环境改变与传染病的发生和流行

单击此处编辑母版标题样式,编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,大家好,全球环境改变对传染病发生及其流行影响,首都医科大学附属北京佑安医院,金荣华,关键词,安全（,Safety,）,趋势（,Trends,）,误区（,Misconception,）,案例（,Case,）,机制（,Mechanism,）,一、安全？,1.2016,全球危险预测,SOURCE:,The Global Risks Report 2016 11th Edition,2.10,个变化中全球危机,Source: Global Risks Perception Survey 2014 and 2015, World Economic Forum.,3.,未来,10,年高度关注全球危机事件,Source: Global Risks Perception Survey 2015, World Economic Forum.,4.,全球新发和复燃传染性疾病例证,SOURCE: Morens et al., 2004.,5.,人畜共患病涌现,SOURCE: Bean et al., 2013.,二、趋势？,1.,全球环境发生哪些变化？,地球环境中所有自然和人为因素引起能够改变地球承载生命能力变化，主要包括气候变化、大气组成变化、生物多样性丧失、荒漠化，以及由于人口、经济、技术和社会压力引起土地利用变化和土地覆盖变化等。,全球气候变化：核心，大气,CO2,等温室气体,浓度上升所引起全球变暖，以及由此引发,降水格局变化、冰川退化、海平面上升等,一系列变化,（,1,）工业革命以来人类活动变化情况,SOURCE: Steffen et al., 2011.,（,2,）人类活动增加后全球变化,SOURCE: Steffen et al., 2011.,（,3,）生存指标超越人类生存警戒,SOURCE: Rockstrom.et al., 2009a.,rate of biodiversity loss,climate change,and human interference with the nitrogen cycle,（,3,）天气改变、生物多样性和氮循环超标,SOURCE: Rockstr et al., 2009a,b.,SOURCE: Rockstrom et al., 2009a,b.,行星边界,（,4,）地表热,3,度对农作物产量影响,Note: 50% change = half as productive in 2050 as in 2015; +100% change = twice as productive in 2050 as in 2015,Source: WRI 2013.,2.,环境改变与传染病,传染病会来？,何时来？,怎么来？,传染病发生和流行受哪些因素影响？,有准备？,（,1,）疾病与疾病流行要素,新发或复燃,EID,三大主因,(2),传染病分类,vector(mosquito or tick) or a non-biological vehicle(soil or water),Attention:,病原菌和媒介小,缺少温控装置,(3),科学研究聚焦,变化或趋势如何影响传染病发生？,寻找证据，传染病流行却因变化引发？,用已有知识和原理构建预测模型：不同变化情况如何影响传染病传播能力,全球预警与联合应对,Approximate numbers of described, or named, species, divided into major groupings. Scientists have described about 1.5 million species of living things on Earth, but the,majority,of species are still,unknown,2024/9/27,22,难点,1,：物种多样,难点,2,研究条件艰难,手段不断更新,单个或协同作用,全球性,难点,3,：因素多,全球变化对人类传染病发生与传播影响,（,4,）,The Convergence Model,（,4,）,-1,气象因子对传染病病原体影响,温度和湿度直接繁殖及其在环境中生存时间；尤其对病毒，大多数病毒、细菌以及寄生生物都有存在临界温度,低于或者高于某个温度其都无法存活。疟疾传播必须在,1633,否则孢子生殖不能发生,.,疟疾最理想传播环境是湿度高、温度在,2030,。,日本脑炎病毒存活临界温度是,20(Mellor,和,Leake, 2000).,温度会影响病毒进化,新型传染病暴发,温度会影响病毒传染力和风险,温度变化趋势,（,4,）,-2,气象因子对传染病宿主影响,节肢动物时空分布,节肢动物生命周期特点,相关虫媒病毒扩散模式,从节肢动物到脊椎动物传播效率,-2,气象因子对传染病宿主影响,节肢动物媒介，带菌者生存和繁殖率。与气温湿度正相关,虫媒宿主地理分布与种群变化都与温度、降雨和湿度格局密切相关,.,温度升高会加速昆虫新陈代谢、增加产卵数量、提高血液循环频率。蚊蝇。,冬季和春季都会使啮齿目动物数量增加,宿主数量波动与鼠疫事件发生次数有关系,(Davis,等, 2004).,在中亚地区气候变化有利于鼠疫传播,据预测温度每升高一度,鼠疫耶尔森氏杆菌病在其宿主内就增加,50%(Stenseth,等, 2006).,ENSO,年份：疟疾、血吸虫（,24-27,时,血吸虫感染率可达最高）、登革热等。,【1991,年并没有霍乱流行,而,1998,年（拉尼娜）却有大规模霍乱流行,】,干旱、暴雨（裂谷热）,-2,温度对特定媒介或媒介生病原体影响,全球温度和核蛋白之间存在一定相关关系,而气候变化在某种程度上会影响虫媒病毒演化,(Gould,和,Higgs, 2009),进而影响突发疾病变化格局。会影响病毒传染力和风险,-2,降雨,/,海平面对特定媒介生病原体影响,（,4,）,-3,气象因子对传染病传播途径影响,水环境,-,赤潮,全球变暖为藻类过度繁殖提供了条件,在温暖水体及污水沟中形成赤潮会产生大量毒素,这造成了近年来肝癌发病率高升,并且随着海水表面温度逐步升高,肝癌开始向高纬度海域及低温海域扩散,(Luber,和,Prudent, 2009).,赤潮一旦在饮用水源中暴发,将会对公众健康产生巨大威胁,全球气候变化导致粮食减产将增加,5%10%,贫困人口。大量难民与流动人口将引发一系列传染病暴发。平均温度上升致使沙门氏菌、弯曲菌致病人数明显增加,影响空气。气候变化可能改变花粉和孢子传播地理范围及时间,从而导致如花粉热和哮喘等过敏性疾病流行,异常气候事件会对蚊媒病、鼠媒病和虱媒病产生显著影响,-3,极端天气改变后因果循环图（缅甸,2008,年纳尔吉斯飓风后,SOURCE: American University, 2011.,SOURCE: American University, 2011.,（,4,）,-4,环境改变与影响途径,Wilson et al, 2001.,（,4,）,-5,环境改变与传染病,环境人动物媒介相互作用,SOURCE: Morens et al., 2013. c2013,SOURCE: Saif presentation, 2014.,Coronaviruses with broad host ranges.,（,4,）,-6,商贸、旅游是疾病散播关键,注意点,1,：,微生物进化或变异是微生物种群特征，是导致新病原体出现内在因素。病原微生物可以在短时间内发生大片段基因获得或缺失“飞跃”式突变，由此产生了致病原，病原微生物获得了对抗生素耐药性和产生毒素能力。,人类免疫功能减弱，进化减慢,注意点,2,：,生态和疾病动力学改变,-,生态改变，疾病模式改变,1,世界生态系统机构和功能已经改变，仍在加速改变，,1/3-1/2,生态产品供人类消耗,40%,无冰覆盖陆地农耕或牧场,一半水被用,发电，控洪，储存水大坝（大,4,万,5,，小,80,万），改变了,60%,水资源流向,真菌散播迁徙,注意点,3,：,生态和疾病动力学改变,-,资源利用,2,改变着营养（盐）循环也改变天气。反过来加速水循环和增加极端天气可能，象干旱、强降水、热浪、飓风、台风和旋风,人口增加（城市化：高速度，高密度；大量迁徙：麦加朝圣、运动和文化、游艇）,注意点,4,：,生态和疾病动力学改变,-,生态区位变化,3,应该严格季节性和地区性,带给人、植物、动物和微生物更易一起,自然环境改变可能改变致病因子自然约束（范围和活力），难以预料。,注意点,5,：,生态和疾病动力学改变,-,野生动物栖息地改变,4,伐木、筑路，毁坏或侵入野生动物栖息地,大量媒介繁殖点和储存宿主分布改变或暴露新物种,生态区位入侵或中间宿主转换,生物多样性改变，包括优势物种丧失，宿主种群密度改变,人类诱导媒介物或病原体基因改变（蚊子耐农药，排泄物污染水源）,注意点,6,：,生态和疾病动力学改变,-,自然环境恶化加剧,5,本世纪，人口量、密度和经济活动增加,2012,50%,在城市；,2030,，,60%,2012,7.1billion;2030,8.3billion;,对食物、水和能源增加,35%,、,40%,和,50%,SOURCE:global trends 2030,NIC.2012,注意点,7,：,生态和疾病动力学改变,-,天气改变,3,恶化临界资源利用,湿更湿，干更干,降水减少中东、北美、西中亚、南欧、南非和美国西南部,更多接触,摧毁物种和生态系统空间和时间屏障,EID,发生率，地理和宿主范围、致病能力、新进化或新发现新认识,注意点,8,：,人类生活环境扩张和森林砍伐,source:Anderson et al.2004;Daszak et al 2000.,引入动物、植物和微生物可以瓦解生态系统，增加,EID,这些改变很难预料和更难预测,医疗旅游；丛林肉买卖,养殖模式改变和养殖场环境污染,注意点,9,：,人类生活环境扩张和森林砍伐物种引入,（,5,）动物源性疾病出现与流行阶段,SOURCE: Morse et al., 2012.,An early stage characterized by environmental disruptions that allow,wildlife to make contact with livestock or people, resulting in spillover,and small outbreaks;,A subsequent increase in number and size of disease outbreaks featuring,short, “stuttering” chains of human-to-human transmission; and finally,Pandemic disease, as has occurred with HIV, WNV, and SARS.,疾病严重程度,hostpathogen,相互作用,SOURCE: Bean et al., 2013.,2003,年后确认人和禽感染,SOURCE: Data based on OIE and national governments reporting. Map produced by PublicHealth Mapping and GIS, Communicable Diseases, WHO. Reprinted with permission fromthe World Health Organization.,（,6,）社会环境对传染病发生影响,国家社会政治、经济因素对传染病影响,战争与恐怖袭击对疫病流行影响,国际经济贸易与人群流动迁移对传染病发生影响,人类活动导致社会环境改变对传染病影响,养殖模式改变和养殖场环境污染对疫病流行影响,全球新发病热点（,“hot spots.”,）,SOURCE: Daszak presentation, 2013 (adapted and updated from Jones et al., 2008).,Their map, based on a comprehensive review of all infectious diseases reported between 1960 and 2008,全球,EID,易损点,A,）,zoonotic EIDS B)vector-borne EIDS,SOURCE: Daszak presentation, 2013.,human activity as a major driving force for disease emergence,“tells us right now where the next pandemic is most likely,to come from,”,Map of relative risk of a zoonotic disease of wildlife origin emerging in people.,Because almost all prior pandemics, and the,majority of emerging infectious diseases, are zoonotic in origin, with the majority of these having a wildlife host, this map acts as a potential,basis for future targeted surveillance and the pre-empting of potential pandemics.,感染性疾病全球危险建模,SOURCE: Figure courtesy of Jane Messina.,三、误区,疾病对国家经济总体影响不大,天气改变一定引发疾病出现（对北极部分鸟类有巨大影响；对南极大多数有巨大影响）,MapS,能够预测病原出现,病毒捕获是监测新发疾病有效手段,新发病原体将近化为更具毒力,免疫是科学，而生态是历史（塞伦盖蒂平原）,1.,传染病对经济影响,Plague, India,$5-6 bn,2.,大灾之后有大疫,理论发生。基础卫生条件不足，缺乏安全用水；尤其极端天气事件后。,实际少。美国,新发传染病,对,1985-2004,年间医学文献、人道主义救援机构和,WHO,公布研究数据。,3/600,。,为何？,3.MapS,能够预测病原出现,流行病学,MAP,确实有用，但非绝对。,“It is essential to clearly state the underlying analysis that creates a map,rather than assume powerful mapping techniques have done this for you.”,人们经常用，如,MERS-coV,。,注意单一和协同因素。关注社会因素对自然因素影响。,4.,病毒捕获是监测新发疾病有效手段,我们不能踏遍每片土地,科学不能追访每种物种,某个地区病毒数量太多,R0(SARS/smallpox,IFLU,HIV/AIDS),多学科，跨国际,多工具，新工具,大联合，大数据,5.,新发病原体将近化为更具毒力,6.,免疫是科学，而生态是历史（塞伦盖蒂平原）,四、案例,MERS-CO,禽流感,流感,Transmission map of outbreak of MERS-CoV infection.NOTE: ICU = intensive care unit.,SOURCES: Perl presentation, August 5, 2015; Assiri et al., 2013.,对,MERS-CoV,思考,如何传给人类？,病毒储存宿主？,蝙蝠是惟一？,骆驼作用？,intermediate host or reservoir community?,有亚临床感染？,为何在并存病或老年有加重？,治疗？,象,SARS,有超级传播者,非呼吸道病毒排泄在传播和致病中作用。,SOURCE: Campbell presentation, August 6, 2015.,Historical overview of swine influenza virus circulation in pigs,and detection of human infections.,SOURCE: Todd Davis, presentation at the workshop.,流感病毒变异！,中国活禽市场系统,SOURCE: Swayne presentation, 2014.,Eco-social system components influencing spread of HPAIV H5N1 in parts of Asia.,五、机制,全球疾病预警和应答,SOURCE: OIE (2009).,难解：,We do not know the number of unknown viruses;,We do not know how human contact with wildlife varies across a landscape,，,nation, or planet; and,We do not know how likely a new virus will be to infect people.,E. Lohet al. 2015. Vector-borne and Zoonotic Diseases 15(7),人类疾病出现驱动动因,如何应对病原体威胁,应答能力,监测,重建地区公共健康能力,探索革新监测系统,新诊断开发,教育和培训微生物威胁应对能力,疫苗研发生产,新抗微生物制剂,不合理使用抗微生物制剂,虫媒和动物源性疾病控制,综合,EID,研究机构,跨学科,EID,合作中心,3,个主动：,建立一个有弹性健康保证体系,协调公,-,私网络,:,关键是早期检测和应答,: Mapping the Outbreak,重大灾害体系构建,SOURCE: Hanfling presentation, August 6, 2015.,结语,人法地，地法天，天法道，道法自然,(T)he real determinants of disease mortality are the environment and the population,both of which are being “doctored” daily, for better or for worse, by gun and axe, and by fire and plow.,Aldo Leopold, 1933,