To evaluate the association between neighborhood-level social vulnerability and risk of surgical site infection.

Retrospective cohort study from January 1, 2019-December 31, 2024

Large academic hospital in the Deep South

Patients undergoing NHSN-defined procedures by CPT coding (coronary artery bypass graft, colon surgery, craniotomy, spinal fusion, hip prosthesis, knee prosthesis, or abdominal hysterectomy) were included. Social vulnerability index (SVI) percentile and themes were defined by the Centers for Disease Control and Prevention criteria and assigned based on residential ZIP code.

The primary outcome was development of SSI. Cox proportional hazards models stratified by SSI surveillance duration (30 or 90 days) were used to estimate hazard ratios (HRs) and 95% confidence intervals, adjusting for demographic, clinical, and procedural characteristics.

Among 40,954 surgeries, 26,067 patients (63.7%) resided in high SVI ZIP codes. The risk of SSI increased across SVI tertiles (low 1.5%, medium 2.2%, high 2.4%). Compared with those in low SVI tertile, SSI risk was higher for patients in the medium-SVI (aHR 1.40, 95% CI 1.03–1.92) and high-SVI tertile (aHR 1.49, 95% CI 1.10–2.01). Higher SVI socioeconomic status was associated with increased SSI risk (aHR 1.33, 95% CI 1.07–1.64) and higher housing and transportation vulnerability was associated with increased deep incisional and organ space SSI.

Higher neighborhood-level SVI was independently associated with increased risk of SSI across a broad surgical population in the South. Incorporating SVI into preoperative risk assessment may allow targeted infection prevention strategies for hospitals to address barriers to care.

In the neonatal intensive care unit (NICU), outbreaks caused by methicillin-susceptible Staphylococcus aureus (MSSA) are less commonly described than outbreaks caused by methicillin-resistant Staphylococcus aureus (MRSA) despite the increased burden of MSSA infections.

To investigate a NICU MSSA outbreak utilizing whole-genome sequencing (WGS) and multi-locus sequencing typing (MLST) to identify transmission events.

An investigation was initiated in a level IV NICU after four patients developed MSSA skin and soft tissue infections (SSTI) within three weeks. MLST and WGS were performed on MSSA isolates obtained from clinical and surveillance specimens.

During the outbreak, 16 infants developed MSSA infections including SSTIs (n = 15) and bacteremia (n = 1). Thirteen SSTIs presented on neonates’ faces, all of whom were on non-invasive respiratory support. During 7 rounds of surveillance, an additional 31 patients were found to be colonized with MSSA. MLST identified a predominant cluster (ST-121). WGS found that all ST-121 isolates were closely related (≤10 genetic variants between isolates) suggesting likely transmission events, harbored the mupA gene, exhibited mupirocin MIC values ≥1,024 µg/mL, and were associated with infection. Multiple infection control measures were implemented including the “bare below the elbows” practice. No further mupirocin-resistant isolates were recovered or ST-121 SSTIs identified after Week 26.

WGS analysis furthered the MLST analysis and identified a single MLST as the outbreak-related strain. Successful control of this outbreak was achieved with a multitude of infection prevention and control methods.

Clostridioides difficile infection (CDI) requiring colectomy carries substantial mortality risk, with optimal timing of surgery remaining poorly defined. We examined temporal trends in colectomy among inpatients with CDI, identified predictors of surgical intervention and postoperative mortality, and evaluated the association between surgical timing and patient outcomes.

A retrospective cohort study was conducted using the National Inpatient Sample database from 2018 to 2022. We compared patients undergoing colectomy with those managed medically. To minimize confounding by hospital-onset cases, the analysis of surgical timing and mortality was restricted to patients undergoing colectomy within 8 days of admission. Predictors were identified using survey-weighted logistic regression and LASSO regression models.

Among 240,564 CDI hospitalizations (representing 1,207,995 weighted nationally), 717 patients underwent colectomy (3,585 weighted). CDI prevalence declined from 0.99% (2018) to 0.76% (2022), while colectomy rates increased from 0.28% to 0.34%. Peritonitis (OR 5.42; 95% CI, 4.46–6.59), coagulopathy (OR 4.96; 95% CI, 3.76–6.55), and sepsis/septic shock (OR 3.89; 95% CI, 3.39–4.47) were the strongest predictors of colectomy. Among patients undergoing colectomy within 8 days (2,830 weighted), in-hospital mortality was 26.5% overall, increasing from 21.0% (2018) to 30.7% (2022). Sepsis/septic shock (OR 8.20; 95% CI 2.92–23.07) and coagulopathy (OR 7.27; 95% CI 3.31–15.97) predicted mortality. Each additional day from admission to colectomy was associated with a 16% (OR 1.16; 95% CI 1.04–1.28) increased mortality risk.

In this nationally representative cohort, surgical timing was an independent and modifiable determinant of survival in patients with CDI requiring colectomy. Our findings underscore the importance of early surgical consultation for CDI patients with peritonitis, sepsis, and coagulopathy.

To determine whether split septum needleless connector prevent central line-associated bloodstream infection (CLABSI) better than mechanical valve in very preterm or very low-birth-weight (VLBW) neonates.

This is an open-label, parallel, randomized controlled trial. Participants were followed up to 48 hours after central line removal for the primary outcome.

This is a single-center study conducted at level III neonatal intensive care unit in public tertiary hospital.

Very premature or VLBW neonates requiring central access.

Participants were randomized to receive either a split septum or mechanical valve needleless connector.

The primary outcomes were CLABSI incidence rate and the estimated hazard ratio of CLABSI between the two groups.

A total of 60 neonates were included in the analysis, in which 30 neonates were allocated to each intervention (split septum) (mean±SD gestational age, 27.37 ± 7.7 weeks; 15 [50%] male) and control (mechanical valve) group (mean±SD gestational age, 30.27 ± 2.7 weeks; 17 [56.7%] male). The CLABSI incidence rate was lower in the intervention group (3.0 vs 16.2 per 1,000 catheter days). The adjusted hazard ratio for the intervention compared to control group was 0.153 (95% CI 0.02–1.52; P = .109). Although not statistically significant, the control group demonstrated higher CLABSI-related mortality (7% vs 0%), length of stay (49.8 ± 24.2 vs 42.3 ± 23.8), and hospital cost (130.5 (79.4–215.9) vs 104.1 (86.4–152.7).

Split septum demonstrated a trend in lower incidence of CLABSI. This result should be weighed carefully in determining the needleless connector type best suited for very preterm or VLBW neonates.

Timely detection of pathogen-related outbreaks in hospitals is important for preventing onward transmission and can be supported by automated outbreak detection systems (AODS). Many methods overlook in-hospital patient transfers and focus only on patient locations at the time of sampling. This study compares three approaches for incorporating patient transfers into AODS.

Two existing AODS frameworks, a local percentile-based system and a statistical modeling-based system were extended to include patient transfers: 1) grouping wards into communities based on frequent patient exchange, 2) including prior ward visits in the past 14 days, and 3) including both prior ward visits and time spent on wards. Alerts generated were reviewed for clinical relevance.

Data from January 2014 to December 2021 from a University Medical Center in the Netherlands.

Using the percentile-based approach, the baseline scenario detected 99 possible outbreaks. Extension with ward community groupings, prior ward visits, and prior ward visits accounting for time spent in each ward increased this number with 16 (+15%), 42 (+42%), and 106 (+110%) possible outbreaks, respectively. Of the alerts generated by including individual patient transfer history, 35% were judged as requiring investigation. The trade-off between increased detection and relevance was less favorable for the other approaches. Similar findings were found for statistical modeling-based methods.

Inclusion of patient transfer data in AODS improved sensitivity, at the cost of increasing the alert burden. Therefore, ongoing refinement should further optimize the balance between accurate outbreak detection and a manageable alert burden.

The GeneXpert® MTB/RIF nucleic acid amplification test has been proposed as an alternative method to smear microscopy in guiding de-isolation for patients with suspected pulmonary tuberculosis, given its convenience and higher diagnostic accuracy. Currently, there is no comprehensive review summarizing the evidence on the isolation duration using GeneXpert. This systematic review and meta-analysis addressed the length of airborne infection isolation in hospitalized patients initially suspected of having pulmonary tuberculosis where de-isolation decisions were guided by GeneXpert nucleic acid amplification test compared to traditional smear microscopy.

We conducted a comprehensive search in databases (Medline, Embase, and Scopus) from January 1, 2001, to April 1, 2026, and applied median-based quantile estimation methods to determine the pooled difference in median times of isolation. We also assessed diagnostic accuracy as well as hospital length of stay as secondary outcomes.

We screened 746 titles and abstracts, of which 7 were eligible for inclusion. Five studies included in the meta-analysis involved 1,409 patients, all within low-incidence tuberculosis settings. The meta-analysis demonstrated that use of a single unconcentrated GeneXpert versus serial acid-fast bacilli smear microscopy resulted in a pooled reduction in median isolation duration by 38.8 hours (95% confidence interval 20.2–57.3 hours).

Compared to serial microscopy, GeneXpert done on a single unconcentrated respiratory specimen reduces airborne infection isolation duration by over 1.5 days, on average, making it an attractive strategy for optimizing healthcare facility resources while evaluating persons for pulmonary tuberculosis.

Protocol Registration (PROSPERO, CRD42024538644)

Pediatric patients undergoing hematopoietic transplant or cellular therapy (TCT) are at increased risk of developing central line-associated bloodstream infections (CLABSI). The role of language barriers in CLABSI risk has not been well-explored in this population. This study aimed to evaluate the risk for CLABSI in pediatric TCT patients with limited English proficiency (LEP).

A retrospective cohort study of patients hospitalized in the TCT unit in a single pediatric oncology center between January 2021 and June 2024.

Clinical data was abstracted from the electronic health records and CLABSI events from the hospital infection prevention and control surveillance database. CLABSI rates were calculated as events per 1,000 inpatient central line days (CLD) and compared between patients with LEP and those English-proficient. Cox proportional hazard analysis was used to evaluate independent risk factors for CLABSI.

Two hundred and eighty patients contributed a total of 12,325 CLD and 93 CLABSIs; of which 57 patients were with LEP contributing 3,113 CLD and 29 CLABSIs. The unadjusted CLABSI rate in patients with LEP was significantly higher (9.32/1,000 CLD) than that in English-proficient patients (6.95/1,000 CLD, P < .001). Patients with LEP had twice the risk of developing CLABSI compared to English-proficient patients (Adjusted HR 2.03, 95% CI [1.23, 3.34]).

This study identified a significantly increased risk of CLABSI in pediatric TCT patients with language barriers. Addressing these barriers through equitable strategies is crucial for improving clinical outcomes and promoting an inclusive healthcare for diverse patient groups.

Chlorhexidine gluconate (CHG) skin treatments are an effective strategy to reduce patients’ risk of central line-associated bloodstream infection (CLABSI); however, compliance with this practice is suboptimal. One barrier is patient refusal of CHG skin treatments. To mitigate this barrier, the purpose of this study was to evaluate the feasibility and outcomes of implementing a patient-facing CHG skin treatment educational video on an inpatient adult bone marrow transplant (BMT) unit.

A quasi-experimental pre–post research study design was used.

The study took place at a large academic hospital in the Southeastern U.S.

Patients admitted to a 16-bed BMT unit were included.

A patient-facing CHG skin treatment educational video was developed with input from a multidisciplinary team, patients, and their family members. Patients accessed the video through a QR code or website link provided on a laminated document.

The video was viewed 173 times, with an average of 84% of the video watched. Of the 117 patients who completed a feedback survey, most felt the video was helpful and increased their likelihood of participating in CHG skin treatments. No improvements were shown in documented CHG compliance or patient refusals. A 27.2% reduction in the CLABSI rate was found, with a decreased rate of 2.54 to 1.85 post-intervention, although this reduction was not statistically significant, P = .58.

While patients found the video beneficial, future research that includes more diverse patient populations is needed to better understand the long-term impact of a CHG skin treatment educational video.

Leukemic and hematopoietic cell transplant patients have one of the highest incidences of Clostridioides difficile infection (CDI). Although CDI patients are considered the primary source of transmission, asymptomatic colonized (AC) patients can progress to CDI or contribute to in-unit transmission. We aim to quantify the roles of CDI and AC patients in C. difficile importation and transmission within oncological units.

Prospective cohort study

Two leukemia and hematopoietic cell transplant units in a large tertiary care hospital in the United States for a 6-month period.

We developed a stochastic, individual-based network model to simulate C. difficile acquisition and transmission. Data from cultures and nucleic acid amplification testing obtained at admission and weekly, and toxin enzyme immunoassay tests used for CDI diagnosis were used to calibrate the model. Healthcare worker room assignments informed the network structure. Key parameters were estimated via particle filtering.

The model reproduced observed weekly test counts and transmission pairs. Only 23% of new colonization events were observed via testing. AC patients were the primary source of new colonizations: 51% (range: 38%–70%) were due to importation (of those, 87% were admitted as AC), and 49% (30%–62%) were due to transmission (AC was the source in 92% of transmissions that resulted in new colonizations).

These findings reinforce the role of AC, particularly via admission importation, in sustaining C. difficile transmission in high-risk hospital settings. Infection control focused on CDI effectively reduced onward transmission, as indicated by CDI’s low contribution to new colonizations.

Recipients of hematopoietic cell transplantation (HCT) are at increased risk for Clostridioides difficile infection (CDI) and its recurrence, which are associated with significant morbidity. We aimed to characterize risk factors for primary and recurrent CDI in a large cohort of HCT recipients.

We conducted a retrospective cohort study of 2725 adults who underwent HCT from 2010–2023 to evaluate the epidemiology, timing, and risk factors for CDI. We compared patients who developed CDI with those who did not, adjusting for patient demographics, comorbidities, transplant factors, medications, and laboratory values. Among patients who developed CDI, we investigated risk factors for recurrent CDI.

The cumulative 1-year incidence of CDI was 17.8% among allogeneic HCT recipients (181/1016) and 4.1% among autologous recipients (71/1709). Overall CDI incidence increased by 1.4% annually during the study period (95%CI: 1.24–1.53%). Independent risk factors for primary CDI included penicillin antibiotics (aOR 1.51; 95%CI: 1.13–2.02), prior chemotherapy (aOR 8.36; 95%CI: 2.95–23.69 for 1–3 regimens), and umbilical cord blood stem cells (aOR 1.95; 95%CI: 1.07–3.57). Autologous HCT was associated with decreased risk. Among 252 patients with primary CDI, 22 (8.7%) developed recurrence. Macrolide use before index CDI (aOR 7.25; 95%CI: 1.80–29.2) and allogeneic HCT (aOR 31.04; 95%CI: 1.37–731.58) were associated with recurrence.

CDI is a common, early complication of HCT particularly among allogeneic recipients. Penicillin exposure, prior chemotherapy, and cord blood stem cell source are key risk factors, while macrolide use is associated with recurrence. Our findings highlight potential targets for risk-stratified prevention strategies.

This study aims to evaluate the effectiveness of an adapted methicillin-resistant Staphylococcus aureus (MRSA) decolonization program in an infirmary unit in Hong Kong that was inspired by successful interventions implemented in Orange County, California.

Nasal, skin, and rectal swabs were collected to assess MRSA colonization. Decolonization involved applying 10% povidone-iodine ointment to the anterior nares twice daily for five days every other week, along with twice weekly chlorhexidine gluconate (CHG) bathing for six months. Compliance with the application of povidone-iodine and CHG bathing techniques was monitored by measuring their respective levels in the anterior nares and on the skin. Air and environmental samples were collected and analyzed over time using linear regression.

Among 60 patients in the infirmary unit (78% baseline MRSA carriers), overall MRSA colonization declined during the program, driven by significant reductions in skin colonization (65% to 29%, P < .001). Environmental contamination on high-touch patient-care equipment (bathing trolleys and slings) also significantly decreased over time (P < .001). These reductions coincided with the high-quality implementation of decolonization, evidenced by stable iodophor detection in nares during application weeks and sustained chlorhexidine levels on the skin, detectable 24 hours after bathing. In contrast, MRSA detection in air samples showed no significant change (P = .096), possibly due to dispersal by persistent carriers during care activities even as skin and environmental contamination declined.

The adapted MRSA decolonization program was effective, significantly reducing overall MRSA colonization, especially at skin sites, while achieving high compliance with the protocol.

To understand how the workflows and infection prevention and control (IPC) practices of certified nursing assistants (CNAs) during high-contact resident care activities contribute to multidrug-resistant organism (MDRO) transmission in nursing homes.

We conducted 10 high-fidelity simulations of two high-contact resident care activities, bed bathing and incontinence care, with CNAs from long-term or mixed-care units. Four genetic variants of λ phage were applied to select surfaces prior to simulations and subsequently sampled from the environment, residents, supplies, and CNAs. Simulations were video recorded and analyzed for patterns of hand-to-surface contact and performance of IPC practices, including hand hygiene, personal protective equipment use, and environmental surface cleaning or disinfection.

A median of 11.5 transmission events occurred per simulation. Most events (60%) occurred within residents’ immediate environments, reflecting how CNAs frequently transitioned between a resident, their surroundings, and care supplies, combined with infrequent hand hygiene and surface disinfection. Contamination of CNA scrubs and hands accounted for 24% of events, primarily from bed bathing, which involved frequent contact without a gown. Transmission to shared objects (e.g., linen bin, trash can, wheelchair) accounted for 16% of events and created additional opportunities for transmission between residents. Transmission between residents or their immediate environments was rare but typically associated with workflow disruptions from limited-supply availability.

In high-fidelity simulations of high-contact resident care activities, transmission of surrogate markers for MDROs closely followed the workflows of CNAs. This method identifies potential transmission pathways and interventions for mitigating MDRO spread in nursing homes.

We evaluated whether patient perceptions of cleanliness are associated with objective measures of Clostridioides difficile infection (CDI), as an early indicator of facility-level CDI rates and prevention.

Cross-sectional analysis of Medicare-certified hospitals across the United States.

Data from the CMS Hospital Compare website and U.S. Census Bureau from 2023 were analyzed using multivariate logistic regression models. The primary outcome was C. difficile standardized infection ratios (SIRs) compared to the national average. The primary exposure was patient-rated cleanliness star ratings from the Hospital Consumer Assessment of Healthcare Providers and Systems survey.

The population studied was 3,616 medicare-certified hospitals with an estimated 17,994,034 unique patient admissions. There was no association between better patient-rated cleanliness and improved CDI performance. Facilities with a 5-star cleanliness rating were not more likely to have an SIR less than or equal to the national average compared to those with a lower star rating. For every 1% increase in patients who reported their room and bathroom as always clean, the odds of CDI observed cases being higher than predicted increases by 4.2% (ie, increasing patient-related cleanliness was weakly associated with worse CDI performance).

Patient-rated cleanliness was not associated with improved CDI performance in U.S. national hospital data. Findings were consistent across multiple operationalizations of cleanliness and CDI suggesting patient perceptions of cleanliness are not a strong indicator of CDI control measure performance.

Surgical site infection (SSI) surveillance can be time consuming and resource intensive. This study investigates the potential of generative artificial intelligence (GenAI) to augment the detection and classification of SSIs.

A case control study of patients with SSI following spine surgery at one US hospital. SSIs were classified into superficial, deep, and organ space. All SSIs were confirmed by infection prevention (IP) experts as they occurred from October, 2023 to September, 2025 and matched 1:1 by year to surgeries deemed non-SSI. A secure GenAI was used to determine if patients had an SSI based on standardized prompts and clinical data. IP nurses used GenAI output to review cases with the ability to ask GenAI questions within the data provided or independently open the medical record. We compared GenAI determinations to initial IP nurses’ determinations.

A total of 555 patients had spine surgeries. All 16 SSIs were matched by year to 16 non-SSI. All SSIs were correctly identified by GenAI (sensitivity 100%, 16/16) and only 1 non-SSI was incorrectly identified as SSI (specificity 93.7%, 15/16). Although GenAI accurately identified all SSI cases, it was discordant with original review at classifying the level of infection in 37.5% (6/16) of cases. Upon final IP physician review, GenAI was correct in 66.7% (4/6) of discordant cases (often determining “organ space infections” rather than “deep”). Median time to complete GenAI assisted SSI reviews was 9 minutes (IQR 7–21).

GenAI is a promising tool to assist in SSI surveillance following spinal surgery that could improve efficiency.

To deconstruct the multiple levels of risk factors for Clostridioides difficile infection, using multilevel models (MLMs) accounting for patient movement.

Case-control study of patients hospitalized in three acute care Delaware hospitals, December 2019–December 2023.

Cases were patients aged ≥18 years who tested positive for hospital-onset C. difficile infection. Controls were patients aged ≥18 years hospitalized more than 72 hours, who did not test positive for C. difficile infection.

Hierarchical and cross-classified MLMs were used to calculate odds of C. difficile infection based on patient-level risk factors and to evaluate the variation in odds of infection attributable to environmental risk factors using the hospital unit(s) a patient was assigned to during hospitalization.

Our study included 1,223 patients (249 cases, 974 controls). In both models, greater odds of infection were associated with antibiotic exposure [adjusted odds ratio (aOR) = 11.20, 95% confidence interval (CI) = 7.19, 17.40; aOR = 12.80, 95% CI = 8.46, 19.40 for hierarchical and cross-classified models respectively] and health insurance (aOR = 1.74, 95% CI = 1.12, 2.68; aOR = 1.62, 95% CI = 1.03, 2.53; public vs. private). Median odds ratios (MOR) for both models indicated greater relevance of between-unit heterogeneity in the outcome than health insurance but less than antibiotic exposure (MOR = 1.83, 95% CI = 1.56, 2.30 and 2.71 95% CI = 2.10, 4.06).

Using multilevel methods accounting for patient movement, we found that while antibiotic use is the most important risk factor in patients that developed C. difficile infection, environmental risk factors are additionally important and should be considered in research involving hospitalized patients and healthcare-associated infections.

Professional guidelines recommend an early switch from intravenous (IV)-to-oral antibiotics for community-acquired pneumonia (CAP) to facilitate early discharge and prevent hospital-related complications. However, it is unknown how often these IV-to-oral switches occur in clinical practice.

We performed a retrospective cohort study across 124 acute-care Veterans Administration hospitals to measure the frequency of early switches.

Patient-admissions during 2018–2023 who had CAP and were started on IV antibiotics upon admission.

We measured the percentage of hospitalized patients with CAP who had an early switch from IV-to-oral antibiotics, i.e., within 72 hours of admission. In addition, we calculated an observed-to-expected ratio for early switches at each hospital and compared a composite outcome (mortality and/or hospital readmission within 30 days of discharge) at hospitals with switch rates that were higher and lower than expected.

Of 31,183 patient-admissions for CAP, 17,282 (55.4%) were switched to oral antibiotics by day three of therapy. Overall, 5,629 (18.1%) died and/or were re-admitted within 30 days. The O:E ratio for early antibiotic switches ranged from 0.78 among hospitals in the lowest quartile to 1.23 in the highest quartile. There was no difference in the composite outcome across quartiles.

Early switches from IV-to-oral antibiotics for CAP occurred in half of eligible cases. The frequency of these switches varied widely across facilities. Outcomes among patients at hospitals with high switch rates were comparable to outcomes at hospitals with low rates, thereby supporting the safety of early switches. More concerted efforts to promote these switches are needed.

To evaluate the effect of copper-coated high-touch surfaces on environmental microbial burden and healthcare-associated infection (HAI) rates.

Observational cohort study over 20 months.

Pediatric intensive care and oncology inpatient units in a tertiary care hospital.

All patients admitted to rooms with or without copper-coated surfaces.

Spray-on copper coating applied to high-touch surfaces in patient rooms.

Patients were admitted to rooms according to routine hospital practices. Demographic and clinical data were collected for a subset of patients admitted to rooms with copper-coated surfaces and matching control rooms. Environmental samples were collected from high-touch surfaces to quantify bacterial colony counts. HAIs were identified via a surveillance database and reported per 10,000 patient days. Poisson regression and negative binomial mixed-effects model were used for analysis.

Patients in copper-coated rooms were more likely to have an infection on admission (29.7% vs 2.9%; P = .003). Bacterial colony counts trended lower in copper-coated rooms (rate ratio (RR) 0.74, 95% CI 0.50–1.08; P = .11; absolute rate difference −12.25, 95% CI −26.12–2.10), with variability by surface type. HAI rates trended higher in copper-coated rooms compared to control rooms (48.2 vs 30.5 per 10,000 patient days; RR 1.58, 95% CI 0.78–3.20; P = .20).

Copper-coated surfaces were not associated with statistically significant reductions in microbial burden or HAI rates. Contributing factors may include low baseline microbial load, low baseline HAI rates, variable copper alloy efficacy, short study duration, and differences between patients in intervention and control rooms.

To identify host and clinical risk factors contributing to the development of Clostridioides difficile infection (CDI) among colonized patients.

Retrospective, matched case-control study.

Duke University Health System, including 3 hospitals and affiliated outpatient clinics.

Adult patients who underwent ≥2 two-step C. difficile tests (nucleic acid amplification test (NAAT) followed by toxin enzyme immunoassay) between 03/15/2020–12/31/2023. Cases were patients with C. difficile colonization (NAAT+/toxin–) who converted to CDI (NAAT+/toxin+) within 90 days; controls were colonized patients who remained toxin-negative. Cases were matched to controls by date of index testing (±1 year).

Data collection encompassed a 90-day “pre-exposure” period preceding index testing and a ≤ 90-day “exposure” period between index and repeat testing. Antibiotic use was stratified by risk for each period. Multivariate conditional logistic regression with forward selection was used to identify predictors of progression.

Among 2,212 colonized patients, 71 cases and 133 matched controls were identified. Several host and clinical characteristics were independently associated with progression to CDI in our multivariate model. Notably, high-risk antibiotic use across the pre-exposure and exposure periods was associated with greater odds of progression to CDI compared to other patterns of antibiotic use (adjusted odds ratio 2.70; P = .03).

Sustained exposure to high-risk antibiotics was a strong predictor of the progression from C. difficile colonization to infection, underscoring the need for further research on longitudinal stewardship strategies for CDI prevention, particularly among patients previously identified as colonized.

To estimate the incidence of healthcare-associated infections (HAIs) in Italian long-term care facilities (LTCFs) and to evaluate whether an artificial intelligence (AI) approach, through unsupervised machine learning (ML), could stratify residents into clinically distinct groups with differing susceptibility to HAIs.

Prospective cohort study with 12-month follow-up.

24 LTCFs in Italy, participating in the European Centre for Disease Prevention and Control 12-month longitudinal study on HAIs in LTCFs, 2022–2023.

395 residents enrolled across the participating LTCFs.

Incidence measures of HAIs (rate and ratio) were estimated, using generalized estimating equations. A hierarchical cluster analysis based on residents’ clinical and demographic characteristics was implemented as an unsupervised ML approach.

Overall, 75 HAIs per 100 residents (95% CI, 70.3–78.3) and 0.23 HAIs per 1,000 resident-days (95% CI, 0.11–0.76) were estimated. Respiratory tract infections (29.5%, 95% CI 24.2–31.1), COVID-19 (26.3%, 95% CI 22.1–28.4), and urinary tract infections (15%, 95% CI 11.0–35.4) were the most frequent. Clustering identified two reproducible resident groups: Group 1 (39%), more independent and cognitively preserved, with fewer comorbidities and lower infection incidence; and Group 2 (61%), more dependent and clinically complex, with higher incidence of HAIs. Cluster stability was high (mean ARI = 0.83).

This study confirms the high burden of HAIs in Italian LTCFs and provides exploratory evidence that AI-based clustering can identify reproducible HAI susceptibility profiles in a setting where such approaches have been scarcely applied.