SARS-CoV-2 seroprevalence among healthcare workers in a highly vaccinated Japanese medical center from 2020-2023

Infection-induced SARS-CoV-2 seroprevalence has been studied worldwide. At Juntendo University Hospital (JUH) in Tokyo, Japan, we have consistently conducted serological studies using the blood residue of healthcare workers (HCWs) at annual health examinations since 2020. In this 2023 study (n = 3,594), N-specific seroprevalence (infection-induced) was examined while univariate and multivariate logistic regression analyses were performed to compute ORs of seroprevalence with respect to basic characteristics of participants. We found that the N-specific seroprevalence in 2023 was 54.1%-a jump from 17.7% in 2022, and 1.6% in 2021-with 37.9% as non-PCR-confirmed asymptomatic infection cases. Those younger than 50 (adjusted OR = 1.62; p < .001) and recipients with 4 doses or less of vaccine had a higher risk to be N-positive, ranging from 1.45 times higher for the participants with 4 doses (p < .001) to 4.31 times higher for the participants with 1 dose (p < .001), compared to those with 5 or more doses. Our findings indicate that robust vaccination programs may have helped alleviate symptoms but consequently caused asymptomatic spread in this hospital, especially among younger HCWs. Although having four doses or less was found to be associated with higher risk of infection, the optimal constitution and intervals for effective booster vaccines warrant further investigations.

Cardiometabolic health in people with HIV: expert consensus review

OBJECTIVES

To develop consensus data statements and clinical recommendations to provide guidance for improving cardiometabolic health outcomes in people with HIV based on the knowledge and experience of an international panel of experts.

METHODS

A targeted literature review including 281 conference presentations, peer-reviewed articles, and background references on cardiometabolic health in adults with HIV published between January 2016 and April 2022 was conducted and used to develop draft consensus data statements. Using a modified Delphi method, an international panel of 16 experts convened in workshops and completed surveys to refine consensus data statements and generate clinical recommendations.

RESULTS

Overall, 10 data statements, five data gaps and 14 clinical recommendations achieved consensus. In the data statements, the panel describes increased risk of cardiometabolic health concerns in people with HIV compared with the general population, known risk factors, and the potential impact of antiretroviral therapy. The panel also identified data gaps to inform future research in people with HIV. Finally, in the clinical recommendations, the panel emphasizes the need for a holistic approach to comprehensive care that includes regular assessment of cardiometabolic health, access to cardiometabolic health services, counselling on potential changes in weight after initiating or switching antiretroviral therapy and encouraging a healthy lifestyle to lower cardiometabolic health risk.

CONCLUSIONS

On the basis of available data and expert consensus, an international panel developed clinical recommendations to address the increased risk of cardiometabolic disorders in people with HIV to ensure appropriate cardiometabolic health management for this population.

Hospitalists' COVID-19 management roles in hospitals without infectious disease specialists

BACKGROUND

Hospitalists may work in a variety of clinical settings to manage COVID-19 cases. However, the extent of their involvement in COVID-19 care is unknown, particularly in hospitals without infectious disease (ID) specialists.

METHODS

This study aimed to confirm whether hospitalists provided COVID-19 management in various clinical settings when ID specialists were unavailable. We conducted a multicenter cross-sectional study using a web-based questionnaire. The participants were full-time hospitalists working in Japanese academic community-based hospitals. The study period was from 15 January 2021 to 15 February 2021, during Japan's third wave of the COVID-19 pandemic. The primary outcome was the rate of hospitalists participating in COVID-19 inpatient management in hospitals with or without ID specialists.

RESULTS

ID specialists were absent in 31% of small hospitals (those with fewer than 249 registered beds), but only 4% of large hospitals (p < 0.001). Hospitalists were more likely to manage both COVID-19 inpatient care and emergency department care in hospitals without than with hospitals with ID specialists (76 versus 56% (p = 0.01) and 90 versus 73% (p = 0.01), respectively). After adjusting for confounders by multivariate analysis, hospitalists who worked in hospitals without ID specialists had higher odds of participating in COVID-19 inpatient care than those who worked in hospitals with such specialists (adjusted odds ratio: 3.0, 95% CI: 1.2-7.4).

CONCLUSION

Hospitalists were more likely to provide COVID-19 inpatient care in various clinical settings in hospitals without ID specialists.

Effects of the induction of humoral and cellular immunity by third vaccination for SARS-CoV-2

INTRODUCTION

To control the spread of severe disease caused by mutant strains of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), it is necessary to determine whether continued vaccination enhances humoral and cellular immunity.

AIM

In this study, we examined the changes in humoral and cellular immunity to SARS-CoV-2 after administration of the third vaccination in Japanese adults who had received the second dose of messenger ribonucleic acid (mRNA)-1273 vaccine and the third vaccination (BNT162b2 or mRNA-1273).

METHODS

We measured anti-spike antibodies in immunoglobulin G (IgG) and anti-nucleocapsid IgG titers in the serum of the vaccinated subjects. To evaluate cellular immunity, the peripheral blood mononuclear cells of inoculated individuals were cultured with spiked proteins, including those of the SARS-CoV-2 conventional strain and Omicron strain, and then subjected to enzyme-linked immunospot (ELISPOT).

RESULTS

The results revealed that the anti-SARS-CoV-2 spike protein antibody titer increased after the third vaccination and was maintained; however, a decrease was observed at 6 months after vaccination. SARS-CoV-2 antigen-specific T helper (Th)1 and Th2 cell responses were also induced after the third vaccination and were maintained for 6 months after vaccination. Furthermore, induction of cellular immunity against Omicron strains by the omicron non-compliant vaccines, BNT162b2 or mRNA-1273, was observed.

CONCLUSION

These findings demonstrate the effectiveness of vaccination against unknown mutant strains that may occur in the future and provide important insights into vaccination strategies.

Effect of poor oral health status at hospital admission on in-hospital outcomes of older patients with aspiration pneumonia

PURPOSE

To investigate the effects of oral health status at admission on in-hospital outcomes and how it varies during hospitalization in older patients with aspiration pneumonia.

METHODS

This prospective cohort study involved patients aged ≥ 65 years who were admitted to an acute care hospital with a diagnosis of aspiration pneumonia. The patients' basic health information, length of hospital stay (LOS), and oral health assessment tool (OHAT), functional oral intake scale (FOIS), pneumonia severity index, and clinical frailty scale scores were recorded. Patients were divided into two groups based on their median OHAT scores, and intergroup changes were analyzed as a function of time. The relationship between the LOS, FOIS score upon discharge, and OHAT scores at admission was examined using multiple regression analysis.

RESULTS

Of the 89 participants (52 were men, with a mean age of 84.8 ± 7.9 years), 75 were discharged. The patients' oral health was measured weekly for 3 weeks after the initial assessment via the OHAT, wherein the median score was 7, with a significant between-group difference. Moreover, OHAT scores improved within both groups throughout their stay. OHAT scores at admission were independently associated with the LOS (B = 5.51, P = 0.009).

CONCLUSION

Poor oral health status at admission was associated with longer hospital stays. Both the high- and low-OHAT groups showed OHAT score improvements. Oral health status is critical in preventing the onset of and treating aspiration pneumonia.

AI Analysis of General Medicine in Japan: Present and Future Considerations

This paper presents an interpretation of artificial intelligence (AI)-generated depictions of the present and future of general medicine in Japan. Using text inputs, the AI tool generated fictitious images based on neural network analyses. We believe that our study makes a significant contribution to the literature because the direction of general medicine in Japan has long been unclear, despite constant discussion. Our AI analysis shows that Japanese medicine is currently plagued by issues with polypharmacy, likely because of the aging patient population. Additionally, the analysis indicated a distressed female physician and evoked a sense of anxiety about the future of female physicians. It discusses whether the ability to encourage the success of female physicians is a turning point for the future of medicine in Japan.

Corrigendum: Urokinase-type plasminogen activator and plasminogen activator inhibitor-1 complex as a serum biomarker for COVID-19

[This corrects the article DOI: 10.3389/fimmu.2023.1299792.].

Isolation and identification of Wickerhamiella tropicalis from blood culture by MALDI-MS

Wickerhamiella is a genus of budding yeast that is mainly isolated from environmental samples, and 40 species have been detected. The yeast isolated from human clinical samples usually only contain three species: W. infanticola, W. pararugosa and W. sorbophila. In this study, we isolated W. tropicalis from a blood sample of a six-year-old female with a history of B-cell precursor lymphoblastic leukemia in Japan in 2022. Though the strain was morphologically identified as Candida species by routine microbiological examinations, it was subsequently identified as W. tropicalis by sequencing the internal transcribed spacer (ITS) of ribosomal DNA (rDNA). The isolate had amino acid substitutions in ERG11 and FKS1 associated with azole and echinocandin resistance, respectively, in Candida species and showed intermediate-resistant to fluconazole and micafungin. The patient was successfully treated with micafungin. Furthermore, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) detected three novel peaks that are specific for W. tropicalis, indicating that MALDI-MS analysis is useful for rapid detection of Wickerhamiella species in routine microbiological examinations.

Seroprevalence of SARS-CoV-2 antibodies among Japanese healthcare workers from 2020 to 2022 as assayed by two commercial kits

Antibody tests are used as surveillance tools for informing health policy making. However, results may vary by type of antibody assay and timing of sample collection following infection. Long-term longitudinal cohort studies on antibody assay seropositivity have remained limited, especially among Asian populations. Using blood samples obtained at health physicals (2020-2022) of healthcare workers (mass vaccinated with mRNA COVID-19 vaccines) at a Japanese medical center, we measured N-specific antibodies using two commercially available systems. Roche Elecsys Anti-SARS-CoV-2 measures total antibodies and Abbott Alinity SARS-CoV-2 IgG measures only IgG. Among 2538 participants, seroprevalence was found to be 16.6% via total antibody assay versus 12.9% by IgG-only (including grayzone) by mid-June 2022. For 219 cases with a previous PCR-confirmed infection, positivity was 97.3% using total antibody assay versus 76.3% using IgG-only assay at the 2022 health physical. Using PCR positive test date as day 0, while the positivity of the total antibody assay was retained for the entire study period (until more than 24-months post-infection), the IgG-only assay's positivity declined after month 4. The Mantel-Haenszel test found a significant difference in the two assays' seropositivity, between stratified groups of "within 3 months" and "4 months or more" from infection (P < 0.001). Our study found significant differences in seropositivity over time of total antibody versus IgG-only assays, suggesting an optimal assay for retaining sensitivity over the entire infection period when designing seroprevalence studies.

Atypical presentation of tight filum terminale with thoracic disc herniation: a case report

BACKGROUND

Tight filum terminale is a rare and challenging condition to diagnose because it presents with nonspecific symptoms and unclear imaging findings. This report documents an atypical case of tight filum terminale.

CASE PRESENTATION

The patient was a previously healthy Asian 18-year-old male presenting with recurrent upper extremity and back pain, initially treated as nonspecific musculoskeletal pain. Notably, the patient's symptoms were inconsistent with the dermatome, showing no correlation with his skin's sensory innervation areas. In contrast to typical tight filum terminale presentations focused on lower extremity and lumbar region disturbances, this patient experienced pain and weakness predominantly in the upper extremities and back, hypothesized to result from traction myelopathy exacerbated by thoracic disc herniation. Investigations including blood and nerve function tests were inconclusive. However, a magnetic resonance imaging scan revealed a combination of tight filum terminale and tiny thoracic disc herniation. A diagnosis of tethered spinal cord syndrome was confirmed following further tests and imaging. The filum terminale was surgically removed, resolving the symptoms at a 7-month follow-up.

CONCLUSIONS

This case underlines the importance of including tight filum terminale as a differential diagnosis in cases of unexplained upper or lower extremity pain. Primary care practitioners, particularly those managing undefined symptoms, should consider tight filum terminale in their diagnostic approach.

Demographic and clinical characteristics of patients with zinc deficiency: analysis of a nationwide Japanese medical claims database

Zinc deficiency, affecting more than 2 billion people globally, poses a significant public health burden due to its numerous unfavorable effects, such as impaired immune function, taste and smell disorders, pneumonia, growth retardation, visual impairment, and skin disorders. Despite its critical role, extensive large-scale studies investigating the correlation between patient characteristics and zinc deficiency still need to be completed. We conducted a retrospective, cross-sectional observational study using a nationwide Japanese claims database from January 2019 to December 2021. The study population included 13,100 patients with available serum zinc concentration data, excluding individuals under 20 and those assessed for zinc concentrations after being prescribed zinc-containing medication. Significant associations with zinc deficiency were noted among older adults, males, and inpatients. Multivariate analysis, adjusting for age and sex, indicated significant associations with comorbidities, including pneumonitis due to solids and liquids with an adjusted Odds Ratio (aOR) of 2.959; decubitus ulcer and pressure area (aOR 2.403), sarcopenia (aOR 2.217), COVID-19 (aOR 1.889), and chronic kidney disease (aOR 1.835). Significant association with medications, including spironolactone (aOR 2.523), systemic antibacterials (aOR 2.419), furosemide (aOR 2.138), antianemic preparations (aOR 2.027), and thyroid hormones (aOR 1.864) were also found. These results may aid clinicians in identifying patients at risk of zinc deficiency, potentially improving care outcomes.

Identification of risk factors for the onset of delirium associated with COVID-19 by mining nursing records

COVID-19 has a range of complications, from no symptoms to severe pneumonia. It can also affect multiple organs including the nervous system. COVID-19 affects the brain, leading to neurological symptoms such as delirium. Delirium, a sudden change in consciousness, can increase the risk of death and prolong the hospital stay. However, research on delirium prediction in patients with COVID-19 is insufficient. This study aimed to identify new risk factors that could predict the onset of delirium in patients with COVID-19 using machine learning (ML) applied to nursing records. This retrospective cohort study used natural language processing and ML to develop a model for classifying the nursing records of patients with delirium. We extracted the features of each word from the model and grouped similar words. To evaluate the usefulness of word groups in predicting the occurrence of delirium in patients with COVID-19, we analyzed the temporal changes in the frequency of occurrence of these word groups before and after the onset of delirium. Moreover, the sensitivity, specificity, and odds ratios were calculated. We identified (1) elimination-related behaviors and conditions and (2) abnormal patient behavior and conditions as risk factors for delirium. Group 1 had the highest sensitivity (0.603), whereas group 2 had the highest specificity and odds ratio (0.938 and 6.903, respectively). These results suggest that these parameters may be useful in predicting delirium in these patients. The risk factors for COVID-19-associated delirium identified in this study were more specific but less sensitive than the ICDSC (Intensive Care Delirium Screening Checklist) and CAM-ICU (Confusion Assessment Method for the Intensive Care Unit). However, they are superior to the ICDSC and CAM-ICU because they can predict delirium without medical staff and at no cost.

Web-Based Search Volume for HIV Tests and HIV-Testing Preferences During the COVID-19 Pandemic in Japan: Infodemiology Study

BACKGROUND

Research has found a COVID-19 pandemic-related impact on HIV medical services, including clinic visits, testing, and antiviral therapy initiation in countries including Japan. However, the change in trend for HIV/AIDS testing during the COVID-19 pandemic has not been explored extensively in the Japanese population.

OBJECTIVE

This infodemiology study examines the web-based search interest for two types of HIV tests, self-test kits and facility-based tests, before and during the COVID-19 pandemic in Japan.

METHODS

The monthly search volume of queried search terms was obtained from Yahoo! JAPAN. Search volumes for the following terms were collected from November 2017 to October 2018: "HIV test," "HIV test kit," and "HIV test health center." The search term "Corona PCR" and the number of new COVID-19 cases by month were used as a control for the search trends. The number of new HIV cases in the corresponding study period was obtained from the AIDS Trend Committee Quarterly Report from the AIDS Prevention Foundation.

RESULTS

Compared to the search volume of "corona-PCR," which roughly fluctuated corresponding to the number of new COVID-19 cases in Japan, the search volume of "HIV test" was relatively stable from 2019 to 2022. When we further stratified by the type of HIV test, the respective web-based search interest in HIV self-testing and facility-based testing showed distinct patterns from 2018 to 2022. While the search volume of "HIV test kit" remained stable, that of "HIV test health center" displayed a decreasing trend starting in 2018 and has remained low since the beginning of the COVID-19 pandemic. Around 66%-71% of the search volume of "HIV test kits" was attributable to searches made by male internet users from 2018 to 2022, and the top three contributing age groups were those aged 30-39 (27%-32%), 20-29 (19%-32%), and 40-49 (19%-25%) years. On the other hand, the search volume of "HIV test health centers" by male users decreased from more than 500 from 2018 to 2019 to fewer than 300 from 2020 to 2022.

CONCLUSIONS

Our study found a notable decrease in the search volume of "HIV test health center" during the pandemic, while the search volume for HIV self-testing kits remained stable before and during the COVID-19 crisis in Japan. This suggests that the previously reported COVID-19-related decrease in the number of HIV tests mostly likely referred to facility-based testing. This sheds light on the change in HIV-testing preferences in Japan, calling for a more comprehensive application and regulatory acceptance of HIV self-instructed tests.

Dental Care to Reduce Aspiration Pneumonia Recurrence: A Prospective Cohort Study

BACKGROUND

Aspiration pneumonia has a high recurrence rate, and oral care by dentists has been found effective in preventing its onset; however, this has not been evaluated using prospective studies. Therefore, we conducted a prospective study to evaluate the effectiveness of professional oral care by dentists in reducing aspiration pneumonia recurrence in older adult patients.

METHODS

In this prospective cohort study, we evaluated a dental oral care intervention, using a historical control group (control group). It was conducted at a single-centre regional core hospital in Japan that serves a large number of patients aged older than 80 years. Patients who were hospitalised for aspiration pneumonia were included in this study. During the study period (1 April 2021 to 31 March 2022), the clinical group received weekly professional cleaning by a dentist and the control group received standard oral care by a nurse as usual from 1 April 2020 to 31 March 2021. The dentist oral care group received weekly professional oral care from a dentist and was followed prospectively for 1 year. A Kaplan-Meier analysis was used to evaluate the timing of recurrent aspiration pneumonia or death. A Cox proportional hazards model was used to obtain a hazard ratio and determine the 95% confidence intervals.

RESULTS

There were 91 participants in the clinical group and 94 in the control group. The mean age of participants was 85 years, and 75 (40.5%) were female. The recurrence rate was 27.5% in the clinical group and 44.7% in the control group (P = .005). Professional cleaning by a dentist reduced the risk of recurrence of aspiration pneumonia by approximately 50% (adjusted hazard ratio, 0.465; 95% confidence interval, 0.278-0.78).

CONCLUSIONS

Professional cleaning by a dentist was associated with a lower rate of aspiration pneumonia recurrence than nurse-provided conventional oral care.

Urokinase-type plasminogen activator and plasminogen activator inhibitor-1 complex as a serum biomarker for COVID-19

Patients with coronavirus disease-2019 (COVID-19) have an increased risk of thrombosis and acute respiratory distress syndrome (ARDS). Thrombosis is often attributed to increases in plasminogen activator inhibitor-1 (PAI-1) and a shut-down of fibrinolysis (blood clot dissolution). Decreased urokinase-type plasminogen activator (uPA), a protease necessary for cell-associated plasmin generation, and increased tissue-type plasminogen activator (tPA) and PAI-1 levels have been reported in COVID-19 patients. Because these factors can occur in free and complexed forms with differences in their biological functions, we examined the predictive impact of uPA, tPA, and PAI-1 in their free forms and complexes as a biomarker for COVID-19 severity and the development of ARDS. In this retrospective study of 69 Japanese adults hospitalized with COVID-19 and 20 healthy donors, we found elevated free, non-complexed PAI-1 antigen, low circulating uPA, and uPA/PAI-1 but not tPA/PAI-1 complex levels to be associated with COVID-19 severity and ARDS development. This biomarker profile was typical for patients in the complicated phase. Lack of PAI-1 activity in circulation despite free, non-complexed PAI-1 protein and plasmin/α2anti-plasmin complex correlated with suPAR and sVCAM levels, markers indicating endothelial dysfunction. Furthermore, uPA/PAI-1 complex levels positively correlated with TNFα, a cytokine reported to trigger inflammatory cell death and tissue damage. Those levels also positively correlated with lymphopenia and the pro-inflammatory factors interleukin1β (IL1β), IL6, and C-reactive protein, markers associated with the anti-viral inflammatory response. These findings argue for using uPA and uPA/PAI-1 as novel biomarkers to detect patients at risk of developing severe COVID-19, including ARDS.

Risk factors for progressing to severe COVID-19 among people living with HIV in Japan: A hospital claims database study

INTRODUCTION

Risk factors for severe COVID-19 associated with people living with HIV (PLWH) have not been well studied in Japan. In this study, we aim to reveal how having AIDS and comorbidities affect adverse COVID-19 outcomes.

METHODS

This observational, retrospective study examined the clinical outcomes for PLWH hospitalized as COVID-19 inpatients in Japan, using data extracted from hospitals with the Diagnosis Procedure Combination (DPC) system between January 2020 and December 2021. From 4672 records of HIV patients receiving antiretroviral therapy, 85 adult PLWH became hospitalized with COVID-19. The associations between patients' AIDS diagnosis, comorbidities, and their adverse COVID-19 outcomes (mild/moderate and severe/death) were analyzed.

RESULTS

Among 85 studied patients, 78 were male (91.8%) with mean (SD) age of 48 (14.4) years. 75 (88.2%) were found to be COVID-19 mild/moderate; 9 (10.6%) were severe; 1 (1.2%) died. Older age (p = 0.002) and hypertension (p = 0.032) were significantly associated with progressing to severe COVID-19 or death. AIDS and other AIDS-defining illnesses were not found to be significant risk factors in this study.

CONCLUSIONS

While interpretation of the results from this hospital claim database study warrants caution, we found that among PLWH hospitalized as COVID-19 inpatients in Japan, those who are older or with hypertension have a higher risk for progression to severe COVID-19 outcomes, suggesting a careful monitoring of clinical course for these patients.

A review of extended coronavirus disease 2019 (COVID-19) isolation duration among inpatients in a tertiary-care hospital-Iowa, 2020-2022

Of the 2,668 patients admitted with coronavirus disease 2019 (COVID-19), 4% underwent prolonged isolation for >20 days. Reasons for extended isolation were inconsistent with Centers for Disease Control and Prevention (CDC) guidelines in 25% of these patients and were questionable in 54% due to an ongoing critically ill condition at day 20 without CDC-defined immunocompromised status.

A Case of Group A Streptococcus Bacteremia and Infective Endocarditis Caused by Right Ovarian Tube Endometriosis Where the Patient's Perspective Was Key to the Diagnostic Process

Group A streptococcus pyogenes (GAS) is a common organism that can cause upper respiratory infections. We encountered a case where GAS caused infective endocarditis (IE) due to an entry from the vagina. In this case, although echocardiography was negative, we were able to make a diagnosis of IE based on the 2023 Duke International Society for Cardiovascular Infectious Diseases Criteria, and we started antimicrobial therapy for IE. However, the patient subsequently developed persistent abdominal pain, which was atypical; hence, we reviewed the differential diagnosis. It is difficult to locate the primary site of infection because GAS rarely causes vaginal infections, and vaginal infections rarely cause IE. This case highlights the significance of revisiting medical history and the value of using a system 3 approach to refine diagnostic directions.

Online search interest in long-term symptoms of coronavirus disease 2019 during the COVID-19 pandemic in Japan: Infodemiology study using the most visited search engine in Japan

Prolonged symptoms that occur after COVID-19 (long-COVID) vary from mild, which do not interfere with daily life, to severe, which require long-term social support. This study assessed the secular trend in online searches on long-COVID in Japan. We conducted an observational study using data provided by Yahoo! JAPAN on the monthly search volume of query terms related to long-COVID from January 2020 to December 2022, including the search volume of the query "コロナ" (long-COVID in Japanese). The number of new cases of COVID-19 by month was used as a control for search trends, and the symptoms retrieved in conjunction with long-COVID were compared. Trends in online searches for each symptom of long-COVID were analyzed. The symptoms of long-COVID were classified according to "Component 1-Symptoms and Complaints" of the International Classification of Primary Care, 2nd edition (ICPC-2). Interest in long-COVID increased in response to peaks in the number of new cases of COVID-19 in Japan. The most frequent symptom searches with long-COVID were hair loss/baldness (3,530, 21,400, and 33,600 searches in 2020, 2021, and 2022, respectively), cough (340, 7,900 and 138,910 searches in 2020, 2021, and 2022, respectively), disturbance of smell/taste (230, 13,340, and 44,160 searches in 2020, 2021, and 2022, respectively), and headache (580, 6,180, and 42,870 searches in 2020, 2021, and 2022, respectively). In addition, the ranking of interest in "weakness/tiredness, general" in long-COVID increased each year (not in the top 10 in 2020, seventh in 2021, and second in 2022), and the absolute number of searches also increased. To our knowledge, this is the first study to investigate secular trends in online interest in long-COVID in the world. Continued monitoring of online interest in long-COVID is necessary to prepare for a possible increase in the number of patients with long-COVID.

A triad molecular conductor: simultaneous control of charge and molecular arrangements

Molecular and charge arrangements in the solid state were controlled by a new building block: a triad molecule. Owing to the appropriate flexibilities in both molecular structure and electron distribution of the triad, the apparently simple salt exhibits an unstable metallic phase, which is promising for superconducting transitions.

Long-term effect of letrozole on metastatic uterine smooth muscle tumors of uncertain malignant potential: A case report

A 48-year-old woman underwent total abdominal hysterectomy and right salpingo-oophorectomy and was initially diagnosed with a uterine leiomyoma and right ovarian cystadenoma. After 4 years, multiple pulmonary metastases were identified, and treatment with gonadotropin-releasing hormone agonists was started, but stopped later due to disease progression. The patient developed dyspnea and underwent right upper lobectomy. The histopathological findings were consistent with those of pulmonary metastases secondary to a uterine smooth muscle tumor of uncertain malignant potential. Slow disease progression after a poor response to adriamycin and hormone receptor positivity led to the start of letrozole. Letrozole induced spontaneous regression of the pulmonary metastases, and about 2 years into the treatment, sustained response was achieved with minimal side effects. This may be the first case supporting the long-term efficacy and safety of letrozole in the management of adriamycin-resistant lung metastases of uterine smooth muscle tumors of uncertain malignant potential.

Predictive Rule for Mortality of Inpatients With Escherichia coli Bacteremia: Chi-Square Automatic Interaction Detector Decision Tree Analysis Model

AIM

A predictive rule for risk factors for mortality due to Escherichia coli (E. coli)bacteremia has not been defined, especially using the chi-square automatic interaction detector (CHAID) decision tree analysis. Here we aimed to create the predictive rule for risk factors for in-hospital mortality due to E. coli bacteremia.

METHODS

The outcome of this retrospective cross-sectional survey was death in the hospital due to E. coli bacteremia. Factors potentially predictive of death in the hospital due to E. coli bacteremia were analyzed using the CHAID decision tree analysis.

RESULTS

A total of 420 patients (male:female=196:224; mean±standard deviation [SD] age, 75.81±13.13 years) were included in this study. 56 patients (13.3%) died in the hospital. The CHAID decision tree analysis revealed that patients with total protein level ≤5.10 g/dL (incidence, 46.2%), total protein level ≤5.90 g/dL with disturbance of consciousness (incidence, 39.4%), and total protein level >5.90 g/dL with hemoglobin level ≤11.10 g/dL and lactate dehydrogenase level ≥312.0 IU/L (incidence, 42.3%) were included in the high-risk group.

CONCLUSIONS

Appropriate preventative therapy should be facilitated in patients with E. coliat a high risk of mortality.

Assessment of antibody dynamics and neutralizing activity using serological assay after SARS-CoV-2 infection and vaccination

The COVID-19 antibody test was developed to investigate the humoral immune response to SARS-CoV-2 infection. In this study, we examined whether S antibody titers measured using the anti-SARS-CoV-2 IgG II Quant assay (S-IgG), a high-throughput test method, reflects the neutralizing capacity acquired after SARS-CoV-2 infection or vaccination. To assess the antibody dynamics and neutralizing potency, we utilized a total of 457 serum samples from 253 individuals: 325 samples from 128 COVID-19 patients including 136 samples from 29 severe/critical cases (Group S), 155 samples from 71 mild/moderate cases (Group M), and 132 samples from 132 health care workers (HCWs) who have received 2 doses of the BNT162b2 vaccinations. The authentic virus neutralization assay, the surrogate virus neutralizing antibody test (sVNT), and the Anti-N SARS-CoV-2 IgG assay (N-IgG) have been performed along with the S-IgG. The S-IgG correlated well with the neutralizing activity detected by the authentic virus neutralization assay (0.8904. of Spearman's rho value, p < 0.0001) and sVNT (0.9206. of Spearman's rho value, p < 0.0001). However, 4 samples (2.3%) of S-IgG and 8 samples (4.5%) of sVNT were inconsistent with negative results for neutralizing activity of the authentic virus neutralization assay. The kinetics of the SARS-CoV-2 neutralizing antibodies and anti-S IgG in severe cases were faster than the mild cases. All the HCWs elicited anti-S IgG titer after the second vaccination. However, the HCWs with history of COVID-19 or positive N-IgG elicited higher anti-S IgG titers than those who did not have it previously. Furthermore, it is difficult to predict the risk of breakthrough infection from anti-S IgG or sVNT antibody titers in HCWs after the second vaccination. Our data shows that the use of anti-S IgG titers as direct quantitative markers of neutralizing capacity is limited. Thus, antibody tests should be carefully interpreted when used as serological markers for diagnosis, treatment, and prophylaxis of COVID-19.

Investigation of the individual genetic evolution of SARS-CoV-2 in a small cluster during the rapid spread of the BF.5 lineage in Tokyo, Japan

There has been a decreasing trend in new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and fatalities worldwide. The virus has been evolving, indicating the potential emergence of new variants and uncertainties. These challenges necessitate continued efforts in disease control and mitigation strategies. We investigated a small cluster of SARS-CoV-2 Omicron variant infections containing a common set of genomic mutations, which provided a valuable model for investigating the transmission mechanism of genetic alterations. We conducted a study at a medical center in Japan during the Omicron surge (sub-lineage BA.5), sequencing the entire SARS-CoV-2 genomes from infected individuals and evaluating the phylogenetic tree and haplotype network among the variants. We compared the mutations present in each strain within the BA.5 strain, TKYnat2317, which was first identified in Tokyo, Japan. From June 29th to July 4th 2022, nine healthcare workers (HCWs) tested positive for SARS-CoV-2 by real-time PCR. During the same period, five patients also tested positive by real-time PCR. Whole genome sequencing revealed that the infected patients belonged to either the isolated BA.2 or BA.5 sub-lineage, while the healthcare worker infections were classified as BF.5. The phylogenetic tree and haplotype network clearly showed the specificity and similarity of the HCW cluster. We identified 12 common mutations in the cluster, including I110V in nonstructural protein 4 (nsp4), A1020S in the Spike protein, and H47Y in ORF7a, compared to the BA.5 reference. Additionally, one case had the extra nucleotide-deletion mutation I27* in ORF10, and low frequencies of genetic alterations were also found in certain instances. The results of genome sequencing showed that the nine HCWs shared a set of genetic mutations, indicating transmission within the cluster. Minor mutations observed in five HCW individuals suggested the emergence of new virus variants. Five amino acid substitutions occurred in nsp3, which could potentially affect virus replication or immune escape. Intra-host evolution also generated additional mutations. The cluster exhibited a mild disease course, with individuals in this case, recovering without requiring any medical treatments. Further investigation is needed to understand the relationship between the genetic evolution of the virus and the symptoms.

A Predictive Rule for COVID-19 Pneumonia Among COVID-19 Patients: A Classification and Regression Tree (CART) Analysis Model

BACKGROUND

In this study, we aimed to identify predictive factors for coronavirus disease 2019 (COVID-19) patients with complicated pneumonia and determine which COVID-19 patients should undergo computed tomography (CT) using classification and regression tree (CART) analysis.

METHODS

This retrospective cross-sectional survey was conducted at a university hospital. We recruited patients diagnosed with COVID-19 between January 1 and December 31, 2020. We extracted clinical information (e.g., vital signs, symptoms, laboratory results, and CT findings) from patient records. Factors potentially predicting COVID-19 pneumonia were analyzed using Student's t-test, the chi-square test, and a CART analysis model.

RESULTS

Among 221 patients (119 men (53.8%); mean age, 54.59±18.61 years), 160 (72.4%) had pneumonia. The CART analysis revealed that patients were at high risk of pneumonia if they had C-reactive protein (CRP) levels of >1.60 mg/dL (incidence of pneumonia: 95.7%); CRP levels of ≤1.60 mg/dL + age >35.5 years + lactate dehydrogenase (LDH)>225.5 IU/L (incidence of pneumonia: 95.5%); and CRP levels of ≤1.60 mg/dL + age >35.5 years + LDH≤225.5 IU/L + hemoglobin ≤14.65 g/dL (incidence of pneumonia: 69.6%). The area of the curve of the receiver operating characteristic of the model was 0.860 (95% CI: 0.804-0.915), indicating sufficient explanatory power.

CONCLUSIONS

The present results are useful for deciding whether to perform CT in COVID-19 patients. High-risk patients such as those mentioned above should undergo CT.

Impact of the COVID-19 Pandemic on Initiation of Antibiotic Treatment After Performing a Blood Culture and Intervention by the Antimicrobial Stewardship Team

Purpose

Whether the coronavirus disease 2019 (COVID-19) pandemic had any effect on the time between blood culture collection and administration of antibiotics in the outpatient Department of Emergency Medicine in a single university hospital in Japan was investigated, and the intervention carried out by the antimicrobial stewardship team (AST) to promote the appropriate use of antibiotics was examined.

Patients and Methods

The monthly percentage of patients who visited the outpatient Department of Emergency Medicine between January 2019 and December 2021 and received an intravenous antibiotic within 3 hours of blood culture collection was calculated. The AST calculated a quality indicator (QI) based on the results of the investigation and started QI monitoring and hospital feedback.

Results

From January 2020 to March 2021 (the third COVID-19 wave), the implementation rate of antibiotic administration within 3 hours after blood culture collection decreased as the COVID-19 pandemic spread, and the implementation rate tended to increase as the number of COVID-19-positive patients decreased. However, when the AST started monitoring and feedback from April 2021, although there was a temporary decline in the early stages of the fifth wave when the scale of infection was large, the implementation rate rose and was maintained by AST intervention. (the fourth and the fifth COVID-19 waves) (P<0.01). Also, the implementation rate was significantly lower during the COVID-19 pandemic than during the non- pandemic (P<0.05).

Conclusion

The early COVID-19 pandemic may have affected the delay in time from blood culture collection to antibiotic administration. Later, in recurring COVID-19 pandemics, AST intervention eliminated this problem. When a bacterial infection such as sepsis is suspected, delayed treatment can be prevented by promptly collecting a blood culture, irrespective of concerns about COVID-19 infection. Calculating the QI may promote AST activities and the appropriate use of antibiotics.

Contributions of Japanese Hospitalists During the COVID-19 Pandemic and the Need for Infectious Disease Crisis Management Education for Hospitalists: An Online Cross-Sectional Study

Introduction

Hospitalists in Japan have been at the forefront of the COVID-19 pandemic. However, contributions of Japanese hospitalists during the COVID-19 pandemic and hospitalists' awareness of crisis management education remain unclear.

Material and Methods

We conducted a questionnaire survey to investigate the role of Japanese hospitalists during the COVID-19 pandemic. The questionnaire was conducted using email and Google Forms targeting the chairpersons of facilities certified by the Japanese Society of Hospital General Medicine (JSHGM). Members of the academic committee of the JSHGM and several hospitals conducted a narrative review and determined the questions for the survey in a discussion.

Results

We conducted descriptive statistics based on the responses of 97 hospitals that agreed to participate in this survey. In total, 91.8% of general medicine departments in the included hospitals were involved in the medical care of COVID-19 patients. Furthermore, in 73.2% of hospitals, hospitalists were involved in infection control for COVID-19 inside or outside the hospital. Our survey revealed that Japanese hospitalists were responsible for COVID-19 treatment in over 60% of hospitals and contributed to hospital management, infection control, and vaccination. In total, 79.4% of hospitals answered that "training of personnel who can provide practical care for emerging infectious diseases is necessary", 78.4% indicated that "the establishment of an infection control system in advance to prepare emerging infectious diseases in the hospital is necessary", and 74.2% stated that "the establishment of an educational system for responding to emerging infectious diseases is necessary.".

Conclusion

In conclusion, during the pandemic, in addition to inpatient care, Japanese hospitalists provided outpatient care for COVID-19, which is the role of primary care physicians in other countries. Furthermore, Japanese hospitalists who experienced the COVID-19 pandemic expressed the need for personnel development and education to prepare for future emerging infectious disease pandemics.

Navigating Complex Diagnostics During COVID-19: Repeated Testing Unveils Infective Endocarditis in a 61-Year-Old Woman

BACKGROUND Infective endocarditis (IE), a systemic infection characterized by bacterial vegetative growths on heart valves and endothelium, often manifests variably and leads to severe complications, sometimes even death. Accurate and timely diagnosis is paramount, yet the variety of symptoms can lead to delays, especially amidst the complexities of the ongoing COVID-19 pandemic. CASE REPORT A 61-year-old woman with a history of mitral valve regurgitation was admitted after a month of low-grade fever, night sweats, and polyarthritis. Initial blood cultures and CT scans were inconclusive. Upon admission, clinical examination uncovered a heart murmur, leukocytosis, and elevated C-reactive protein levels. Further examination by another physician revealed conjunctival hemorrhage and Janeway lesions. Subsequent blood cultures tested positive for Streptococcus oralis, and transesophageal echocardiography revealed mitral valve prolapse with vegetation, leading to a diagnosis of IE. Following a 6-week course of ampicillin, the patient recovered successfully. CONCLUSIONS This case underlines the necessity of maintaining a high index of suspicion and flexible diagnostic approach, particularly in high-risk patients and complex care environments like the COVID-19 pandemic. A single inconclusive test should not preclude a diagnosis, underscoring the importance of repeated testing and comprehensive assessments in timely disease identification.

Roles considered important for hospitalist and non-hospitalist generalist practice in Japan: a survey study

BACKGROUND

An increased focus on quality and patient safety has led to the evolution of hospitalists. The number of hospitalists covering ward and outpatient care is on the rise in Japan. However, it is unclear what roles hospital workers themselves consider important in their practice. Therefore, this study investigated what hospitalists and non-hospitalist generalists in Japan consider important for the practice of their specialty.

METHODS

This was an observational study that included Japanese hospitalists (1) currently working in a general medicine (GM) or general internal medicine department and (2) working at a hospital. Using originally developed questionnaire items, we surveyed the items important to hospitalists and non-hospitalist generalists.

RESULTS

There were 971 participants (733 hospitalists, 238 non-hospitalist) in the study. The response rate was 26.1%. Both hospitalists and non-hospitalists ranked evidence-based medicine as the most important for their practice. In addition, hospitalists ranked diagnostic reasoning and inpatient medical management as the second and third most important roles for their practice, while non-hospitalists ranked inpatient medical management and elderly care as second and third.

CONCLUSIONS

This is the first study investigating the roles Japanese hospitalists consider important and comparing those to that of non-hospitalist generalists. Many of the items that hospitalists considered important were those that hospitalists in Japan are working on within and outside academic societies. We found that diagnostic medicine and quality and safety are areas that are likely to see further evolution as hospitalists specifically emphasized on them. In the future, we expect to see suggestions and research for further enhancing the items that hospital workers value and emphasise upon.

High body temperature increases gut microbiota-dependent host resistance to influenza A virus and SARS-CoV-2 infection

Fever is a common symptom of influenza and coronavirus disease 2019 (COVID-19), yet its physiological role in host resistance to viral infection remains less clear. Here, we demonstrate that exposure of mice to the high ambient temperature of 36 °C increases host resistance to viral pathogens including influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High heat-exposed mice increase basal body temperature over 38 °C to enable more bile acids production in a gut microbiota-dependent manner. The gut microbiota-derived deoxycholic acid (DCA) and its plasma membrane-bound receptor Takeda G-protein-coupled receptor 5 (TGR5) signaling increase host resistance to influenza virus infection by suppressing virus replication and neutrophil-dependent tissue damage. Furthermore, the DCA and its nuclear farnesoid X receptor (FXR) agonist protect Syrian hamsters from lethal SARS-CoV-2 infection. Moreover, we demonstrate that certain bile acids are reduced in the plasma of COVID-19 patients who develop moderate I/II disease compared with the minor severity of illness group. These findings implicate a mechanism by which virus-induced high fever increases host resistance to influenza virus and SARS-CoV-2 in a gut microbiota-dependent manner.

Evaluation of a Medical Interview-Assistance System Using Artificial Intelligence for Resident Physicians Interviewing Simulated Patients: A Crossover, Randomized, Controlled Trial

Medical interviews are expected to undergo a major transformation through the use of artificial intelligence. However, artificial intelligence-based systems that support medical interviews are not yet widespread in Japan, and their usefulness is unclear. A randomized, controlled trial to determine the usefulness of a commercial medical interview support system using a question flow chart-type application based on a Bayesian model was conducted. Ten resident physicians were allocated to two groups with or without information from an artificial intelligence-based support system. The rate of correct diagnoses, amount of time to complete the interviews, and number of questions they asked were compared between the two groups. Two trials were conducted on different dates, with a total of 20 resident physicians participating. Data for 192 differential diagnoses were obtained. There was a significant difference in the rate of correct diagnosis between the two groups for two cases and for overall cases (0.561 vs. 0.393; p = 0.02). There was a significant difference in the time required between the two groups for overall cases (370 s (352-387) vs. 390 s (373-406), p = 0.04). Artificial intelligence-assisted medical interviews helped resident physicians make more accurate diagnoses and reduced consultation time. The widespread use of artificial intelligence systems in clinical settings could contribute to improving the quality of medical care.

RS3PE Syndrome with Subsequent PMR Caused by Long-Term DPP-4 Inhibitor Use

Remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome has been reported in patients treated with dipeptidyl peptidase-4 inhibitors (DPP-4i). We experienced a case of RS3PE syndrome in a 73-year-old man with a history of type 2 diabetes, who developed RS3PE as a side effect of vildagliptin. Further to this, the patient developed polymyalgia rheumatica (PMR), the first such case associated with long-term DPP-4i use.

LEARNING POINTS

RS3PE syndrome and PMR are rare diseases that cause painful extremities in adults. We need to know if it occurs by DPP-4i.RS3PE syndrome and PMR can be complicated with malignancy or giant cell arteritis. However, we must rule out side effects of drugs at first from the standpoint of medical resources.

Effect of a mobile app chatbot and an interactive small-group webinar on COVID-19 vaccine intention and confidence in Japan: a randomised controlled trial

INTRODUCTION

We investigated the effect of social media-based interventions on COVID-19 vaccine intention (VI) and confidence in Japan.

METHODS

We conducted a three-arm randomised controlled trial between 5 November 2021 and 9 January 2022 during a low incidence (<1000/day) of COVID-19 in Japan in the midst of the second and the third waves. Japanese citizens aged ≥20 who had not received any COVID-19 vaccine and did not intend to be vaccinated were randomly assigned to one of the following three groups: (1) a control group, (2) a group using a mobile app chatbot providing information on COVID-19 vaccines and (3) a group using interactive webinars with health professionals. VI and predefined Vaccine Confidence Index (VCI) measuring confidence in the importance, safety and effectiveness were compared before and after the interventions under intention-to-treat principle. Logistic regression models were used to investigate the effect of each intervention on postintervention VI and changes of VCI compared with control.

RESULTS

Among 386 participants in each group, 359 (93.0%), 231 (59.8%) and 207 (53.6%) completed the postsurvey for the control, chatbot and webinar groups, respectively. The average duration between the intervention and the postsurvey was 32 days in chatbot group and 27 days in webinar group. VI increased from 0% to 18.5% (95% CI 14.5%, 22.5%) in control group, 15.4% (95% CI 10.8%, 20.1%) in chatbot group and 19.7% (95% CI 14.5%, 24.9%) in webinar group without significant difference (OR for improvement=0.8 (95% CI 0.5, 1.3), p=0.33 between chatbot and control, OR=1.1 (95% CI 0.7, 1.6), p=0.73 between webinar and control). VCI change tended to be larger in chatbot group compared with control group without significant difference (3.3% vs -2.5% in importance, OR for improvement=1.3 (95% CI 0.9, 2.0), p=0.18; 2.5% vs 1.9% in safety, OR=1.1 (95% CI 0.7, 1.9), p=0.62; -2.4% vs -7.6% in effectiveness, OR=1.4 (95% CI 0.9, 2.1), p=0.09). Improvement in VCI was larger in webinar group compared with control group for importance (7.8% vs -2.5%, OR=1.8 (95% CI 1.2, 2.8), p<0.01), effectiveness (6.4% vs -7.6%, OR=2.2 (95% CI 1.4, 3.4), p<0.01) and safety (6.0% vs 1.9%, OR=1.6 (95% CI 1.0, 2.6), p=0.08).

CONCLUSION

This study demonstrated that neither the chatbot nor the webinar changed VI importantly compared with control. Interactive webinars could be an effective tool to change vaccine confidence. Further study is needed to identify risk factors associated with decreased vaccine confidence and investigate what intervention can increase VI and vaccine confidence for COVID-19 vaccines.

TRIAL REGISTRATION NUMBER

UMIN000045747.

The user experience of a mobile medication support application and its impact on medication compliance for people living with HIV: Results of a 12-week pilot study

BACKGROUND

Continuity of care between hospital visits through mobile application (app) creates new opportunities for people living with HIV (PLWH) in situations where face-to-face interventions are difficult.

OBJECTIVE

This study investigated the user experience of a mobile medication support app and its impact on improving anti-retroviral therapy (ART) compliance and facilitating teleconsultation between PLWH and medical staff.

METHODS

Two clinics in Japan were invited to participate in a 12-week trial of the medication support app between July 27, 2018, and March 31, 2021. Medication compliance was assessed based on responses to scheduled medication reminders; Users, including PLWH and medical staff, were asked to complete an in-app satisfaction survey to rate their level of satisfaction with the app and its specific features on a 5-point Likert scale.

RESULTS

A total of 10 PLWH and 11 medical staff were included in this study. During the trial, the medication compliance rate was 90%, and the mean response rates to symptom and medication alerts were 73% and 76%, respectively. Overall, 81% of PLWH users and 65% of medical staff were satisfied with the medication support app. Over 80% of medical staff and PLWH users were satisfied with the ability to record medication taken, record symptoms of concern, and enquire about drug combinations. Further, 90% of PLWH users were satisfied with the communication function with medical staff.

CONCLUSIONS

Our preliminary results demonstrate the feasibility of this medication support app in improving medication compliance and enhancing communication between PLWH and medical staff.

CLINICALTRIAL

Evaluation of a Previously Developed Predictive Model for Infective Endocarditis in 320 Patients Presenting with Fever at 4 Centers in Japan Between January 2018 and December 2020

BACKGROUND In our previous single-center study, we developed an infective endocarditis (IE) prediction model among patients with undiagnosed fever (UF) based on 5 factors that can be obtained on admission: ambulance transfer, presence of cardiac murmur or pleural effusion, blood neutrophil percentage, and platelet count. The present study aimed to retrospectively evaluate the prediction model for IE in 320 patients presenting with fever at 4 university hospitals in Japan from January 2018 to December 2020. MATERIAL AND METHODS Patients aged ≥20 years admitted to 4 hospitals with I-330 (IE) or R-50-9 (UF) according to the International Statistical Classification of Diseases and Related Health Problems-10 were enrolled. More than 2 physicians at each hospital reviewed the patient diagnoses using the modified Duke criteria, allocating "definite IE" to IE group (n=119) and "non-definite IE" to UF group (n=201). Five factors on admission were analyzed by multivariate logistic regression. The discriminative ability and calibration of the model were evaluated using the area under the curve (AUC) and the shrinkage coefficient, respectively. RESULTS A total of 320 patients were enrolled. The odds ratios (95% confidence intervals) were as follows: ambulance transfer 1.81 (0.91-3.55); cardiac murmur 13.13 (6.69-27.36); pleural effusion 2.34 (0.62-2.42); blood neutrophil percentage 1.09 (1.06-1.14); and platelet count 0.96 (0.93-0.99). The AUC was 0.783 (0.732-0.834) with a shrinkage coefficient of 0.961. CONCLUSIONS The IE prediction model is useful to estimate the probability of IE immediately after admission for fever in patients aged ≥20 years.

Subcutaneous panniculitis-like T-cell lymphoma post-mRNA-1273 COVID-19 vaccination

This is a case of subcutaneous panniculitis-like T-cell lymphoma (SPTCL) was diagnosed by skin biopsy in a patient who presented with fever and erythema nodosum in the umbilicum following mRNA-1273 COVID-19 vaccination. COVID-19 vaccines may cause SPTCL and skin biopsy may help in the diagnosis of erythema nodosum.

Dietary Intake in Older Patients with Dementia Prior to and After the Onset of Coronavirus Disease 2019

This was an observational study of hospitalized patients with dementia who developed COVID-19. The disease course, dietary intake, and disease severity (mild/severe) were evaluated. Twenty-nine patients with a median age of 84 years, with both mild (18) and severe conditions, (11) were evaluated. Mild group had decreased food intake from the day of symptom onset. In the severe group, the decline began the day before symptom onset. On day 30 of the disease, the median food intake of the mild group returned to levels observed prior to symptom onset, in contrast to those in the severe group.

Increased SARS-CoV-2 seroprevalence and spread of infection without awareness among healthcare workers through 2020-2022 in a Japanese medical center

Despite Japan's high vaccination coverage, daily numbers of new COVID-19 cases have been high. However, studies on the seroprevalence among Japanese people and the causative factors for rapid spread have remained limited. In this study, we aimed to examine the seroprevalence and associated factors in healthcare workers (HCWs) of a medical center in Tokyo using blood samples drawn at annual check-ups from 2020 to 2022. We found that of the 3,788 HCWs in 2022 (by mid-June), 669 were seropositive for N-specific antibodies (tested by Roche Elecsys Anti-SARS-CoV-2 assay); the seroprevalence surged from 0.3% in 2020 and 1.6% in 2021 to 17.7% in 2022. Notably, our study found 325 (48.6%; 325/669) cases were infected without awareness. Among those with a previously PCR-confirmed SARS-CoV-2 infection during the past three years, 79.0% (282/357) were found after January 2022, after the Omicron variant was first detected in Tokyo at the end of 2021. This study indicates the fast spread of the SARS-CoV-2 among HCWs during the Omicron surge in Japan. The high percentage of infection without awareness may be a key driving factor causing rapid person-to-person transmission, as shown in this medical center with high vaccination coverage and strict infection control measures.

Clinical prediction rule for bacterial arthritis: Chi-squared automatic interaction detector decision tree analysis model

Objectives:

Differences in demographic factors, symptoms, and laboratory data between bacterial and non-bacterial arthritis have not been defined. We aimed to identify predictors of bacterial arthritis, excluding synovial testing.

Methods:

This retrospective cross-sectional survey was performed at a university hospital. All patients included received arthrocentesis from January 1, 2010, to December 31, 2020. Clinical information was gathered from medical charts from the time of synovial fluid sample collection. Factors potentially predictive of bacterial arthritis were analyzed using the Student’s t-test or chi-squared test, and the chi-squared automatic interaction detector decision tree analysis. The resulting subgroups were divided into three groups according to the risk of bacterial arthritis: low-risk, intermediate-risk, or high-risk groups.

Results:

A total of 460 patients (male/female = 229/231; mean ± standard deviation age, 70.26 ± 17.66 years) were included, of whom 68 patients (14.8%) had bacterial arthritis. The chi-squared automatic interaction detector decision tree analysis revealed that patients with C-reactive protein > 21.09 mg/dL (incidence of septic arthritis: 48.7%) and C-reactive protein ⩽ 21.09 mg/dL plus 27.70 < platelet count ⩽ 30.70 × 10⁴/μL (incidence: 36.1%) were high-risk groups.

Conclusions:

Our results emphasize that patients categorized as high risk of bacterial arthritis, and appropriate treatment could be initiated as soon as possible.

Association between serum uric acid levels and achievement of target blood pressure among Japanese community residents with hypertension

The authors examined the sex-specific association between serum uric acid (SUA) levels and achievement of target blood pressure among Japanese patients with hypertension. This cross-sectional study was conducted between January 2012 and December 2015 and examined 17 113 eligible participants (6499 men; 10 614 women) with hypertension among 66 874 Japanese community residents who underwent voluntary health checkups. Multivariate analysis was used to estimate the association between high SUA level (≥7.0 mg/dL for men and ≥6.0 mg/dL for women) and "therapeutic failure" in achieving target blood pressure (BP) of 140/90 and 130/80 mmHg in both sexes. Multivariate analysis revealed that high SUA level was significantly associated with failure to achieve the 130/80 mmHg treatment goal among men (AOR = 1.24, 95% CI = 1.03-1.50, p = .03). Among women, high SUA level was significantly associated with failure to achieve both the 130/80 and 140/90 mmHg treatment goals (AOR = 1.33, 95% CI = 1.20-1.47, p < .01 and AOR = 1.17, 95% CI = 1.04-1.32, p < .01, respectively). Each increase in SUA quartile was positively associated with increases in systolic BP (SBP) and diastolic BP (DBP) (p < .01 for trend) in both sexes. SBP and DBP in each quartile (Q2-Q4) were also significantly higher compared with those of Q1 in both sexes (p < .01). Our data confirms the difficulties in maintain goal BP control in those with elevated SUA.

Concurrent hypereosinophilic syndrome and deep vein thrombosis after Pfizer-BioNTech COVID-19 vaccination: A case report

Herein, we report a case of eosinophilia syndrome and deep vein thrombosis presenting concurrently after the administration of the BNT162b2 mRNA-based coronavirus disease 2019 (COVID-19) vaccine. It is extremely rare to have both hypereosinophilic syndrome and deep vein thrombosis simultaneously. Both are serious diseases and should be treated with caution.

Medical Malpractice and Diagnostic Errors in Japanese Emergency Departments

INTRODUCTION

Emergency departments (ED) are unpredictable and prone to diagnostic errors. In addition, non-emergency specialists often provide emergency care in Japan due to a lack of certified emergency specialists, making diagnostic errors and associated medical malpractice more likely. While several studies have investigated the medical malpractice related to diagnostic errors in EDs, only a few have focused on the conditions in Japan. This study examines diagnostic error-related medical malpractice lawsuits in Japanese EDs to understand how various factors contribute to diagnostic errors.

METHODS

We retrospectively examined data on medical lawsuits from 1961-2017 to identify types of diagnostic errors and initial and final diagnoses from non-trauma and trauma cases.

RESULTS

We evaluated 108 cases, of which 74 (68.5%) were diagnostic error cases. Twenty-eight of the diagnostic errors were trauma-related (37.8%). In 86.5% of these diagnostic error cases, the relevant errors were categorized as either missed or diagnosed incorrectly; the others were attributable to diagnostic delay. Cognitive factors (including faulty perception, cognitive biases, and failed heuristics) were associated with 91.7% of errors. Intracranial hemorrhage was the most common final diagnosis of trauma-related errors (42.9%), and the most common initial diagnoses of non-trauma-related errors were upper respiratory tract infection (21.7%), non-bleeding digestive tract disease (15.2%), and primary headache (10.9%).

CONCLUSION

In this study, the first to examine medical malpractice errors in Japanese EDs, we found that such claims are often developed from initial diagnoses of common diseases, such as upper respiratory tract infection, non-hemorrhagic gastrointestinal diseases, and headaches.

SARS-CoV-2 evolution among patients with immunosuppression in a nosocomial cluster of a Japanese medical center during the Delta (AY.29 sublineage) surge

Background

Previous studies have shown that patients with immunosuppression tend to have longer-lasting SARS-CoV-2 infections and a number of mutations were observed during the infection period. However, these studies were, in general, conducted longitudinally. Mutation evolution among groups of patients with immunosuppression have not been well studied, especially among Asian populations.

Methods

Our study targeted a nosocomial cluster of SARS-CoV-2 infection in a Japanese medical center during Delta surge (AY.29 sublineage), involving ward nurses and inpatients. Whole-genome sequencing analyses were performed to examine mutation changes. Haplotype and minor variant analyses were furtherly performed to detect the mutations on the viral genomes in detail. In addition, sequences of the first wild-type strain hCoV-19/Wuhan/WIV04/2019 and AY.29 wild-type strain hCoV-19/Japan/TKYK15779/2021 were used as references to assess the phylogenetical development of this cluster.

Results

A total of 6 nurses and 14 inpatients were identified as a nosocomial cluster from September 14 through 28, 2021. All were Delta variant (AY.29 sublineage) positive. 92.9% of infected patients (13 out of 14) were either cancer patients and/or receiving immunosuppressive or steroid treatments. Compared to AY.29 wild type, a total of 12 mutations were found in the 20 cases. Haplotype analysis found one index group of eight cases with F274F (N) mutation and 10 other haplotypes with one to three additional mutations. Furthermore, we found that cases with more than three minor variants were all cancer patients under immunosuppressive treatments. The phylogenetical tree analysis, including 20 nosocomial cluster-associated viral genomes, the first wild-type strain and the AY.29 wild-type strain as references, indicated the mutation development of the AY.29 virus in this cluster.

Conclusion

Our study of a nosocomial SARS-CoV-2 cluster highlights mutation acquisition during transmission. More importantly, it provided new evidence emphasizing the need to further improve infection control measures to prevent nosocomial infection among immunosuppressed patients.

Mortality Prediction of COVID-19 in Hospitalized Patients Using the 2020 Diagnosis Procedure Combination Administrative Database of Japan

Objectives Numerous people have died from coronavirus disease 2019 (COVID-19) infection. Identifying crucial predictive biomarkers of disease mortality is critical to support decision-making and logistic planning in healthcare systems. This study investigated the association between mortality and medical factors and prescription records in 2020 in Japan, where COVID-19 prevalence and mortality remain relatively low. Methods This retrospective cohort study analyzed anonymous administrative data from the Diagnosis Procedure Combination (DPC) database in Japan. Results A total of 22,795 patients were treated in DPC hospitals in 2020 in Japan, and of these, 5,980 patients over 50 years old were hospitalized, with 299 (5.0%) dying. There were 2,399 severe patients among 11,440 total hospitalized patients (all ages). The results of a logistic model analysis revealed that an older age, male sex, Parkinson's disease, cerebrovascular diseases, and chronic kidney diseases were risk factors for mortality. A machine learning analysis identified an older age, male sex (mortality), pneumonia, drugs for acid-related disorders, analgesics, anesthesia, upper respiratory tract disease, drugs for functional gastrointestinal disorders, drugs for obstructive airway diseases, topical products for joint and muscular pain, diabetes, lipid-modifying agents, calcium channel blockers, drugs for diabetes, and agents acting on the renin-angiotensin system as risk factors for a severe status. Conclusions This COVID-19 mortality risk tool is a well-calibrated and accurate model for predicting mortality risk among hospitalized patients with COVID-19 in Japan, which is characterized by a relatively low COVID-19 prevalence, aging society, and high population density. This COVID-19 mortality prediction model can assist in resource utilization and patient and caregiver education and be useful as a risk stratification instrument for future research trials.

Successful Treatment of a Case of Metallo-Beta-Lactamase-Producing Raoultella ornithinolytica Bacteremia by Antimicrobial Stewardship Team Intervention and Therapeutic Drug Monitoring-Based Amikacin Treatment

An 80-year-old woman underwent pancreatoduodenectomy. Post-operation, she experienced a fever, and a culture of blood revealed metallo-beta-lactamase-producing Raoultella ornithinolytica. For treatments with aminoglycoside antimicrobial agents, a therapeutic drug monitoring-based dosing design can lower the risk of adverse events and enable appropriate treatment. Key Clinical Message. When aminoglycoside antimicrobial agents are administered for MBL-producing bacteremia, prescription suggestions based on TDM by antimicrobial stewardship team can reduce the occurrence of adverse events and enable appropriate treatment.

Rhabdomyolysis secondary to hypervirulent Klebsiella pneumoniae infection: A case report

Hypervirulent Klebsiella pneumoniae (hvKP) is recognized as a lifethreatening community-acquired infection associated with pyogenic liver abscess. However, rhabdomyolysis secondary to hvKP infection is rare. To the best of our knowledge, we report the first case of rhabdomyolysis due to hvKP infection in a patient who survived septic shock syndrome.

224. Effect of a Mobile App Chatbot and an Interactive Small Group Webinar on COVID-19 Vaccine Intention and Confidence in Japan: A Randomized Clinical Trial

Background

Little is known about how social media platforms can be used to increase COVID-19 vaccine intent. We aimed to investigate the effect of social media-based interventions on vaccine hesitancy in Japan.

Methods

We conducted a three-arm randomized controlled trial between 5 November 2021 and 9 January 2022. Japanese aged 20 or above who had not received any COVID-19 vaccine and did not intend to be vaccinated were randomly assigned to one of the following three groups: (i) a control group (with no intervention), (ii) a group with a free chatbot in a popular messenger app called ‘LINE,’ which provided general information on COVID-19 vaccines and (iii) a group with free webinars where healthcare professionals interactively provided participants with the information on COVID-19 vaccines. The vaccine intention (VI) and three pre-defined Vaccine Confidence Index (VCI), including the importance, safety, and effectiveness of COVID-19 vaccines, were compared.

Results

1,158 persons were included, and the baseline characteristics and demographics were balanced across three groups (Table 1). Among 386 persons assigned to the chatbot group, 231 (59.8%) accessed the chatbot and answered the post-survey. The post-survey revealed no significant difference in VI or VCI between the chatbot group and the control group (Table 2). Among 386 persons assigned to the webinar group, 207 (53.6%) attended webinars and answered the post-survey. The post-survey revealed no difference in VI between the webinar group and the control group. However, the VCI for the importance and the effectiveness significantly increased in the webinar group. There was no difference in VCI for the safety. VCI for the importance and the effectiveness in the control group decreased without any intervention during the study period.

Vaccine intention and confidence after interventions Table 1Table 2

Conclusion

While this study demonstrated that neither the chatbot nor the webinar changed VI, VCI for the importance and the effectiveness significantly increased with the webinar intervention. Interactive webinars with live Q and A provided by professionals may have a role in increasing COVID-19 vaccine confidence. Given the degree of vaccine hesitancy worsened over time in the control group, timely intervention is required.

Disclosures

All Authors: No reported disclosures.