Abstract Background Overseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China. To better prevent and control such local outbreaks, the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provincial-level administrative divisions (PLADs) where dengue fever is outbreak in the mainland of China were explored. Methods Using the Chinese National Notifiable Infectious Disease Reporting Information System (CNNDS), we identified overseas imported dengue fever cases in dengue fever outbreak areas in the mainland of China from 2005 to 2019 to draw the epidemic curve and population characteristic distribution of overseas imported cases in each PLAD. Based on spatial autocorrelation analysis of ArcGIS 10.5 and temporal-spatial scanning analysis of SaTScan 9.5, we analyzed the temporal-spatial distribution of overseas imported dengue fever in dengue fever outbreak areas in the mainland of China. Results A total of 11,407 imported cases, mainly from Southeast Asia, were recorded from 2005 to 2019 in these 13 PLADs. Of which 62.1% were imported into Yunnan and Guangdong Provinces. Among the imported cases, there were more males than females, mainly from the 21–50 age group. The hot spots were concentrated in parts of Yunnan, Guangdong and Fujian Provinces. We found the cluster of infected areas were expanding northward. Conclusions Based on the analysis of overseas imported dengue cases in 13 PLADs of the mainland of China from 2005 to 2019, we obtained the epidemiological characteristics and spatial distribution of imported dengue cases. Border controls need to pay attention to key population sectors, such as 21–50 years old men and education of key populations on dengue prevention. There is a need to improve the awareness of the prevention and control of imported cases in border areas. At the same time, northern regions cannot relax their vigilance. Graphical Abstract

目的比较云南省瑞丽和景洪市登革热流行特征,为两市登革热精准防控提供依据。方法收集2006-2018年云南省瑞丽及景洪市登革热本地和输入病例信息,采用SPSS 22.0和R 3.6.2软件进行统计学分析。结果2006-2018年,瑞丽市共报告登革热病例3 022例,其中输入病例占59.13%（59.00%为境外输入）,本地病例占40.87%;景洪市报告的3 923例病例中,输入病例占3.08%（其中3.01%为境外输入病例）,本地病例占96.92%;瑞丽市输入病例数是景洪市的14.77倍,两市输入病例年龄主要集中在16～45岁,主要来源于东南亚国家,尤其是缅甸。两市的输入病例和本地病例在性别、年龄、职业和发病至诊断间隔时间上差异均有统计学意义（χ~2=7.529、14.169、201.686,均P＜0.05;χ~2=18.342、43.723、557.247,均P＜0.001;Mann-Whitney U=75 032.500、2 116 735.000,均P＜0.001）。结论瑞丽市登革热病例境外输入较多,景洪市以本地病例为主;建议两市相关部门加强登革热病例监测,及时发现、隔离、治疗和采取疫情处置措施。

(1) Background: Overseas imported dengue fever is an important factor in the local epidemic of dengue fever in mainland China. Therefore, in order to effectively prevent and control the local epidemic of dengue fever in mainland China, the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provinces where dengue fever is endemic in mainland China are explored. (2) Methods: Through the infectious disease report information management system of the Chinese Disease Prevention and Control Information System, we sorted out overseas imported dengue fever cases in local outbreaks of dengue fever in mainland China from 2005 to 2019. Using Excel 2016 to sort out the data and draw the epidemic curve and population characteristic distribution of overseas imported cases in each province. Using ArcGIS 10.7 and SaTScan 9.5, we analyzed the temporal-spatial distribution of dengue fever in provinces where dengue fever is outbreak in mainland China. (3) Results: A total of 11407 imported cases, mainly from Southeast Asia, were recorded from 2005 to 2019 in 13 provinces, of which 62.08% were imported into Yunnan and Guangdong provinces. Among the imported cases, there were more males than females, mainly from 21-50 age group. 59.18% of the cases were farmers, businessmen, housework or unemployed. The hot spots were concentrated in parts of Yunnan and Guangdong provinces. Meanwhile,we found the clustered areas were expanding northward. (4) Conclusions: Focus on the publicity and education of dengue fever prevention knowledge among men, 21-50 years old, farmers, business services, housework or unemployed professionals. Further improve the awareness of the prevention and control of imported cases in border areas and economically developed cities. At the same time, the northern region cannot relax its vigilance.

Left unmitigated, climate change poses a catastrophic risk to human health, demanding an urgent and concerted response from every country. The 2015 Lancet Commission on Health and Climate Change and The Lancet Countdown: Tracking Progress on Health and Climate Change have been initiated to map out the impacts of climate change and the necessary policy responses. To meet these challenges, Tsinghua University, partnering with the University College London and 17 Chinese and international institutions, has prepared the Chinese Lancet Countdown report, which has a national focus and builds on the work of the global Lancet Countdown: Tracking Progress on Health and Climate Change. Drawing on international methodologies and frameworks, this report aims to deepen the understanding of the links between public health and climate change at the national level and track them with 23 indicators. This work is part of the Lancet’s Countdown broader efforts to develop regional expertise on this topic, and coincides with the launch of the Lancet Countdown Regional Centre in Asia, based at Tsinghua University. The data and results of this report are presented at the provincial level, where possible, to facilitate targeted response strategies for local decision-makers. Based on the data and findings of the 2020 Chinese Lancet Countdown report, five recommendations are proposed to key stakeholders in health and climate change in China: (1) Enhance inter-departmental cooperation. Climate change is a challenge that demands an integrated response from all sectors, urgently requiring substantial inter-departmental cooperation among health, environment, energy, economic, financial, and education authorities. (2) Strengthen health emergency preparedness. Knowledge and findings on current and future climate-related health threats still lack the required attention and should be fully integrated into the emergency preparedness and response system. (3) Support research and raise awareness. Additional financial support should be allocated to health and climate change research in China to enhance health system adaptation, mitigation measures, and their health benefits. At the same time, media and academia should be fully motivated to raise the public and politicians’ awareness of this topic. (4) Increase climate change mitigation. Speeding up the phasing out of coal is necessary to be consistent with China’s pledge to be carbon neutral by 2060 and to continue to reduce air pollution. Fossil fuel subsidies must also be phased out. (5) Ensure the recovery from COVID-19 to protect health now and in the future. China’s efforts to recover from COVID-19 will shape public health for years to come. Climate change should be a priority in these interventions.

目的分析2005-2019年中国北部的甘肃省、宁夏回族自治区、陕西省、山西省、河北省、北京市、天津市、辽宁省（简称8省）流行性乙型脑炎（乙脑）的流行特征,探讨乙脑发生规律,为乙脑的有效防控提供科学依据。方法通过中国疾病预防控制信息系统和乙脑监测信息报告管理系统收集2005-2019年中国北部8省乙脑病例,进行描述性流行病学分析。结果 2005-2019年研究区域乙脑年平均发病率为0.14/10万,死亡390例,病死率为7.25%。乙脑分布范围由2005年的157个县（区）扩展到2018年的254个县（区）。8-9月乙脑发病数占总发病数的81.26%,是乙脑发病高峰月份。0～14岁年龄组占比从2005年的54.55%下降至2019年的3.96%,≥15岁年龄组占比从2005年的45.18%升至2019年的96.03%（χ2趋势=998.524,P＜0.001）。农民、幼托儿童及散居儿童和学生分别占58.76%、14.81%和12.38%,农民占比由2005年的37.19%上升至2019年的79.21%。结论中国北部8省乙脑分布范围扩大,年龄分布向高年龄组倾斜,人群职业构成中农民占比增加。

Left unmitigated, climate change poses a catastrophic risk to human health, requiring an urgent and concerted response from every country. As the home to one fifth of the world's population and the largest emitter of carbon dioxide globally, China's interventions in climate change are of pivotal importance, both to human health and to the planet. Similar to other countries, climate change mitigation and adaptation would bring immense health benefits for China's 1·4 billion people, and building these considerations into any COVID-19 recovery strategy and the detailed pathway to fulfil the 2060 carbon neutrality pledge will ensure it improves human wellbeing, both now and in the future. Decisions made over the coming months and years will establish the course of climate change policy for decades to come. To meet this challenge, Tsinghua University (Beijing, China), partnering with University College London (London, UK) and 17 Chinese and international institutions, has produced the Lancet Countdown China report, focusing at the national level and building on the work of the global Lancet Countdown. Drawing on international methods and frameworks, this report aims to understand and track the links between public health and climate change at the national level. This paper is one part of the Lancet Countdown's broader efforts to develop regional expertise and understanding. Uniquely, the data and results in this report are presented at the provincial level where possible, to facilitate the targeted response strategies for local decision makers. Taken as a whole, the findings of the 23 indicators convey two key messages. The first message is that the health effects from climate change in China are accelerating, posing an unacceptably high amount of health risk if global temperatures continue to rise. Every province is affected, each with its unique health threats, and targeted response strategies should be made accordingly. The effects of climate change, manifested in rising temperatures, more extreme weather events, and shifting vector ecology, are being felt in China. Heatwave-related mortality has risen by a factor of four from 1990 to 2019, reaching 26 800 deaths in 2019. The monetised cost of the high number of deaths is equivalent to the average annual income of 1·4 million people in China. Older people (>65 years old), who face a 10·4% higher risk of dying during a heatwave, endured an average of 13 more heatwave days in 2019 compared with the 1986–2005 baseline. For outdoor workers, their potential heat-related labour productivity loss reached 0·5% of total national work hours, costing 1% of China's gross domestic product (GDP), equivalent to its annual fiscal expenditure on science and technology. Driven in part by rising temperatures and a changing climate, the advent of more extreme wildfires and the spread of dengue fever will in turn lead to profound health effects. Different regions have unique health threats, requiring a targeted response—19 provinces have had an at least 10% rise over the past two decades in three or more of the six health effect indicators reported. Importantly, many highly populated and economically advanced provinces, such as Henan, Shandong, and Zhejiang, are faced with health risks that are larger and more rapidly accelerating than others. The second message is that impressive and concerted improvements have been made across several sectors in China; however, the gap in the country's response to the health effects of climate change is large. In some sectors, China has taken large steps to address climate change. Solar power generation is growing at an unprecedented rate of 26·5% per year, rising to 26·8 gigawatts (GW) of newly installed capacity in 2019. Investments in low-carbon energy are now nine times greater than those in fossil fuels (rising from a 1:1 ratio in 2008); and, providing 4·1 million jobs in 2018, renewable energy now employs more people in China than fossil fuel extraction industries. As a result of strong policy measures, severe air pollution has also decreased, with a 28% reduction in annual average particulate matter of 2·5 μm or less (PM2·5) concentration in cities from 2015 to 2019, resulting in 90 000 fewer PM2·5-related premature deaths annually. These air pollution control policies also act to mitigate climate change and have resulted in a decline in China's coal share in total primary energy supply from 66% in 2014 to 59% in 2018. Showing leadership at the subnational level, three provinces already have a provincial health and climate change plan in place, with four more provinces underway. However, although these changes have been rapid, more shifts of a greater size are necessary to enact a response that is of the scale required to fulfil China's carbon neutrality by 2060 pledge and to minimise the rising health burdens of climate change, both in China and around the world. Although renewable energy use is rising, coal stills holds a 59% share of the total primary energy supply in China. Fossil fuel subsidies were US$41·9 billion in 2018, without considering the contribution of fossil fuels to the estimated $10·7 billion economic losses because of premature mortality from PM2·5 air pollution. Although there have been substantial reductions in air pollution, 42% of China's population still live in areas that do not meet the interim air quality guidelines from WHO, and almost all cities have PM2·5 concentrations more than the recommended annual average of 10 μg/m3. The health effects of climate change are not adequately recognised or addressed, as climate change is not referenced in the Healthy China Action Plan (2019–30), and China is yet to introduce a standalone national adaptation plan for health. Taking a broader perspective, media coverage and individual engagement in health and climate change are low, with little spread of knowledge and engagement. China will need to scale up progress in all sectors to counteract the rising curve of the health risks from climate change. Five recommendations are proposed to key stakeholders in health and climate change in China: (1)Enhance interdepartmental cooperation. Climate change is a challenge that requires an integrated response from all sectors. Although China commits to integrate health into all policies, substantial interdepartmental cooperation among health, environment, energy, economic, financial, and education authorities is urgently needed.(2)Strengthen health emergency preparedness. Although the amount of health emergency preparedness in China would be greatly enhanced after COVID-19, knowledge and findings on current and future climate-related health threats still do not have enough attention and should be fully integrated into the emergency preparedness and response system, so that future health service, medical supplies, and infrastructure needs could be planned ahead.(3)Support research and raise awareness. Additional financial support should be allocated to health and climate change research in China, to enhance the knowledge of health system adaptation, mitigation measures, and their resulting health benefits. At the same time, media and academia should be fully motivated to raise awareness on this topic for the public and for politicians. Additionally, the Government of China should update the Healthy China Action Plan (2019–30) to address the health risks of climate change as soon as possible.(4)Increase climate change mitigation. China's new pledges towards carbon neutrality by 2060 is a major step forward. Speeding up the coal phase-out process is therefore necessary to be consistent with the carbon neutrality pledges and continue China's progress on air pollution reduction. Fossil fuel subsidies should also be phased out to reflect the true cost of ongoing fossil fuel use and to avoid undermining the effect of China's emissions trading scheme, scheduled to take effect in 2021.(5)Ensure the country's recovery from the COVID-19 pandemic protects health both now and in the future. Decisions made as part of China's efforts to recover from COVID-19 will shape the public's health for years to come. The longer-term prospects for lives, livelihoods, and a sustainable economy will be put in jeopardy if these interventions do not prioritise climate change.