The Tokyo 2020 and Beijing 2022 Olympic Games held during the COVID-19 pandemic: planning, outcomes, and lessons learnt.

The COVID-19 pandemic profoundly affected all mass gatherings for sporting and religious events, causing cancellation, postponement, or downsizing. On March 24, 2020, the Japanese Government, the Tokyo Organising Committee of the Olympic and Paralympic Games, and the International Olympic Committee decided to postpone the Tokyo 2020 Olympic and Paralympic Games until the summer of 2021. With the emergence of SARS-CoV-2, the potential creation of a superspreading event that would overwhelm the Tokyo health system was perceived as a risk. Even with a delayed start date, an extensive scale of resources, planning, risk assessment, communication, and SARS-CoV-2 testing were required for the Games to be held during the COVID-19 pandemic. The effectiveness of various mitigation and control measures, including the availability of vaccines and the expansion of effective testing options, allowed event organisers and the Japanese Government to successfully host the rescheduled 2020 Tokyo Olympic Games from July 23 to Aug 8, 2021 with robust safety plans in place. In February and March, 2022, Beijing hosted the 2022 Winter Olympic Games as scheduled, built on the lessons learnt from the Tokyo Games, and developed specific COVID-19 countermeasure plans in the context of China's national framework for the plan called Zero COVID. Results from the testing programmes at both the Tokyo and Beijing Games show that the measures put in place were effective at preventing the spread of COVID-19 within the Games, and ensured that neither event became a COVID-19-spreading event. The extensive experience from the Tokyo and Beijing Olympic Games highlights that it is possible to organise mass gatherings during a pandemic, provided that appropriate risk assessment, risk mitigation, and risk communication arrangements are in place, leaving legacies for future mass gatherings, public health, epidemic preparedness, and wider pandemic response.

Alcohol and toxicological factors influencing fatal falls from height in the Greater Tokyo Area: a retrospective study.

Falls from height pose a significant public health concern in urban regions, including the highly urbanized Greater Tokyo Area. The Japanese population is characterized by high rates of suicide and psychoactive drug usage, underscoring the importance of investigating these attributes in falls from height. This study aimed to retrospectively analyze the alcohol and toxicological aspects influencing falls from height in the Greater Tokyo Area between 2014 and 2022 and compare the findings with existing reports on other populations. In total, 75 cases of falls from height and 159 cases of natural deaths were included. Consistent with previous findings, Fisher's exact test revealed a predominance of males (66.67%, 50/75) and young adults (57.33%, 43/75) in falls from height. Multivariate logistic regression analysis identified antidepressant usage as the most significant risk factor within the target population, while younger individuals under alcohol influence constituted another high-risk group. Notably, contradictory to other populations, female individuals involved in fatal falls in the Greater Tokyo Area exhibited a higher frequency of alcohol consumption than males (48.00%, 12/25 vs. 26.00%, 13/50), and most of them were associated with suicide (83.33%, 10/12). These findings elucidate the population characteristics that pose a high risk for fatal falls from height in Japan and can serve as a reference for other Asian populations residing in similar megacities.

[Characteristics and courses of COVID-19 in patients from the first through fifth waves of the disease: Focused on a single public health center in Tokyo, Japan].

Objective　Coronavirus disease 2019 (COVID-19) became a global public health threat, and local public health centers in Japan implemented an infectious disease response to support patients. The response was subsequently modified to meet the needs for each of the five waves of infection. The study aim was to analyze the characteristics and courses of the disease in patients with COVID-19 at a single public health center. The study period included the first through fifth waves of the disease.Methods　We utilized a descriptive epidemiological design in this study and data of patients with COVID-19 from one administrative district in Tokyo, Japan. We analyzed age, gender, nationality, symptoms at diagnosis, the route of infection, the recovery environment, and associated morbidity intervals, including case fatality rate, days from symptom onset to diagnosis, days from diagnosis to hospitalization, and recovery time for each of the first through fifth waves.Results　From February 2020 to November 2021, 11,252 patients were diagnosed with COVID-19. Specifically, in the first wave, 151 patients were diagnosed, followed by 803 in the second wave, 2,406 in the third wave, 1,480 in the fourth wave, and 6,412 in the fifth wave. Hospitalization was the primary recovery environment during the first wave, while home recovery became the primary approach from the third wave onward. The case fatality rate was highest during the first wave, likely because of limited testing and treatment options for severe cases. The median time from onset to diagnosis was seven days in the first wave, significantly longer than for the other waves. The median time from diagnosis to hospitalization was one day in the first through fourth waves but three days in the fifth wave. The extension of this interval suggests that hospitalization was delayed in this wave as the number of severe patients increased rapidly, likely because of the novel COVID-19 variant.Conclusion　This study of patients testing positive for COVID-19 provides valuable insights into the characteristics and courses of the pandemic within this district. These findings can inform regarding the development of effective strategies to manage the ongoing COVID-19 pandemic and other future emerging infectious diseases.

Injection drug use and sexually transmitted infections among men who have sex with men: A retrospective cohort study at an HIV/AIDS referral hospital in Tokyo, 2013-2022.

Men who have sex with men (MSM) who use injection drugs (MSM-IDU) are at high risk of sexually transmitted infections (STIs), but the long-term incidence is unclear. We conducted a single-centre retrospective cohort study using the clinical records of non-haemophilia men with human immunodeficiency virus (HIV) who visited the Institute of Medical Science, the University of Tokyo (IMSUT) Hospital, located in Tokyo, Japan, from 2013 to 2022. We analysed 575 patients including 62 heterosexual males and 513 MSM patients, of whom 6.8% (35/513) were injection drug use (IDU). Compared to non-IDU MSM, MSM-IDU had a higher incidence of hepatitis C virus (HCV) (44.8 vs 3.5 /1,000 person-years (PY); incidence rate ratio (IRR) [95% confidence interval (95% CI)], 12.8 [5.5-29.3], p < 0.001) and syphilis (113.8 vs 53.3 /1,000 PY; IRR, 2.1 [1.4-3.1], p < 0.001). The incidence of other symptomatic STIs (amoebiasis, chlamydia, and gonorrhoea infections) was <4/1,000 PY. In multivariable Poisson regression analysis, HCV incidence was associated with MSM (IRR, 1.8 × 106 [9.9 × 105-3.4 × 106], p < 0.001), IDU (IRR, 10.1 [4.0-25.6], p < 0.001), and syphilis infection during the study period (IRR, 25.0 [1.2-518.3]/time/year, p < 0.001). Among men with HIV, the prevalence of IDU in MSM and the long-term incidence of STIs in MSM-IDU were high. IDU and sexual contact are important modes of transmission of HCV among HIV-infected MSM in Tokyo.

Cumulative and undiagnosed SARS-CoV-2 infection among the staff of a medical research centre in Tokyo after the emergence of variants.

To describe the trend of cumulative incidence of coronavirus disease 19 (COVID-19) and undiagnosed cases over the pandemic through the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants among healthcare workers in Tokyo, we analysed data of repeated serological surveys and in-house COVID-19 registry among the staff of National Center for Global Health and Medicine. Participants were asked to donate venous blood and complete a survey questionnaire about COVID-19 diagnosis and vaccine. Positive serology was defined as being positive on Roche or Abbott assay against SARS-CoV-2 nucleocapsid protein, and cumulative infection was defined as either being seropositive or having a history of COVID-19. Cumulative infection has increased from 2.0% in June 2021 (pre-Delta) to 5.3% in December 2021 (post-Delta). After the emergence of the Omicron, it has increased substantially during 2022 (16.9% in June and 39.0% in December). As of December 2022, 30% of those who were infected in the past were not aware of their infection. Results indicate that SARS-CoV-2 infection has rapidly expanded during the Omicron-variant epidemic among healthcare workers in Tokyo and that a sizable number of infections were undiagnosed.

Assessing the COVID-19 vaccination program during the Omicron variant (B.1.1.529) epidemic in early 2022, Tokyo.

BACKGROUND: Many countries, including high-income nations, struggled to control epidemic waves caused by the Omicron variant (B.1.1.529), which had an antigenically distinct evolution. Evaluating the direct and indirect effects of vaccination during the Omicron waves is essential to assess virus control policies. The present study assessed the population impacts of a vaccination program during the sixth wave caused by BA.1 and BA.2 from January to May 2022, in Tokyo. METHODS: We analyzed the primary series and booster vaccination coverages and the confirmed cases stratified by vaccination history. We estimated the number of COVID-19 cases that were directly and indirectly prevented by vaccination. To estimate the direct impact, we used a statistical model that compared risks between unvaccinated and vaccinated individuals. A transmission model employing the renewal process was devised to quantify the total effect, given as the sum of the direct and indirect effects. RESULTS: Assuming that the reporting coverage of cases was 25%, mass vaccination programs, including primary and booster immunizations, directly averted 640,000 COVID-19 cases (95% confidence interval: 624-655). Furthermore, these programs directly and indirectly prevented 8.5 million infections (95% confidence interval: 8.4-8.6). Hypothetical scenarios indicated that we could have expected a 19% or 7% relative reduction in the number of infections, respectively, compared with the observed number of infections, if the booster coverage had been equivalent to that of the second dose or if coverage among people aged 10-49 years had been 10% higher. If the third dose coverage was smaller and comparable to that of the fourth dose, the total number of infections would have increased by 52% compared with the observed number of infections. CONCLUSIONS: The population benefit of vaccination via direct and indirect effects was substantial, with an estimated 65% reduction in the number of SARS-CoV-2 infections compared with counterfactual (without vaccination) in Tokyo during the sixth wave caused by BA.1 and BA.2.

An online survey on differences in knowledge and stigma about epilepsy among the Tokyo metropolitan area and non-urban areas in Japan, a post-hoc study.

PURPOSE: Extant research elucidating the domains of knowledge and bias on epilepsy has consistently underscored a deficiency in cognizance and an inclination toward bias within non-urban areas. Investigations into geographical disparities concerning epilepsy awareness and prejudice within the Japanese context remain conspicuously absent. To address this lacuna in the literature, we undertook a post-hoc analysis to elucidate the discernible regional differentials in epilepsy awareness and the associated stigma. METHODS: From July to August 2021, we conducted an internet questionnaire survey for 310 people with epilepsy (PWE) and 213 ordinary people without epilepsy who registered on the database of the Japanese Research Company. We inquired PWE to answer the Epilepsy Self-Stigma Scale (ESSS), the Rosenberg Self-Esteem Scale (RSES), and the Epilepsy Knowledge Scale (EKS). We inquired to answer ordinary people without epilepsy EKS. We analyzed residential addresses separately for Greater Tokyo and non-urban areas by comparing the degree of knowledge of people with epilepsy and people without epilepsy. RESULTS: The average knowledge of people with and without epilepsy in the Greater Tokyo area was 39.60 and 28.43 points, although in non-urban areas (nine regions from all over Japan except for the Greater Tokyo, Tokai region, and Kinki region), the knowledge averages were 38.44 and 28.66 points of 100. In addition, self-stigma was highest in the Greater Tokyo area: 22.99 and in non-urban areas: 22.77. An two-way ANOVA with knowledge as the dependent variable and epilepsy diagnosis status and region (Greater Tokyo area/non-urban areas) as the independent variables revealed no interaction between diagnosis and region (F(1,346) = 1.48, η2 = 0.003). Knowledge was significantly higher in PWE than in people without epilepsy, but we could not identify any significant difference between ESSS (t = 0.24, d = 0.03) and RSES (t = 1.16, d = 0.16) in the Greater Tokyo/non-urban areas. CONCLUSIONS: We obtained specific information about regional differences in the level of knowledge and stigma about epilepsy in Japan. Because Japan underwent educational reforms after World War II and more than 90% of the population received equally advanced education, the results found no regional differences in knowledge and stigma about epilepsy. We believe collecting information about the respondents' birth and upbringing environment and conducting a thorough investigation is necessary in the future.

Peculiar weather patterns effects on air pollution and COVID-19 spread in Tokyo metropolis.

As a pandemic hotspot in Japan, between March 1, 2020-October 1, 2022, Tokyo metropolis experienced seven COVID-19 waves. Motivated by the high rate of COVID-19 incidence and mortality during the seventh wave, and environmental/health challenges we conducted a time-series analysis to investigate the long-term interaction of air quality and climate variability with viral pandemic in Tokyo. Through daily time series geospatial and observational air pollution/climate data, and COVID-19 incidence and death cases, this study compared the environmental conditions during COVID-19 multiwaves. In spite of five State of Emergency (SOEs) restrictions associated with COVID-19 pandemic, during (2020-2022) period air quality recorded low improvements relative to (2015-2019) average annual values, namely: Aerosol Optical Depth increased by 9.13% in 2020 year, and declined by 6.64% in 2021, and 12.03% in 2022; particulate matter PM2.5 and PM10 decreased during 2020, 2021, and 2022 years by 10.22%, 62.26%, 0.39%, and respectively by 4.42%, 3.95%, 5.76%. For (2021-2022) period the average ratio of PM2.5/PM10 was (0.319 ± 0.1640), showing a higher contribution to aerosol loading of traffic-related coarse particles in comparison with fine particles. The highest rates of the daily recorded COVID-19 incidence and death cases in Tokyo during the seventh COVID-19 wave (1 July 2022-1 October 2022) may be attributed to accumulation near the ground of high levels of air pollutants and viral pathogens due to: 1) peculiar persistent atmospheric anticyclonic circulation with strong positive anomalies of geopotential height at 500 hPa; 2) lower levels of Planetary Boundary Layer (PBL) heights; 3) high daily maximum air temperature and land surface temperature due to the prolonged heat waves (HWs) in summer 2022; 4) no imposed restrictions. Such findings can guide public decision-makers to design proper strategies to curb pandemics under persistent stable anticyclonic weather conditions and summer HWs in large metropolitan areas.

Do health concerns stemming from personality trait influence the choice of drinking water at home? An analysis of the survey results conducted in the Tokyo area under the COVID-19 pandemic.

Many previous studies have already pointed out that health concerns influence people's choice of drinking water. The health concerns discussed in the preceding studies are those that are associated with the choice of a particular type of water. On the other hand, people also experience health concerns in their daily lives, unrelated to the choice of drinking water. These two need to be discussed separately, but preceding studies have failed to make a distinction. In this study, we refer to the former as 'health concerns attributable to water characteristics' and the latter as 'health concerns stemming from personality traits.' The purpose of this study is to explore the relationship, if any, between people's health concerns stemming from personality traits and their choice of drinking water. We use three types of health concerns that are stemming from personality traits (e.g. health maintenance, pesticide residues in food, and COVID-19 infection) to elucidate their influences on the choice of drinking water. Based on the results of the analysis, this study reveals that the influence of health concerns stemming from personality traits on the choice of drinking water differs depending on its typology.

Behavioral changes of preventive activities of influenza among children in satellite cities of a metropolitan area of Tokyo, Japan, by the COVID-19 pandemic.

OBJECTIVE: In children in a metropolitan area of Tokyo, Japan, behavioral change and influenza infection associated with the frequency of nonpharmaceutical interventions (NPI) was assessed from the 2018-2019 season (Preseason) and the 2020-2021 season (coronavirus disease 2019 [COVID-19] season). METHODS: We conducted an exclusive survey among children attending preschool, elementary school, and junior high school in the Toda and Warabi regions, Japan, during the 2018-2019 (Preseason, distributed via mail) and 2020-2021 seasons (COVID-19 season, conducted online). The proportion of preventive activities (hand washing, face mask-wearing, and vaccination) was compared in the Preseason with that of the COVID-19 season. The multivariate logistic regression model was further applied to calculate the adjusted odds ratio (AOR) with 95% confidence intervals (CIs) for influenza infection associated with NPI frequency (hand washing and face mask wearing) in each Preseason and COVID-19 season. RESULTS: The proportion of vaccinated children who carried out hand washing and face mask wearing was remarkably higher during the COVID-19 season (48.8%) than in the Preseason (18.2%). A significant influenza infection reduction was observed among children who washed hands and wore face masks simultaneously (AOR, 0.87; 95% CI, 0.76-0.99; P = 0.033). CONCLUSIONS: A strong interest and performance in the intensive measures for the prevention of influenza under the COVID-19 pandemic was demonstrated. Positive association was observed from a combination of NPI, hand washing, and face mask-wearing and influenza infection. This study's findings could help in activities or preventive measures against influenza and other communicable diseases in children.

Evaluating workforce well-being: an investigation of healthcare professionals' mental health and burnout symptoms at the Tokyo 2020 and Beijing 2022 Paralympic Games.

OBJECTIVE: To explore the prevalence of symptoms of mental health conditions and burnout of healthcare professionals (HCPs) working during the Tokyo 2020 Paralympic Games and the Beijing 2022 Paralympic Winter Games. METHODS: In this cross-sectional, observational study, HCPs working during the Tokyo 2020 and Beijing 2022 Paralympic Games were asked to complete an online, anonymous survey, which included demographic questions and questions regarding mental health symptoms including depression (Patient Health Questionnaire 9-item depression scale) and anxiety (Generalized Anxiety Disorder 7-item scale) as well as burnout (Maslach Burnout Inventory-Human Services Survey: depersonalisation, emotional exhaustion, personal accomplishment). Correlation coefficients (r) were calculated between demographic characteristics and mental health symptoms. RESULTS: In total, 256 HCPs (of 857 HCPs; 30%) completed the surveys. Twelve and eight per cent of HCP scores fell within the moderate to severe depression and moderate to severe anxiety categories, respectively. More than 30% reported moderate to high burnout (depersonalisation: 36%; emotional exhaustion: 36%; personal accomplishment: 58%). In addition, thoughts of self-harm and/or suicidality were reported by some HCPs (8%). Weak correlations were observed between age and depression (r=-0.13, p=0.046), anxiety (r=-0.16, p=0.010) and burnout (emotional exhaustion: r=-0.14, p=0.032; personal accomplishment: r=0.27, p<0.001). CONCLUSION: Although most HCPs reported good mental health, this study suggests that a subset of HCPs experienced symptoms of depression, anxiety, burnout or thoughts of self-harm during the Tokyo 2020 and Beijing 2022 Paralympic Games. While the generalisability of these findings outside of COVID-19 restrictions should be tested, appropriate guidance and mental health support of HCPs leading up to the Paralympic Games should be prioritised.

Acute in-competition medical care at the Tokyo 2020 Olympics: a retrospective analysis.

OBJECTIVE: To analyse injuries and illnesses during the 2020 Tokyo Olympic Summer Games. METHODS: This retrospective descriptive study included 11 420 athletes from 206 National Olympic Committees and 312 883 non-athletes. Incidences of injuries and illnesses during the competition period from 21 July to 8 August 2021 were analysed. RESULTS: A total of 567 athletes (416 injuries, 51 non-heat-related illnesses and 100 heat-related illnesses) and 541 non-athletes (255 injuries, 161 non-heat-related illnesses and 125 heat-related illnesses) were treated at the competition venue clinic. Patient presentation and hospital transportation rates per 1000 athletes were 50 and 5.8, respectively. Marathons and race walking had the highest incidence of injury and illness overall (17.9%; n=66). The highest incidence of injury (per participant) was noted in boxing (13.8%; n=40), sport climbing (12.5%; n=5) and skateboarding (11.3%; n=9), excluding golf, with the highest incidence of minor injuries. Fewer infectious illnesses than previous Summer Olympics were reported among the participants. Of the 100 heat-related illnesses in athletes, 50 occurred in the marathon and race walking events. Only six individuals were transported to a hospital due to heat-related illness, and none required hospital admission. CONCLUSION: Injuries and heat-related illnesses were lower than expected at the 2020 Tokyo Olympic Summer Games. No catastrophic events occurred. Appropriate preparation including illness prevention protocols, and treatment and transport decisions at each venue by participating medical personnel may have contributed to these positive results.

Income-related inequalities in the association of smoking with periodontitis: a cross-sectional analysis in Tokyo Metropolitan Districts.

OBJECTIVE: Socio-economic status (SES) and smoking are risk factors for periodontitis; however, their interaction has not been determined. We investigated the effect of modification of SES and smoking with periodontal conditions. MATERIALS AND METHODS: Data on the social background, smoking status, and dental examination of 1033 individuals residing in the Tokyo Metropolitan District were analyzed. The outcomes were the number of remaining teeth and the proportion of teeth with probing pocket depth (PPD) ≥ 4 mm and ≥ 6 mm. Multilevel linear and Poisson regression analyses were performed after adjusting for possible confounding factors, including SES, assessed by the average income of the residential area. RESULTS: The mean number of remaining teeth was 24.6 ± 4.8, and the proportion of teeth with PPD ≥ 4 mm and ≥ 6 mm was 31.2 ± 28.5% and 12.2 ± 18.1%, respectively. After adjusting for confounding factors, the lowest-income population had significantly lesser teeth (coefficient: - 0.46, 95% CI - 0.89, 0.02, p = 0.039) and a higher proportion of teeth with PPD ≥ 4 mm than the highest-income population (ratio of means: 1.22, 95% CI 1.03-1.44, p = 0.013). Significant interactions were observed; income inequalities in periodontitis were significant only among current smokers. CONCLUSION: Inequality in socio-economic status is associated with oral health inequalities. The adverse effects of smoking on periodontitis might be greater in the low-income population. CLINICAL RELEVANCE: The low-income population, especially current smokers, had significantly more compromised oral health than the high-income population. In addition to the emphasis on smoking cessation, the promotion of universal health coverage for dental care is necessary to reduce oral health inequalities.

Coronavirus Disease 2019 (COVID-19) Breakthrough Infection and Post-Vaccination Neutralizing Antibodies Among Healthcare Workers in a Referral Hospital in Tokyo: A Case-Control Matching Study.

BACKGROUND: While increasing coverage of effective vaccines against coronavirus disease 2019 (COVID-19), emergent variants raise concerns about breakthrough infection. Data are limited, however, whether breakthrough infection during the epidemic of the variant is ascribed to insufficient vaccine-induced immunogenicity. METHODS: We describe incident COVID-19 in relation to the vaccination program among workers of a referral hospital in Tokyo. During the predominantly Delta epidemic, we followed 2415 fully vaccinated staff (BNT162b2) for breakthrough infection and selected 3 matched controls. We measured post-vaccination neutralizing antibodies against the wild-type, Alpha (B.1.1.7), and Delta (B.1.617.2) strains using live viruses and anti-spike antibodies using quantitative assays, and compared them using the generalized estimating equation model between the 2 groups. RESULTS: No COVID-19 cases occurred 1-2 months after the vaccination program during the fourth epidemic wave in Japan, dominated by the Alpha variant, while 22 cases emerged 2-4 months after the vaccination program during the fifth wave, dominated by the Delta variant. In the vaccinated cohort, all 17 cases of breakthrough infection were mild or asymptomatic and participants had returned to work early. There was no measurable difference between cases and controls in post-vaccination neutralizing antibody titers against the wild-type, Alpha, Delta, and anti-spike antibody titers, while neutralizing titers against the variants were considerably lower than those against the wild-type. CONCLUSIONS: Post-vaccination neutralizing antibody titers were not decreased among patients with breakthrough infection relative to their controls under the Delta variant outbreak. The result points to the importance of infection-control measures in the post-vaccination era, irrespective of immunogenicity profile.

Age-Dependent Effects of COVID-19 Vaccine and of Healthcare Burden on COVID-19 Deaths, Tokyo, Japan.

COVID-19 vaccine effectiveness against death in Japan remains unknown. Furthermore, although evidence indicates that healthcare capacity influences case-fatality risk (CFR), it remains unknown whether this relationship is mediated by age. With a modeling study, we analyzed daily COVID-19 cases and deaths during January-August 2021 by using Tokyo surveillance data to jointly estimate COVID-19 vaccine effectiveness against death and age-specific CFR. We also examined daily healthcare operations to determine the association between healthcare burden and age-specific CFR. Among fully vaccinated patients, vaccine effectiveness against death was 88.6% among patients 60-69 years of age, 83.9% among patients 70-79 years of age, 83.5% among patients 80-89 years of age, and 77.7% among patients >90 years of age. A positive association of several indicators of healthcare burden with CFR among patients >70 years of age suggested an age-dependent effect of healthcare burden on CFR in Japan.

Viral loads and profile of the patients infected with SARS-CoV-2 Delta, Alpha, or R.1 variants in Tokyo.

The rapid spread of the Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a serious concern worldwide in summer 2021. We examined the copy number and variant types of all SARS-CoV-2-positive patients who visited our hospital from February to August 2021 using polymerase chain reaction (PCR) tests. Whole genome sequencing was performed for some samples. The R.1 variant (B.1.1.316) was responsible for most infections in March, replacing the previous variant (B.1.1.214); the Alpha (B.1.1.7) variant caused most infections in April and May; and the Delta variant (B.1.617.2) was the most prevalent in July and August. There was no significant difference in the copy numbers among the previous variant cases (n = 29, median 3.0 × 104 copies/µl), R.1 variant cases (n = 28, 2.1 × 105 copies/µl), Alpha variant cases (n = 125, 4.1 × 105 copies/µl), and Delta variant cases (n = 106, 2.4 × 105 copies/µl). Patients with Delta variant infection were significantly younger than those infected with R.1 and the previous variants, possibly because many elderly individuals in Tokyo were vaccinated between May and August. There was no significant difference in mortality among the four groups. Our results suggest that the increased infectivity of Delta variant may be caused by factors other than the higher viral loads. Clarifying these factors is important to control the spread of Delta variant infection.

Emergence of Hepatitis C Virus Genotype 2c Infection Among Human Immunodeficiency Virus-Infected Men Who Have Sex With Men in Tokyo, Japan.

ABSTRACT: We report on hepatitis C virus genotype 2c infection in 12 human immunodeficiency virus-infected men who have sex with men in Tokyo, Japan. The uncommon strains from the 12 patients were genetically clustered; they suggested an emerging outbreak in this population at high risk of sexually transmitted infections.

Diogenes syndrome in a 10-year retrospective observational study: An elderly case series in Tokyo.

OBJECTIVES: Supporting people suffering from Diogenes Syndrome (DS) is a challenge for geriatric psychiatry. However, there is a lack of knowledge about DS in Japan. Therefore, a systematic longitudinal study to clarify the factors associated with DS and its prognosis was conducted. METHODS/DESIGN: A retrospective study using data from case records of a municipal psychogeriatric service was conducted. The study population was socially isolated older adults with complex mental health and social care needs who had been referred to the service over 10 years. The participants were stratified into DS and non-DS groups, multivariate analysis was performed to identify factors associated with DS, and survival analysis was performed. RESULTS: Of the 270 participants, 61 with Environmental Cleanliness and Clutter Scale (ECCS) scores >12 were assigned to the DS group, and 209 with ECCS scores ≤12 were assigned to the non-DS group. On multiple logistic regression analysis, significantly more people in the DS group were living alone, had advanced dementia, and had reduced basic activities of daily living (BADL) compared to the non-DS group. Furthermore, survival analysis showed that the DS group had a higher risk of early death than the non-DS group. CONCLUSIONS: In the present study, social isolation, living alone, advanced dementia, and reduced BADL were found to be associated with DS. In addition, DS had a high risk of early death. Support for DS must take into account not only mental and social health, but also physical health from an early stage.

Impact of the coronavirus disease 2019 pandemic on first-visit patients with oesophageal cancer in the first infection wave in Saitama prefecture near Tokyo: a single-centre retrospective study.

BACKGROUND: Although the novel coronavirus disease 2019 did not lead to a serious medical collapse in Japan, its impact on treatment of oesophageal cancer has rarely been investigated. This study aimed to investigate the influence of the pandemic on consultation status and initial treatment in patients with primary oesophageal cancer. METHODS: A retrospective study was conducted among 546 patients with oesophageal cancer who visited our hospital from April 2018 to March 2021. Pre-pandemic and pandemic data were compared with the clinical features, oncological factors and initial treatment as outcome measures. RESULTS: Diagnoses of oesophageal cancer decreased during the early phase of the pandemic from April to June (P = 0.048); however, there was no significant difference between the pre-pandemic and pandemic periods throughout the year. The proportion of patients diagnosed with distant metastases significantly increased during the pandemic (P = 0.026), while the proportion of those who underwent initial radical treatment decreased (P = 0.044). The rate of definitive chemoradiotherapy decreased by 58.6% relative to pre-pandemic levels (P = 0.001). CONCLUSIONS: Patients may have refrained from consultation during the early phase of the coronavirus disease 2019 pandemic. The resultant delay in diagnosis may have led to an increase in the number of patients who were not indicated for radical treatment, as well as a decrease in the number of those who underwent definitive chemoradiotherapy. Our findings highlight the need to maintain the health care system and raise awareness on the importance of consultation.

Serologic Survey of IgG Against SARS-CoV-2 Among Hospital Visitors Without a History of SARS-CoV-2 Infection in Tokyo, 2020-2021.

BACKGROUND: Tokyo, the capital of Japan, is a densely populated city of >13 million people, so the population is at high risk of epidemic severe acute respiratory coronavirus 2 (SARS-CoV-2) infection. A serologic survey of anti-SARS-CoV-2 IgG would provide valuable data for assessing the city's SARS-CoV-2 infection status. Therefore, this cross-sectional study estimated the anti-SARS-CoV-2 IgG seroprevalence in Tokyo. METHODS: Leftover serum of 23,234 hospital visitors was tested for antibodies against SARS-CoV-2 using an iFlash 3000 chemiluminescence immunoassay analyzer (Shenzhen YHLO Biotech, Shenzhen, China) with an iFlash-SARS-CoV-2 IgG kit (YHLO) and iFlash-SARS-CoV-2 IgG-S1 kit (YHLO). Serum samples with a positive result (≥10 AU/mL) in either of these assays were considered seropositive for anti-SARS-CoV-2 IgG. Participants were randomly selected from patients visiting 14 Tokyo hospitals between September 1, 2020 and March 31, 2021. No participants were diagnosed with coronavirus disease 2019 (COVID-19), and none exhibited COVID-19-related symptoms at the time of blood collection. RESULTS: The overall anti-SARS-CoV-2 IgG seroprevalence among all participants was 1.83% (95% confidence interval [CI], 1.66-2.01%). The seroprevalence in March 2021, the most recent month of this study, was 2.70% (95% CI, 2.16-3.34%). After adjusting for population age, sex, and region, the estimated seroprevalence in Tokyo was 3.40%, indicating that 470,778 individuals had a history of SARS-CoV-2 infection. CONCLUSIONS: The estimated number of individuals in Tokyo with a history of SARS-CoV-2 infection was 3.9-fold higher than the number of confirmed cases. Our study enhances understanding of the SARS-CoV-2 epidemic in Tokyo.