Background: The COVID-19 pandemic has imposed a large, initially uncontrollable, public health crisis both in the United States and across the world, with experts looking to vaccines as the ultimate mechanism of defense. The development and deployment of COVID-19 vaccines have been rapidly advancing via global efforts. Hence, it is crucial for governments, public health officials, and policy makers to understand public attitudes and opinions towards vaccines, such that effective interventions and educational campaigns can be designed to promote vaccine acceptance.Objective: The aim of this study was to investigate public opinion and perception on COVID-19 vaccines in the United States. We investigated the spatiotemporal trends of public sentiment and emotion towards COVID-19 vaccines and analyzed how such trends relate to popular topics found on Twitter.Methods: We collected over 300,000 geotagged tweets in the United States from March 1, 2020 to February 28, 2021. We examined the spatiotemporal patterns of public sentiment and emotion over time at both national and state scales and identified 3 phases along the pandemic timeline with sharp changes in public sentiment and emotion. Using sentiment analysis, emotion analysis (with cloud mapping of keywords), and topic modeling, we further identified 11 key events and major topics as the potential drivers to such changes.Results: An increasing trend in positive sentiment in conjunction with a decrease in negative sentiment were generally observed in most states, reflecting the rising confidence and anticipation of the public towards vaccines. The overall tendency of the 8 types of emotion implies that the public trusts and anticipates the vaccine. This is accompanied by a mixture of fear, sadness, and anger. Critical social or international events or announcements by political leaders and authorities may have potential impacts on public opinion towards vaccines. These factors help identify underlying themes and validate insights from the analysis.Conclusions: The analyses of near real-time social media big data benefit public health authorities by enabling them to monitor public attitudes and opinions towards vaccine-related information in a geo-aware manner, address the concerns of vaccine skeptics, and promote the confidence that individuals within a certain region or community have towards vaccines.

Disease and lifestyle patterns have been changing rapidly especially in Africa due to transformation in economic development and urbanization. Research on the magnitude and consequences of these transformations in Africa is limited. This study investigates the shifts in nutritional status in children and adults in four selected low-, middle- and high-income countries in Africa, identifies factors associated with the shifts, and provides recommendations for future studies. Malawi, Kenya, Ghana, and South Africa were selected based on their Gross Domestic Product (GDP). Nationally representative data were obtained from the 2017 Global Nutrition Report, Demographic Health Surveys (DHSs), and the World Health Organization (WHO) database. Prevalence of underweight, overweight, and obesity were assessed and compared across the countries, gender, residence, and over time. Results: South Africa had the highest GDP and largest prevalence of overweight and obesity rates in children < 5 years old and adults > 18 (13.3% and 51.9%, respectively). Malawi, with the lowest GDP, had the highest stunting rate (37.0%). In all 4 countries, but most notably in South Africa, trends indicated that the increasing prevalence of overweight and obesity was much greater than the declining rate of underweight. Malawi, Kenya, and Ghana had a slight decline in overweight prevalence in children under 5 years. Nutritional shifts are occurring in Africa and seem to be heavily influenced by economic development. The double-burden of malnutrition presents prioritization challenges for policymakers. Attention needs to be shifted towards prevention of obesity, at least in the higher income countries in Africa.

Background: The Chinese Great Famine caused widespread starvation in 1959–1961. Its long-term association with depressive symptoms has not been studied.Aims: To estimate the burden of depressive symptoms and the association of famine exposure with depressive symptoms.Method: The China Health and Retirement Longitudinal Study is a nationwide representative survey of 17 708 Chinese adults aged ≥45. Propensity score matching and modified Poisson regression were used to evaluate the association between self-reported famine exposure in early life and depressive symptoms among the overall participants. Such associations were also assessed by developmental stage using modified Poisson regression and logistic regression.Results: The prevalence of depressive symptoms was 26.2% (95% CI 25.1–27.3%) in 2011. As defined by loss of family members because of starvation, 11.6% (95% CI 10.1–13.1%) of this population experienced severe famine. When compared with participants who did not experience starvation, those who had experienced severe famine during fetal, mid-childhood, young-teenage and early-adulthood stages had 1.87 (95% CI 1.36–2.55), 1.54 (95% CI 1.23–1.94), 1.47 (95% CI 1.09–2.00) and 1.77 (95% CI 1.42–2.21) times higher odds of having depressive symptoms in late adulthood, respectively. The first two trimesters of pregnancy were a critical time window during the fetal stage when severe famine had a stronger association with depressive symptoms. Famine during infant, toddler, preschool or teenage stages was not associated with depressive symptoms. Overall, famine contributed to 13.6% of the depressive symptom burden in this population.Conclusions: The Chinese Great Famine contributed substantially to the burden of depressive symptoms in China.Declaration of interest: None.

Without a widely distributed vaccine, controlling human mobility has been identified and promoted as the primary strategy to mitigate the transmission of COVID-19. Many studies have reported the relationship between human mobility and COVID-19 transmission by utilizing the spatial-temporal information of mobility data from various sources. To better understand the role of human mobility in the pandemic, we conducted a systematic review of articles that measure the relationship between human mobility and COVID-19 in terms of their data sources, mathematical models, and key findings. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we selected 47 articles from the Web of Science Core Collection up to September 2020. Restricting human mobility reduced the transmission of COVID-19, although the effectiveness and stringency of policy implementation vary temporally and spatially across different stages of the pandemic. We call for prompt and sustainable measures to control the pandemic. We also recommend researchers 1) to enhance multi-disciplinary collaboration; 2) to adjust the implementation and stringency of mobility-control policies in corresponding to the rapid change of the pandemic; 3) to improve mathematical models used in analysing, simulating, and predicting the transmission of the disease; and 4) to enrich the source of mobility data to ensure data accuracy and suability.

Our purpose was to explore the impact of atmospheric pollutants on the incidence of tuberculosis and provide new ideas for the prevention and control of tuberculosis in the future. We explored the relationship between air pollutants and meteorological factors, as well as between air pollutants and heating through Spearman correlation analysis and rank sum test. Additionally, we analyzed the relationship between air pollutants and tuberculosis incidence using the general additive model. Statistical analysis results at the P < 0.05 level were considered significant. Three months after exposure to air pollutants (PM2.5, SO2, NO2 and CO), tuberculosis incidence increased. However, tuberculosis incidence increased 9 months after exposure to PM10. The single pollutant model showed when concentrations of PM2.5, PM10, SO2, NO2, CO and O3 increased by 1 μg/m3 (or 1 mg/m3), the number of tuberculosis cases would increase 0.09%, 0.08%, 0.58%, 0.42%, 6.9% and 0.57%, respectively. The optimal multi-pollutant model was a two-factor model (PM10+NO2). Air pollutants including PM2.5, PM10, SO2, NO2, CO and O3 increased the risk of tuberculosis. Few studies have been conducted in this area of research, especially regarding the mechanism; thus, the results of this study should contribute to our understanding of TB incidence and prompt additional research.

Refugees remain vulnerable to acute food insecurity, malnutrition, and critically inadequate food and nutrient intake after migration, regardless of the economic level of the host country. We conducted this systematic review to summarize and evaluate the dietary intake and nutritional status among refugees resettled in non-camp settings worldwide. We searched PubMed and Web of Science databases to review relevant studies published between 2009 and 2020 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We also conducted an additional manual search through PubMed and Google Scholar. Studies that evaluated both dietary intake and nutritional status of refugees in host countries were included. A total of 15 articles from 10 countries were included and assessed for study quality and outcomes. Poor dietary diversity and insufficient intake of specific food groups were reported. In addition to these dietary patterns, a high prevalence of stunting, underweight, and anemia was reported, particularly among children. A double burden of malnutrition was also observed across and within studies. Post-resettlement dietary intake and nutritional status of refugees are both influenced by factors at the pre- and post-resettlement stages as refugees transition to their host countries. Those factors, including pre-resettlement experiences, host country resources, socioeconomic status, acculturation, and food security, were summarized and presented in a conceptual model. There is a need for comprehensive dietary and health screening as well as culturally appropriate and sustainable nutrition education resources and interventions for refugees to improve their diet and nutrition. Longitudinal studies and novel methodological approaches are also suggested to measure changes in refugees’ food intake and nutritional status as well as to further investigate factors associated with these 2 components.