Yuya Kawamoto

Evidence regarding the diagnostic value of quantitative interferon-gamma release assay (IGRA) results in elderly populations is limited, and large-scale data for QuantiFERON-TB Gold Plus (QFT-Plus) are scarce. We evaluated QFT-Plus and T-SPOT.TB (T-SPOT) for distinguishing active tuberculosis (ATB) from latent infection (LTBI) in elderly individuals in Japan, a super-aged country. We conducted a retrospective, cross-sectional diagnostic accuracy study of patients ≥65 years who underwent IGRA testing between 2015 and 2024 at two hospitals: a tuberculosis referral center (QFT-Plus and T-SPOT) and a tertiary hospital (T-SPOT only). ATB was defined as microbiologically confirmed TB. Quantitative IGRA values were compared between ATB and LTBI in all patients and in IGRA-positive subsets. Receiver operating characteristic (ROC) curves assessed discriminatory performance. Among 10,745 elderly patients (ATB: n = 310; LTBI: n = 1,158), values showed substantial overlap. For T-SPOT, the area under the curves (AUCs) improved at Tosei General Hospital (TGH) (ESAT-6: 0.679, CFP-10: 0.670) in IGRA-positive cases. In contrast, all-patient AUCs at Fujita Health University Hospital (FHUH) were low (ESAT-6: 0.367, CFP-10: 0.362), demonstrating an inverse association, though they improved (ESAT-6: 0.607 and CFP-10: 0.554) in IGRA-positive cases. For QFT-Plus, all-patient AUCs were low (TB1 antigen: 0.462, TB2 antigen: 0.470), but improved in the IGRA-positive cohort (TB1 antigen: 0.630, TB2 antigen: 0.645). The optimal quantitative cutoffs in IGRA-positive cases provided modest diagnostic accuracy. In elderly individuals, quantitative IGRA values alone have limited ability to distinguish ATB from LTBI, but QFT-Plus and T-SPOT show modest improvement in IGRA-positive cases. Although not suitable as a stand-alone diagnostic, quantitative IGRA may assist risk stratification and decision-making in selected scenarios.IMPORTANCETuberculosis remains a major health concern in aging societies, such as Japan, where most patients are elderly adults with impaired immune function. Interferon-gamma release assays (IGRA) are widely used for detecting infection, but the role of their quantitative values in differentiating active tuberculosis from latent tuberculosis infection has been uncertain. Our study is the first to evaluate the quantitative performance of the latest QuantiFERON-TB Gold Plus and T-SPOT.TB specifically in elderly patients, across both a tuberculosis referral hospital and a university hospital. Although absolute separation between active and latent disease was not achieved, we found that, in test-positive individuals, active cases tended to yield higher values, particularly with T-SPOT.TB. This indicates that quantitative information, when interpreted within the clinical context, can assist physicians in assessing risk and guiding further diagnostic steps, offering practical value for improving decision-making in the care of vulnerable elderly patients.

OBJECTIVES: Advances in critical care have increased antimicrobial use in intensive care units (ICUs), often extending to end-of-life patients without clear clinical benefit. This systematic review and meta-analysis investigated antimicrobial use in critically ill ICU patients with end-of-life care status. METHODS: A comprehensive search of Medline (PubMed) and Embase identified articles published from January 2000 through August 2023. Interventional and observational studies focusing on antimicrobial use for critically ill ICU patients with end-of-life status were included. Study types, demographics, clinical characteristics, and antimicrobial use (i.e., continuation or discontinuation) were extracted. A meta-analysis was conducted to estimate the proportion of antimicrobial use, with subgroup analyses by region and national income status. RESULTS: From 13,542 publications, 26 studies met the inclusion criteria; no randomized or prospective studies were identified. Thirteen studies (50.0%) reported antimicrobial use and were included in the quantitative synthesis. The pooled proportion of antimicrobial prescriptions was 0.35 (95% CI, 0.18-0.54) with significant heterogeneity (I2=99.7%, P<0.01). Subgroup analysis revealed regional differences: 0.50 (95% CI, 0.11-0.89) in North America, 0.40 (95% CI, 0.10-0.76) in Europe, and 0.24 (95% CI, 0.10-0.76) in the Asia-Pacific region. CONCLUSIONS: Despite increasing emphasis on judicious antimicrobial use, studies comprehensively assessing antimicrobial prescribing in ICU patients with end-of-life care status remain scarce. Based on the limited available evidence, approximately one-third of such patients received antimicrobials. Regional differences in prescribing patterns were also observed, potentially influencing overall antimicrobial consumption in ICUs.

BACKGROUND: Carbapenem-resistant Gram-negative bacilli (CR-GNB) are a major public health threat, traditionally linked to hospital settings. However, infections are increasingly reported in the community, and the clinical distinctions between community-associated (CA) and healthcare-associated (HA) infections remain unclear. METHODS: We conducted a prospective multicenter study of hospitalized patients with CR-GNB infections across 13 Japanese tertiary hospitals between April 2019 and March 2024. Infections were categorized as CA, HA, or hospital-onset (HO) using standardized criteria. We compared patient demographics, microbiological findings, infection sites, and clinical outcomes based on the setting of onset. RESULTS: Among 425 patients, 43 had CA, 59 HA, and 323 HO infections. Pseudomonas aeruginosa was the predominant pathogen in all groups. Aeromonas species were more frequently associated with CA than HO cases (23.3% of CA vs 2.2% of HO cases), whereas Stenotrophomonas maltophilia was detected almost exclusively among HO cases. Hospital-onset infections were associated with longer median hospital stays compared with CA infections (68 vs 17 days) and a trend toward higher 30-day mortality (23.9% vs 9.5%). In contrast, HA infections demonstrated no significant differences from CA infections in either hospital length of stay (23 vs 17 days) or 30-day mortality rate (10.3% vs 9.5%). CONCLUSIONS: Community-associated CR-GNB infections are an emerging concern in Japan, showing distinct pathogen profiles and infection sites compared to HO cases. Importantly, HA infections resembled CA infections in terms of clinical characteristics and outcomes, suggesting a need to reexamine the clinical relevance of current HA classification criteria for guiding therapy and risk stratification.

INTRODUCTION: Cases of hospital-onset bacteremia and fungemia (HOBF) are on the rise in Japanese hospitals, but little is known about their incidence in hospitals and how it relates to the availability of services provided by infectious diseases departments. METHODS: We herein investigated the monthly incidence density of HOBF per 1,000 patient days from 2013 through 2023 at a tertiary care hospital in Japan. The incidence of overall HOBF and pathogen-specific HOBF, including those caused by Enterobacterales, Staphylococcus aureus, coagulase-negative staphylococci (CNS), and Candida species, was tracked. Changes in the HOBF trend before and after the establishment of an infectious diseases department at the hospital were evaluated. RESULTS: In total, 4,315 HOBF-related events were identified. The overall incidence density of HOBF increased by 2.4-fold from 0.58 per 1,000 PD in 2013 to 1.42 per 1,000 PD in 2023. Both the level and trend changes in the incidence density of overall HOBF (+0.3142 for change in level [P < .001]; +0.0085 for change in trend [P < .001]), HOBF caused by S. aureus (+0.0983 for change in level [P < .001]; +0.0016 for change in trend [P = 0.016]), and Candida spp. (+0.0466 for change in level [P = 0.030]; +0.0019 for change in trend [P = 0.002]) significantly increased after the establishment of the infectious diseases department. CONCLUSION: The incidence density of overall HOBF and clinically important pathogen-specific HOBF increased over the last decade. The availability of services through the infectious diseases department was significantly associated with an increase in the HOBF incidence, likely suggesting improvement in the diagnosis of HOBF.