as bait increased the trap success rate. These results suggest that using elevated traps baited with fruit is a practical, effective method to capture the ngwayir.

Background: An overall decrease of prescriptions for outpatient fluoroquinolones (FQs) following the FDA’s release of boxed warnings in 2016 was shown in a previous analysis1. An additional study found that this decline held true when further broken down by specialty 2. We sought to determine which different clinician specialties in Washington State (WA) continue to prescribe FQs and if these rates are congruent with previously conducted national analyses. Methods: We conducted a comprehensive analysis of Medicare Part D data from 2021. We identified specialty types contributing the highest proportions of FQ claims from the total volume of claims in 2021. Subsequently, we calculated the average FQ claims per 1,000 Medicare Part D beneficiaries for each specialty. The analysis excluded providers with missing beneficiary data. All dosage formulations were included (i.e. topical & oral). We repeated this process for each year from 2021 to 2013 to assess changes in the average FQ prescription rate for each specialty over time. Results: Our analysis encompassed 99,250 FQ prescriptions involving 976,209 Medicare Part D beneficiaries from January 1 to December 30, 2021. Among the specialties, urologists emerged as the highest prescribers of FQs to Medicare Part D beneficiaries, closely followed by ophthalmologists and family practitioners (Table 1). Notably, 72.4% of urologists prescribed FQs, while only 12.4% of family practitioners did so in 2021. Trend analysis indicated that the average FQ claims per 1,000 beneficiaries for urologists decreased from 251 claims per 1,000 beneficiaries (SD = 177.98) in 2013 to 130 claims per 1,000 beneficiaries (SD = 122.50) in 2021 (Figure 1A). In contrast, the only specialty types that had positive trends in average FQ claims per 1,000 beneficiaries from 2013 to 2021 included ophthalmologists, optometrists, and otolaryngologists (Figure 1A). Conclusion: Throughout the years leading up to 2021, most prescriber specialties contributing high volumes of FQ claims experienced a decline in FQ prescriptions. The positive trend noted amongst ophthalmologists, optometrists, and otolaryngologists could be due to the limited ability to differentiate between oral & topical FQ formulations within the dataset. These findings underscore the importance of understanding specialist prescribing behaviors and partnering with them to formulate tailored antibiotic stewardship guidance. By doing so, we can further promote patient safety and well-being in the context of FQ usage. Public health departments can promote more holistic antibiotic stewardship interventions and better patient safety outcomes with FQs. Ambulatory Fluoroquinolone Use in the United States 2015–2019 Outpatient Fluoroquinolone Prescription Fills.

Disclosure: Erica Stohs: Contracted research - Merck; Contracted research – bioMerieux

Background: In rural areas, antimicrobial stewardship programs often have limited access to infectious disease (ID) expertise. Videoconference Antimicrobial Stewardship Teams (VASTs) pair rural Veterans Affairs (VA) medical centers with an ID expert to discuss treatment of patients with concerns for infection. In a pilot study, VASTs were effective at improving antimicrobial use. Here, we evaluated 12-month operating costs for staffing for 3 VASTs. Methods: We used the following data to describe 12 months of clinical encounters for 3 VASTs operating from January 2022 – March 2023: the number of VAST sessions completed and clinical encounters; Current Procedural Terminology (CPT) codes associated with clinical encounters; session attendees (by role) and the time spent (percent effort) on VAST-related activities. The annual operating cost was based on the annual salaries and percent effort of VAST attendees. We used these characteristics combined with private-sector and Medicare reimbursements to evaluate the cost of implementation and number of clinical encounters needed to offset those costs (breakeven) for each site. Results: Three VASTs recorded 229 clinical encounters during 117 sessions (Table 1). Based on CPT codes, the approximate revenue per patient was $516.46. Site A, the only site to break even, had the most sessions and clinical encounters as well as the lowest operating costs. For Site B, a slight increase in the clinical encounters, which might be achieved by 3 additional VAST sessions, would help achieve breakeven. For Site C, increasing the number of clinical encounters to 3-4 per session would have helped their VAST break even without requiring a decrease in operating costs. Conclusions: The frequency of VAST sessions, volume of clinical encounters, and low operating costs all contributed the VAST at Site A achieving a financial break-even point within 12 months. Consideration of the potential number of clinical encounters and sessions will help other VASTs achieve financial sustainment, independent of cost-savings related to potential decreases in expenditures for antibiotics and antibiotic-related adverse events. These results also provide insight into possible adoption and diffusion of VAST-like programs in the Medicare hospital setting.

Background: Tracking antimicrobial use (AU) is a Core Element of Hospital Antimicrobial Stewardship Programs and important to help curb the public health threat of antimicrobial resistance. The National Healthcare Safety Network’s (NHSN) AU Option serves as a way for facilities, healthcare systems, and health departments to track and report AU rates within their jurisdictions. Many analyses at the state and national levels do not assess unit-level AU rates. This study investigates AU rates among patient care units in Tennessee reporting facilities from 2015 to 2023 and the most frequently used antimicrobial agents based on AU rates within select unit types. Methods: A retrospective analysis was conducted utilizing data obtained from the NHSN AU Option for inpatient units in Tennessee acute care hospitals. Units were defined as critical care (including neonatal), ward, oncology ward, stepdown, operating room (OR), and mixed acuity and specialty care areas, termed ‘other’. Unit types with fewer than five facilities represented were excluded. AU rates were determined by Antimicrobial Days of Therapy (DOT) per 1000 Days Present (DP). Statistical analyses , including descriptive statistics and comparison among the units by ANOVA test , were calculated using SAS Version 9.4. Results: Eighty-three facilities reported at least one month of data into the NHSN AU Option between 2015–2023. Among 70 facilities reporting inpatient units, the highest AU rate was observed in oncology ward units (n=12, 1114.6 DOT/1000 DP). A significant difference in AU rates was observed between oncology ward units compared to different unit types (p < 0 .001). Vancomycin, ceftriaxone, and piperacillin/tazobactam were the most used antimicrobials with AU rates of 83, 76, and 65 DOT/1000 DP, respectively. Vancomycin AU rates were significantly higher in oncology ward units compared to stepdown, ward, other, and OR units (p < 0 .0001). Ceftriaxone AU rate was significantly higher in stepdown units compared to oncology ward, other, and OR units (p < 0 .0001). Piperacillin/tazobactam AU rate was significantly higher in critical care units compared to different unit types (p < 0 .0001). Conclusion: During the study period, the AU rate varied across hospital inpatient units in Tennessee, with the highest AU rate in oncology wards. This unit-specific approach is critical to address the diverse antimicrobial prescribing behaviors observed, indicating that interventions should be customized to each unit’s distinct antimicrobial usage patterns for successful stewardship efforts. Targeted strategies focused on individual wards rather than facility-wide initiatives appear essential for effective reduction in antibiotic usage.