Epidemiology of Coronavirus Disease 2019 in Yamagata Prefecture, Japan, January-May 2020: the Importance of Retrospective Contact Tracing.

Public health interventions have played an important role in controlling coronavirus disease 2019 (COVID-19), which is a rapidly spreading infectious disease. To contribute to future COVID-19 countermeasures, we aimed to verify the results of the countermeasures employed by public health centers (PHCs) against the first wave of COVID-19 in Yamagata Prefecture, Japan (Yamagata). Between January and May 2020, 1,253 patients suspected of SARS-CoV-2 infection were invited for testing. Simultaneously, based on retrospective contact tracings, PHCs investigated the infection sources and transmission routes of laboratory-confirmed COVID-19 cases and tested 928 contacts. Consequently, 69 cases were confirmed between March 31 and May 4, 58 of whom were from among the contacts (84.1%; 95% confidence interval [CI] 75.5-92.7). The spread of infection was triggered in cases harboring epidemiological links outside Yamagata. Subsequently, the number of cases rapidly increased. However, PHCs identified epidemiological links in 61 (88.4%; 95% CI 80.8-96.0) of the 69 cases, and transmission chains up to the fifth generation. Finally, the spread of infection ended after approximately one month. Our results indicate that the identification of infection sources and active case finding from contacts based on retrospective contact tracing was likely to be an effective strategy in ending the first wave of COVID-19 in Yamagata.

Loneliness, social isolation, and pain following the COVID-19 outbreak: data from a nationwide internet survey in Japan.

The aim of cross-sectional study was to investigate the association between loneliness, increased social isolation, and pain following the COVID-19 outbreak. A total of 25,482 participants, aged 15-79 years, were assessed using an internet survey; the University of California, Los Angeles Loneliness Scale (Version 3), Short Form 3-item (UCLA-LS3-SF3) was used to assess loneliness, and a modified item of the UCLA-LS3-SF3 was used to measure the perception of increased social isolation during the pandemic. The outcome measures included the prevalence/incidence of pain (i.e., headache, neck or shoulder pain, upper limb pain, low back pain, and leg pain), pain intensity, and the prevalence of past/present chronic pain. Pain intensity was measured by the pain/discomfort item of the 5-level version of the EuroQol 5 Dimension scale. Odds ratios of pain prevalence/incidence and past/present chronic pain prevalence according to the UCLA-LS3-SF3 scoring groups (tertiles) and the frequency of the perceived increase in social isolation (categories 1-5) were calculated using multinomial logistic regression analysis. The mean pain intensity values among different loneliness and social isolation levels were tested using an analysis of covariance. Increased loneliness and the severity of the perceived social isolation were positively associated with the prevalence/incidence of pain, pain intensity, and the prevalence of past/present chronic pain.

Sitting for long periods is associated with impaired work performance during the COVID-19 pandemic.

OBJECTIVES: The unprecedented coronavirus disease 2019 (COVID-19) pandemic and the corresponding government state of emergency have dramatically changed our workstyle, particularly through implementing teleworking and social distancing. We investigated the degree to which people's work performance is affected and the association between sedentary behavior under the state of emergency and worsened work performance during the COVID-19 pandemic, as previous studies have suggested that sedentary behavior decreases work performance. METHODS: We used data from the Japan "COVID-19 and Society" Internet Survey (JACSIS) study, a cross-sectional, web-based, self-reported questionnaire survey. The main outcome was change in work performance after the COVID-19 pandemic compared with that before the pandemic. We analyzed the association between the change in work performance and sitting duration under the state of emergency, adjusted for work-related stress, participants' demographics, socio-economic status, health-related characteristics, and personality. RESULTS: The change of work environment from the pandemic decreased work performance in 15% of workers, which was 3.6 times greater than the number of workers reporting increased performance in 14 648 workers (6134 women and 8514 men). Although telework both improved and worsened performance (odds ratio [OR], 95% confidence interval [CI] = 2.0, 1.6-2.5 and 1.7, 1.5-1.9, respectively), sitting for long periods after the state of emergency was significantly associated only with worsened performance (OR, 95% CI = 1.8, 1.5-2.2) in a dose-response manner. CONCLUSION: Sitting duration is likely a risk barometer of worsened work performance under uncertain working situations, such as the COVID-19 pandemic.