Liver injury in patients with COVID-19 who received dexamethasone monotherapy

Introduction: Liver injury is frequently seen in coronavirus disease 2019 (COVID-19), and it has been reported to be associated with the severity of COVID-19. The direct action of the virus, cytokine storm, coagulation abnormalities, drug-induced, etc. are considered to be the causes of liver injury, and antiviral agents against COVID-19 and steroids used as anti-inflammatory agents have also been reported to contribute to the appearance of liver injury. In Japan, remdesivir, dexamethasone (Dex), baricitinib, etc. are used as therapeutic agents for COVID-19, but there is still not enough evidence about the frequency of liver injury as an adverse event. Aims & Methods: This study aimed to clarify the influence of Dex monotherapy for liver injury in COVID-19 with respiratory failure. We examined 171 patients with COVID-19 with liver injury in the respiratory failure groups and the nonrespiratory failure groups and investigated 41 patients with moderate COVID-19 with respiratory failure who received Dex monotherapy in the liver injury group and the nonliver injury group at the time before treatment. Result(s): The respiratory failure group had 64% more liver damage than the non-respiratory failure group, was older, had more men, and had significantly more complications of lifestyle-related diseases such as hypertension and diabetes. Obesity was more common in the liver injury group prior to Dex monotherapy, and the liver CT value was significantly lower than in the non-liver injury group. Liver injury worsened in 41% of patients after Dex monotherapy, but there was no significant difference in the frequency before Dex monotherapy between the liver injury group and the non-liver injury group, and the degree of liver injury was mild in all cases, improving in 38% of the liver injury group. Conclusion(s): Dex monotherapy was a safe treatment for moderate COVID-19 with respiratory failure, which frequently resulted in liver injury.

Variability of Thermal Comfort and Energy Consumption by Introducing Working from Home

Owing to the COVID-19 pandemic, many companies have introduced working from home to avoid the risk of infection. In this study, we conducted questionnaire surveys and analysed the building energy management system (BEMS) in an office building where the number of employees working from home increased after the onset of the pandemic. The influence of working from home on the indoor environment satisfaction and the variability in energy consumption at home and office was determined. The indoor environment satisfaction was significantly higher when working from home than when working at the office. In 2020, the total energy consumption at home and office decreased by 30% in April and increased by 22% in August compared to the previous year. To work from home while saving energy regardless of the season, it is necessary to reduce office energy consumption by decreasing the number of workers present at the office. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

Analysis of COVID-19 mRNA Vaccine-induced Mouth Ulcers Using the Japanese Adverse Drug Event Report Database.

There are case reports of mouth ulcers caused by the coronavirus disease 2019 (COVID-19) messenger ribonucleic acid (mRNA) vaccine; however, the actual number and characteristics of cases are unknown. Therefore, we examined this issue using the Japanese Adverse Drug Event Report (JADER), a large Japanese database. We calculated the reported odds ratio (ROR) of drugs that may be specifically associated with mouth ulcers and assumed that a signal was present if the lower limit of the calculated ROR's 95% confidence interval (CI) was > 1. In addition, the time to symptom onset after administration of the COVID-19 mRNA and influenza HA vaccines was investigated. We found that the JADER database contained 4,661 mouth ulcer cases between April 2004 and March 2022. The COVID-19 mRNA vaccine was the eighth most common causative drug for mouth ulcers, with 204 reported cases. The ROR was 1.6 (95% CI, 1.4-1.9) and a signal was detected. There were 172 mouthulcer cases associated with the Pfizer-BioNTech's COVID-19 mRNA vaccine, 76.2% of which were female. The outcome was no unrecovered cases with the influenza HA vaccine, whereas the COVID-19 mRNA vaccine showed unrecovered cases (Pfizer-BioNTech: 12.2%, Moderna: 11.1%). The median time-to-onset of the mouth ulcers was two days for the COVID-19 mRNA vaccine and one day for the influenza HA vaccine, indicating that mouth ulcers caused by the COVID-19 mRNA vaccine were delayed adverse events. In this study, the COVID-19 mRNA vaccine was shown to cause mouth ulcers in a Japanese population.

Safe administration of sotrovimab to a COVID-19 patient with acute phase type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) and poor glycemic control are risk factors for severe coronavirus disease 2019 (COVID-19). Sotrovimab can treat mild-to-moderate COVID-19 in patients at a high risk of progression to severe COVID-19. However, its safety and efficacy in T1DM patients remain to be elucidated. We report the case of a 12-yr-old patient who was treated with sotrovimab for COVID-19 immediately after treatment for diabetic ketoacidosis (DKA) due to new-onset T1DM. He presented with nausea and sore throat and was diagnosed with severe DKA and COVID-19. A productive cough and sputum developed after admission. On the 3rd day of admission, the DKA resolved, and sotrovimab was administered to prevent exacerbation of COVID-19. Although the blood glucose levels increased after the administration of sotrobimab, there was no recurrence of DKA. Hyperglycemia may be a sotrovimab-related adverse event in T1DM patients. Nevertheless, the benefits of sotrovimab treatment may far outweigh the potential risks. Thus, sotrovimab was considered safe for patients with T1DM immediately after treatment of severe DKA.

Protection for the Self-Employed in Japan: Needs and Measures

This article examines the protection needs of the self-employed and the developments in such protection in Japan. Arguments are put forward for further improving the protection for the self-employed beyond the existing protection framework. These efforts towards improving protection are expected to continue in the future. However, this is not to suggest that a specific stance has been adopted with regard to the content of such protection for those self-employed who are eligible. Such protection is still very much in the stage of preliminary consideration. While the development of such protection is still in the early stages, emergency steps taken in the COVID-19 pandemic have included income support measures to cover the loss of work for self-employed people whose tasks are similar to those of an employee. The self-employed who are eligible for such protection are those who seek protection. It may be argued that, regardless of the intentions of policy-makers, the policies that are pursued are a reflection of how the self-employed perceive their needs. © 2022 Kluwer Law International BV, The Netherlands

Diagnostic performance of computed tomography imaging for COVID-19 in a region with low disease prevalence

Coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China, in December 2019 as an out-break of pneumonia of unknown origin. Previous studies have suggested the utility of chest computed tomography (CT) in the diagnosis of COVID-19 because of its high sensitivity (93%-97%), relatively simple procedure, and rapid test results. This study, performed in Japan early in the epidemic when COV1D-19 prevalence was low, evaluated the diagnostic accuracy of chest CT in a population present-ing with lung diseases having CT findings similar to those of COVID-19. We retrospectively included all consecutive patients (18 years old) presenting to the outpatient department of Keio University Hospital between March 1 and May 31, 2020, with fever and respiratory symptoms. We evaluated the perfor-mance of diagnostic CT for COVID-19 by using polymerase chain reaction (PCR) results as the refer-ence standard. We determined the numbers of false-positive (FP) results and assessed the clinical utility using decision curve analysis. Of the 175 patients, 22 were PCR-positive. CT had a sensitivity of 68% and a specificity of 57%. Patients with FP results on CT diagnosis were mainly diagnosed with diseases mimicking COVID-19, e.g., interstitial lung disease. Decision curve analysis indicated that the clinical utility of CT imaging was limited. The diagnostic performance of CT for COVID-19 was inadequate in an area with low COV ID-19 prevalence and a high prevalence of other lung diseases with chest CT findings similar to those of COVID-19. Considering this insufficient diagnostic performance, CT findings should be evaluated in the context of additional medical information to diagnose COVID-19.

A nationwide survey on school lunch provision during the COVID-19 pandemic

Objectives: Although the nutritional status of children is affected by receiving or not receiving school lunch, the actual state of school lunches among children during the coronavirus disease 2019 (COVID-19) epidemic has not been clarified. Therefore, we conducted a nationwide survey of the status of school lunch provision from April to October 2020 to clarify the actual situation of school lunches during the COVID-19 epidemic.

Impaired Humoral Response to Second Dose of BNT162b2 Messenger RNA COVID-19 Vaccine in Kidney Transplant Recipients in Japan: Prospective Observational Study

Purpose: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has a major impact on solid organ transplant (SOT) recipients, with mortality rate up to 22%. The effect of SARS-CoV-2 vaccination are known to have poor responses even after 2nddose in SOT in Europe and the United States. We investigated immune response by detecting SARS-CoV-2 antibody (Ab) post two-doses of messenger RNA (mRNA)-based SARS-CoV-2 vaccinesin Japanese renal transplant recipients as prospective observational study. Method(s): 352 recipients who have no history of COVID-19, were confirmed no SARS-CoV-2 antibody before vaccination and received 2nd dose of BNT162b2 mRNA vaccine are enrolled in this study.Antibody detection test was performed by using the Roche Elecsys Anti-SARS-CoV-2 immunoassay after more than 4weeks following 2nddose of it. Negative for N-Ab (0.4U/ml>) and positive for S-Ab (0.8U/ml<) considered to be positive for SARS-CoV-2 Ab.As a healthy control, SARS-CoV-2 Ab was determined in 990 healthy volunteers (HV) as well as 98 kidney donors as control for chronic kidney disease (Donor). Result(s): The rate of positive for S-Ab was 56.2% in recipients while that was 100% in HV and Donor. Titer of S-Ab (U/ml) was 77 in recipients although that was 2400 in HV and 1100 in Donor, respectively, which indicating significantly lower in recipients. (Fig. 1) Interestingly, positive rate for s-Ab by detecting time following 2ndvaccination in recipients was 44% in 4-6 weeks, 54% in 6-8 weeks, 67% in 8-10 weeks, 72% in 10-12 weeks, 80% in 12-weeks, which suggesting that recipients have delayed response to 2ndvaccination while that was 100% in any time point in HV and Donor. (Fig.2) Moreover, to elucidate difference between responder (n=198) and non-responder (n=154) in recipients, we compared clinical background that influencedoutcome. In non-responder, there were significant difference in older age at vaccination, less lymphocyte, previousdoses of rituximab, concomitant use of mycophenolate mofetil and oral administration of more than three immunosuppressants. (Table.1) Conclusion(s): Kidney recipients have delayed response with lower titer of SARSCoV- 2 antibodyfollowing second dose of mRNA-based COVID-19 Vaccine.

Japan prospective multicenter study for optimization of COVID-19 vaccinations based on the immune response and safety profile in Inflammatory Bowel Disease patients: Interim analyses of the J-COMBAT trial

Background Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Methods IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and non-administrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti-TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1–62.3;p=0.0293), and tended to be influenced by COVID-19 infection (139.1, 41.0–472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA-1273 (90.3 [60.8–134.1]) than for BNT162b2 (39.6 [35.2–44.6], p= 0.0001). Systemic steroids (22.9 [13.9–37.7], p=0.0119), IM (24.2 [18.7–31.4], p<0.0001), anti-TNF agents (20.8 [15.3–28.3], p<0.0001), vedolizumab (25.2 [15.0–42.2], p=0.0409), ustekinumab (28.9 [18.5–45.0], p=0.0754), and tofacitinib (5.5 [2.8–10.9], p<0.0001), but not oral 5-ASA (39.1 [31.9–47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs.

JAPAN PROSPECTIVE MULTICENTER STUDY FOR OPTIMIZATION OF COVID-19 VACCINATIONS BASED ON THE IMMUNE RESPONSE AND SAFETY PROFILE IN INFLAMMATORY BOWEL DISEASE PATIENTS: INTERIM ANALYSES

Background: Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Subjects and Methods: IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results: In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and non-administrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti- TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1-62.3;p=0.0293), and tended to be influenced by COVID- 19 infection (139.1, 41.0-472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA- 1273 (90.3 [60.8-134.1]) than for BNT162b2 (39.6 [35.2-44.6], p= 0.0001). Systemic steroids (22.9 [13.9-37.7], p=0.0119), IM (24.2 [18.7-31.4], p<0.0001), anti-TNF agents (20.8 [15.3-28.3], p<0.0001), vedolizumab (25.2 [15.0-42.2], p=0.0409), ustekinumab (28.9 [18.5-45.0], p=0.0754), and tofacitinib (5.5 [2.8-10.9], p<0.0001), but not oral 5- ASA (39.1 [31.9-47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion: Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs. (Table Presented) (Table Presented)

Impact of declaration of a state of emergency due to the COVID-19 pandemic on school lunches: a nationwide survey

Objective: To investigate the implementation status of school lunches and simplified school lunches after a state of emergency was declared due to the coronavirus disease 2019 (COVID-19) pandemic, and the content of a simplified school lunch.

COVID-19 INFECTION PREVENTION MEASURES IN 2-D LAND SEISMIC SURVEY, NIIGATA, JAPAN

Under the severe COVID-19 infection circumstance as rapidly spreading in JAPAN since March 2020, we conducted 2-D land seismic survey in residential area, Niigata, JAPAN from November to December 2020 with necessary infection prevention measures. We set the criteria for the survey start propriety in advance and discussed about the survey implementation with related parties. We also obtained the understanding about this survey from local governments and residents before the survey start. During seismic survey, we took two types of original infection prevention measures as “Enclosure” and “Separation”, in addition to basic measures indicated by guidelines of the Japanese government. “Enclosure” measures aimed to prevent coronavirus from entering inside of the survey site. “Separation” measures were risk diversification of spreading coronavirus in the survey site. By planning and thoroughly adhering original countermeasures that matched the survey area COVID-19 status, we were able to complete the survey in the planned duration without interrupted the survey. In this paper, we introduce our original on-site infection prevention measures “Enclosure” and “Separation” and discuss how to manage the risk of COVID-19 infection at the seismic survey site. © (2021) by the European Association of Geoscientists & Engineers (EAGE)All rights reserved.

COVID-19 transmission in dental and oral/maxillofacial surgical practice during pandemic: questionnaire survey in 51 university hospitals in Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a major public health problem. Dental procedures that generate aerosols are considered to impose a high risk of infection; therefore, dental professionals, such as dentists and dental hygienists, may be at high risk of viral transmission. However, few studies have reported COVID-19 clusters in dental care settings. AIM: To investigate whether dental and oral/maxillofacial procedures are associated with the occurrence of COVID-19 clusters and measures taken to prevent nosocomial infection in dental clinics. METHODS: An online questionnaire survey on clinical activities (administrative control), infection control measures (environmental/engineering control, personal protective equipment, etc.), and confirmed or probable COVID-19 cases among patients and clinical staff was administered to the faculties of the dental and oral/maxillofacial surgical departments of university hospitals. FINDINGS: Fifty-one faculty members completed the questionnaire. All members were engaged in the treatment of dental and oral surgical outpatients and actively implemented standard precautions. Fourteen faculty members treated patients with COVID-19, but no infections transmitted from the patients to the medical staff were observed. In seven facilities, patients were found to have the infection after treatment (medical staff came in close contact), but there was no transmission from patients to medical staff. Four facilities had medical staff with infections, but none of them exhibited disease transmission from staff to patients. CONCLUSION: COVID-19 clusters are unlikely to occur in dental and oral surgical care settings if appropriate protective measures are implemented.

Context-Aware Chatbot Based on Cyber-Physical Sensing for Promoting Serendipitous Face-to-Face Communication

To promote the face-to-face communication reduced by COVID-19, we proposed and implemented a context-aware Slack chatbot based on Cyber-Physical sensing that helps colleagues meet more often in the same place. Our system periodically collects the user’s internal context through Slack (cyber sensing) and uses small BLE beacons distributed to colleagues and beacon scanners installed in a laboratory to sense physical attendance (physical sensing). In addition, the system notifies the user of recommended actions, such as lunch or coffee break, depending on the context determined by the Cyber-Physical sensors. We deployed the proposed system in a laboratory environment and conducted an initial experiment for six weeks. Experimental results confirmed that our system can encourage serendipitous face-to-face communication during periods when the frequency of attending school and going to work dropped due to COVID-19. It was also found that in an environment such as a laboratory, where a certain level of trust has already been established, the openness of the collected information can further motivate users to participate in the system. © 2022, Springer Nature Switzerland AG.

Trends in the incidence of symptomatic COVID-19 during the first endemic wave in the Japanese population

Object: First coronavirus disease 2019 (COVED-19) endemic wave in Japan was almost stabilized in late May in 2020, without strong physical distancing interventions. Our objective was to analyze temporal trends in the incidence of symptomatic COVID-19 during this phase in Osaka Prefecture (population of 8.8 million).

Japan prospective multicenter study for optimization of COVID-19 vaccinations based on the immune response and safety profile in Inflammatory Bowel Disease patients: Interim analyses of the J-COMBAT trial

Background: Immune responses to the SARS-CoV-2 vaccination may be influenced by immunomodulatory drugs (IMDs). We investigated the immune responses and safety in fully vaccinated Japanese patients with IBD. Methods: IBD patients and control subjects at 39 institutes were invited to participate in the study from March to October 2021. Blood sample collections to measure anti-SARS-CoV-2 spike IgG antibody titers were planned pre-1st vaccination, pre-2nd vaccination, and at 4 weeks, 3 months and 6 months post-2nd vaccination. Immune responses were compared between groups, considering baseline characteristics and IMD treatments. (UMIN000043545) The interim analyses presented here include mainly data from the 4-weeks post-2nd vaccination time-point. Results: In total, 679 IBD patients and 203 controls were enrolled (Table 1). The IBD group received the BNT162b2 vaccine (86.2%) and the mRNA-1273 vaccine (12.5%), and the control group received the BNT162b2 vaccine (86.9%) and the mRNA-1273 vaccine (12.1%). Only 4 cases (0.7%) in the IBD group and 2 (1.0%) in the control group were infected with COVID-19. Adverse events of 2nd vaccination occurred in 48.4% of the IBD group and 35.1% of the control group. Comparison between administrated and nonadministrated IBD patients for each IMD revealed an attenuated genomic mean titer (GMT [U/mL]) in those taking systemic steroids (18.85 vs 31.24), anti-TNF monotherapy (28.31 vs 42.99), anti-TNF therapy+ immunomodulator (IM) (12.86 vs 35.26), vedolizumab+IM (19.49 vs 30.39), ustekinumab+IM (20.44 vs 30.79), and tofacitinib (9.54 vs 32.08), but not in those taking oral 5-ASA (29.50 vs 32.40), or vedolizumab (41.85 vs 40.20) and ustekinumab (55.56 vs 39.26) monotherapies. Estimated least square means of the GMT by a multiple linear regression model are shown in Table 2. GMTs were significantly influenced by increasing age and allergy (51.2, 95%CI 42.1-62.3;p=0.0293), and tended to be influenced by COVID-19 infection (139.1, 41.0-472.2;p=0.0572). Sex, smoking, drinking, IBD, and adverse events of 2nd vaccination did not affect the GMT. The GMT was significantly higher for mRNA-1273 (90.3 [60.8-134.1]) than for BNT162b2 (39.6 [35.2-44.6], p= 0.0001). Systemic steroids (22.9 [13.9-37.7], p=0.0119), IM (24.2 [18.7-31.4], p<0.0001), anti-TNF agents (20.8 [15.3-28.3], p<0.0001), vedolizumab (25.2 [15.0-42.2], p=0.0409), ustekinumab (28.9 [18.5-45.0], p=0.0754), and tofacitinib (5.5 [2.8-10.9], p<0.0001), but not oral 5-ASA (39.1 [31.9-47.9], p=0.3225), attenuated GMTs at 4 weeks post-2nd vaccination (Table 2). Conclusion: Aging and most IMD options attenuated immunogenicity in fully vaccinated IBD patients. Prioritization of a booster vaccination should be considered for IBD patients treated with IMDs.

Estimating Work Engagement from Online Chat Logs

The Covid-19 pandemic has transformed our lives, and in order to aid in the prevention and spread of infection, a remote work style has rapidly proliferated. As this remote work style has proliferated, new problems have come to light. One problem is that managers cannot fully grasp the engagement level of subordinates such as in terms of absorption, dedication, and vigor due to limited in-person communications. However, as a substitute for in-person communications, online communications via text-based chat tools such as Slack and Microsoft's Teams have become popular. Recognizing the level of work engagement in a remote work setting is difficult, so we propose a new approach that estimates this level using text-based chat tools. To evaluate the proposal, we conduct experiments using actual Slack data. The experimental results reveal that the content of the conversations do not influence the level of work engagement, but the frequency of conversations among the teams and team members does. Therefore, we develop a machine learning model that estimates the level of work engagement using only the frequency and affiliation as features. The model estimates the work engagement level using true and predicted values at a correlation coefficient of 0.72. Since the proposed model uses only the frequency and affiliation, it is valuable in actual business situations. © 2021 Owner/Author.