Journal of Infection

BackgroundElectronic prescribing registries are widely used for antimicrobial stewardship surveillance. Existing indicators predominantly measure structure or process, while validated outcome indicators remain rare. The present study evaluates how well rule-based measures capture clinically meaningful postdiagnostic antibiotic decision making in pediatric febrile urinary tract infection. MethodsWe conducted a retrospective, multicenter validation study including all empirically treated febrile UTI episodes across three Swedish pediatric emergency departments. Prescribing outcomes were classified using registry rules and compared with outcomes determined by clinician review and laboratory findings. Guidance Ratio (GR) and Discontinuation Ratio (DR) were calculated monthly and in aggregate for both clinically validated- and registry rule classifications. ResultsIn total, 909 febrile UTI episodes were included across all sites. The rule-based GR was 49%. GR increased consistently with stronger diagnostic evidence. Among the 431 episodes with clinician-adjudicated follow-up, 63% resulted in guided treatment; 28% discontinued treatment, and 9% lacked follow-up documentation. The rule-based algorithm showed a sensitivity of 0.78 and a specificity of 1.00 for identifying guided outcomes. Monthly rule-based GR tracked validated temporal patterns but underestimated absolute values. A calibration function substantially improved agreement. ConclusionsRule-based indicators captured overall prescribing patterns but underestimated the level of prescribing concordant with guidelines. Validation against clinician reviewed reference data enabled calibration and improved the interpretability of indicators based on registry data for antimicrobial stewardship.

BackgroundFive-biomarker-defined hypervirulent Klebsiella pneumoniae (hvKp) causes invasive infections, but its burden in bloodstream infections versus classical K. pneumoniae (cKp) is unclear. MethodsThis retrospective cohort study at a tertiary hospital in Japan included K. pneumoniae bloodstream infection episodes from January 2022-December 2024. hvKp was defined by the presence of all 5 genotypic biomarkers (rmpA, rmpA2, iucA, iroB, and peg-344). The primary outcome was abscess complications, and secondary outcomes were length of stay and antibiotic duration. Whole-genome sequencing was performed for 164 isolates. ResultsAmong the 207 episodes, 28 (14%) were of hvKp. Abscess complication occurred in 17 (61%) hvKp versus 23 (13%) cKp episodes (adjusted odds ratio 10.7; 95% CI, 4.36-26.2). Median length of stay in hvKp versus cKp was 28 versus 14 days (adjusted ratio 1.60; 95% CI, 1.18-2.16) and median antibiotic duration was 43 versus 14 days (adjusted ratio 2.13; 95% CI, 1.64-2.77). These associations were attenuated after adjusting for abscess-related complications. No significant difference in 30-day mortality was observed, although the study was underpowered. Multidrug resistance was less frequent in hvKp strains than in cKp strains (11% vs. 30%; P = .040). Among the sequenced hvKp episodes, abscess rates varied across lineages, from 9 of 10 in ST23 to 1 of 4 in ST412. ConclusionsFive biomarker-defined hvKp strains delineated a bloodstream infection subgroup with frequent abscess complications and prolonged care. hvKp and cKp present distinct clinical challenges; diagnostic tools distinguishing these subgroups may aid abscess evaluation and source control.

BackgroundTuberculous meningitis (TBM) is the most sinister form of extrapulmonary tuberculosis (EPTB), associated with high mortality due to delayed diagnosis and limited sensitivity of conventional and molecular tests. Current study evaluated the diagnostic utility of Lipoarabinomannan antigen (LAM) detection in CSF and urine and explored host inflammatory biomarkers for diagnosis and prognosis of TBM. MethodsThis prospective observational study enrolled 80 patients with presumptive TBM at a tertiary care centre. CSF samples were subjected to AFB microscopy, liquid culture(MGIT-960), GeneXpert MTB/RIF (GX), and LAM lateral flow assay. Urine LAM was performed at baseline. Serum and CSF levels of IL-1{beta}, IL-6, TNF-, IFN-{gamma}, IL-17A, and IP-10 were measured at baseline and after 1 month treatment. ResultsAmong 80 participants, 23 (28.7%) had definite TBM and 46 (57.5%) had probable TBM. CSF LAM sensitivity and specificity against microbiological reference standards was 43.5% and 80.7%, while urine LAM sensitivity (60.9%) and specificity 82.5% was higher. Against composite reference standards, both CSF and urine LAM showed reduced sensitivity but achieved 100% specificity. Serum IL-1{beta} showed the best diagnostic performance (AUC 0.943; sensitivity 88.9%, specificity 90.9%). Elevated serum and CSF IP-10 levels were associated with poor outcomes, whereas declining IL-6 and TNF- levels correlated with treatment response. ConclusionLAM detection in CSF and urine may serve as a highly specific, rapid rule-in test for TBM. Host inflammatory biomarkers, especially IL-1{beta} and IP-10, show additional diagnostic and prognostic value. Combining LAM testing with cytokine biomarkers may improve early diagnosis and efficient clinical management of TBM.

BackgroundAn upsurge in Streptococcus pyogenes infections 2022-2023 highlighted potential benefits of point-of-care tests (POCT) to support clinical pathways, prevent outbreaks, and optimise antibiotic use. ObjectivesWe conducted a pilot research study in a west London paediatric emergency department (ED) to determine whether a molecular POCT had potential to alter management in children who were also having a conventional throat swab taken for culture. MethodsChildren <16 years presenting to ED who had a throat swab requested by a clinician were invited to have a second swab taken for research purposes only. Clinical management was unaffected by the research swab result, which was processed using a molecular POCT that was not approved for use in the host NHS Trust. ResultsPrevalence of streptococcal infection was low during the study (May 2023-June 2025); swab positivity in symptomatic children was 12.8% (6/47). Overall, 38/49 (77.6%) participants who had throat swabs received antibiotics. Of those children recommended to receive antibiotics, 29/38 (76.3%) had a negative POCT. Mean time to reporting of positive throat swab culture results was 3.67 days (range 3-5 days) leading to occasional delay in treatment, although POCT identified positive results within minutes. ConclusionAntibiotic use was frequent and could be avoided or stopped by use of a rule out POCT in over three-quarters of children in the ED, if suspicion of S. pyogenes is the main driver for prescribing. POCT were easy to process and produced immediate results compared with culture, in theory enabling timely decision-making and avoiding treatment delay.

Infections caused by carbapenem-producing Enterobacterales (CPEs) are a persistent and growing threat in healthcare settings. Yet, current infection prevention and control (IPC) surveillance methods, which largely rely on the spatial and temporal proximity of patients, often misattribute or miss infection transmission events. Here, we develop and retrospectively evaluate an integrated methodology that combines analyses of ward-level patient movement data and whole-genome sequencing (WGS) data analyses, providing measures of bacterial and plasmid similarity. Specifically, we evaluate this methodology across two datasets: a CPE outbreak of diverse carbapenem types (103 genomes, January 2021 to March 2021) and an Imipenem-Hydrolysing beta-lactamase-positive CPE outbreak (82 genomes, June 2016 to October 2019), using standard clinical criteria and conservative genomic thresholds to quantify how often current IPC surveillance methods correctly identify genomically confirmed transmission events. Findings show that, across 3,423 patient contact-genome pairs, current IPC surveillance methods detected only 20.5% of genomically confirmed transmission events whilst maintaining 98.5% specificity, with missed events arising from temporal, spatial, and cross-species, mechanistic blindspots. In contrast, WGS-enabled IPC surveillance methods provided a 25 to 47-day earlier detection window and, in a linked economic evaluation, delivered annualised savings of up to GBP 3.6 million, as well as a return on investment exceeding 2-fold in 7 of 8 cost scenarios. By operationalising high-throughput WGS data analysis with clinically relevant patient movement data, we evidence that it may be possible to disrupt and thereby mitigate the effects of AMR-driven CPE outbreaks, supporting investigations into the adoption of WGS-enabled IPC surveillance as a standard-of-care tool.

ObjectiveTo evaluate the diagnostic performance of FeverPAIN and Centor with point-of-care test (POCT) results for Group A Streptococcus (GAS) among children and adults presenting with sore throat in community pharmacies. MethodsCross-sectional analysis of patients aged six years and over with sore throat presenting to community pharmacies across Wales delivering the Sore Throat Test and Treat (STTT) service from November 2018 to September 2024. Patients who scored FeverPAIN [&ge;]2 or Centor [&ge;]3 and were able to undergo POCT were eligible for analysis. We described GAS positivity by age group and assessed diagnostic performance of FeverPAIN at the National Institute for Health and Care Excellence (NICE) antibiotic threshold ([&ge;]4), reporting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under receiver operating characteristic curve (AUROC) with 95% confidence intervals (CI). We estimated potential overtreatment and undertreatment if antibiotics were supplied based on FeverPAIN alone. ResultsAmong 73,617 eligible patients, 37.0% (n=27,220) tested POCT-positive for GAS. Positivity was highest in children aged 6-10 years (47.0%: 5,339/11,371). FeverPAIN was used in 92.5% (n=68,099) of assessments. At the NICE-recommended threshold for antibiotic treatment (FeverPAIN [&ge;]4), sensitivity was 55.0% (95% CI: 54.4-55.6%) and specificity 77.0% (95% CI: 76.6-77.4%). PPV was 57.6% (95% CI: 57.0-58.2%) and NPV 75.1% (95% CI: 74.7-75.5%). Overall AUROC was 0.70 (95% CI: 0.70-0.71), with the lowest AUROC of 0.69 (95% CI: 0.68-0.70) observed among children aged 6-10 years. Using FeverPAIN alone would undertreat 44% and overtreat 23% of patients based on POCT results. ConclusionsFeverPAIN alone showed limited diagnostic performance for identifying GAS, with more pronounced discordance observed among children. Incorporating POCTs within community pharmacy sore throat pathways may support more targeted antibiotic prescribing. Our findings support a re-evaluation of the role of POCTs within community pharmacy sore throat pathways.

Objective. To evaluate the diagnostic and prognostic significance of C reactive protein (CRP) level dynamics within the first five days after surgery for the early detection of surgical site infections (SSI) and to identify independent risk factors, taking into account regional specifics of surgical management (types of surgeries, duration of procedures), as well as the local hospital microbial landscape. Materials and Methods. A single-center retrospective cohort analysis of data from 127 patients who underwent surgical procedures between 2022 and 2024 was conducted. CRP levels on postoperative days 1, 3, and 5 were assessed, and delta values were calculated. Descriptive statistics, ROC analysis, and multivariate logistic regression were used to identify predictors of SSI. Results. Patients with SSI lacked the physiological decrease in CRP levels by day 5. The most informative indicator was the CRP level on day 3: a threshold of >106 mg/L was associated with a high risk of SSI (AUC=0.76; sensitivity 85%, specificity 63%). Independent predictors of SSI included surgery duration (OR=1.015 per 1 min; p<0.001) and the increase in CRP between days 3 and 5 (delta CRP3-5: OR=1.027; p=0.023). A combined model (clinical parameters + CRP) demonstrated the highest predictive ability (AUC=0.79). Conclusion. Monitoring CRP dynamics, particularly on days 3 and 5, is a highly informative and accessible method for the early diagnosis of SSI. A CRP threshold of >100 mg/L on day 3 and its subsequent increase should serve as a trigger for in-depth diagnostic investigation and rationalization of antimicrobial therapy. Keywords: C reactive protein, postoperative complications, surgical site infection, antibiotic therapy, predictive factors, diagnosis

Objectives: Optimising parenteral antimicrobial use is central to antimicrobial resistance (AMR) control, yet its appropriateness is difficult to assess. We aimed to develop a quantitative indicator to evaluate the appropriateness of parenteral antimicrobial therapy in hospitalised patients with bloodstream infections. Methods: We developed the Susceptibility-Spectrum Discrepancy Index (S2DI), reflecting the discrepancy between antimicrobial susceptibility of blood culture isolates and the spectrum width of prescribed agents. Using a database from 67 National Hospital Organization hospitals in Japan, we identified patients with Staphylococcus aureus or Escherichia coli bacteraemia from 2017 to 2023. An expert panel of 10 infectious disease physicians independently ranked antimicrobial susceptibility (A) and spectrum width of commonly used agents (B). S2DI was defined as B minus A on day 7 after treatment initiation, with values closer to zero indicating more appropriate therapy. S2DI was calculated for individual cases, aggregated at the hospital level, and analysed using linear mixed-effects models with hospital-level random effects. Results: A total of 4,505 S. aureus and 9,563 E. coli bacteraemia cases were included. Median S2DI was 1 (IQR 0-1) for S. aureus and 2 (IQR 0-3) for E. coli. For both pathogens, later calendar years were significantly associated with more favourable S2DI, suggesting gradual improvement in antimicrobial use. In E. coli bacteraemia, female sex and younger age were also associated with more appropriate therapy. Conclusions: Although variation across hospitals persists, appropriateness of parenteral antimicrobial use has improved over time. S2DI is a simple metric that may support optimisation of antimicrobial use.

Introduction Data on bloodstream infections (BSI) indicate a growth in incidence over time. This analysis utilised national data from England and the best available United States (US) evidence to predict BSI incidence over the years 2025 to 2029. The analysis utilised evidence on the cost-effectiveness of molecular rapid diagnostic tests (mRDT) to estimate the cost and mortality associated with BSI, and the potential for increased use of mRDT to save lives. Methods Data on BSI incidence by age group and sex for England in 2017 and the US (Minnesota) for 2003 to 2005 were combined with demographic projections over the years 2025 to 2029 to estimate the number of BSIs. Published costs and mortality associated with BSI, according to the method of identification of the pathogen, were used to estimate the lives saved and the cost impact of widespread use of mRDT in England and the US. Results BSI cases in England and the US are predicted to total 1.02 million and 6.24 million over the years 2025 to 2029, associated costs are GBP14.6 million and $221 million, respectively. Expanding the use of mRDT would save 2,219 and 7,554 lives in England and the US, respectively, over a 5-year period and would reduce healthcare expenditure in both countries. Conclusion There is a compelling argument to increase the uptake of mRDT to improve patient outcomes. This analysis demonstrates that expanded mRDT adoption can significantly reduce BSI burden, saving over 9,700 lives and decreasing healthcare expenditure in both countries.

Background: CD276 has been proposed as a candidate gene associated with the biological characteristics of meningioma, but its predictive position and interpretive significance within a transcriptomic classifier have not yet been clearly established. Accordingly, this study aimed to evaluate CD276 stepwise across internal model development, external validation, calibration, decision-analytic assessment, feature stability, and robustness analyses using public transcriptomic cohorts. Methods: The analyses in this study were organized into two interconnected notebooks. In Notebook A, we reconstructed the internal training cohort (GSE183653), evaluated the CD276 single-gene signal, and then developed a transcriptome-wide multigene classifier. We also performed permutation importance, bootstrap confidence interval, label permutation test, repeated cross-validation, CD276 ablation, and internal calibration analyses. In Notebook B, we reproduced the external validation cohort (GSE136661) in a fixed common-gene space, applied train-only recalibration and train-only threshold transfer, and extended the interpretation through decision curve analysis, stability analysis, enrichment analysis, and one-factor-at-a-time robustness analysis. Results: The internal training cohort consisted of 185 samples and 58,830 genes, of which 25 were WHO grade III cases. CD276 expression showed a significant association with WHO grade, but the internal discrimination of the CD276-only baseline was limited (ROC-AUC 0.628, average precision 0.323, balanced accuracy 0.540). In contrast, the initial transcriptome-wide model showed ROC-AUC 0.834 and PR-AUC 0.509, and under 5-fold cross-validation, the canonical fulltranscriptome model and the CD276-forced 5,001-feature branch showed mean ROC-AUC/PR-AUC of 0.854/0.564 and 0.855/0.606, respectively, outperforming the CD276-only baseline at 0.644/0.391. CD276 was not included in the initial 5,000-feature filtered set and ranked 900th among 5,001 features even in the forcibly included 5,001-feature branch. In paired ablation analysis, the performance difference attributable to inclusion of CD276 was effectively close to zero (delta ROCAUC 0.000062, delta PR-AUC 0.000056). Internal calibration analysis showed an overconfident probability pattern (Brier score 0.10501, intercept -1.421392, slope 0.413241). In external validation, the fixed multigene pipeline achieved ROC-AUC 0.928 and PR-AUC 0.335. Train-only recalibration improved calibration metrics while preserving discrimination, and decision curve analysis showed threshold-dependent but limited external utility. Stability analysis showed overlap between core-stable genes and high-impact genes, but CD276 was not supported as a dominant stable core feature and remained in the target-of-interest tier. In robustness analysis, some perturbations preserved the primary interpretation, whereas others revealed transform sensitivity or an alternative high-performing feature-space solution. Conclusions: CD276 is a gene of interest associated with meningioma grade, but it was difficult to interpret it as a strong standalone predictor or a dominant stable classifier feature. In this study, the main basis of predictive performance lay not in CD276 alone but in a broader multigene transcriptomic structure, and probability output needed to be interpreted conservatively with calibration taken into account. These findings position CD276 not as a direct single-gene classifier but as a biologymotivated target-of-interest that should be interpreted within a broader transcriptomic program.

BackgroundBacterial co-infection contributes substantially to influenza-associated morbidity and mortality. Patterns of viral circulation, diagnostic testing and antimicrobial use changed markedly during the COVID-19 pandemic, yet contemporary estimates of bacterial co-infection and antimicrobial use in influenza have not been synthesised. ObjectivesTo estimate the pooled prevalence of microbiologically confirmed bacterial co-infection among hospital-attended patients with laboratory-confirmed influenza. Secondary objectives were to characterise co-infecting bacterial pathogens, quantify antimicrobial prescribing overall and across key subgroups. This study was registered with PROSPERO (CRD420251072782). Data sources and eligibilityWe searched Embase (Ovid), MEDLINE, PubMed, Scopus, and Web of Science to 15th June 2025 for English-language studies including [&ge;]50 hospital-attended patients with laboratory-confirmed influenza and reporting bacterial co-infection. MethodsPooled prevalence estimates and antimicrobial prescription proportions were calculated using a generalised linear mixed model with logit link. Subgroup analyses included age group, clinical setting, and seasonal vs. pandemic influenza. Risk of bias was assessed using ROBINS-E and certainty of evidence using GRADE. ResultsNinety-three studies from 30 countries, comprising 111,889 patients with influenza, met inclusion criteria; 9,899 had confirmed bacterial co-infection. The pooled prevalence was 17.3% (95%CI 13.6-21.7%; I2=99.2%). Prevalence was higher in ICU compared to non-ICU settings (28.3% vs. 13.6%). The most frequently identified bacterial pathogens were Streptococcus pneumoniae (35.7%) and Staphylococcus aureus (30.3%). Antimicrobial use, reported in 38 studies, was high (pooled prevalence 88.1%, 95%CI 76.0-94.5%; I2=99.9%), and was more common in adults than children (97.8% vs 65.0%), and in ICU compared with non-ICU settings (96% vs 81%). ConclusionsBacterial co-infection was identified in approximately one in six hospital-attended influenza cases, yet antimicrobial prescribing is near-universal. Substantial heterogeneity and diagnostic variability constraint interpretation but underscore persistent challenges in clinical decision-making. These findings support strengthened diagnostic capacity and antimicrobial stewardship to optimise management of suspected influenza-associated bacterial co-infection.

Background: Human metapneumovirus (hMPV) is commonly associated with respiratory tract infections (RTIs) in young children. Methods: We estimated the annual hospital incidence of hMPV RTIs in children under 5 years in Scotland from 2017 to 2023 using national hospital and laboratory data. Incidence outside Lothian, where testing practices were uncertain, was extrapolated from Lothian laboratory data, where hMPV testing was advised for all RTI admissions. We also examined the severity and mortality of laboratory-confirmed hMPV cases. We developed similar estimates for RSV and Influenza A for comparison. Results: This analysis included 1,462 laboratory-confirmed hMPV hospitalisations in children aged under 5 years. The extrapolated hMPV hospital incidence ranged from 19 per 100,000 to 537 per 100,000 in children aged under 5 years. The extrapolated incidence was two to three times higher than that based on laboratory-confirmed data. Hospital incidence was higher in infants than in toddlers. hMPV incidence dropped substantially during the 2020/21 season, followed by a rebound during the 2021/22 season. About 10% of hMPV RTI hospital admissions required hospital stay [&ge;]5 days, but <1% required intensive care unit admissions or resulted in in-hospital death. RSV hospital incidence appeared substantially higher than the hMPV hospital incidence in this population. Conclusions: hMPV RTIs contribute to a substantial hospital burden in young children in Scotland. However, the RSV RTI burden is likely to be higher in the population unvaccinated against both viruses. Improved surveillance and diagnosis strategies are required to develop robust hospital burden estimates.

SARS{square}CoV{square}2 infection is associated with marked changes of the upper respiratory tract mycobiome. URT mycobiome Changes in non-hospitalized patients however, remains poorly defined. We performed shotgun metagenomic sequencing of 95 upper respiratory tract swab samples from 48 symptomatic SARS{square}CoV{square}2-positive individuals and 47 healthy controls from central India. Fungal diversity and community structure were compared using alpha- and beta-diversity analyses, while differential taxa were identified using prevalence-based testing and LEfSe. SARS{square}CoV{square}2-positive samples showed significantly higher fungal alpha diversity than controls, with increased Shannon diversity (p = 0.000319) and Simpson diversity (p = 0.017). Beta-diversity analysis showed significant separation between groups for both Bray-Curtis and Jaccard distances (PERMANOVA p = 0.001), with significant dispersion effects as well (PERMDISP p = 0.001). Differential analysis identified more SARS{square}CoV{square}2-enriched than control-enriched taxa, including Candida orthopsilosis, Malassezia furfur, M. sympodialis, M. globosa, Aspergillus niger, A. terreus, and A. nidulans. Aspergillus sydowii was the main control-enriched taxon. LEfSe and concordant multi-test analysis supported these findings, and sensitivity analysis confirmed robustness across thresholds. Certain SARS{square}CoV{square}2-enriched taxa were linked to confirmed or probable COVID{square}19-associated fungal infections, whereas no such pathogens were detected in controls. These findings indicate that SARS{square}CoV{square}2 infection is associated with URT mycobiome dysbiosis and enrichment of clinically relevant opportunistic fungi in community cases.

Background: The choice of hand-drying method affects microbial contamination levels but its economic consequences have not been systematically quantified. Methods: By applying a quantitative microbial risk assessment framework, we translated the documented contamination differential between jet air dryers and paper towels into infection risk estimates, and embedded these into an established health economic model of healthcare-associated infections in NHS hospitals and an illustrative productivity analysis for the EU workforce. Results: The median estimated avoidable HCAI cost attributable to jet air dryer presence in UK NHS clinical areas was 58 million pounds per year, representing 2.1% of total HCAI expenditure for the affected hospital population, with a 50% certainty interval of 33-84 million pounds. Extended to the EU workforce, the same contamination differential implied a median of 1.7 billion euros in annual productivity gains, due to reduced absenteeism, for a shift to use of paper towels in public restrooms. Conclusions: These findings suggest that hand-drying method selection carries measurable economic implications that are not currently reflected in facility management practice. The evidence supports the prioritisation of paper towels in clinical and public settings as a cost-effective infection control measure

ObjectivesTo develop a population pharmacokinetic (PPK) model of polymyxin B (PMB) for intravenous (IV) and combined intravenous plus inhaled (IV+IH) administration in critically ill patients, and evaluate the association between the 24-h steady-state area under concentration-time curve to minimum inhibitory concentration ratio (AUCss,24h/MIC) and clinical outcomes. MethodsThis prospective cohort was conducted in the ICU of the Third Xiangya Hospital, Central South University (ethics R19048; ChiCTR1900028602). Adults with multidrug-resistant Gram-negative bacterial infections receiving PMB [&ge;]48 h were enrolled and assigned to IV or IV+IH groups. Serial plasma samples were analyzed by validated LC-MS/MS. The PPK model was developed with NONMEM(R). Clinical efficacy at end of treatment was blindly assessed. ResultsForty-three patients were enrolled (IV, n=22; IV+IH, n=21), with an overall clinical success rate of 66.7%. A two-compartment PPK model best described the data, with typical values of clearance (2.6 L/h), central volume (13.6 L), and peripheral volume (17.6 L). Clearance was influenced by creatinine clearance and total bile acids. In the overall cohort, neither AUCss,24h nor AUCss,24h/MIC differed significantly between clinical success and failure (p=0.591 and 0.143). In the IV group, AUCss,24h/MIC was significantly higher in responders (p=0.005) with an ROC-derived efficacy threshold of 94.37; AUCss,24h showed a non-significant trend (p=0.076). No exposure- response relationship was observed in the IV+IH group (p=0.398 and 0.495). ConclusionsPlasma AUCss,24h/MIC appears to be associated with clinical efficacy during IV monotherapy but not in IV+IH regimens, likely due to high pulmonary exposure. Plasma-based PK/PD targets should be applied cautiously when inhalation is added.

Large epidemics of invasive meningococcal disease are rare in temperate regions. Here, we analyse administrative data on the largely forgotten epidemic of bacterial meningococcal meningitis that occurred in Glasgow in 1907, probably the largest on record in the UK. The epidemic, predominantly confined to the city, killed around 1,000 people, had a case fatality rate of nearly 70%, and hit infants and young children the hardest. We show the rapid rise and fall in cases and the spatial distribution of incidence and mortality rates within the city. We find that within-household overcrowding was a key driver of incidence whereas between-household geographic proximity was not. We also find that the spatial distribution of disease risk during the epidemic persisted in the post-epidemic period and during a later outbreak. The findings suggest that interventions should prioritise populations in areas that have experienced higher incidence rates to mitigate the risk of future outbreaks.

BackgroundIdiopathic epilepsy (IE) is the most common chronic nervous system disorder of dogs, and its cause is poorly understood. Emerging evidence suggests that microbiome alterations can occur with IE via the microbiota-gut-brain axis. Therefore, we analyzed the fecal microbiomes of 98 dogs (49 IE, 49 control) in a pairwise case-control observational study using 16S rRNA gene sequencing. ResultsAlthough the microbial community was mostly similar between groups, IE was associated with a modest but significant shift in Weighted-Unifrac distance (P = 0.042). We used six differential abundance (DA) methods to identify differentially abundant amplicon sequencing variants (ASVs) between IE and control groups. Notably, one Collinsella ASV was found to be significantly more abundant in IE dogs by all six methods. The gut microbial compositions varied drastically across households (accounting for about 69% of the total variation), but did not have significant differences between sex, age, or breed. Phenobarbital administration in IE dogs had a significant effect on seizure control, and was not associated with changes in the microbiome. ConclusionOur findings suggest a relationship between gut microbiomes and IE. However, the specific mechanism needs to be further investigated.

Objectives: Scrub typhus, caused by the bacterium Orientia tsutsugamushi, is frequently underdiagnosed due to its non-specific clinical presentation and the frequent absence of eschar. Most molecular diagnostic assays target single-copy genes of O. tsutsugamushi, which can limit diagnostic sensitivity. We aimed to develop an ultra-sensitive quantitative PCR (qPCR) assay targeting a highly repetitive element in O. tsutsugamushi genome. Methodology: We developed a SYBR Green-based qPCR assay (TranScrub) targeting a multicopy transposase gene of O. tsutsugamushi and compared its performance with assays targeting the 56kDa (single-copy) and traD (multicopy) genes. Diagnostic performance was evaluated using clinical specimens and a panel of blood-borne pathogens. The limit of detection (LOD) was estimated using serial dilutions of quantified template. The assay was further applied to dried blood spot (DBS) samples from patients with acute febrile illness of unknown aetiology, with positives confirmed by Oxford Nanopore amplicon sequencing. Results: Targeting the multicopy transposase gene enabled highly sensitive detection of O. tsutsugamushi, outperforming the conventional 56-kDa assay and matching the traD assay. TranScrub achieved a 91% sensitivity (29/32) and 100% specificity (77/77) using blood-derived DNA, with no cross-reactivity. The LOD was 0.024 genome equivalents/L. Among 81 DBS samples from acute febrile patients of unknown aetiology, 6 (7.5%) tested positive, all confirmed by sequencing. Conclusions: The transposase gene represents a novel target that improves molecular detection of scrub typhus. TranScrub enables sensitive and specific detection from both blood and DBS, supporting its use in clinical diagnosis and field surveillance.

1Canine atopic dermatitis (CAD) is a chronic inflammatory skin condition sometimes associated with microbial dysbiosis, including alterations in colonization by the lipophilic yeast Malassezia pachydermatis. This study investigated the population diversity of M. pachydermatis in the ear canals of healthy and CAD-affected dogs using Fourier-transform infrared (FTIR) spectroscopy and whole genome sequencing (WGS). Among 60 dogs, M. pachydermatis prevalence was significantly higher in CAD cases than in healthy controls. FTIR spectroscopy revealed greater strain heterogeneity in CAD-affected dogs, often with distinct genotypes in each ear, while healthy dogs exhibited more homogeneous populations. Using a previously developed FTIR-based artificial neural network classifier, we assigned strains to three phylogroups. Strains from phylogroups I and III were significantly enriched in CAD-affected dogs, while phylogroup II was most prevalent overall and the dominant phylogroup in healthy controls. This suggests that CAD-associated inflammation may favor specific M. pachydermatis phylogroups and sub-clusters within phylogroups, shaping colonization dynamics. FTIR-based typing showed full concordance with WGS across 35 sequenced isolates, recapitulating relationships among phylogenetically related isolates and their similar phenotypic profiles. Overall, our findings reveal strain-level shifts in M. pachydermatis populations associated with CAD and establish FTIR spectroscopy as a rapid, cost-effective tool for large-scale epidemiological studies.

The Epic Sepsis Model version 2 (ESMv2) is a prediction model embedded into the electronic medical record used to warn clinicians which hospitalized patients are at risk for sepsis. We conducted a retrospective cohort study of 31,951 hospitalizations of 25,760 patients to compare analyses conducted at the commonly used patient-level (where a maximum prediction prior to the onset of sepsis is used to measure performance) vs novel prediction-level (where each prediction is used to measure performance). Sepsis, defined by the Sepsis 3 criteria occurred during 1,049 hospitalizations (3.3%). Patient-level analyses suggested excellent discrimination AUC 0.86; [IQR 0.85, 0.87], whereas prediction-level analyses demonstrated lower performance AUC 0.62; [IQR 0.57, 0.65]. Low estimates of the positive predictive value (14.5% at the patient level vs 4% at the prediction level) imply a high number of false alerts. Common evaluation approaches may overstate the performance of dynamic prediction models and mislead clinical decision-making.