Daily Sepsis Research Analysis
Three impactful studies on sepsis and related critical infections emerged today: a methodological review shows most real-time sepsis prediction models lose performance under rigorous external, full-window validation; a large US surveillance study reports a doubling of invasive group A streptococcal disease with rising macrolide/clindamycin resistance; and a multinational ICU cohort suggests 7–10 day antibiotic courses for selected hospital-acquired bloodstream infections reduce complications wit
Summary
Three impactful studies on sepsis and related critical infections emerged today: a methodological review shows most real-time sepsis prediction models lose performance under rigorous external, full-window validation; a large US surveillance study reports a doubling of invasive group A streptococcal disease with rising macrolide/clindamycin resistance; and a multinational ICU cohort suggests 7–10 day antibiotic courses for selected hospital-acquired bloodstream infections reduce complications without increasing mortality.
Research Themes
- Validation standards for AI-based real-time sepsis prediction
- Epidemiologic surveillance and antimicrobial resistance in invasive GAS
- Antibiotic stewardship and duration in ICU hospital-acquired bloodstream infections
Selected Articles
1. A methodological systematic review of validation and performance of sepsis real-time prediction models.
Across 91 studies, only 54.9% used external full-window validation with both model- and outcome-level metrics. Performance declined under external and full-window validation (median AUROC down to 0.783), and Utility Scores dropped from positive in internal validation to negative externally. Hand-crafted features improved performance, and only 18.7% of studies identified top-performing models when jointly considering AUROC and utility.
Impact: Sets methodological benchmarks for sepsis prediction model validation, highlighting the need for external, full-window, multi-metric evaluation to avoid overestimation. Timely guidance for AI in healthcare.
Clinical Implications: Hospitals should require external full-window validation and utility assessment before deploying sepsis alert systems. Model development should incorporate hand-crafted clinical features and plan for multicenter prospective trials.
Key Findings
- Only 54.9% of studies applied external, full-window validation with both model- and outcome-level metrics.
- Median AUROC at 6–12 hours pre-onset (0.886/0.861) dropped to 0.783 under full-window external validation.
- Median Utility Score declined from 0.381 (internal) to −0.164 (external) validation.
- Hand-crafted features significantly improved model performance.
- Combining AUROC and Utility identified top-performing SRPMs in only 18.7% of studies.
Methodological Strengths
- Comprehensive multi-database systematic review with explicit comparison of validation strategies
- Use of both discrimination (AUROC) and decision-utility metrics across time horizons
Limitations
- Heterogeneity in sepsis definitions, model architectures, and outcome labeling across studies
- Potential publication and reporting biases; limited number of prospective clinical evaluations
Future Directions: Promote multicenter, prospective, full-window external validation with standardized definitions and utility metrics; develop reporting guidelines tailored for real-time clinical AI in sepsis.
Sepsis real-time prediction models (SRPMs) provide timely alerts and may improve patient outcomes but face limited clinical adoption due to inconsistent validation methods and potential biases. Comprehensive evaluation, including external full-window validation with model- and outcome-level metrics, is crucial for real-world effectiveness, yet performance evidence remains scarce. This study systematically reviewed SRPM performance across validation methods, analyzing 91 studies from multiple databases. Only 54.9% applied full-
2. Invasive Group A Streptococcal Infections in 10 US States.
In population-based surveillance across 10 US states (21,312 cases; 1,981 deaths), invasive GAS incidence rose from 3.6 to 8.2 per 100,000 persons between 2013 and 2022, with the largest relative increase among adults aged 18–64 and the highest absolute incidence in those ≥65. High-risk groups included American Indian/Alaska Native populations, people experiencing homelessness, people who inject drugs, and long-term care residents. Nonsusceptibility to macrolides and clindamycin increased from 12.7% to 33.1%.
Impact: Defines a decade-long doubling of invasive GAS with rising macrolide/clindamycin nonsusceptibility, informing risk-targeted prevention and empiric therapy decisions.
Clinical Implications: Heightened surveillance and targeted prevention for high-risk groups are needed. Rising clindamycin nonsusceptibility may affect adjunctive antitoxin strategies in severe GAS (e.g., streptococcal toxic shock), prompting local susceptibility review when selecting adjunctive therapy.
Key Findings
- 21,312 invasive GAS cases with 1,981 deaths were identified across 10 US states (2013–2022).
- Incidence increased from 3.6 to 8.2 per 100,000; largest relative increase in adults 18–64, highest absolute incidence in ≥65.
- Higher incidence among American Indian/Alaska Native persons, people experiencing homelessness, people who inject drugs, and long-term care residents.
- Macrolide and clindamycin nonsusceptibility rose from 12.7% to 33.1% among tested isolates.
Methodological Strengths
- Large, population-based, active surveillance across 10 states with standardized case definitions
- Isolate characterization with emm typing and antimicrobial susceptibility; whole-genome sequencing from 2015 onward
Limitations
- Observational design limits causal inference; potential under-ascertainment or reporting variability across sites
- Surveillance limited to 10 states; generalizability to national estimates may be imperfect
Future Directions: Evaluate drivers of incidence increase, assess clinical outcomes by resistance phenotype, and accelerate GAS vaccine development and implementation research in high-risk populations.
IMPORTANCE: Invasive group A Streptococcus (GAS) infections are associated with substantial morbidity, mortality, and economic burden. OBJECTIVE: To update trends in invasive GAS disease incidence rates in 10 US states between 2013 and 2022. DESIGN, SETTING, AND PARTICIPANTS: Clinical, demographic, and laboratory data for invasive GAS cases were collected as part of population-based surveillance in the Active Bacterial Core surveillance network covering 34.9 million persons across 10 US states. A case was defined as isolation of GAS from a normally sterile site or from a wound in a patient with necrotizing fasciitis or streptococcal toxic shock syndrome between January 1, 2013, and December 31, 2022. Demographic and clinical data were collected from medical record review. From 2013 to 2014, avai
3. Shortening antibiotic therapy duration for hospital-acquired bloodstream infections in critically ill patients: a causal inference model from the international EUROBACT-2 database.
In a prospective international ICU cohort (EUROBACT-2), among 550 eligible HA-BSI patients, 7–10 day antibiotic courses were associated with lower 28-day treatment failure (OR 0.64) driven by fewer subsequent infectious complications (OR 0.58), with no difference in mortality or persistent infection. Most infections were catheter-related and caused by Enterobacterales; longer courses were more often used for S. aureus or difficult-to-treat organisms.
Impact: Supports shorter antibiotic durations for selected ICU HA-BSI, aligning ICU practice with stewardship goals while maintaining safety.
Clinical Implications: Consider 7–10 day courses for uncomplicated HA-BSI in ICU when source control is achieved and pathogens are susceptible, while individualizing for S. aureus or difficult-to-treat organisms.
Key Findings
- Short-course (7–10 days) therapy reduced 28-day treatment failure (OR 0.64, 95% CI 0.44–0.93) versus long-course (14–21 days).
- Reduction driven by fewer subsequent infectious complications (OR 0.58, 95% CI 0.37–0.91); mortality and persistent infection were similar.
- Most HA-BSIs were catheter-related (33%) and due to Enterobacterales (39%); longer durations were used more often for S. aureus and difficult-to-treat organisms.
Methodological Strengths
- Prospective, multinational cohort with prespecified eligibility and registered protocol (NCT03937245)
- Causal inference using IPTW to adjust for treatment selection and confounding
Limitations
- Non-randomized design with residual confounding and indication bias despite IPTW
- Pathogen and source distributions differed between groups; findings apply to carefully selected uncomplicated HA-BSI
Future Directions: Conduct randomized trials and pragmatic multicenter studies to confirm optimal duration by pathogen and source, and integrate biomarker-guided stopping rules.
INTRODUCTION: Hospital-acquired bloodstream infections (HA-BSIs) are severe and require antibiotic therapy. In non-complicated BSIs, shortened therapy reduces side effects without compromising efficacy. The impact of shortened antibiotic therapy in HA-BSI critically ill patients without indication of prolonged therapy requires further evaluation. METHODS: Using the international prospective EUROBACT-2 cohort, we compared shortened (7-10 days) versus long (14-21 days) treatment durations in ICU patients eligible for shortened therapy. Patients without antibiotic therapy within 3 days after HA-BSI occurrence or requiring prolonged therapy (due to infection source, microorganism, or clinical deterioration) were excluded. Treatment failure, defined as death, persistent infection, or subsequent infectious complications by Day 28, was assessed using an inverse-probability of treatment weighted (IPTW) logistic regression. RESULTS: Among 2600 patients, 550 were eligible for shortened treatment, 213 received short, and 337 received long treatment. The most common infection source was intravascular catheters (33%), most common microorganisms were Enterobacterales (39%). Patients with long treatment were more frequently infected with Staphylococcus aureus (11% vs. 5.6%, p = 0.025) or difficult-to-treat microorganisms (23% vs. 7%, p < 0.001), and received more commonly combination therapy (46% vs. 30%, p < 0.001). Short treatment was associated with reduced 28-day treatment failure (OR 0.64, 95% CI 0.44-0.93, p = 0.019), mainly due to reduction in subsequent infectious complications (OR 0.58, 95% CI 0.37-0.91, p = 0.018). Mortality (OR 0.92 [95% CI 0.59, 1.43], p = 0.7) and persistent infection rates (OR 0.47 [95% CI 0.17, 1.14], p = 0.12) were similar. CONCLUSIONS: In selected ICU patients with HA-BSI, shortened antibiotic treatment might be considered. Eurobact2 was a prospective international cohort study, registered in ClinicalTrials.org (NCT03937245).