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Objective To investigate the seasonal Aedes population fluctuation and the resistance of Aedes populations to common insecticides in Jiangsu Province in 2020, so as to provide insights into vector-borne infectious diseases control.. Methods One village was randomly sampled from each of Xinbei District of Changzhou City and Zhangjiagang County of Suzhou City in southern Jiangsu Province, Hai’an County of Nantong City and Yandu District of Yancheng City in Central Jiangsu Province, and Suining County of Xuzhou City and Sihong County of Suqian City in northern Jiangsu Province during the period between May and October, 2020. A small ponding container was sampled, and larval Aedes mosquitoes were collected using straws once each in early and late stages of each month. All larvae were bred in laboratory to adults for population identification. In addition, larval breeding were observed in all small ponding containers in and out of 30 households that were randomly sampled from six surveillance sites, and the larval mosquito density was estimated using Breteau index. Larval A. albopictus mosquitoes were sampled around Cuiyuan New Village in Jintan District of Changzhou City, and bred in laboratory to the first offspring generation, and the susceptibility of adult female mosquitoes to deltamethrin, lambda-cyhalothrin, malathion, and propoxur was tested using the filter-paper bioassay recommended by WHO. Results A total of 1 165 larval Aedes mosquitoes were captured from small ponding containers in six surveillance sites of Jiangsu Province in 2020, and all were identified as A. albopictus following eclosion. The largest number of Aedes larvae captured was found in July. A total of 1 152 households were investigated in six surveillance sites, and the mean Breteau indexes were 9.58, 13.20, 13.71, 13.20, 12.18 and 5.58 from May to October, respectively, while a high Aedes transmission risk was seen in Xinbei District of Changzhou City, with a higher Breteau index than in Suining (H = 23.667, Padjusted = 0.001) and Sihong (H = 22.500, Padjusted = 0.003) counties. The field-captured A. albopictus from Cuiyuan New Village in Jintan District of Changzhou City remained sensitive to malathion, but was resistant to propoxur, and developed high-level resistance to deltamethrin and lambda-cyhalothrin. Conclusions A. albopictus was present in southern, central and northern Jiangsu Province in 2020, and the larval density peaked in July. A. albopictus captured from Cuiyuan New Village in Jintan District of Changzhou City has developed high-level resistance to pyrethroid pesticides.
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Objective To create risk predictive models of healthcare-seeking delay among imported malaria patients in Jiangsu Province based on machine learning algorithms, so as to provide insights into early identification of imported malaria cases in Jiangsu Province. Methods Case investigation, first symptoms and time of initial diagnosis of imported malaria patients in Jiangsu Province in 2019 were captured from Infectious Disease Report Information Management System and Parasitic Disease Prevention and Control Information Management System of Chinese Center for Disease Control and Prevention. The risk predictive models of healthcare-seeking delay among imported malaria patients were created with the back propagation (BP) neural network model, logistic regression model, random forest model and Bayesian model using thirteen factors as independent variables, including occupation, species of malaria parasite, main clinical manifestations, presence of complications, severity of disease, age, duration of residing abroad, frequency of malaria parasite infections abroad, incubation period, level of institution at initial diagnosis, country of origin, number of individuals travelling with patients and way to go abroad, and time of healthcare-seeking delay as a dependent variable. Logistic regression model was visualized using a nomogram, and the nomogram was evaluated using calibration curves. In addition, the efficiency of the four models for prediction of risk of healthcare-seeking delay among imported malaria patients was evaluated using the area under curve (AUC) of receiver operating characteristic curve (ROC). The importance of each characteristic was quantified and attributed by using SHAP to examine the positive and negative effects of the value of each characteristic on the predictive efficiency. Results A total of 244 imported malaria patients were enrolled, including 100 cases (40.98%) with the duration from onset of first symptoms to time of initial diagnosis that exceeded 24 hours. Logistic regression analysis identified a history of malaria parasite infection [odds ratio (OR) = 3.075, 95% confidential interval (CI): (1.597, 5.923)], long incubation period [OR = 1.010, 95% CI: (1.001, 1.018)] and seeking healthcare in provincial or municipal medical facilities [OR = 12.550, 95% CI: (1.158, 135.963)] as risk factors for delay in seeking healthcare among imported malaria cases. BP neural network modeling showed that duration of residing abroad, incubation period and age posed great impacts on delay in healthcare-seek among imported malaria patients. Random forest modeling showed that the top five factors with the greatest impact on healthcare-seeking delay included main clinical manifestations, the way to go abroad, incubation period, duration of residing abroad and age among imported malaria patients, and Bayesian modeling revealed that the top five factors affecting healthcare-seeking delay among imported malaria patients included level of institutions at initial diagnosis, age, country of origin, history of malaria parasite infection and individuals travelling with imported malaria patients. ROC curve analysis showed higher overall performance of the BP neural network model and the logistic regression model for prediction of the risk of healthcare-seeking delay among imported malaria patients (Z = 2.700 to 4.641, all P values < 0.01), with no statistically significant difference in the AUC among four models (Z = 1.209, P > 0.05). The sensitivity (71.00%) and Youden index (43.92%) of the logistic regression model was higher than those of the BP neural network (63.00% and 36.61%, respectively), and the specificity of the BP neural network model (73.61%) was higher than that of the logistic regression model (72.92%). Conclusions Imported malaria cases with long duration of residing abroad, a history of malaria parasite infection, long incubation period, advanced age and seeking healthcare in provincial or municipal medical institutions have a high likelihood of delay in healthcare-seeking in Jiangsu Province. The models created based on the logistic regression and BP neural network show a high efficiency for prediction of the risk of healthcare-seeking among imported malaria patients in Jiangsu Province, which may provide insights into health management of imported malaria patients.
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After achieving malaria elimination, preventing re-establishment from imported malaria and consolidating malaria elimination achievements are top priorities of the national malaria control program in China. Due to the long-term existence of overseas imported malaria cases and incomplete eradication of local epidemic conditions, there are multiple challenges for prevention of re-establishment from imported malaria in China. Hereby, we propose that regular assessment is an effective approach to maintaining the capability of prevention of re-establishment from imported malaria, and describe the purpose, significance, management and implementation of the capability assessment for prevention of re-establishment from imported malaria, so as to provide insights into the formulation and adjustment of malaria control strategies during the post-elimination phase.
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Objective@#To investigate the current status of malaria rapid diagnostic test (RDT) strips application and malaria laboratory technicians' evaluation about them at primary healthcare provider level in Jiangsu Province.@*Methods@#From November to December 2016, 878 medical institutions and 118 CDCs of city, county and township/community level in Jiangsu Province were selected as study samples using stratified random sampling method. Self-designed questionnaire was distributed to investigate the institution's malaria work task, RDT strips application and evaluation status in 2015. We also investigated the socio-demographic information and collected the RDT strips evaluation score from the malaria laboratory technicians selected from the institutions investigated (one technician from each institution). Rank sum test was performed to compare the RDT strips evaluation scores between medical institutions and CDCs, and among different medical institutions and CDCs.@*Results@#In 2015, 405 cases of malaria were reported, 362 200 person-time of malaria blood testing task was conducted, and 100 000 RDT strips were procured and provided for healthcare providers in Jiangsu province for free. Of the 996 healthcare institutions investigated, 628 used RDT strips in the year 2015 and the median (P25, P75) of RDT strips volume used in these institutions was 10 (2, 25). The volume of RDT strips used in CDCs (15 (5, 52)) was significantly higher than that in medical institutions (10 (2, 25), (Z=3.42, P=0.001)). The investigated CDCs gave higher score on RDT strips' testing time per operation (10 (8.5, 10)) than medical institutions (9(8, 10), (Z=-2.20, P=0.028)). The employers of 614 investigated malaria laboratory technicians used RDT strips in 2015. The median of the scores given by CDC malaria laboratory technicians for RDT strips in terms of testing time per operation, testing operation and results judgement difficulties were 10 (9, 10), 10 (9, 10) and 10 (9, 10), respectively, which were significantly higher than those from technicians of medical institutions (9 (8, 10), 9 (8, 10), 9 (8, 10), (Z values were -2.55, -2.97 and -2.96, respectively; P values were all less than 0.05)).@*Conclusion@#RDT strips had been widely performed in health institutions in Jiangsu Province. The amount of RDT strips used in CDCs was significantly higher than that in medical institutions. Primary-level institutions and malaria laboratory technicians generally recognized RDT strips' advantage for application in terms of testing time and operational procedure. CDCs and malaria laboratory technicians from them gave higher regards on RDT strips in terms of testing time per operation, testing operation and results judgement difficulties compared with that of medical institutions.
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Objective To understand the situation related to health seeking and diagnosis of imported malaria and to provide practical measures for malaria elimination in Jiangsu province.Methods Data on imported malaria cases in Jiangsu province was retrieved in CISDCP from 2014 to 2016.Relevant information on health seeking behavior,diagnosis and treatment of the disease was gathered.Results A total of 1 068 imported cases were reported in Jiangsu province from 2014 to 2016.Except for one malaria case that was caused by blood transfusion,the rest patients were all recognized as'imported'.Majority of the cases were migrant laborers working in African countries.The accurate rates on the diagnosis of ovale,vivax and quartan malaria and mixed infection were relatively low,as 79.3％ (107/135),29.5％ (18/61),52.9％ (18/34) and 0.0％ (0/2) at the primary health care settings,respectively.Rate of seeking health care on the same day of onset was more in 2015 than in 2014 and 2016 (X2=18.6,P=0.001).While only 65.4％ (699/1 068) of the patients were diagnosed correctly at the primary health care settings.There appeared no statistical difference in the 3-year-study period (x2=5.4,P=0.246).Capacity on'correct diagnosis' seemed stronger at the CDC than at the hospital levels (x2=13.2,P=0.000;x2=5.4,P=0.020).Totally,72.7％ (32/44) of the severe falciparum malaria cases did not immediately seek for health care when the symptoms started.Conclusions Migrant workers returning from the high endemic malaria areas seemed to have poor awareness in seeking health care services.Capability on correct diagnosis for malaria at the primary health care settings remained unsatisfactory and staff from these settings needs to receive adequate training.
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Objective To understand the situation related to health seeking and diagnosis of imported malaria and to provide practical measures for malaria elimination in Jiangsu province.Methods Data on imported malaria cases in Jiangsu province was retrieved in CISDCP from 2014 to 2016.Relevant information on health seeking behavior,diagnosis and treatment of the disease was gathered.Results A total of 1 068 imported cases were reported in Jiangsu province from 2014 to 2016.Except for one malaria case that was caused by blood transfusion,the rest patients were all recognized as'imported'.Majority of the cases were migrant laborers working in African countries.The accurate rates on the diagnosis of ovale,vivax and quartan malaria and mixed infection were relatively low,as 79.3％ (107/135),29.5％ (18/61),52.9％ (18/34) and 0.0％ (0/2) at the primary health care settings,respectively.Rate of seeking health care on the same day of onset was more in 2015 than in 2014 and 2016 (X2=18.6,P=0.001).While only 65.4％ (699/1 068) of the patients were diagnosed correctly at the primary health care settings.There appeared no statistical difference in the 3-year-study period (x2=5.4,P=0.246).Capacity on'correct diagnosis' seemed stronger at the CDC than at the hospital levels (x2=13.2,P=0.000;x2=5.4,P=0.020).Totally,72.7％ (32/44) of the severe falciparum malaria cases did not immediately seek for health care when the symptoms started.Conclusions Migrant workers returning from the high endemic malaria areas seemed to have poor awareness in seeking health care services.Capability on correct diagnosis for malaria at the primary health care settings remained unsatisfactory and staff from these settings needs to receive adequate training.
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Objective To understand the population,density,seasonal fluctuation and nocturnal pattern of malaria vectors in Jiangsu Province,thus to provide evidences for malaria elimination in this province. Methods Seven counties(cities,dis?tricts)were selected as the monitoring sites for malaria vectors in Jiangsu Province from 2013 to 2015. The mosquitoes were cap?tured by human bait trapping in bed nets and mosquito?lured lamp overnight,and the seasonal fluctuation and nocturnal pattern of malaria vectors were observed. Results A total of 11 041 Anopheles sinensis mosquitoes were captured by the mosquito?lured lamps in 7 counties of Jiangsu Province from 2013 to 2015,and no An. anthropophagous was found. Among all the 7 monitoring sites,the number of An. sinensis captured in Sihong County was the most(6 742 mosquitoes),while that in Xuyu County was the least(34 mosquitoes). During this period,the density peaks of An. sinensis were the first half of July,the first half of August and the second half of July. A total of 2 421 An. sinensis were collected in 7 monitoring sites from 2013 to 2015 by human bait trapping in bed nets overnight. Among all the 7 monitoring sites,the captured number of An. sinensis in Sihong County was the most(1 085 mosquitoes),while that in Ganyu County was the least(13 mosquitoes). The nocturnal peak of An. sinensis was from 19:00 to 20:00 and 525 An. sinensis mosquitoes were captured during this period of time,which accounted for 21.68%of the total. Hereafter,the captured number of An. sinensis reduced over time. Conclusion The density of An. sinensis mosquitoes is still high in individual areas in Jiangsu Province,so the epidemic and vector monitoring still should be strengthened to prevent the local transmission of imported malaria.
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Objective To understand the malaria epidemic situation and characteristics in Jiangsu Province in 2015,so as to provide the evidence for malaria elimination. Methods The data of malaria cases in Jiangsu Province in 2015 were collected from China's routine diseases surveillance information system. Results Totally 405 imported cases were reported in Jiangsu Province in 2015,and the cases increased by 14.08％compared with those in 2014. All the malaria cases were imported,and 5 cases(1.23％)were from Southeast Asia and 400(98.77％)were from 25 African countries or regions. The imported malaria cases were reported in 13 cities across Jiangsu Province,where Taizhou,Lianyungang,Nantong,Huaian and Yangzhou cities accounted for 68.64％of all the cases in the province. Jiangsu Institute of Parasitic Diseases(JIPD)reference lab checked all the cases and classified 299 falciparum malaria cases,13 vivax malaria cases,18 quartan malaria cases,71 ovale malaria cas-es,and 4 mixed Plasmodium infection cases. Conclusions In Jiangsu Province,there are no local malaria cases for 4 consecu-tive years,but the imported cases are on the rise. Compared to 2014,the imported vivax cases increased significantly in 2015. It should be the key points to strengthen the surveillance of imported malaria cases,improve malaria diagnosis and treatment abili-ties for all levels of medical institutions,and promote the abilities of Plasmodium check,and focus survey and disposal of all Center for Disease Control(CDC)staffs across Jiangsu Province.
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Objective To understand the integrated ability of parasitic disease prevention and control of professional person-nel of Jiangsu Province through the contest. Methods Totally 56 players from the whole province were selected,and all the players participated in the contest. The theory knowledge and skill scores were collected and the statistical analyses were con-ducted. Results The average theoretical score of the participants was 88.86±15.56 and the passing rate was 91.1％. The aver-age skill operating score was 69.16 ± 16.01 and the passing rate was 67.9％. The average Plasmodium microscopy score was 16.54±8.09 and the passing rate was 50％. The average helminth egg microscopy score was 34.27±10.66 and the passing rate was 67.9％. There were statistical differences among the age groups and different levels of schistosomiasis endemic situation (F =5.10,6.39,both P<0.01). The theoretical knowledge including schistosomiasis,malaria,hydatid disease and others and the score rates were 91.07％,90.94％,85.83％and 90.93％,respectively. The hydatid disease score rate was lower(χ2=19.17, P<0.01). The radar chart displayed that the score rates of tabletting and microscopy test in Kato-Katz film production ,malaria blood film production and microscopy test were all low. Conclusion In Jiangsu Province,the participants have higher score in the theory test. However,they have lower skill test score,especially in the parasite species identification. The operational skills still need to be strengthened for center for disease control(CDC)participants.
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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.
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<p><b>OBJECTIVE</b>To study the population genetic variation, genetic diversity and phylogenesis of Anopheles sinensis in China.</p><p><b>METHODS</b>Anopheles sinensis samples collected from Shandong, Anhui, Jiangsu, Guizhou, and Yunnan Provinces and Guangxi Zhuang Autonomous Region with different geographical conditions between 2010 and 2012 were analyzed by mitochondrial DNA cytochrome oxidase subunit I (mtDNA-COI) gene amplification and sequencing. Bioedit 7.0 and DnaSP 5.0 software was used to compare the gene sequences and analyze the population genetic structure, respectively. Arlequin 3.1 was used to calculate the genetic distance and parameters of population differentiation. The relationship between the geographic and genetic distances was analyzed using IBD Web Service. PHYLIP 3.6 was used to construct the phylogenetic tree.</p><p><b>RESULTS</b>PCR amplification and sequencing was performed successfully for 6 Anopheles sinensis populations containing 123 female mosquitoes. The length of mtDNA-COI gene fragment was 841 bp with an average A+T content of 71.2% and G+C content of 28.8%. High nucleotide diversity and genetic differentiation were observed among the Anopheles sinensis populations based on mtDNA-COI gene. Analysis of the molecular variance revealed a greater variation between populations than that within populations with isolation by distance between the populations. The Anopheles sinensis populations appeared to have undergone expansion, but the Yunnan population constituted an isolated branch in the phylogenetic tree.</p><p><b>CONCLUSION</b>mtDNA-COI can serve as the molecular marker to analyze population genetic variation and phylogenesis of Anopheles sinensis. The Yunnan population shows a phylogenetic difference from the other populations analyzed in this study.</p>
Subject(s)
Animals , Female , Anopheles , Genetics , China , DNA, Mitochondrial , Genetics , Electron Transport Complex IV , Genetics , Genetic Variation , Genetics, Population , PhylogenyABSTRACT
Objective To explore the effect of different temperatures on the different development stages of Aedes albopic?tus. Methods The changes at different development stages of mosquitoes(egg,larva,pupae)and gonotrophic cycle were ob?served at different temperature conditions of 10,15,20,25,30,35℃and 40℃. The full developmental cycles were com?pared during different temperatures. Results All the stages of the mosquitoes could not develop at 10℃. Under the different temperatures of 15,20,25,30,35℃and 40℃,the hatchabilities of the mosquitoes were 0,32%,82%,83%,82%and 59%respectively;the pupation rates of the mosquitoes were 38%,53%,84%,88%,72%and 42%respectively;and the emer?gence rates of the mosquitoes were 92% 95% 97% 97% 83%and 17%respectively. The mosquitoes could well develop at 20 25 30℃and 35℃ the development time was 37.73 18.50 16.92 and 13.66 days respectively. Conclusion The devel?opment time of Aedes albopictus is shorter at the higher temperature. The optimum temperature for the mosquitoes to develop is between 25-30℃ and higher or lower the temperatures will suppress the development of the mosquitoes.
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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.
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Objective To evaluate the toxic effect of Bacillus thuringiensis var. israelensis(Bti)wettable powder against Ae-des,Culex and Anopheles larvae. Methods The biological assay was applied to test the lethal concentration of 50%(LC50)of Bti wettable powder against Aedes,Culex and Anopheles larvae. Results The LC50(s) of Bti wettable powder against Aedes albopictus, Culex pipiens pallens and Anopheles sinensis larvae were 0.104,0.160μg/ml and 0.324μg/ml,respectively;its biological poten-cies against them were 0.125,0.192 IU/ml and 0.389 IU/ml,respectively. The LC50(s) of continuous contact of Bti wettable powder with An. sinensis stageⅢlarvae for 1,2 d and 3 d were 0.324,0.092μg/ml and 0.032μg/ml,respectively,and its biological po-tencies were 0.389,0.110 IU/ml and 0.038 IU/ml,respectively. The LC50(s) of the bacteria against An. sinensis stageⅠ,Ⅱ,Ⅲ,Ⅳwere 0.024,0.137,0.324 μg/ml and 0.450 μg/ml,respectively,and the biological potencies were 0.029,0.164,0.389 IU/ml and 0.540 IU/ml,respectively. Conclusion Bti wettable powder has a good toxicity to Aedes,Culex and Anopheles larvae,espe-cially for the latter two. It is better to apply the bacteria at the early stage of mosquito larvae.
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Resistance of Plasmodium spp. to anti-malarial drugs is the primary obstacle in the fight against malaria, and molecular markers for the drug resistance have been applied as an adjunct in the surveillance of the resistance. In this study, we investigated the prevalence of mutations in pvmdr1, pvcrt-o, pvdhfr, and pvdhps genes in temperate-zone P. vivax parasites from central China. A total of 26 isolates were selected, including 8 which were previously shown to have a lower susceptibility to chloroquine in vitro. For pvmdr1, pvcrt-o, and pvdhps genes, no resistance-conferring mutations were discovered. However, a highly prevalent (69.2%), single-point mutation (S117N) was found in pvdhfr gene. In addition, tandem repeat polymorphisms existed in pvdhfr and pvdhps genes, which warranted further studies in relation to the parasite resistance to antifolate drugs. The study further suggests that P. vivax populations in central China may still be relatively susceptible to chloroquine and sulfadoxine-pyrimethamine.
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Humans , Antimalarials/pharmacology , China , Chloroquine/pharmacology , DNA, Protozoan/chemistry , Drug Resistance/genetics , Folic Acid Antagonists/pharmacology , Genotype , Malaria, Vivax/epidemiology , Plasmodium vivax/drug effects , Point Mutation , Polymorphism, Single Nucleotide/genetics , Prevalence , Protozoan Proteins/genetics , Sequence Analysis, DNA , Tandem Repeat Sequences/geneticsABSTRACT
Objective To explore the sample reIated factors affecting the short-term culture of erythrocytic Plasmodium dvax in vitro.Methods The vivax malaria blood samples were collected from the patients with malaria in endemic areas,and then incubated with McCoy's 5A medium in an incubator containing 5%CO_2 at 37℃.The factors affecting the short-term culture of Plasmodium vivax were analyzed.Results Plasmodium vivax could finish one asexual cycle in the selected medium.By analyzing the culture results of 74 samples.it was found that the factors affecting the short-term culture included long time delaying al room temperature(>4 h),single stage(only parasites in ring stage were found),patients taking antimalarials,antibiotics or sulfonamides.and low parasitemia.Conclusion The sample related factors are important to the short-term culture of erythrocytic Plasmodium vivax in vitro.
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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,P0.05).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.
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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.
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Objective To analyse the epidemic characteristics and control measures of malaria in Jiangsu Province during the past fifty years, evaluate the control effect and explore the current appropriate control strategy and measures. Methods The historical data about malaria cases and control measures from 1951 to 2008 in Jiangsu Province were collected, and the effects of malaria control in different stages were assessed. Results The integrated control measures with emphasis on the control of infectious source were adopted during the stage of two outbreaks of malaria. In the stage of basical elimination of malaria, the comprehensive measures with emphasis on the vector control in the areas of Anopheles anthropophagus were adopted, and the measures with emphasis on the surveillance of infectious source surveillance and early treatment of malaria in other areas were adopted. In the stage of consolidation, the measures including the surveillance of infectious source and management, surveillance of vector and epidemic situation, management of floating population, etc, were adopted. The malaria incidence dropped from 2 495/10 000 in 1960 to 0.09/10 000 in 2008, and was under 1/10 000 in all the counties of Jiangsu Province during the past 2 years, which demonstrated the various measures were feasible and effective in different stages of malaria. Conclusions Malaria has been controlled effectively in Jiangsu Province, however, the improvement of early diagnosis and norm treatment of malaria cases, the enhancement of health education and promotion, as well as the malaria surveillance and management among floating population, are still necessary for achieving the goal of malaria elimination.
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Objective To analyze the genetic characteristics of ribosomal DNA ITS 2 region for differenciating anopheline mosquitoes within Hyrcanus group. Methods The ribosomal DNA ITS 2 region of both laboratory line and filed collected An. anthropophagus and An. sinensis as well as the field collected An. yatsushiroensis and An. lester i were amplified and sequenced. The sequencing data were then analyzed for the restriction mapping using Omega Sequencing analysis program. Results and Conclusion The length of the sequences of An. sinensis, An. anthropophagus, An. yatsushiroensis and An. lesteri are 472, 452, 456 and 456 bp respectively. The restriction mapping showed that there were different restriction digesting sites among the ribosomal DNA ITS2 region sequences from An. sinensis, An. anthropophagus, An. yatsushiroensis and An. lesteri . On the basis of the sequence differences among the anopheline species within Hyrcanus group, it is possible to develop new technique for genetic identification of anopheline mosquitoes.