Objective To understand the epidemic situation and epidemiological characteristics of malaria in Jiangsu Prov?ince from 2005 to 2014,so as to provide the evidence for formulating and adjusting the strategies and measures on malaria elimi?nation in this province. Method The epidemiological data of malaria in Jiangsu province from 2005 to 2014 were collected, and the prevalence situation,infection sources as well as the temporal,regional and population distribution of the cases were an?alyzed. Result A total of 5 069 malaria cases were reported in Jiangsu Province form 2005 to 2014,there were 3 422 cases (67.51%)of vivax malaria,1 497 cases(29.53%)of falciparum malaria,and 150 cases(2.96%)that were unclassified. Among all the reported cases,2 139(42.20%)were local cases,1 131 were(22.31%)imported cases from other places in Chi?na ,and 1 799(35.49%)were imported cases from abroad. There were 3 809 male cases and 1 260 female cases,with a sex ratio of 3.02∶1. The patients were mainly aged from 25 to<60 years(accounting for 67.15%),and were mainly young adult farmers (40.26%)and migrant workers(23.63%),who mainly distributed(accounting for 60.58%)in Xuzhou,Suqian,Huai’an,Su?zhou and Nantong cities. The predominant malaria type from 2005 to 2009 were vivax malaria,while after 2010,it changed to falciparum malaria. Conclusions The malaria epidemic situation has been effectively controlled in Jiangsu Province,which re?flects the initiative achievements of malaria elimination. However,there are still many imported malaria cases from abroad,and the species of the Plasmodium are diverse. Therefore,the imported malaria from abroad still remains the key of malaria control in Jiangsu Province.

Objective To compare the susceptibility of Anopheles anthropophagus from Jiangsu, Guangdong and Liaoning provinces in China to Plasmodium vivax.Methods The blood samples of patients with P. vivax in endemic areas of China were collected to feed the mosquitoes of An. anthropophagus from different areas by using the artificial in vitro membrane feeding system in the lab, and then the mosquitoes were dissected during the 7-9th day and on the 14th day after the feeding and the oocysts and sporozoites in the stomach and salivy gland of mosquitoes were counted. Results The mosquitoes from Jiangsu, Guangdong and Liaoning were simultaneously fed with the blood of 35 cases of P. vivax. The oocyst positive rates of An. anthropophagus from Jiangsu, Guangdong and Liaoning during the 7-9th day after the feeding were 68.57%, 60.00% and 68.57%, as well as the sporozoite positive rates of them on the 14th day after the feeding were 22.86%, 14.29% and 22.86%, respectively. On the 7th day after the feeding, 228, 235, 228 mosquitoes of An. anthropophagus from Jiangsu, Guangdong and Liaoning were dissected, and the positive mosquito rates with oocyst infection were 28.07%, 25.11% and 26.75%, respectively. On the 14th day after the feeding, 150, 142, 135 mosquitoes of An. anthropophagus from the three areas were dissected, the positive rates with sporozoite infection were 10.67%, 8.45% and 11.85%, respectively. The num-bers of mosquitoes dissected with infective grade("+","++","+++","++++") of sporozoites of An. anthropophagus from Jiangsu, Guangdong and Liaoning were 4, 3, 2, 7; 2, 2, 3, 7 and 1, 6, 3, 8, respectively. Conclusions An. anthropophagus from Jiangsu, Guangdong and Liaoning is susceptible to the parasites of Plasmodium vivax and there is no significant difference among the susceptibilities of An. anthropophagus from the three areas to Plasmodium vivax.

Objective To understand the malaria epidemic situation and characteristics in Jiangsu Province in 2012,so as to provide the evidence for formulating and adjusting effective malaria elimination strategies and measures. Methods The reported malaria cases from the Internet Reporting System and the epidemiological data of malaria in Jiangsu Province were collected and analyzed. Results A total of 198 malaria cases were reported in Jiangsu Province in 2012 with the incidence of 0.026/10 000, which decreased by 47.06%compared with that in 2011(374 cases). A total of 198 malaria cases were reported from 13 prefec-tures of Jiangsu and the cases were mainly distributed in Yangzhou(34 cases),Nantong(31 cases),Nanjing(22 cases),Tai-zhou(21 cases),Xuzhou(17 cases)and Huaian(17 cases),which accounted for 71.72%(142/198)among the total cases of the province. There were no local malaria cases reported from Jiangsu in 2012,and the imported malaria cases from other countries de-creased by 45.15%compared with that in 2011. Conclusions For the first time,there are no local malaria cases reported from Ji-angsu in 2012. However,the imported case distribution is further expanded and the infected plasmodium parasites are more di-verse. Imported malaria from other countries remains the key for malaria control in Jiangsu Province.

Objective To understand the malaria epidemic situation and characteristics in Jiangsu Province in 2013,so as to provide the evidence for formulating and adjusting effective malaria elimination strategies and measures. Methods The re-ported malaria cases from the Internet Reporting System and the epidemiological data of malaria in Jiangsu Province were collect-ed and analyzed. Results A total of 341 malaria cases were reported in Jiangsu Province in 2013 with the incidence of 0.050/10 000,which increased by 72.22% compared with that in 2012(198 cases). All the cases were imported from other countries including one infected by blood transfusion resulted from imported infection. The cases were mainly distributed in Li-anyungang City(15.84%,54 cases),Nantong City(14.08%,48 cases),Yangzhou City(14.08%,48 cases),Huaian City (11.44%,39 cases)and Yancheng City(8.50%,29 cases). All the cases were confirmed in Jiangsu Provincial Reference Labo-ratory and there were 286 cases of Plasmodium falciparum,8 cases of P. vivax,9 cases of P. malariae,30 cases of P. ovale and 8 cases of mixed infections. Conclusions There were no local malaria cases reported from Jiangsu Province in the last two years which reflected effective achievements of malaria elimination. However,the situation of imported malaria is more serious and the species of infected plasmodium are more diverse. Imported malaria from other countries remains the key of malaria con-trol in Jiangsu Province.

Objective To evaluate the effect of automatic early warning information system on the response of malaria elimi-nation in Jiangsu Province through the operation of the national automatic early warning system of infectious diseases. Methods The malaria early warning information was collected from the automatic early warning information subsystem in the national infor-mation system for diseases control and prevention. Malaria early warning signals were analyzed from September 1 to December 31, 2012. The statistical analysis was conducted for the completion rates of case investigation within 3 days before and after the applica-tion of malaria early warning information system. Results Jiangsu Province received 85 mobile phone short messages(SMS)of malaria case from early warning system from September 1 to December 31,2012. After judgments,23 cases were deleted includ-ing 8 repeated cases and 15 cases that were excluded through the microscopy examination and epidemiological investigation by the confirmation of county CDC. From July to December in 2012,the monthly completion rates of case investigation within 3 days were 55.56%,78.57%,90.00%,100%,100%and 100%,respectively. The completion rates of case investigation within 3 days in Ju-ly,August,September and October were significantly different by χ2 test(χ2=10.66,P<0.05). The completion rates of foci in-vestigation and action within 7 days in Jiangsu Province were all 100%from July to December in 2012. Conclusions The comple-tion rates of case investigation within 3 days are associated with SMS from the early warning system. The malaria warning system from the national infectious diseases can effectively improve the response to malaria cases for primary CDC. It also plays an impor-tant role for the timely confirmation and diagnosis of malaria cases.

Objective To analyze the channels of going abroad of imported malaria patients in Jiangsu Province,so as to provide the evidence for the control of imported malaria and health intervention for high?risk population. Methods The data of imported malaria cases in Jiangsu Province in 2015 were collected and the channels of going abroad were analyzed. The Quan?tum GIS 1.7.4 software was applied to map. Results Totally 405 imported cases were reported in Jiangsu Province in 2015, and the cases increased by 14.1%compared with those in 2014. All the patients were migrant workers. The migrant workers were mostly sent abroad by construction companies[43.21%(175/405)]. The dispatching companies were mainly concentrated in Taizhou,Lianyungang,Zhenjiang and Yangzhou cities,accounting for 6.17%(25/405),3.21%(13/405),2.72%(11/405) and 2.22%(9/405),respectively. Totally 176(43.46%)patients returned to China having accompanied workers,and 1.21%(9/745)of accompanied workers were found having symptoms of malaria later. Conclusions It is difficult to monitor malaria in overseas migrant works in Jiangsu Province. The channels of going abroad of migrant workers are various and complicated ,for?mulating the main difficulty and challenge of imported malaria control.

Objective To observe the residual effect of Demand CS - impregnated bednets to Anopheles sinensis.Methods The numbers of adult mosquitoes which were knocked down at every minute after treatment were observed by using the enforced contact method recommended by WHO,and the mortality of mosquitoes tested after 24 h was calculated.Results The Kt_(50) of Demand CS - impregnated bednets with impregnations concentrations of 10,15,20 mg/m~2 to Anopheles sineasis were 21.40,16.20,15.70 min,respectively,and the 24 h mortality was 100%.The Kt_(50) of Responsar SC (12.5 % Beta - cyfluthrin) impregnated bednets with a impregnation concentration of 15 mg/m~2 to Anopheles sinensis was 16.06 min,and the 24 h mortality was 100%,too.Conclusions Both the Demand CS - impregnated bednets and the Responsar SC impregnated bednets can kill Anopheles sinensis.

Abstract: Objective To conduct genotyping and molecular tracing analysis on Plasmodium vivax samples from a cluster of P. vivax malaria outbreak in order to provide a reference for case geographical origin determination. Methods Blood samples from 4 patients in a vivax malaria cluster in Longhui County, Hunan Province from June to July 2018 were collected for species identification by qPCR, and 9 microsatellite molecular markers were used to genotype the parasite strains from four samples. The population genetic STRUCTURE analysis was performed based on the VivaxGEN-MS microsatellite genotype database of P. vivax in the Asia Pacific Malaria Elimination Network, to determine the genetic subgroups and geographical origin of the strains. Results By qPCR, all 4 cases were identified as Plasmodium vivax infection, and 9 microsatellite loci of the 4 cases were successfully typed, and the four samples had different genetic haplotypes, among which case 1, case 3, and case 4 were infected by a single clonal strain, and case 2 was infected by a polyclonal strain. When all P. vivax samples were divided into 2 subpopulations (K=2) by STURCTURE analysis, 4 Hunan samples were classified into tropical genetic subpopulations (comprising strains from Ethiopia, Iran, Bhutan, Malaysia, Indonesia, and southern China). When the samples were divided into 4 subgroups by STURCTURE analysis (K=4), the 4 Hunan samples were classified as South Asian/Southeast Asian genetic subgroups (originating from Bhutan, Malaysia, Indonesia, and southern China). Conclusions The results of molecular tracing do not support that the 4 P. vivax strains in this outbreak originated from the population of central China. The technology of molecular tracing of P. vivax can provide objective evidence for determining the source of infection in malaria cases during the stage of malaria elimination and post-elimination.

Objective To understand the epidemic situation and influencing factors of malaria in Jiangsu Province and grasp its epidemic regularity and trend. Methods According to the malaria prevalence in Jiangsu Province,6 counties(city,dis-trict)including Yixing,Suining,Wujin,Hai’an,Ganyu and Xuyi were selected as provincial surveillance sites to survey malar-ia epidemic conditions. The basic information,blood test results of fever patients,case investigation information of malaria pa-tients,monitoring data of investigation and disposition of the malaria focus were collected and analyzed. Results In 2013,the blood tests of 66 723 fever patients were performed,the average blood smear checking rate was 1.10%,and the average positive rate was 0.08%(52 plasmodium positive individuals)in the 6 areas. For these 52 plasmodium positive individuals,the blood re-tests and case investigations were completed within 3 days after these cases were reported by the network system,and the investi-gation confirmed that they were foreign imported malaria cases. The malaria focus investigation and disposition were finished within 1 week and the data were reported by the Parasitic Diseases Information System. Four of 52 cases were recrudescence dur-ing the follow-up. Among the 52 cases,20 people went abroad themselves and 4 were labors of private enterprises,21 people came back without the accompanied. Conclusions With the development of the malaria elimination program in Jiangsu Prov-ince,the eliminating malaria“targeted 1-3-7”working pattern has been comprehensively implemented. The personnel monitor-ing for labors who returned from overseas working will be a key in the future.

Objective To establish a simple,convenient,quick and high sensitive method of loop-mediated isothermal amplification (LAMP) for detection of Plasmodium vivax-carrying mosquitoes.Methods The species conservative regions of P.v CSP gene were selected to design 2 pairs of primers which recognized 6 distinct regions.To evaluate the specificity of detection by LAMP,infected Anopheles,An.sinensis (An.s),Plasmodium falciparum (P.f),and healthy human blood DNA were selected as templates.To assess the sensitivity of detection,1.3×10~6,1.3×10~5,1.3×10~4,1.3×10~3,1.3×10~2,1.3×10~1 and 1.3×10~0 copies of P.v CSP plasmid DNA mixed with 1.0 μl An.s DNA were used as the templates of LAMP.The infected An.s DNAs were diluted with negative An.s DNA by 1:2,1:4,1:8,1:16,1:32,1:64,1:128 and 1:256 and then detected by LAMP to show the sensitivity of batch quantity detection.The applied value of this method was evaluated by detecting the same batch of 67 artificial infected An.s mosquitoes,and compared with the detection of microscopic examination and nested PCR in parallel.Results By using LAMP,the detection of infected An.s was positive,while the control samples were all negative.The limits of detection of different proportion dilutions of the mixture of P.v CSP plasmid DNA with An.s DNA were 1.3×10~2 copies.The limits of detection of different proportion dilutions of the mixture of infected An.s DNA with An.s DNA were 1:128.The positive rate of detecting the same batch of 67 artificial infected mosquitoes was 47.76% by LAMP,25.37% by the microscopic examination (X~2 = 7.24,P<0.01),40.30% by nested PCR (X~2 = 0.73,P>0.05).Compared with the test of the microscopic examination and then with a statistical analysis,the sensitivity of LAMP was 100%,which agreed well with the sensitivity of nested PCR (100%).Conclusion The method of LAMP is simple,convenient and high sensitive,and it is a potential method for detecting Plasmodium vivax-carrying mosquitoes in the field.