[Temporal relationships between a state of emergency declaration or request and trends in the incidence of unlinked COVID-19 cases in Osaka from October 2020 to May 2021].

Objective　We examined the effectiveness of governmental declarations on the changing temporal trends in the incidence of COVID-19 cases with unknown transmission routes (unlinked cases) before SARS-CoV-2 vaccines became available in Osaka.Methods　Seven-day moving averages of the incidence of unlinked COVID-19 cases were calculated using daily reports posted on the official website of the Osaka Prefectural Government for the third (October 10, 2020-February 28, 2021) and fourth COVID-19 waves and about one week before and after (February 23, 2021-June 27, 2021). Then, we calculated daily percentage changes and identified dates of significant change ("Joinpoint") with a Joinpoint regression analysis. The date of a major change in the behavior of prefectural residents associated with the risk of infection (the date of a sudden change in behavior) was defined as the date counting backward from each Joinpoint date and considering the incubation period and interval between the date of onset and disclosure of the daily report. Subsequently, we examined the temporal relationships between the declaration date and defined date of the sudden change in behavior associated with the risk of infection.Results　Five Joinpoint dates contributing to a significant downward trend were identified: November 23, 2020, and in 2021, January 7, January 18, April 12, and April 30. We defined dates of sudden changes in behavior from each Joinpoint date from the corresponding time lag (8 to 9.9 days): in 2020, November 13 and December 30; in 2021, January 9, April 4, and April 22. Regarding the five estimated dates, the second emergency declaration was issued on January 9, 2021. Further, the first introduction of priority preventive measures was given on April 4, 2021. April 22 fell between the date that the third emergency declaration was requested and the date of its issuance.Conclusion　These descriptive epidemiological findings suggest that the issuance of these declarations could be triggers that reinforced infection avoidance behavior among Osaka prefectural residents, which resulted in the downward trends in unlinked COVID-19 cases.

COVID-19 outbreak trends in South Africa: A comparison of Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods.

OBJECTIVES: We provided COVID-19 outbreak trends in South Africa during the Omicron (B.1.1.529), Delta (B.1.617.2), and Beta (B.1.351) variants outbreak periods from November 2020 to March 2022. METHODS: We used the time series summary data of the COVID-19 outbreak for South Africa available in the COVID-19 data repository created by the Center for System and Science and Engineering at Johns Hopkins University and the Our World in Data database by the University of Oxford from January 2020 to March 2022. We used the joinpoint regression model with a data-driven Bayesian information criterion method for analyzing the outbreak trends. In addition, we used density ellipses and partition modeling on the outbreak data. RESULTS: During the Omicron outbreak period, COVID-19 cases in South Africa significantly jumped by 4.7 times from December 01 to December 08, 2021. The average daily growth rate of incidence peaked at 23,000 cases/day until December 16, 2021, which was 18.6 % higher than the peak growth during the Delta outbreak period. South Africa experienced peak growth in COVID-19 cases with 18,611 cases/day (January 04 to January 14, 2021) during the Beta outbreak period and with 19,395 cases/day (July 01 to July 11, 2021) during the Delta outbreak period. Density ellipsoid showed a significant correlation between daily cases and daily death count during the Beta and Delta outbreak period which was not prominent in the Omicron outbreak period. Comparatively higher daily death tolls were reported in days with a recovery rate of less than 89.1 % and 91.9 % in the Beta and Delta outbreak period respectively. The backlog counts may be one of the reasons for the significant increase in daily death tolls during the Omicron period. CONCLUSIONS: During the Omicron period, COVID-19 cases peaked growth was 18.6 % higher than the peak growth during the Delta outbreak period. Despite that fact, growth in death trends in the Omicron outbreak period was found low which might be due to the low mortality rate and case fatality proportion. The emergence of the Omicron variant once again reminds us that- "no one is safe until everyone is safe".

Trends in the Prevalence of Hypertensive Heart Disease in China From 1990 to 2019: A Joinpoint and Age-Period-Cohort Analysis.

To the best of our knowledge, no comprehensive estimates of the descriptive epidemiology of and trends in hypertensive heart disease (HHD) in China have been reported. In this study, the temporal trends in the prevalence of HHD in China from 1990 to 2019 were estimated using an age-period-cohort model. Data related to HHD burden were collected from the Global Burden of Disease Study 2019. From 1990 to 2019, HHD prevalence in China showed decreasing trends in both sexes combined (average annual percentage change [AAPC]: -0.2%, 95% confidence interval (CI: -0.3% to -0.2%) and in males (AAPC: -0.5%, 95% CI: -0.5% to -0.4%), but significant increases in the age groups of 15-19, 20-24, …, and 60-64 years. The age effect analysis showed an increase in HHD prevalence from 50 to 94 years in both males and females, the period effect analysis showed a slight increase in HHD prevalence from 2009 to 2019 in females, and the cohort effect analysis showed a consistent decline in HHD prevalence from earlier to later birth cohorts in both males and females.

Increased suicide mortality in Japan during the COVID-19 pandemic in 2020.

Socioeconomic stagnation and social isolation due to the spread of novel coronavirus disease 2019 might have contributed to the increase in suicide mortality in 2020. Using Joinpoint regression analysis, we estimated the expected suicide mortality in 2020 based on suicide mortality from 2011 to 2019, and compared results to the actual suicide mortality in Japan. We found that actual suicide mortality was significantly higher than the expected mortality among both men (excess mortality rate: 107.0%) and women (120.1%). This higher excess suicide mortality rate was particularly notable in women aged in their 20 s (154.0%) and 30s-40 s (130.7%).