Research progress on the mutation of SARS-CoV-2

At the end of December 2019,an outbreak of pneumonia caused by SARS-CoV-2 occurred in Wuhan, Hubei Province. So far, the epidemic caused by the virus is still circulating globally, infecting more than 180 million people in total. With the continuous spread of SARS-CoV-2 among populations, its genome has continued to mutate, from the first discovery of D614G mutation of the S protein in SARS-CoV-2 to Alpha, Beta, Gamma, Delta listed as concerns by the World Health Organization and some other variants of interest. The continuous emergence of new variants has aroused widespread public concern. Therefore, this article will briefly summarize the genome structure and function of SARS-CoV-2, some of the characteristics of the main international variants, the protection results of SARS-CoV-2 vaccines against the variants, and the vaccine strategies to deal with SARS-CoV-2 mutations.

Associations Between Poor Sleep Quality, Anxiety Symptoms, and Depressive Symptoms Among Chinese Adolescents Before and During COVID-19: A Longitudinal Study.

Since the novel coronavirus disease 2019 (COVID-19) outbreak, adolescents' emerging mental health and behavior issues have been an international public health concern. This longitudinal study aimed to examine the situation of poor sleep quality, anxiety, and depressive symptoms among Chinese adolescents and to explore the associations between them before and during COVID-19. A total of 1,952 middle and high school students as eligible participants at baseline (pre-COVID-19, Wave 1; response rate: 98.79%), 1,831 eligible students were followed up at Wave 2 (October 2019 to December 2019, pre-COVID-19; retention rate: 93.80%), and 1,790 completed the follow-up at Wave 3 (during the COVID-19; retention rate: 97.80%). The mean age of the baseline students was 13.56 (SD: 1.46) years. The differences in anxiety and depressive symptoms between Wave 1, Wave 2, and Wave 3 were not statistically significant. The proportion of students with poor sleep quality increased over time, from Wave 1 (21.0%) to Wave 3 (26.0%, OR = 1.37, 95% CI = 1.17-1.60, P = 0.001) and from Wave 2 (21.9%) to Wave 3 (OR = 1.29, 95% CI = 1.11-1.51, P < 0.001). The cross-lagged generalized linear mixed models revealed that the concurrent and cross-lagged associations of poor sleep quality with anxiety symptoms across the three waves were significant (P < 0.05) and vice versa. Only a marginally significant positive cross-lagged association between poor sleep quality at Wave 2 and depressive symptoms at Wave 3 was found (standardized ß estimate = 0.044, SE = 0.022, P = 0.045). Sleep quality was adversely affected during COVID-19, and the bidirectional associations of poor sleep quality with anxiety symptoms could not be neglected.

Suicide reduction in Canada during the COVID-19 pandemic: lessons informing national prevention strategies for suicide reduction.

OBJECTIVE: The objective of this research was to evaluate the impact of federal, public health and social support programs on national suicide rates in Canada. DESIGN: Cross-sectional study. SETTING: Canadian National Database (i.e., Statistics Canada) and Statista. PARTICIPANTS: Population-level data, and economic and consumer market data. MAIN OUTCOME MEASURES: Suicide mortality data, population data and unemployment data were obtained from available statistical databases (e.g. Statistics Canada). We quantified suicide rate by dividing the total number of suicide deaths by the national population expressed as a rate per 100,000 population. RESULTS: Overall suicide mortality rate decreased in Canada from 10.82 deaths per 100,000 in the March 2019 - February 2020 period to 7.34 per 100,000 (i.e. absolute difference of 1300 deaths) in the March 2020 - February 2021 period. The overall Canadian unemployment rate changed from an average monthly rate of 5.7% in 2019 to 9.5% in 2020. CONCLUSION: Our results indicate that for the first post-pandemic interval evaluated (i.e., March 2020 - February 2021), suicide rates in Canada decreased against a background of extraordinary public health measures intended to mitigate community spread of COVID-19. An externality of public health measures was a significant rise in national unemployment rates in population measures of distress. Our results suggest that government interventions that broadly aim to reduce measures of insecurity (i.e., economic, housing, health), and timely psychiatric services, should be prioritised as part of a national suicide reduction strategy, not only during but after termination of the COVID-19 pandemic.

Comparing mortality from covid-19 to mortality due to overdose: A micromort analysis.

OBJECTIVE: To compare the mortality risk due to covid-19 with death due to overdose in British Columbia, Canada. The opioid epidemic was declared a public health emergency in 2016. METHODS: Mortality risk was calculated in micromorts with covid-19 data for January-October 2020, derived from the BC center for Disease Control, and illicit drug toxicity deaths for January 2010-September 2020, derived from the BC Coroners Service. Age-stratified covid-19 incidence and deaths per 100,000 population and age-stratified illicit drug toxicity death rates per 100,000 population were calculated. A micromort is a unit of risk equivalent to a one-in-a-million chance of death. RESULTS: During the covid-19 pandemic, illicit drug toxicity deaths reached 1.0 micromorts per day, representing an increase of 0.5 micromorts per day relative to 2019 rates. In comparison, covid-19 mortality risk was 0.05 micromorts per day among individuals from the general population living in British Columbia and 21.1 micromorts per day among those infected with covid-19. Covid-related mortality risk was significantly lower among individuals aged <60 years, relative to older adults, whereas drug toxicity-related mortality was highest for individuals aged 30-59 years. CONCLUSIONS: The mortality associated with covid-19 is apparent and distributed unevenly across subpopulations. The mortality due to overdose has increased during covid-19 and exceeds mortality due to covid-19. Our results instantiate the triple threat caused by covid-19 (i.e., public health crisis, economic crisis and mental health crisis) and quantitatively highlight the externality of increased mortality due to deaths of despair in response to public health efforts to reduce covid-related mortality.

Effect of School-Based Family Health Education via Social Media on Children's Myopia and Parents' Awareness: A Randomized Clinical Trial.

Importance: Myopia is a common cause of vision loss, and its prevalence is increasing globally. Objective: To evaluate the effects of school-based family health education via WeChat in raising parents' awareness of myopia prevention and behavior and in controlling the development of myopia in children. Design, Setting, and Participants: A single-masked cluster randomized clinical trial of children was conducted from October 1, 2018, to December 31, 2020, among grade 1 students from 12 primary schools in Guangzhou, China. The 12 primary schools were randomly selected in 2 districts and randomized to the intervention and control groups. All grade 1 students were invited to participate, and 688 students were included in the intervention group and 752 in the control group. Interventions: Weekly health education via the social media platform WeChat was provided to the parents in the intervention group. Main Outcomes and Measures: Data include results of eye examinations of children and questionnaires completed by parents. The primary outcome was the 2-year cumulative incidence rate of myopia. Myopia was defined as a spherical equivalent (SE) refractive error (sphere of +0.5 cylinder) of at least -0.50 diopters (D). The secondary outcomes were the 2-year changes in the axis length and SE refraction, parental awareness, children's screen time, outdoor activities, and learning tools during COVID-19. Results: Among the 1525 children included at baseline (835 boys [54.8%]; mean [SD] age, 6.3 [0.5] years), 1244 competed the final assessment; the 2-year cumulative incidence rate of myopia was 106 of 544 (19.5%) in the intervention group and 171 of 700 (24.4%) in the control group (difference, 4.9% [95% CI, 0.3%-9.5%]; P = .04). The mean myopic shift in SE refraction in the intervention group (-0.82 D) was lower than that in the control group (-0.96 D; difference, -0.14 [95% CI, -0.22 to -0.06] D; P < .001). No difference in change in axial length was detected (difference, 0.02 [95% CI, -0.06 to 0.09] mm; P = .70). Conclusions and Relevance: School-based weekly family health education via WeChat resulted in a small decrease in the 2-year cumulative incidence rate of myopia with a difference in SE of less than 0.25 D not accompanied by any axial length differences. Whether these findings extrapolate elsewhere in the world or are clinically relevant in the short or long term remain to be determined. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR1900022236.

Rates of Myopia Development in Young Chinese Schoolchildren During the Outbreak of COVID-19.

Importance: During the outbreak of COVID-19, outdoor activities were limited and digital learning increased. Concerns have arisen regarding the impact of these environmental changes on the development of myopia. Objective: To investigate changes in the development of myopia in young Chinese schoolchildren during the outbreak of COVID-19. Design, Setting, and Participants: In this observational study, 2 groups of students from 12 primary schools in Guangzhou, China, were prospectively enrolled and monitored from grade 2 to grade 3. Comparisons between the exposure and nonexposure groups were made to evaluate any association between environmental changes during the COVID-19 outbreak period and development of myopia. The exposure group received complete eye examinations in November and December 2019 and November and December 2020. The nonexposure group received examinations in November and December 2018 and November and December 2019. Main Outcomes and Measures: Changes in cycloplegic spherical equivalent refraction (SER), axial length (AL) elongation, and myopia incidence from grade 2 to grade 3. Results: Among the 2679 eligible students in grade 2 (mean [SD] age, 7.76 [0.32] years; 1422 [53.1%] male), 2114 (1060 in the nonexposure group and 1054 in the exposure group) were reexamined in grade 3. Compared with the period from November and December 2018 to November and December 2019, the shift of SER, AL elongation, and myopia incidence from grade 2 to grade 3 from November and December 2019 to November and December 2020 was 0.36 D greater (95% CI, 0.32-0.41; P < .001), 0.08 mm faster (95% CI, 0.06-0.10; P < .001), and 7.9% higher (95% CI, 5.1%-10.6%; P < .001), respectively. In grade 3 students, the prevalence of myopia increased from 13.3% (141 of 1060 students) in November and December 2019 to 20.8% (219 of 1054 students) in November and December 2020 (difference [95% CI], 7.5% [4.3-10.7]; P < .001); the proportion of children without myopia and with SER greater than -0.50 D and less than or equal to +0.50 D increased from 31.1% (286 of 919 students) to 49.0% (409 of 835 students) (difference [95% CI], 17.9% [13.3-22.4]; P < .001). Conclusions and Relevance: In this study, development of myopia increased during the COVID-19 outbreak period in young schoolchildren in China. Consequently, myopia prevalence and the proportion of children without myopia who were at risk of developing myopia increased. Future studies are needed to investigate long-term changes in myopia development after the COVID-19 pandemic.

Government response moderates the mental health impact of COVID-19: A systematic review and meta-analysis of depression outcomes across countries.

BACKGROUND: The COVID-19 pandemic represents a public health, economic and mental health crisis. We hypothesized that timely government implementation of stringent measures to reduce viral transmission would benefit mental health, as evidenced by reduced rates of depressive symptoms (i.e., Patient Health Questionnaire [PHQ]-9≥10, PHQ-2≥3). METHODS: The systematic review herein (PROSPERO CRD42020200647) evaluated to what extent differences in government-imposed stringency and timeliness of response to COVID-19 moderate the prevalence of depressive symptoms across 33 countries (k=114, N=640,037). We included data from six lower-middle-income countries, nine upper-middle-income countries, and 18 higher-income countries. Government-imposed stringency and timeliness in response were operationalized using the Oxford COVID-19 Government Response ("Stringency") Index. RESULTS: The overall proportion of study participants with clinically significant depressive symptoms was 21.39% (95% CI 19.37-23.47). The prevalence of clinically significant depressive symptoms was significantly lower in countries wherein governments implemented stringent policies promptly. The moderating effect of government response remained significant after including the national frequency of COVID cases at the time of study commencement, Healthcare Access and Quality index, and the inclusion of COVID patients in the study. LIMITATIONS: Factors that may have confounded our results include, for example, differences in lockdown duration, lack of study participant and outcome assessor blinding, and retrospective assessment of depressive symptom severity. CONCLUSIONS: Governments that enacted stringent measures to contain the spread of COVID-19 benefited not only the physical, but also the mental health of their population.

Mental health conditions among the general population, healthcare workers and quarantined population during the coronavirus disease 2019 (COVID-19) pandemic.

This study sought to assess the differences in mental health conditions among the general population, quarantined population and healthcare workers during the COVID-19 outbreak in China. An online rapid assessment captured depressive and anxiety symptoms, and sleep quality data. A total of 2689 participants (n=374 general population, n=403 healthcare workers, n=1912 quarantined population) were included in the final statistical analysis. The proportion of individuals with mild and/or serious depression and anxiety were higher in the general population when compared to the quarantined population and healthcare workers (58.6% vs. 25.1%vs. 48.6%, P<0.001; 41.2% vs. 18.5% vs. 35.7%, P<0.001). The prevalence of sleep disturbance was higher among healthcare workers than the general population and quarantined population (29.8% vs. 24.1% vs. 22.7%, P=0.013). Logistic regression analysis showed that, perceived effect on daily life was associated with depression, anxiety and sleep disturbance in the general population, quarantined population and the healthcare workers. The general population had a greater risk of developing psychological problems. The healthcare workers suffered the poorest sleep quality. Future research must further explorethe targeted measures for the general population and healthcare workers while combating COVID-19.