目的了解中缅边境地区景洪市2019年登革热时空分布特征及传播影响因素。方法收集中缅边境地区景洪市2019年登革热本地病例逐日发病数,将人口密度、人均GDP、日平均气温、日平均相对湿度和日照时数等因素作为协变量,构建基于Power-law算...目的了解中缅边境地区景洪市2019年登革热时空分布特征及传播影响因素。方法收集中缅边境地区景洪市2019年登革热本地病例逐日发病数,将人口密度、人均GDP、日平均气温、日平均相对湿度和日照时数等因素作为协变量,构建基于Power-law算法的时空多成分模型,通过赤池信息量(Akaike information criterion,AIC)来评价模型的拟合效果。结果中缅边境地区景洪市2019年累计报告3303例登革热本地病例,发病率为763.44/10万。将人均GDP纳入时间自相关成分,同时将人口密度、日平均气温、日平均最高气温和日平均相对湿度纳入局部特性成分的时空多成分模型的拟合效果最优(AIC=2317),此时时间自相关成分为0.2151[95%CI:(0.0812,0.5702)]、空间流行成分为0.0004[95%CI:(0.0002,0.0010)]、局部特性成分为3.0152[95%CI:(1.6507,5.5078)]。协变量日平均相对湿度、人口密度、人均GDP、日平均气温、日平均最高气温的作用强度依次为2.8159[95%CI:(0.0216,367.1685)]、1.8227[95%CI:(1.4976,2.2183)]、1.2088[95%CI:(1.0577,1.3816)]、0.3561[95%CI:(0.0119,10.6739)]、0.3104[95%CI:(0.0036,126.5482)]。对发病数>20例的区域分析发现,允景洪街道、西双版纳旅游度假区和景洪工业园区时间自相关成分影响较大,嘎洒镇、勐龙镇和勐罕镇局部特性成分影响较大。结论景洪市不同区域登革热时空构成存在差异性,具有不同的时空传播特征。人均GDP会扩大前期疫情对后期疫情传播的影响,人口密度、日平均气温、日平均最高气温和日平均相对湿度则会影响研究区域登革热本地风险水平。展开更多
目的明确中缅边境地区间日疟原虫几丁质酶(Plasmodium vivax chitinase,PvCHT1)基因的遗传多样性,探究PvCHT1基因的地理差异,为我国间日疟疫苗的设计提供参考。方法收集中缅边境地区(云南腾冲)、中国内陆地区(安徽合肥、河南郑州)PvCHT...目的明确中缅边境地区间日疟原虫几丁质酶(Plasmodium vivax chitinase,PvCHT1)基因的遗传多样性,探究PvCHT1基因的地理差异,为我国间日疟疫苗的设计提供参考。方法收集中缅边境地区(云南腾冲)、中国内陆地区(安徽合肥、河南郑州)PvCHT1基因序列,同时从美国国家生物技术信息中心(National Center for Biotechnology Information,NCBI)下载获取缅甸、柬埔寨、泰国、越南、印度尼西亚、马来西亚、巴布亚新几内亚、巴西、哥伦比亚、秘鲁和墨西哥等11个国家的PvCHT1基因序列。采用MEGA、DnaSP、KaKs_Calculator、Arlequin、STRUCTURE和NETWORK软件,分别对所有基因序列的遗传多样性、基因进化、遗传分化、种群结构和单倍型网络进行分析。结果共获得中缅边境地区(6条)、中国内陆地区(10条)PvCHT1基因序列16条,从NCBI下载其他11个国家的PvCHT1基因序列551条。遗传多样性分析显示,中缅边境地区的PvCHT1基因有25个多态位点,其中16个为非同义突变,最常见的突变位点是E617D(占31.57%)和I272M(占31.04%);中缅边境地区的PvCHT1基因核苷酸多样性(π=0.00079)略高于中国内陆地区(π=0.00071)和缅甸(π=0.00075)。基因进化分析显示,中缅边境PvCHT1基因的中性检验(Tajima’s D)值<0,非同义替换与同义替换之比(Ka/Ks)>1。遗传分化分析显示,中缅边境地区PvCHT1基因与中国内陆之间的近交系数(FST)为0.31,与缅甸的FST为-0.05,与柬埔寨、泰国、越南、印度尼西亚、马来西亚之间的范围为0.04~0.15,与巴布亚新几内亚、巴西、哥伦比亚、秘鲁、墨西哥之间的FST范围为0.24~0.56。种群结构分析显示,所有种群结构的最佳组数为7,其中,中缅边境种群由K1~K6组分构成,以K5为主。单倍型网络分析显示,存在4个单倍型地理集群,除中国内陆和墨西哥外,其他国家均共享单倍型H5。结论中缅边境地区PvCHT1基因高度保守,提示其可作为传播阻断疫苗候选靶标;PvCHT1基因在不同种群中存在明显的地理差异,因此在设计疫苗时应更具针对性。展开更多
Background: Malaria cases have declined significantly along the China-Myanmar border in the past 10 years and this region is going through a process from control to elimination.The aim of this study is to investigate ...Background: Malaria cases have declined significantly along the China-Myanmar border in the past 10 years and this region is going through a process from control to elimination.The aim of this study is to investigate the epidemiology of malaria along the border,will identify challenges in the progress from control to elimination.Methods:: National reported malaria cases from China and Myanmar,along with the data of 18 Chinese border counties and 23 townships in Myanmar were obtained from a web-based diseases information reporting system in China and the national malaria control program of Myanmar,respectively.Epidemiological data was analyzed,including the number of reported cases,annual parasite index and proportion of vivax infection.Spatial mapping of the annual parasite index(API)at county or township level in 2014 and 2018 was performed by ArcGIS.The relationship of malaria endemicity on both sides of the border was evaluated by regression analysis.Results: The number of reported malaria cases and API declined in the border counties or townships.In 2014,392 malaria cases were reported from 18 Chinese border counties,including 8.4%indigenous cases and 91.6%imported cases,while the highest API(0.11)was occurred in Yingjiang County.There have been no indigenous cases reported since 2017,but 164 imported cases were reported in 2018 and 97.6%were imported from Myanmar.The average API in 2014 in 23 Myanmar townships was significantly greater than that of 18 Chinese counties(P<0.01).However,the API decreased significantly in Myanmar side from 2014 to 2018(P<0.01).The number of townships with an API between 0 and 1 increased to 15 in 2018,compared to only five in 2014,while still four townships had API>10.Plasmodium vivax was the predominant species along the border.The number of reported malaria cases and the proportion of vivax infection in the 18 Chinese counties were strongly correlated with those of the 23 Myanmar townships(P<0.05).Conclusions: Malaria elimination is approaching along the China-Myanmar border.However,in order to achieve the malaria elimination in this region and prevent the re-establishment of malaria in China after elimination,continued political,financial and scientific commitment is required.展开更多
目的助力云南省消除疟疾后防止输入再传播工作。为选择或更换适宜的杀虫剂,控制当地媒介按蚊提供科学依据。方法在中缅边境地区云南省沧源县开展传疟媒介中华按蚊对常用杀虫剂抗药性和抗性基因突变调查,选定沧源县勐董镇勐董社区芒勐寨...目的助力云南省消除疟疾后防止输入再传播工作。为选择或更换适宜的杀虫剂,控制当地媒介按蚊提供科学依据。方法在中缅边境地区云南省沧源县开展传疟媒介中华按蚊对常用杀虫剂抗药性和抗性基因突变调查,选定沧源县勐董镇勐董社区芒勐寨旁永和下7组为监测点,使用吸蚊管于试验前夜在现场采集牛圈内的中华按蚊成蚊,带回实验室饲以10%葡萄糖水供试验用。参照《蚊虫抗药性检测方法生物测定法》(GB/T26347-2010),采用成蚊接触筒法开展中华按蚊对常用杀虫剂的抗药性监测调查。测定结束后分别收集死亡(敏感表型)和存活(抗性表型)个体,用无水乙醇保存带回,提取蚊DNA后,开展抗药性靶标kdr(knockdown resistance)、ace-1基因突变检测。结果接触0.05%高效氯氰菊酯、0.05%高效氯氟氰菊酯、0.05%溴氰菊酯、0.1%残杀威、5%马拉硫磷和1%杀螟硫磷后,中华按蚊首只被击倒的时间分别为5 min 34 s、5 min 11 s、6 min 46 s、4 min 30 s、5 min 13 s和3 min 36 s;击倒率分别为17.49%、17.32%、15.44%、29.72%、57.39%和46.82%。其中,中华按蚊对溴氰菊酯首只击倒时间最长,击倒率最低,表明对溴氰菊酯的抗击倒力最强,其次为高效氯氟氰菊酯和高效氯氰菊酯。中华按蚊对马拉硫磷区分剂量死亡率是98.33%,为敏感群体(S),对杀螟硫磷区分剂量死亡率是90%,为初步抗性群体(M),对高效氯氰菊酯、高效氯氟氰菊酯、溴氰菊酯和残杀威区分剂量死亡率均小于80%,为抗性群体(R)。检测接触拟除虫菊酯类杀虫剂的中华按蚊共386只,kdr基因的1014位点全部为L1014野生型,未检测到突变;检测接触有机磷和氨基甲酸酯的中华按蚊113只,仅存在G119S型突变。中华按蚊ace-1的119位点突变与氨基甲酸酯类杀虫剂抗性相关。结论当地传疟媒介中华按蚊对高效氯氰菊酯等拟除虫菊酯类杀虫剂和残杀威已产生较大抗药性,为防止输入性疟疾引起再传播,今后宜选用马拉硫磷等有机磷类或不同类别杀虫剂联合制剂开展媒介控制工作。展开更多
Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and m...Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and maintaining border security. With remote sensing tech- nologies, we analyzed the rubber distribution pattern and spatial-temporal dynamic; with GIS and a newly proposed index of Planted Intensity (PI), we further quantified the impacts and limits of topographical factors on rubber plantation in the border region of China, Laos and Myanmar (BRCLM) between 1980 and 2010. The results showed that: (1) As the dominant land use type in this border region, the acreage of rubber plantation was 6014 km2 in 2010, accounting for 8.17% of the total area. Viewing from the rubber plantation structure, the ratio of mature- (〉10 year) and young rubber plantation (〈 10 year) was 5:7. (2) From 1980 to 2010, rubber plantation expanded significantly in BRCLM, from 705 km2 to 6014 km2, nearly nine times. The distribution characteristics of rubber plantation varied from concentrated toward dispersed, from border inside to outside, and expanded further in all directions with Jinghong City as the center. (3) Restricted by the topographical factors, more than 4/5 proportion of rubber plantation concentrated in the appropriate elevation gradients between 600 and 1000 m, rarely occurred in elevations beyond 1200 m in BRCLM. Nearly 2/3 of rubber plantation concentrated on slopes of 8^-25~, rarely distributed on slopes above 35~. Rubber plantation was primarily distributed in south and east aspects, relatively few in north and west aspects. Rubber planted intensity displayed the similar distribution trend. (4) Comparative studies of rubber plantation in different countries showed that there was a remarkable increase in area at higher elevations and steeper slopes in China, while there were large appropriate topog- raphical gradients for rubber plantation in Laos and Myanmar which benefited China for rubber trans-boundary expansion. (5) Rubber plantation in BRCLM will definitely expend cross borders of China to the territories of Laos and Myanmar, and the continuous expansion in the border region of China will be inevitable.展开更多
文摘目的了解中缅边境地区景洪市2019年登革热时空分布特征及传播影响因素。方法收集中缅边境地区景洪市2019年登革热本地病例逐日发病数,将人口密度、人均GDP、日平均气温、日平均相对湿度和日照时数等因素作为协变量,构建基于Power-law算法的时空多成分模型,通过赤池信息量(Akaike information criterion,AIC)来评价模型的拟合效果。结果中缅边境地区景洪市2019年累计报告3303例登革热本地病例,发病率为763.44/10万。将人均GDP纳入时间自相关成分,同时将人口密度、日平均气温、日平均最高气温和日平均相对湿度纳入局部特性成分的时空多成分模型的拟合效果最优(AIC=2317),此时时间自相关成分为0.2151[95%CI:(0.0812,0.5702)]、空间流行成分为0.0004[95%CI:(0.0002,0.0010)]、局部特性成分为3.0152[95%CI:(1.6507,5.5078)]。协变量日平均相对湿度、人口密度、人均GDP、日平均气温、日平均最高气温的作用强度依次为2.8159[95%CI:(0.0216,367.1685)]、1.8227[95%CI:(1.4976,2.2183)]、1.2088[95%CI:(1.0577,1.3816)]、0.3561[95%CI:(0.0119,10.6739)]、0.3104[95%CI:(0.0036,126.5482)]。对发病数>20例的区域分析发现,允景洪街道、西双版纳旅游度假区和景洪工业园区时间自相关成分影响较大,嘎洒镇、勐龙镇和勐罕镇局部特性成分影响较大。结论景洪市不同区域登革热时空构成存在差异性,具有不同的时空传播特征。人均GDP会扩大前期疫情对后期疫情传播的影响,人口密度、日平均气温、日平均最高气温和日平均相对湿度则会影响研究区域登革热本地风险水平。
文摘目的明确中缅边境地区间日疟原虫几丁质酶(Plasmodium vivax chitinase,PvCHT1)基因的遗传多样性,探究PvCHT1基因的地理差异,为我国间日疟疫苗的设计提供参考。方法收集中缅边境地区(云南腾冲)、中国内陆地区(安徽合肥、河南郑州)PvCHT1基因序列,同时从美国国家生物技术信息中心(National Center for Biotechnology Information,NCBI)下载获取缅甸、柬埔寨、泰国、越南、印度尼西亚、马来西亚、巴布亚新几内亚、巴西、哥伦比亚、秘鲁和墨西哥等11个国家的PvCHT1基因序列。采用MEGA、DnaSP、KaKs_Calculator、Arlequin、STRUCTURE和NETWORK软件,分别对所有基因序列的遗传多样性、基因进化、遗传分化、种群结构和单倍型网络进行分析。结果共获得中缅边境地区(6条)、中国内陆地区(10条)PvCHT1基因序列16条,从NCBI下载其他11个国家的PvCHT1基因序列551条。遗传多样性分析显示,中缅边境地区的PvCHT1基因有25个多态位点,其中16个为非同义突变,最常见的突变位点是E617D(占31.57%)和I272M(占31.04%);中缅边境地区的PvCHT1基因核苷酸多样性(π=0.00079)略高于中国内陆地区(π=0.00071)和缅甸(π=0.00075)。基因进化分析显示,中缅边境PvCHT1基因的中性检验(Tajima’s D)值<0,非同义替换与同义替换之比(Ka/Ks)>1。遗传分化分析显示,中缅边境地区PvCHT1基因与中国内陆之间的近交系数(FST)为0.31,与缅甸的FST为-0.05,与柬埔寨、泰国、越南、印度尼西亚、马来西亚之间的范围为0.04~0.15,与巴布亚新几内亚、巴西、哥伦比亚、秘鲁、墨西哥之间的FST范围为0.24~0.56。种群结构分析显示,所有种群结构的最佳组数为7,其中,中缅边境种群由K1~K6组分构成,以K5为主。单倍型网络分析显示,存在4个单倍型地理集群,除中国内陆和墨西哥外,其他国家均共享单倍型H5。结论中缅边境地区PvCHT1基因高度保守,提示其可作为传播阻断疫苗候选靶标;PvCHT1基因在不同种群中存在明显的地理差异,因此在设计疫苗时应更具针对性。
基金This work was supported by the Natural Science Foundation of Shanghai(No.18ZR1443400)the National Important Scientific&Technological Project 2018ZX10101002-002)the Forge Ahead Together for Elimination Towards Malaria free China–Myanmar border and National Malaria Elimination Program of China.
文摘Background: Malaria cases have declined significantly along the China-Myanmar border in the past 10 years and this region is going through a process from control to elimination.The aim of this study is to investigate the epidemiology of malaria along the border,will identify challenges in the progress from control to elimination.Methods:: National reported malaria cases from China and Myanmar,along with the data of 18 Chinese border counties and 23 townships in Myanmar were obtained from a web-based diseases information reporting system in China and the national malaria control program of Myanmar,respectively.Epidemiological data was analyzed,including the number of reported cases,annual parasite index and proportion of vivax infection.Spatial mapping of the annual parasite index(API)at county or township level in 2014 and 2018 was performed by ArcGIS.The relationship of malaria endemicity on both sides of the border was evaluated by regression analysis.Results: The number of reported malaria cases and API declined in the border counties or townships.In 2014,392 malaria cases were reported from 18 Chinese border counties,including 8.4%indigenous cases and 91.6%imported cases,while the highest API(0.11)was occurred in Yingjiang County.There have been no indigenous cases reported since 2017,but 164 imported cases were reported in 2018 and 97.6%were imported from Myanmar.The average API in 2014 in 23 Myanmar townships was significantly greater than that of 18 Chinese counties(P<0.01).However,the API decreased significantly in Myanmar side from 2014 to 2018(P<0.01).The number of townships with an API between 0 and 1 increased to 15 in 2018,compared to only five in 2014,while still four townships had API>10.Plasmodium vivax was the predominant species along the border.The number of reported malaria cases and the proportion of vivax infection in the 18 Chinese counties were strongly correlated with those of the 23 Myanmar townships(P<0.05).Conclusions: Malaria elimination is approaching along the China-Myanmar border.However,in order to achieve the malaria elimination in this region and prevent the re-establishment of malaria in China after elimination,continued political,financial and scientific commitment is required.
文摘目的助力云南省消除疟疾后防止输入再传播工作。为选择或更换适宜的杀虫剂,控制当地媒介按蚊提供科学依据。方法在中缅边境地区云南省沧源县开展传疟媒介中华按蚊对常用杀虫剂抗药性和抗性基因突变调查,选定沧源县勐董镇勐董社区芒勐寨旁永和下7组为监测点,使用吸蚊管于试验前夜在现场采集牛圈内的中华按蚊成蚊,带回实验室饲以10%葡萄糖水供试验用。参照《蚊虫抗药性检测方法生物测定法》(GB/T26347-2010),采用成蚊接触筒法开展中华按蚊对常用杀虫剂的抗药性监测调查。测定结束后分别收集死亡(敏感表型)和存活(抗性表型)个体,用无水乙醇保存带回,提取蚊DNA后,开展抗药性靶标kdr(knockdown resistance)、ace-1基因突变检测。结果接触0.05%高效氯氰菊酯、0.05%高效氯氟氰菊酯、0.05%溴氰菊酯、0.1%残杀威、5%马拉硫磷和1%杀螟硫磷后,中华按蚊首只被击倒的时间分别为5 min 34 s、5 min 11 s、6 min 46 s、4 min 30 s、5 min 13 s和3 min 36 s;击倒率分别为17.49%、17.32%、15.44%、29.72%、57.39%和46.82%。其中,中华按蚊对溴氰菊酯首只击倒时间最长,击倒率最低,表明对溴氰菊酯的抗击倒力最强,其次为高效氯氟氰菊酯和高效氯氰菊酯。中华按蚊对马拉硫磷区分剂量死亡率是98.33%,为敏感群体(S),对杀螟硫磷区分剂量死亡率是90%,为初步抗性群体(M),对高效氯氰菊酯、高效氯氟氰菊酯、溴氰菊酯和残杀威区分剂量死亡率均小于80%,为抗性群体(R)。检测接触拟除虫菊酯类杀虫剂的中华按蚊共386只,kdr基因的1014位点全部为L1014野生型,未检测到突变;检测接触有机磷和氨基甲酸酯的中华按蚊113只,仅存在G119S型突变。中华按蚊ace-1的119位点突变与氨基甲酸酯类杀虫剂抗性相关。结论当地传疟媒介中华按蚊对高效氯氰菊酯等拟除虫菊酯类杀虫剂和残杀威已产生较大抗药性,为防止输入性疟疾引起再传播,今后宜选用马拉硫磷等有机磷类或不同类别杀虫剂联合制剂开展媒介控制工作。
基金National Natural Science Foundation of China, No.41271117 Strategy of Science and Technology Planning Project of Institute of Geographic Sciences and Natural Resources Research, CAS, No.2012SJ008
文摘Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and maintaining border security. With remote sensing tech- nologies, we analyzed the rubber distribution pattern and spatial-temporal dynamic; with GIS and a newly proposed index of Planted Intensity (PI), we further quantified the impacts and limits of topographical factors on rubber plantation in the border region of China, Laos and Myanmar (BRCLM) between 1980 and 2010. The results showed that: (1) As the dominant land use type in this border region, the acreage of rubber plantation was 6014 km2 in 2010, accounting for 8.17% of the total area. Viewing from the rubber plantation structure, the ratio of mature- (〉10 year) and young rubber plantation (〈 10 year) was 5:7. (2) From 1980 to 2010, rubber plantation expanded significantly in BRCLM, from 705 km2 to 6014 km2, nearly nine times. The distribution characteristics of rubber plantation varied from concentrated toward dispersed, from border inside to outside, and expanded further in all directions with Jinghong City as the center. (3) Restricted by the topographical factors, more than 4/5 proportion of rubber plantation concentrated in the appropriate elevation gradients between 600 and 1000 m, rarely occurred in elevations beyond 1200 m in BRCLM. Nearly 2/3 of rubber plantation concentrated on slopes of 8^-25~, rarely distributed on slopes above 35~. Rubber plantation was primarily distributed in south and east aspects, relatively few in north and west aspects. Rubber planted intensity displayed the similar distribution trend. (4) Comparative studies of rubber plantation in different countries showed that there was a remarkable increase in area at higher elevations and steeper slopes in China, while there were large appropriate topog- raphical gradients for rubber plantation in Laos and Myanmar which benefited China for rubber trans-boundary expansion. (5) Rubber plantation in BRCLM will definitely expend cross borders of China to the territories of Laos and Myanmar, and the continuous expansion in the border region of China will be inevitable.