Shogo Hanai

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.

BACKGROUND: The incidence of syphilis has been rising globally but effective screening strategies are lacking. Preoperative syphilis screening is commonly performed at Japanese hospitals for infection prevention purposes. However, its effectiveness in improving subsequent management is unclear. METHODS: A retrospective cohort study was conducted to assess the effectiveness of universal preoperative syphilis screening testing implemented at a Japanese tertiary care hospital from April 2017 to March 2023. The annual prevalence of positive preoperative treponemal tests was tracked, and subsequent clinical management for patients with a positive test result was investigated. Attributes of patients with a positive result who were more likely to receive further evaluation were also elucidated. RESULTS: In total, 82,439 patients underwent surgery during the study period. Preoperative treponemal testing was performed in 94.8% (78,170/82,439) of the patients. A positive test result was recorded in 544 (0.70%) with an annual positivity rate ranging from 0.61 to 0.83%, whereas the proportion of presumed active syphilis ranged from 0.02 to 0.08%. A total of 85 patients with a positive syphilis screening test, a nontreponemal test with a positive titer, and without history of syphilis were identified. Of those, only 45 patients (52.9%) received further evaluation. CONCLUSION: The positivity of preoperative treponemal testing was low despite the rising incidence of syphilis in Japan, and the prevalence of presumed active syphilis identified during the preoperative period was even smaller. Routine treponemal testing in the preoperative setting had limited utility in effectively identifying patients with active syphilis.

OBJECTIVES: Consultation with infectious disease specialists is associated with reduced patient mortality in the care of patients with Staphylococcus aureus bacteremia (SAB) through appropriate management of complications including infective endocarditis. This study aimed to determine the rates of confirmation of a negative blood culture, implementation of echocardiography, and administration of appropriate antibiotics in patients with SAB at a university hospital in Japan that provides general internal medicine and not an infectious disease consultation service. METHODS: We conducted a retrospective cohort study at Dokkyo Medical University Hospital in Japan. Patients eligible for inclusion in the study were ≥20 years of age with ≥1 positive blood culture for S. aureus identified in a clinical microbiology laboratory. The primary outcome was the proportion of patients with confirmation of a negative blood culture, implementation of echocardiography, and administration of appropriate antimicrobial agents. RESULTS: A total of 109 patients with SAB were included in the analysis. Follow-up blood cultures were collected in 91 patients and negative results were documented in 88 patients. Follow-up blood culture collection was performed within 4 days of the initial blood culture collection in 49 patients. Echocardiography was performed appropriately in 40 patients. Appropriate antibiotic therapy was administered in 36 patients. CONCLUSIONS: Quality-of-care indicators were more commonly implemented in patients with SAB who received general internal medicine consultation than in those who did not.

PURPOSE: The effect of antibiotics administered before blood cultures performed in general internal medicine outpatient settings is not well known. PATIENTS AND METHODS: We conducted a retrospective case-control study including adult patients who underwent blood cultures in the general internal medicine outpatient department of a Japanese university hospital between 2016 and 2022. Patients with positive blood cultures were included as cases and matched patients with negative blood cultures were included as controls. Univariable and multivariable logistic regression analyses were performed. RESULTS: A total of 200 patients and 200 controls were included. Antibiotics were administered prior to blood culture in 20% of patients (79/400). Oral antibiotics were prescribed to 69.6% of the prior antibiotics (55/79). Prior antibiotic use was significantly lower among patients with positive than negative blood cultures (13.5% vs 26.0%, p = 0.002) and was an independent predictive factor in univariable (odds ratio, 0.44; 95% confidence interval, 0.26-0.73; p = 0.002) and multivariable (adjusted odds ratio, 0.31; 95% confidence interval, 0.15-0.63; p = 0.002) logistic regression models for positive blood culture. The area under the receiver operating characteristic (AUROC) curve of the multivariable model for predicting positive blood cultures was 0.86. CONCLUSION: There was a negative correlation between prior antibiotic use and positive blood cultures in the general internal medicine outpatient department. Therefore, physicians should interpret the negative results of blood cultures performed after the administration of antibiotics with care.