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Objective: To investigate the epidemiological characteristics and diagnosis of imported Plasmodium malariae and P. ovale malaria cases in Anhui Province, Hubei Province, Zhejiang Province, Guangxi Zhuang Autonomous Region and Henan Province from 2014 to 2021, so as to provide insights into malaria control in these five provinces., Methods: All data pertaining to malaria cases reported in five provinces of China were captured from Chinese Disease Control and Prevention Information System from 2014 to 2021, and the epidemiological characteristics of imported P. malariae and P. ovale malaria cases were analysed using a descriptive epidemiological method. The duration from onset of malaria to initial diagnosis, duration from initial diagnosis to definitive diagnosis, institutions of initial and definitive diagnoses, and proportion of correct malaria diagnosis at initial diagnosis were statistically analyzed., Results: A total of 1 223 imported P. malariae and P. ovale malaria cases were reported in Anhui Province, Hubei Province, Zhejiang Province, Henan Province and Guangxi Zhuang Autonomous Region from 2014 to 2021, there were 158 P. malariae malaria cases (12.92%) and 1 065 P. ovale malaria cases (87.08%). Totally 98.53% (1 205/1 223) of the imported malaria cases were from Africa, with Angola (18.99%, 30/158), Nigeria (11.39%,18/158), Cameroon (10.76%, 17/158), Ghana (10.13%, 16/158) and the Democratic Republic of the Congo (10.13%,16/158) as predominant countries where P. malariae malaria cases were from, and Ghana (23.19%, 247/1 065), Cameroon (14.74%, 157/1 065), Nigeria (9.39%, 100/1 065) and Angola (6.95%, 74/1 065) as predominant countries where P. ovale malaria cases were from. There were significant differences in the duration from onset of malaria to initial diagnosis (χ 2 = 27.673, P = 0.000) and duration from initial diagnosis to definitive diagnosis of P. malariae and P. ovale malaria cases (χ 2 = 29.808, P = 0.000), and the proportions of correct initial diagnosis of P. malariae and P. ovale malaria cases were 38.61% (61/158) and 56.53% (602/1 065). There were 74.69% (118/158) of P. malariae malaria cases with definitive diagnosis in county-, city-, and province-level medical institutions, and 79.25% (844/1 065) of P. ovale malaria cases with definitive diagnosis in county- and city-level medical institutions and county-level centers for disease control and prevention., Conclusions: The imported P. malariae and P. ovale malaria cases in Anhui Province, Hubei Province, Zhejiang Province, Henan Province and Guangxi Zhuang Autonomous Region from 2014 to 2021 were mainly returned from Africa and the proportion of correct diagnosis of P. malariae and P. ovale malaria was low at initial diagnosis. Persistent improvements in the diagnostic capability of malaria are required in medical institutions.

Objective: To analyze the quality of blood smear examinations for malaria parasites in Chenzhou City, so as to provide insights into sustainable consolidation of malaria elimination achievements., Methods: All positive blood smears from fever patients were irregularly sampled from each county (district) of Chenzhou City from 2018 to 2022 and reexamined, and no less than 3% negative blood smears were reexamined. The preparation, dyeing, cleanliness and microscopic examination results of blood smear were reexamined, and the quality of blood smear reexaminations was assessed using a descriptive statistical method., Results: A total of 13 625 fever patients received blood smear examinations for malaria parasites in Chenzhou City from 2018 to 2022, of which 21 were positive and 13 604 were negative; 687 blood samples were reviewed, and the percentage of negative blood smear reexaminations was 4.90% (666/13 604), with a 63.51% rate of qualified negative blood smears preparation, a 67.87% rate of qualified dyeing and a 76.13% rate of qualified cleanliness, and no missing diagnosis found. There were 21 positive blood smears reexamined, and the proportions of qualified blood smears preparation, dyeing and cleanliness were all 85.71%, with 2 smears mistaking Plasmodium species (9.52%). The percentage of qualified negative blood smears preparation was 51.41% in 2022, which reduced by 31.61% in relative to that (75.17%) in 2019 (χ 2 = 9.033, P < 0.05), and the percentage of qualified negative blood smears dyeing was 60.19% in 2022, which reduced by 28.82% in relative to that (84.56%) in 2019 (χ 2 = 19.498, P < 0.05), while the percentage of qualified negative blood smears cleanliness was 62.96% in 2022, which reduced by 28.93% in relative to that (88.59%) in 2019 (χ 2 = 23.826, P < 0.001). In addition, there were no significant differences in the proportion of qualified negative blood smears preparation (χ 2 = 0.260, P > 0.05) or dyeing (χ 2 = 1.094, P > 0.05) among the three years, while a significant difference was detected in the percentage of qualified negative blood smears cleanliness (χ 2 = 12.175, P < 0.05)., Conclusions: No missing diagnosis was seen in blood smear examinations for malaria parasites among fever patients in Chenzhou City after malaria elimination; however, there were reductions in proportions of qualified blood smears preparation, dyeing and cleanliness. Quality control of blood smear examinations is recommended to be reinforced in key regions of Chenzhou City.

This article presents a severe cerebral malaria patient in shock with a close contact of COVID-19 that was successfully cured in a negative pressure ward during the global pandemic of COVID-19. The patient experienced a sudden onset of high fever and coma in a designated isolation hotel after returning from Africa, and was transferred to a designated hospital. Following antimalarial therapy, blood pressure elevation, increase of blood volume, bedside hemodialysis, mechanical ventilation, plasma and platelet transfusions, the case gradual recovered.

Objective: To analyse the epidemiological characteristics of imported malaria cases after malaria elimination in Yixing City, Jiangsu Province, so as to provide reference for malaria prevention and control in grassroots healthcare institutions., Methods: All data pertaining to malaria cases reported in Yixing City from 2016 to 2022 were retrieved from Chinese Disease Control and Prevention Information System, and the data pertaining to vector monitoring and human malaria parasite infections from 2016 to 2022 were collected for a descriptive statistical analysis., Results: A total of 14 imported malaria cases were reported in Yixing City from 2016 to 2022, including 12 cases with Plasmodium falciparum malaria, one case with P. vivax malaria and one case with P. ovale malaria, and all cases acquired infections in Africa and then returned to Yixing City. Malaria cases were reported across 2016 to 2022 except in 2020 and 2021. Malaria cases were predominantly reported during the period between December and February of the next year, and workers were the predominant occupation. The institutions where malaria was initially diagnosed included county-level general hospitals, county-level disease prevention and control institutions and grassroots healthcare centers, and there were 10 cases with definitive diagnosis of malaria on the day of initial diagnosis, with a 64.29% (9/14) correct rate of initial diagnosis. There were 5 cases diagnosed with severe malaria, and the standardized response rate was 100.00% following the "1-3-7" surveillance and response strategy. Of all malaria vectors, only Anopheles sinensis was monitored in Yixing City from 2016 to 2022, and all humans were tested negative for blood smears exceptimportedmalariacases., Conclusions: The correct rate of initial malaria diagnosis was not high in healthcare institutions in Yixing City from 2016 to 2022, and there are still multiple challenges for prevention of re-establishment of imported malaria.

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.

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.

Objective: To establish a fluorescent assay for rapid detection of Plasmodium falciparum based on recombinaseaided amplification (RAA) and CRISPR-Cas12a system,and to preliminarily evaluate the diagnostic efficiency of this system., Methods: The 18S ribosomal RNA ( rRNA ) gene of P. falciparum was selected as the target sequence, and three pairs of RAA primers and CRISPR-derived RNA (crRNA) were designed and synthesized. The optimal combination of RAA primers and crRNA was screened and the reaction conditions of the system were optimized to create a fluorescent RAA/CRISPR-Cas12a system. The plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 was generated, and diluted into concentrations of 1 000, 100, 10, 1 copy/μL for the fluorescent RAA/CRISPR-Cas12a assay, and its sensitivity was evaluated. The genomic DNA from P. vivax , P. malariae , P. ovum , hepatitis B virus, human immunodeficiency virus and Treponema pallidum was employed as templates for the fluorescent RAA/CRISPR-Cas12a assay, and its specificity was evaluated. Fifty malaria clinical samples were subjected to the fluorescent RAA/CRISPR-Cas12a assay and nested PCR assay, and the consistency between two assays was compared. In addition, P. falciparum strain 3D7 was cultured in vitro . Then, the culture was diluted into blood samples with parasite densities of 1 000, 500, 200, 50, 10 parasites/μL with healthy volunteers' O-positive red blood cells for the RAA/CRISPR-Cas12a assay, and the detection efficiency was tested., Results: The Pf-F3/Pf-R3/crRNA2 combination, 2.5 μL as the addition amount of B buffer, 40 min as the RAA reaction time, 37 °C as the reaction temperature of the CRISPR-Cas12a system were employed to establish the fluorescent RAA/CRISPR-Cas12a system. Such a system was effective to detect the plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 at a concentration of 1 copy/μL, and presented fluorescent signals for detection of P. falciparum , but failed to detect P. ovum , P. malariae , P. vivax , T. pallidum , hepatitis B virus or human immunodeficiency virus. The fluorescent RAA/CRISPR-Cas12a system and nested PCR assay showed completely consistent results for detection of 50 malaria clinical samples ( kappa = 1.0, P < 0.001). Following 6-day in vitro culture of the P. falciparum strain 3D7, 10 mL cultures were generated and the fluorescent RAA/CRISPR-Cas12a system showed the minimal detection limit of 50 parasites/μL., Conclusions: The fluorescent RAA/CRISPR-Cas12a system is rapid, sensitive and specific for detection of P. falciparum , which shows promising value for rapid detection and risk monitoring of P. falciparum .

As the first country that has been certified malaria-free in the WHO Western Pacific Region for more than 3 decades, China should share its successful experiences of malaria control and provide globally recognized anti-malaria products by making full uses of its advantages in provision and production capacity of artemisinin raw materials, to fill the gaps of international demands for mosquito nets, rapid diagnostic reagents and antimalarial compounds. Increasing the investment of research and development of antimalarial products, building overseas bases for artemisinin raw material production, establishing international regulatory authority and promoting the local production of antimalarial products are needed to further promote the internationalization of Chinese antimalarial products, so as to achieve the equity and accessibility of Chinese antimalarial products in highburden regions for malaria.

Objective: To investigate the health-seeking behaviors of imported malaria cases after returning to China, and to investigate the factors affecting the time to initial diagnosis, so as to provide the scientific evidence for early identification of imported malaria cases and prevention of severe cases development and secondary transmission., Methods: The individual demographic features, and the disease onset and the time to initial diagnosis of imported malaria cases in Jiangsu Province in 2019 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China. The characteristics of health-seeking behaviors and epidemiological features of imported malaria cases were descriptively analyzed, and the factors affecting the time to initial diagnosis of imported malaria cases after returning to China were identified using multivariate logistic regression analysis., Results: A total of 244 imported malaria cases were reported in Jiangsu Province in 2019, and the time to initial diagnosis of the cases were 1-12 days, with mean time of (1.53 ± 1.65) days, with median time of one day. The highest number of malaria cases seeking healthcare services were found on the day of developing primary symptoms (76 cases, 31.1%), followed by on the second day (68 cases, 27.9%), on the third day (46 cases, 18.9%), and 54 cases (22.1%) received initial diagnosis 3 days following presence of primary symptoms, including 3 cases with initial diagnosis at more than one week. High proportions of imported malaria cases with a delay in the time to initial diagnosis were seen in migrant workers who returned to China in January (14 cases, 5.7%) and December (13 cases, 5.3%) and those aged between 41 and 50 years (32 cases, 13.1%). Multivariate logistic regression analysis showed relative short time to initial diagnosis among imported malaria cases returning to China on March [odds ratio ( OR ) = 0.16, P = 0.03, 95% confidence interval ( CI ): (0.03, 0.85)] and those with a history of overseas malaria parasite infections [ OR = 0.36, P = 0.001, 95% CI : (0.19, 0.67)]., Conclusions: Timely health-seeking behaviors should be improved among imported malaria cases in Jiangsu Province, patients with a history of overseas malaria infections require faster health-seeking activities.

Objective: To investigate the epidemiological characteristics and diagnosis of malaria cases in Nantong City from 2015 to 2020, so as to provide insights into the prevention of re-establishment of imported malaria and consolidation of malaria elimination achievements in the city., Methods: The epidemic data of malaria in Nantong City from 2015 to 2020 were captured from the National Notifiable Disease Report System, the Information Management System for Parasitic Disease Control and individual epidemiological survey reports of malaria cases. The malaria parasite species, source of infections, population distribution, temporal distribution, spatial distribution and diagnosis of imported malaria cases were descriptively and statistically analyzed., Results: A total of 241 malaria cases were reported in Nantong City from 2015 to 2020, and all were overseas imported cases, including 191 cases with Plasmodium falciparum malaria (79.25%), 8 cases with P. vivax malaria (3.32%), 33 cases with P. ovale malaria (13.69%) and 9 cases with P. malaria malaria (3.73%). Overseas imported malaria cases acquired infections from 34 countries in Asia, Africa and Latin America, and 97.93% of the cases were infected in Africa, and 90.04% (217/241) were reported in Chongchuan District, Hai'an City and Haimen District. Imported malaria cases were aged from 20 to 68 years, and a median age of 45 (13) years, and 97.10% were male. The median duration between returning to China and malaria onset was 7 (9) days among all imported malaria cases, and the median duration from initial diagnosis to definitive diagnosis was 2 (2) days. There were 167 cases that were initially diagnosed as malaria, with a correct rate of 69.29%, and 53.53 (129/241) of malaria cases were diagnosed at city-level medical institutions and 41.49% (100/241) at county-level medical institutions. In addition, the proportion of malaria cases reported by city-level medical institutions increased from 39.62% in 2015 to 81.25% in 2020 ( χ 2 = 6.94, P < 0.01)., Conclusions: The accuracy of initial malaria diagnosis requires to be improved in Nantong City. Malaria control knowledge should be specially given to migrant workers to shorten the duration of seeking medical care, and malaria training requires to be intensified among healthcare professionals to improve the diagnostic capability of imported malaria cases and the cure of severe P. falciparum malaria cases.

Objective: To analyze the epidemiological characteristics of reported imported malaria cases in Zhengzhou City from 2016 to 2020, so as to provide insights into the management of imported malaria in the city., Methods: All data pertaining to cases with definitive diagnosis of malaria in Zhengzhou City from 2016 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including individual demographic data, and malaria onset, initial diagnosis and definitive diagnosis data. All data were descriptively analyzed. The duration from malaria onset to initial diagnosis, from initial diagnosis to definitive diagnosis and from onset to definitive diagnosis was compared among cases. In addition, the diagnoses of imported malaria cases in which definitive diagnosis was made were compared with the reexaminations by Zhengzhou Municipal Malaria Diagnosis Reference Laboratory., Results: A total of 302 cases with definitive diagnosis of malaria were reported in Zhengzhou City from 2016 to 2020, and all were imported cases, with Plasmodium falciparum malaria as the predominant type (230 cases, 76.2%). There were 293 malaria cases imported from Africa (293 cases, 97.0%), which mainly included Nigeria (48 cases, 15.9%), Angola (40 cases, 13.2%), and the Democratic Republic of the Congo (29 cases, 9.6%). There was no obvious seasonality found in the date of malaria onset and time of reporting malaria. The ratio of male to female malaria cases was 49.3:1, and there were 103 cases (34.1%) with the current residency address in Zhengzhou City, 193 cases (63.9%) with the current residency address in other cities of Henan Province and 6 cases (2.0%) in other provinces of China. There were 271 cases (89.7%) seeking initial diagnosis in medical institutions, and the diagnostic accuracy of malaria was 56.6% (171/302) at initial diagnosis institutions. A total of 122 cases (40.4%) sought medical care on the day of malaria onset, and 252 cases (86.4%) within 3 days; however, only 22 cases (7.3%) were definitively diagnosed on the day of onset, and 162 cases (53.6%) diagnosed within 3 days. There were no significant differences between malaria cases seeking initial diagnosis at medical institutions and disease control and prevention institutions in terms of the duration from malaria onset to initial diagnosis ( Z = -1.663, P > 0.05), from initial diagnosis to definitive diagnosis ( Z = -0.413, P > 0.05) or from malaria onset to definitive diagnosis ( Z = -0.838, P > 0.05). The median duration (interquartile range) from initial diagnosis to definitive diagnosis of malaria was 3.00 (2.00), 3.00 (6.00), 2.00 (4.00) d and 1.00 (1.00) d among cases seeking medical care at township-level and lower, county-, city- and province-level medical institutions, and the median duration from initial diagnosis to definitive diagnosis of malaria was significantly longer among cases seeking medical care at township-level and lower medical institutions than at city ( Z = -3.286, P < 0.008 33) and province-level medical institutions ( Z = -9.119, P < 0.008 33), while the median duration from initial diagnosis to definitive diagnosis [1.00 (3.00) d vs. 2.00 (4.00) d; Z = -4.099, P < 0.016] and from malaria onset to definitive diagnosis [3.00 (4.00) d vs. 4.00 (5.00) d; Z = -2.868, P < 0.016] among malaria cases with the current residency address in Zhengzhou City was both shorter than in other cities of Henan Province. The diagnostic accuracy was 89.1% (269/302) among malaria cases in which definitive diagnosis was made, and the accuracy of malaria reexaminations was 94.0% (284/302) in Zhengzhou Municipal Malaria Diagnosis Reference Laboratory., Conclusions: P. falciparum malaria was predominant among reported imported malaria cases in Zhengzhou City from 2016 to 2020, and these imported malaria cases were predominantly diagnosed at medical institutions; however, the diagnostic capability of malaria is poor in township-level and lower medical institutions. Strengthening the collaboration between medical institutions and disease control and prevention institutions and improving the diagnostic capability building at medical institutions are recommended to consolidate malaria elimination achivements.

Objective: To analyze the epidemiological characteristics of imported cases with Plasmodium ovale infections in Jiangsu Province from 2012 to 2020, so as to provide insights into the development of the imported malaria control strategy in the province., Methods: All data pertaining to cases with definitive diagnosis of P. ovale malaria in Jiangsu Province from 2012 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including the date of going abroad and returning to China, time of malaria infections overseas, date of malaria onset, initial diagnosis and definitive diagnosis. All data pertaining to epidemic status were descriptively analyzed., Results: A total of 347 cases of P. ovale malaria were reported in Jiangsu Province from 2012 to 2020, with the highest number seen in 2015 (71 cases). All cases were laboratory-confirmed overseas imported malaria cases, accounting for 14.32% of all reported malaria cases in Jiangsu Province during the period from 2012 to 2020. The 5 cities with the highest number of imported P. ovale malaria cases included Lianyungang City (53 cases, 15.27%), Nantong City (44 cases, 12.68%), Huai'an (44 cases, 12.68%), Taizhou City (44 cases, 12.68%) and Yangzhou City (36 cases, 10.37%). The highest number of imported P. ovale malaria cases was reported in October (39 cases, 11.24%), and the lowest number was seen in December (21 cases, 6.05%). P. ovale infections mainly occurred in were Equatorial Guinea (97 cases, 37.95%), Angola (60 cases, 17.29%) and Nigeria (40 cases, 11.53%). The median duration between returning to China and malaria onset was 64 (144) days, and 7.49% (26/347) of all cases developed malaria one year after returning to China. The initial diagnosis of P. ovale malaria was mainly made at county-level medical institutions (117 cases, 33.72%), and the definitive diagnosis was mainly made at city-level medical institutions (122 cases, 35.16%). The correct rate of initial diagnosis of P. ovale malaria increased from 0 in 2012 to 78.26% in 2020, appearing a tendency towards a rise year by year (χ 2 = 50.90, P < 0.01)., Conclusions: Imported P. ovale malaria cases were reported in Jiangsu Province each year from 2012 to 2020, and P. ovale infections predominantly occurred in Africa. Initial and definitive diagnoses of P. ovale malaria were mainly made at city- and county-level medical institutions. Training on the detection ability of malaria parasites is recommended among grassroots microscopists to improve the diagnostic ability of P. ovale malaria, and consolidate the achievements of malaria elimination in Jiangsu Province.

Objective: To re-examine the diagnosis results of reported malaria cases in Sichuan Province from 2014 to 2020, so as to assess the malaria diagnostic capability of Sichuan Provincial Malaria Diagnostic Reference Laboratory., Methods: The blood and blood smear samples from reported malaria cases were collected by Sichuan Provincial Malaria Diagnostic Reference Laboratory from 2014 to 2020, and subjected to re-examinations using microscopy and nested PCR assay. The re-examination results were compared., Results: A total of 1 710 samples from reported malaria cases were re-examined by Sichuan Provincial Malaria Diagnostic Reference Laboratory from 2014 to 2020, and 1 634 samples were identified positive, with a positive coincidence rate of 95.56% (1 634/1 710) and a 92.29% (1 508/1 634) total coincidence rate of the Plasmodium species. The coincidence rates with P. falciparum , P. vivax , P. malariae and P. ovale were 99.48% (961/966), 97.07% (430/443), 83.05% (98/118) and 67.86% (19/28), respectively, and the coincidence rate was 91.81% (1 513/1 648) between microscopic and nested-PCR results., Conclusions: The capability of microscopists remains weak at grassroot medical institutions in Sichuan Province. Further training is required among microscopists to improve the malaria surveillance capability in Sichuan Province during the post-elimination stage.

Objective: To analyze the epidemiological characteristics and diagnosis of imported malaria before and after malaria elimination in Nanjing City of Jiangsu Province, so as to provide the scientific evidence for formulating the malaria control strategy after malaria elimination., Methods: Data pertaining to the epidemic situation and individual investigation of malaria in Nanjing City before (from 2012 to 2016) and after malaria elimination (from 2017 to 2020) were captured from the National Notifiable Communicable Disease Reporting System and the Information System for Parasitic Diseases Control and Prevention and were analyzed statistically., Results: A total of 178 malaria cases were reported in Nanjing City from 2012 to 2020, and all were imported cases. There were 99 malaria cases reported before malaria elimination in Nanjing City, including 78 cases with Plasmodium falciparum malaria (78.79%), 5 cases with P. vivax malaria (5.05%), 10 cases with P. ovale malaria (10.10%), 3 cases with P. malariae malaria (3.03%) and 3 cases with mixed infections (3.03%), and 79 malaria cases reported after elimination, including 63 cases with P. falciparum malaria (79.75%), 5 cases with P. vivax malaria (6.33%), 9 cases with P. ovale malaria (11.39%), 2 cases with P. malariae malaria (2.53%). There was no significant difference in the proportion of each type of malaria cases in Nanjing City before and after malaria elimination ( χ 2 =2.400, P > 0.05). Malaria cases mainly acquired Plasmodium infections in African regions, and no significant difference was seen in the proportion of malaria cases returning to Nanjing City from African countries before and after malaria elimination ( χ 2 = 0.093, P > 0.05). The number of malaria cases peaked in Nanjing City in January and during the period from May to July before elimination, and there was no apparent seasonal variation in the distribution of malaria cases after elimination. The proportion of malaria cases living in Nanjing City was significantly greater after malaria elimination than before elimination (72.15% vs. 55.56%; χ 2 = 5.187, P = 0.023). The proportions of businessmen and international students were both 5.05% before malaria elimination, and increased to 15.19% and 13.92% after elimination, respectively ( χ 2 = 5.229 and 4.229, both P values < 0.05). The percentage of definitive diagnosis of malaria at initial diagnosis was 18.75% in county-level hospitals before malaria elimination and increased to 61.11% after elimination ( χ 2 = 6.275, P = 0.012), while the proportion of malaria cases with definitive diagnoses in county-level hospitals was 4.04% before malaria elimination and increased to 13.92% after elimination ( χ 2 = 5.562, P = 0.018). During the period from 2012 to 2020, the proportion of malaria cases with definitive diagnoses within 1 to 3 days post-admission increased from 27.27% in Nanjing City before malaria elimination to 45.57% after elimination ( χ 2 = 6.433, P = 0.011)., Conclusions: The epidemic situation of imported malaria remains serious in Nanjing City during the post-elimination stage, and malaria parasite infections predominantly occur in African regions. In addition, there are changes in regional and occupational distributions of malaria cases and the diagnostic capability of malaria increases in county-level hospitals in Nanjing City after malaria elimination. Further improvements in the malaria surveillance system and the diagnostic and treatment capability of malaria in medical institutions at each level are required to consolidate malaria elimination achievements in Nanjing City.

Objective: To analyze the epidemiological features and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020, so as to provide the scientific evidence for the management of imported malaria in the province., Methods: The data of malaria cases reported in Zhejiang Province were captured from the Information Management System for Parasitic Disease Control of China Information System for Disease Control and Prevention from 2017 to 2020, and the temporal, spatial and human distribution, and initial and definitive diagnosis of imported malaria cases were descriptively analyzed., Results: A total of 593 malaria cases were reported in Zhejiang Province from 2017 to 2020, and all were overseas imported cases, including 532 men and 61 women, with a mean age of 41 years. There were 93.93% of the malaria cases from African countries, and the malaria parasites infecting these cases included Plasmodium falciparum , P. vivax , P. ovale , P. malariae and mixed infections, with P. falciparum as the predominant species (76.73%, 455/593). All malaria cases received totally correct initial diagnoses in county- and city-level centers for disease control and prevention (CDC) and entry-exit inspection and quarantine sectors, and the proportion of malaria cases with confirmation at the day of initial diagnosis was 41.48% (207/499) in medical institutions and 66.18% (45/68) in CDC ( χ 2 = 14.779, P < 0.001). In addition, the median interval [ M ( Q R )] of malaria cases was 1 (2) d from onset to initial diagnosis and 1 (2) d from initial diagnosis to confirmation in Zhejiang Province from 2017 to 2020, and the median interval [ M ( Q R )] of severe malaria cases was significantly longer than that of non-severe cases [2 (3) d vs. 1 (2) d; Z = -3.002, P < 0.05]., Conclusions: Zhejiang Province faces great challenges of malaria control, and post-elimination surveillance of malaria still requires to be reinforced. Meanwhile, the awareness of seeking medical services requires to be improved among returners from malaria-endemic regions and the diagnostic capability of malaria requires to be improved among medical professionals.

Imported malaria has become a major risk factor for malaria prevention and control in China. How to screen malaria quickly for people entering China is an urgent problem to be solved. Protein microarrays are widely used in high-throughput screening and diagnosis. In this study, surface plasmon resonance (SPR) technique for malaria detection was established by using the specific adsorption surface treated by polyethylene glycol polymer, and the malaria specific antigen HRP2 was used as capture probe. The optimal concentration of antigen, sensitivity and specificity of detection, as well as anti-interference ability of the chip were analyzed. The SPR protein chip was applied to detect specific antibodies of malignant malaria in serum with the advantage of label-free, instant and fast. Compared with fluorescence quantitative PCR, there were no significant difference in sensitivity and specificity between the two methods. This study lays a foundation for further development of protein microarray for malaria typing identification, and it is conducive to the rapid screening of malaria for people entering.

Objective: To analyze the diagnosis of imported malaria cases in Henan Province from 2015 to 2019, so as to provide the evidence for malaria surveillance during the post-elimination stage., Methods: The data pertaining to malaria cases in Henan Province from 2015 to 2019 were extracted via the web-based Chinese Information System for Infectious Diseases Control and Prevention and the Parasitic Diseases Information Reporting Management System (PDIRMS) of Chinese Center for Disease Control and Prevention, and the diagnostic methods, diagnostic institutions and diagnostic time of imported malaria cases were analyzed., Results: A total of 952 imported malaria cases were reported in Henan Province during the period from 2015 through 2019, and all cases were laboratory-confirmed. The positive rate of malaria rapid diagnostic tests (RDTs) was 98.61% (779/790), which was significantly greater than that (94.22%, 897/952) of microscopic examinations ( χ 2 = 22.773, P < 0.05). The proportion of imported malaria cases diagnosed in medical institutions increased from 65.22% (120/184) in 2015 to 81.50% (185/227) in 2019. Among the 238 imported malaria cases diagnosed in centers for disease control and prevention (CDC), 71.01% (169/238) were diagnosed in county-level CDC, and among the 704 cases diagnosed in medical institutions, only 8.38% (59/704) were diagnosed at county-level medical institutions. The median time from onset to definitive diagnosis of malaria was 3 days, and the median duration between onset and initial diagnosis of malaria was 1 day. The duration between initial diagnosis and definitive diagnosis of malaria varied significantly among years ( χ 2 = 24.956, P < 0.05), and the interquartile range from initial diagnosis to definitive diagnosis reduced from 4 days in 2016 to 2 days in 2019. In addition, the median time from initial diagnosis to definitive diagnosis was significantly longer in severe falciparum malaria cases than in non-severe falciparum malaria cases (2 days vs. 1 day; Z = 7.557, P < 0.05)., Conclusions: Medical institutions play a more and more important role in the identification and surveillance of malaria cases; however, the diagnostic capability of malaria remains low in county-level medical institutions. The diagnostic awareness and capability of county-level medical institutions requires to be improved, in order to play their roles as sentinel hospitals in the malaria surveillance during the post-elimination stage.

Objective: To analyze the re-examination results of malaria cases captured from the National Notifiable Communicable Disease Reporting System in Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, so as to pro- vide the scientific evidence for improving the malaria control capability in the province., Methods: Microscopy and nested PCR assay were performed to re-examine the diagnosis of malaria cases registered in the National Notifiable Communicable Disease Reporting System in Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, and the coincidences of ma- laria diagnosis and malaria parasite species were evaluated., Results: A total of 410 malaria cases were reported in Hubei Province from 2017 to 2019 according to the data retrieved from the National Notifiable Communicable Disease Reporting System. Among the 407 samples re-examined by Hubei Provincial Malaria Diagnostic Reference Laboratory from 2017 to 2019, the diag- nosis 374 malaria cases were confirmed, with an overall coincidence of 91.89% (374/407) for malaria diagnosis and 89.04% (333/374) for parasite species identification. The coincidence rates of malaria diagnosis and parasite species identification were 50.00% to 100.00% and 66.67% to 100.00% in 16 cities (prefectures) of Hubei Province during the re-examinations, which both varied in regions ( χ 2 = 40.46 and 42.30, both P values < 0.01). The coincidence rates of Plasmodium falciparum , P. vivax , P. malariae and P. ovale identification were 95.80%, 100.00%, 58.33% and 51.92% during the re-examinations, respectively ( χ 2 = 76.66, P < 0.01). The consistency rate between microscopic and nested PCR results was 89.83% (362/403)., Conclusions: The overall diagnostic quality of malaria is high in medical institutions at all levels in Hubei Province; however, the diagnostic capability of malaria remains to be improved in some regions.

Objective: To analyze the quality of malaria blood smears from fever patients in Zibo City from 2011 to 2018, so as to provide the scientific evidence for the development of the malaria post-elimination surveillance strategy., Methods: All negative malaria blood smears from fever patients reexamined in the municipal microscopic examination station and all positive blood smears in Zibo City during the period from 2011 to 2018 were reexamined, and the blood smear preparation, dyeing, cleanliness and reexamination results were analyzed., Results: A total of 2 141 negative malaria blood smears and 39 positive blood smears were re-reviewed by the municipal microscopic examination station of Zibo City from 2011 to 2018, with a 99.44% qualification rate of negative blood smears preparation, a 97.62% qualification rate of dyeing, a 93.65% qualification rate of cleanliness, and a 100% consistence with the re-review, and no missing diagnosis was found. A total of 39 positive blood smears were re-reviewed, with a 46.15% qualification rate of blood smears preparation, a 61.54% qualification rate of dyeing, a 76.92% qualification rate of cleanliness, and a 97.44% consistence with the re-review, and a blood smear mistaking the Plasmodium species was found. There were significant differences in the qualification rate of blood smears preparation and dyeing among all districts (counties) in Zibo City (all P values < 0.05), and no significant difference was detected in the qualification rate of blood smear cleanliness ( χ 2 = 13.72, P >0.05), while significant differences were seen in the qualification rate of blood smears preparation, dyeing and cleanliness each year from 2011 to 2018 (all P values < 0.05)., Conclusions: The quality of malaria blood smears is high in all districts of Zibo City; however, the quality of city-level blood smears remains to be improved. Further actions to improve the training of grassroots microscopic examinations and quality control of malaria blood smears are required to ensure the capability of microscopic examinations of Plasmodium during the malaria post-elimination stage.

Objective: To analyze the epidemiological characteristics of imported malaria cases in Fujian Province from 2014 to 2018, so as to provide scientific basis for the development of the control strategy for imported malaria., Methods: The epidemiological data of malaria cases in Fujian Province from 2014 to 2018 were retrieved from the Notifiable Disease Reporting System and Parasitic Disease Information Reporting System of Chinese Center for Disease Control and Prevention, and the classification, origin of infections, temporal distribution, spatial distribution, population distribution, reporting institutions and diagnosis were analyzed., Results: A total of 540 overseas imported malaria cases were reported in Fujian Province from 2014 to 2018, and all cases were laboratory-confirmed, including 398 cases with falciparum malaria, 88 cases with vivax malaria, 38 cases with ovale malaria, 14 cases with malariae malaria and 2 cases with mixed infections. There were 90.56% (489/540) of the imported malaria cases with infections in 27 African countries, 5.92% (32/540) with infections in 5 Asian countries and 3.52% (19/540) with infections in one Oceania country. There was no significant seasonal distribution of the cases, and the imported malaria cases were predominantly detected in Fuzhou City (80.00%, 432/540) and at ages of 20 to 49 years (81.48%, 440/540). Initial diagnosis was predominantly at the city-level medical institutions, and 77.96% (421/540) were diagnosed as malaria at the initial diagnosis institutions. The median duration from onset to initial diagnosis was 2 days and 70.19% (379/540) were diagnosed within 3 days of onset. The interval between initial diagnosis and definitive diagnosis was 0 day, with 85.37% (461/540) definitively diagnosed within 3 days of initial diagnosis., Conclusions: Overseas imported malaria is a continuous problem challenging the malaria elimination programme of Fujian Province. Improving the healthcare-seeking awareness and the diagnostic capability of healthcare workers, and intensifying the monitoring and management of malaria among overseas labors are strongly recommended.

Objective: To perform epidemiological survey and laboratory diagnosis of a Plasmodium ovale malaria case imported into Hefei City, so as to provide scientific evidence for the prevention and control of imported malaria in the future., Methods: The epidemiological history and clinical data of the imported malaria case were collected and analyzed., Results: The patient returned to China from Mozambique, and was admitted to the hospital due to repeated fever several months after returning to China. Rapid diagnostic test (RDT) suggested non- P. falciparum infection, and microscopy displayed normal or slightly swelled malaria parasite-infected erythrocytes, unapparent serrated changes, increased cytoplasm in large trophozoite with irregular morphology, and almost no vacuoles. qPCR assay revealed P. ovale infection., Conclusions: Clinical medical professionals should improve their awareness of malaria diagnosis in people with a history of living or working in overseas malaria-epidemic areas, and early and rational administration of antimalarials should be given promptly to prevent the spread of malaria epidemics.

Objective: To understand the laboratory technicians' abilities in blood slide making and reading in 10 prefectures of Yunnan Province which have passed the provincial malaria elimination evaluation, so as to provide the evidence for improving the malaria elimination surveillance and parasite examination., Methods: Thirty negative blood slides were randomly sampled to evaluate coating, dyeing and clean quality and reading results, and 4 laboratory technicians were sampled to evaluate their reading abilities from each prefecture level and its 2 subordinate counties (districts) respectively, and then the results were analyzed., Results: A total of 869 negative blood samples were evaluated. The coincidence rate was 100%. The proportions of good coating, dyeing and clean quality were 96.09%, 91.71% and 96.89%, respectively. Totally 576 blood slides were used to evaluate the reading ability. The number of correct reading was 505, and the correct rate was 87.67%. Among them, the Plasmodium vivax correct reading rate was 87.76%, the P. falciparum correct reading rate was 87.50%, and the correct reading rate of mixed infections was 47.62%. The laboratory technicians' ability to the mixed infections was significantly lower than the ability to the others ( χ 2 = 37.169, P < 0.05), however, in the laboratory technicians' abilities, there was no significant difference among the center (s) for disease control and prevention, general hospitals and township hospitals ( χ 2 = 2.782, P > 0.05), and the prefecture, county and township levels ( χ 2 = 0.358, P > 0.05) ., Conclusions: The 10 prefectures have passed the provincial evaluation in blood slide making and microscopic examination skill indicators requested, but the medical and public health institutions at all levels still should further improve their laboratory technicians' abilities in blood slide making and microscopic examination skills.

Objective: To analyze the results of samples testing of Jiangsu Provincial Malaria Diagnostic Reference Laboratory in 2017, so as to provide the evidence for improving the malaria diagnostic performance in this province., Methods: The samples of reported malaria cases in Jiangsu were collected by the provincial reference laboratory (PRL) in 2017. The microscopy and nucleic acid test were performed to confirm the infection of Plasmodium species of each case, while Plasmodium antigen tests (rapid diagnostic test, RDT) were performed as well. The detection results were analyzed among different areas and different species., Results: Totally 242 malaria cases were reported and the samples were collected by PRL in 2017. A total of 239 cases were confirmed Plasmodium infections, including 163 cases of Plasmodium falciparum infection, 21 cases of P. vivax infection, 11 cases of P. malariae infection, 43 cases of P. ovale infection, and 1 case of P. falciparum and P. ovale mixed-infection. The diagnostic coincidence rates of reported malaria case in 13 prefectures with districts were all > 80%, and the total coincidence rate was 88.8%. The species diagnostic coincidence rates of P. falciparum , P. vivax , P. malariae , and P. ovale were 98.8%, 57.1%, 63.6%, and 81.4% respectively, and the detection rates by RDT to those four species infections were 95.7%, 85.0%, 63.6% and 79.1% respectively., Conclusions: In 2017, the malaria diagnostic quality of medical technicians is generally high in Jiangsu Province. However, the diagnostic capacity is slightly different among different regions, and the ability to identify non- P. falciparum parasites remains to be improved. RDT is not ideal for the detection of non- P. falciparum infection. In the current stage of malaria elimination, the malaria diagnostic capacity of technicians in all the sectors should be strengthened and maintained.

Objective: To identify 10 imported cases of Plasmodium ovale wallikeri infection in Sichuan Province from January to April in 2018, and to analyze the P. ovale wallikeri infection status of 1 079 malaria cases reported in this area from 2013 to 2017., Methods: The 10 cases collected in 2018 were examined by microscopy, RDT, nested PCR and sequencing. Meanwhile, the retrospective detections of P. ovale wallikeri of the 1 079 blood samples from past 5 years were conducted by nested PCR using wallikeri -specific primers., Results: For the 10 cases, the microscopic examinations were all positive for P. ovale , of which 2 were mixed infection with P. falciparum , and the results of RDT were all positive for Plasmodium . Except for 2 cases of P. falciparum infection, the routine nested PCR showed negative results for rest of the samples. The nested PCR for the specific detection of P. ovale wallikeri showed the 10 cases were all positive, and the following sequencing confirmed that the 10 cases were all infected with P. ovale wallikeri . The retrospective tests discovered 2 cases both reported in 2017 and recorded as simple P. falciparum infection tuned out to be mixed infection with P. falciparum and P. ovale wallikeri ., Conclusions: This is the first time that imported P. ovale wallikeri infection is founded in Sichuan Province.

Objective: To investigate the malaria rapid diagnostic testing (RDT) - related knowledge, attitude, practice (KAP) of primary healthcare professionals in Jiangsu Province and analyze the corresponding influencing factors., Methods: Four cities in Jiangsu Province were selected as the study sites by the typical sampling method to conduct a survey for the RDT related KAP and work satisfaction of primary healthcare professionals, and the multiple logistic regression model was used to explore the relevant influencing factors., Results: Totally 1 150 questionnaires were issued and 949 valid questionnaires were collected with the recovery rate of 82.52%. The valid questionnaires included 453 questionnaires from laboratory technicians, 466 from clinicians, and 30 from malaria prevention and control workers. Totally 83.98% of the surveyed professionals had a low mastering level of essential RDT-related knowledge. A total of 52.17% of the surveyed laboratory technicians recognized that the application of RDT technology could effectively improve the current primary-level microscopy work, and the degree of recognition of RDT technological advantage in the laboratory technicians was higher than that in the clinicians. Totally 79.25% of the surveyed laboratory technicians regarded themselves to be capable of conducting the standardized RDT operation, and 84.55% of the surveyed clinicians regarded themselves to be capable of conducting the qualified malaria clinical diagnostic practice. The key influencing factors of RDT-related KAP of primary healthcare professionals included the laboratory technicians' gender, educational level, employer's institutional level, professional title, and working years, and the employer's institutional level of clinicians., Conclusions: The primary healthcare professionals in Jiangsu Province exhibita good acceptability towards RDT technology. However, their essential knowledge on RDT remains to be improved. Therefore, it is necessary to establish a specific training and educational system for primary healthcare professionals to better guarantee the advantageous impact of RDT technology on the consolidation of the malaria elimination work achievements.

Objective: To evaluate the implementation effect of the optimization strategy for the use and management of malaria rapid diagnostic testing (RDT) technology in Jiangsu Province, so as to provide the empirical evidence and suggestions for promoting the standardized use of RDT technology., Methods: Questionnaire surveys of primary-level health professionals' RDT-related knowledge, attitude, and practice (KAP) and work satisfaction were conducted in 4 pilot cities in Jiangsu Province before and after the intervention., Results: After the implementation of the intervention, 13.9% of surveyed laboratory technicians, 21.9% of surveyed clinicians and 4.1% of surveyed staff of the centers for disease control and prevention (CDCs) had significant improvements in RDT-related knowledge. About 10.9% of the surveyed laboratory technicians and 25.6% of the surveyed CDC staff improved their attitudes toward RDT technology. About 38.4% of the surveyed laboratory technicians and 10.0% of the surveyed clinicians improved the standardized use of RDT technology. All types of primary-level health professionals had high evaluation in the satisfaction and effectiveness of the optimization strategy. However, the evaluation of the surveyed clinicians was slightly lower than that of the laboratory technicians and CDC staff., Conclusions: The optimization strategy in this project can effectively improve the knowledge, attitude and behavior of all types of primary-level health professionals and help to promote the standardized use of RDT technology.

Objective: To understand the quality of production of blood slides and laboratory personnel's ability to microscopically examine Plasmodium at Jiangsu Province clinic inspection stations at all levels, so as to provide the evidence for the construction of malaria diagnostic laboratories and the evaluation of malaria elimination effect., Methods: After the reexamination of the negative blood slides of the examination stations of the malaria center in each county (district), the negative blood slides of the outpatient inspection station in the district and all the positive blood slides of the direct report of the network from 2011 to 2017, the staining and cleanliness of the blood smears, microscopic examination results and the coincidence rate of positive blood species were comprehensively analyzed., Results: A total of 19 109 checked blood samples were examined. The qualified rates of blood preparation, dyeing and cleanliness were 87.5%, 89.3% and 87.6%, respectively. The quality of reexamined blood slides in different years showed statistically significant difference (all P < 0.05), by using chi-square trend test, and there was a trend of increasing year by year. There was a significant difference in the quality of the reexamined blood slides among the different cities with districts ( P < 0.05). In addition, there were 1 860 blood samples from 2012 to 2017, and the total coincidence rate was 87.4% and the coincidence rate of positive blood smear examinations was 98.9%. The species coincidence rates of Plasmodium falciparum , Plasmodium vivax , Plasmodium malariae , Plasmodium ovale and mixed infection were 95.4%, 33.3%, 56.0%, 76.5% and 9.1%, respectively ( P < 0.05). The total coincidence rates of blood smear reexaminations in different years were 85.0%, 90.1%, 86.0%, 85.3%, 90.0% and 87.6% from 2012 to 2017, respectively, and the difference was not statistically significant ( P > 0.05)., Conclusions: The quality of blood slides at the primary clinic inspection stations in Jiangsu Province conforms to the standard established by the provincial malaria reference laboratory; however, the ability of Plasmodium species identification is insufficient and needs to be improved.

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 ( P (25), P (75)) 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.

Objective: To understand the epidemiological characteristics of imported malaria and the control and diagnostic capacities of the medical institutions in Wuhan City, so as to offer the evidence for formulating the surveillance and control strategies., Methods: From 2008 to 2017, the epidemiological data of imported malaria were collected. The information including gender, age, distribution, vocational background, positive rate of fever patients, and time of final diagnosis was analyzed with the descriptive statistic method. The Plasmodium species composition and infection source were analyzed by chi square test. The initial and confirmed diagnosis abilities of medical institutions were analyzed by rank sum test., Results: Totally, 424 imported malaria cases were reported, including 301 falciparum malaria cases (70.99%). The male population aged 20 to 49 years was the main morbidity group, and the incidence was not related to seasons. For the parasite species, there was a significant difference between African countries and Southeast Asian countries ( χ 2 = 205.83, P < 0.01). Plasmodium ovale and P. malariae were all imported from sub-Saharan Africa. For diagnostic capacities of the medical institutions at different levels, the initial diagnosis ( Z = -3.89, P < 0.01) and confirmed diagnosis ( χ < 0.01) were significantly different, respectively. The ability of malaria diagnosis was improved rapidly in the clinical laboratory after 2008 and achieved to 100% in 2010. The detection rate within 24 hours increased to at least 90% and the detection rate within 6 days decreased to 0 in 2016.2 = 53.88, P < 0.01) were significantly different, respectively. The ability of malaria diagnosis was improved rapidly in the clinical laboratory after 2008 and achieved to 100% in 2010. The detection rate within 24 hours increased to at least 90% and the detection rate within 6 days decreased to 0 in 2016., Conclusions: Although the medical institutions in Wuhan City have strong ability to treat imported malaria, they are still faced with a serious situation for malaria control and elimination. The capacity building should be strengthened constantly.

Objective: To analyze the working conditions and evaluate the effectiveness of blood smear examinations in fever patients after the start of national malaria elimination program (NMEP), and explore the suitable strategy for malaria diagnosis and surveillance in NMEP, so as to provide the evidence for the development and adaptation of malaria elimination strategies and measures in Jiangsu Province., Methods: The data of malaria epidemic situation reported by network, fever patients' blood test tables, and epidemiological surveys of malaria cases were collected and statistically analyzed by SPSS 16.0 in Jiangsu Province from 2010 to 2016., Results: A total of 2 367 cases of malaria cases were reported from 2010 to 2016. Among the 3 691 188 person-times of fever patients tested, there were 2 252 positives (0.06%). The number of blood tests of fever patients decreased from 742 900 in 2010 to 277 000 in 2016. At the same time, the positive rate increased from 0.04% in 2010 to 0.16% in 2016. The positive rate of blood tests of fever patients in 2016 was significantly higher than that in 2010 ( χ 2 = 161.61, P < 0.01). From 2010 to 2016 in Jiangsu province, the centers for disease control and prevention of cities and counties, that completed the blood review within 3 days, deleted 273 negative cases. In 2010, the centers for disease control and prevention of cities and counties deleted 61 negative cases, but in 2016, the centers deleted only 14 negative cases, and the negative rate of blood review in 2010 was significantly higher than that in 2016 ( χ 2 = 22.99, P < 0.01)., Conclusions: A large number of blood smear examinations have been tested in fever patients in Jiangsu Province. It not only conforms to the strong monitoring system requirements issued by World Health Organization (WHO) in malaria elimination, but also provides the evidence for no local malaria case in Jiangsu since 2012.

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 ( χ (2)=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 ( χ (2)=5.4, P =0.246). Capacity on 'correct diagnosis' seemed stronger at the CDC than at the hospital levels ( χ (2)=13.2, P =0.000; χ (2)=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.

Objective To investigate the epidemiological characteristics of imported malaria in Suining City from 2011 to 2016, so as to provide the evidence for improving the surveillance, risk assessment and control measures of imported malaria. Methods The malaria epidemic data in Suining City from 2011 to 2016 were collected from the reporting system, and statistical analyzed. Results Totally 71 malaria cases were reported in Suining City from 2011 to 2016, and they were all imported cases. Sixty cases (84.51%) were imported from Africa. There were cases reported throughout the year, and no obvious seasonal distribution characteristics. The median time from onset to seeing a doctor was 2 days; the median time from seeing a doctor to confirmed diagnosis of malaria was 4 days. Totally 63.38% of the cases were diagnosed of malaria in initially seeing a doctor. Forty-three cases were diagnosed by county and municipal medical institutions, accounting for 60.56%. All cases were laboratory confirmed cases, and they all received the standardized treatment. Conclusion The imported malaria epidemic situation in Suining City is still severe, and it is necessary to strengthen the management of floating population and professional training of medical staff so as to prevent the second malaria cases and deaths.

Objective: To analyze the results of malaria focus investigation and disposal in Tengchong City, Yunnan Province between 2015 and 2016, so as to provide evidences for interrupting potential malaria transmission., Methods: The malaria foci were investigated and disposed according to the malaria cases reported from "China Information System for Disease Control and Prevention" in Tengchong City between 2015 and 2016. The mosquitoes were captured by mosquito-lured lamp overnight to investigate the malaria vector in local. The peripheral blood samples were collected from the local residents with a febrile history in the foci within two weeks and the accompanists of the cases, and then the rapid malaria diagnosis tests were used to screen the malaria carriers., Results: Totally 145 imported malaria cases were reported in Tengchong City between 2015 and 2016, and the focus investigation and disposal rate within 7 d was 100% (145/145). A total of 16 186 mosquitoes of 12 species of Anopheles were captured, among which An. sinensis was the predominant, accounting for 64.31% (10 410/16 186), followed by An. kunmingensis and An. minimus , with the constituent ratios of 14.15% (2 291/16 186) and 11.66% (1 887/16 186), respectively. One person (1.96%, 1/51) in the 51 accompanists of the cases was positive in the malaria rapid diagnosis test., Conclusions: The malaria transmission vectors such as An. sinensis , An. kunmingensis , An. minimus etc. are still distributed in Tengchong City, and An. sinensis is the predominant species. Therefore, the relevant authorities should continue to strengthen the focus investigation and disposal to interrupt the potential introduced malaria transmission by imported cases in the future.

This paper reviews the computer vision and image analysis studies aiming at automated diagnosis or screening of malaria in microscope images of thin blood film smears. On the basis of introducing the background and significance of automatic detection technology, the existing detection technologies are summarized and divided into several steps, including image acquisition, pre-processing, morphological analysis, segmentation, count, and pattern classification components. Then, the principles and implementation methods of each step are given in detail. In addition, the promotion and application in automatic detection technology of thick blood film smears are put forwarded as questions worthy of study, and a perspective of the future work for realization of automated microscopy diagnosis of malaria is provided.

Objective To optimize the application of the nested PCR method for the detection of malaria according to the working practice, so as to improve the efficiency of malaria detection. Methods Premixing solution of PCR, internal primers for further amplification and new designed primers that aimed at two Plasmodium ovale subspecies were employed to optimize the reaction system, reaction condition and specific primers of P . ovale on basis of routine nested PCR. Then the specificity and the sensitivity of the optimized method were analyzed. The positive blood samples and examination samples of malaria were detected by the routine nested PCR and the optimized method simultaneously, and the detection results were compared and analyzed. Results The optimized method showed good specificity, and its sensitivity could reach the pg to fg level. The two methods were used to detect the same positive malarial blood samples simultaneously, the results indicated that the PCR products of the two methods had no significant difference, but the non-specific amplification reduced obviously and the detection rates of P . ovale subspecies improved, as well as the total specificity also increased through the use of the optimized method. The actual detection results of 111 cases of malarial blood samples showed that the sensitivity and specificity of the routine nested PCR were 94.57% and 86.96%, respectively, and those of the optimized method were both 93.48%, and there was no statistically significant difference between the two methods in the sensitivity ( P > 0.05), but there was a statistically significant difference between the two methods in the specificity ( P < 0.05). Conclusion The optimized PCR can improve the specificity without reducing the sensitivity on the basis of the routine nested PCR, it also can save the cost and increase the efficiency of malaria detection as less experiment links.

Objective: To compare the application effects of three methods, namely microscopic examination, antigen detection (RDT) and nucleic acid test (PCR) in malaria detection between municipal and districts/counties centers for disease control and prevention in Shanghai, and analyze the malaria detection ability of the laboratories in Shanghai., Methods: The blood smears, whole blood samples, case review confirmation records and case data of malaria cases and suspected cases in Shanghai from 2012 to 2015 were collected by Shanghai Municipal Center for Disease Control and Prevention, and the detection results were analyzed and compared., Results: A total of 212 samples with complete data were submitted by all districts (counties) in Shanghai from 2012 to 2015, the samples submitted by Jinshan Districts were the most (41.98%), and among the first diagnosis hospitals, those submitted by the tertiary hospitals were the most (82.07%). The submitted samples in the whole year were increased gradually from January to October. All the 212 samples were detected by three methods (the microscopic examination, RDT and PCR) in the laboratory of Shanghai Municipal Center for Disease Control and Prevention, and 167 were tested and confirmed comprehensively as positives, accounting for 78.77%, and 45 were confirmed as negatives, accounting for 21.23%. The samples were detected by the method of microscopy and domestic RDT in the laboratories of the centers for disease control and prevention at district/county level, totally 153 were tested as positives, accounting for 72.17%, 41 were unclassified, accounting for 19.34%, 53 were negative, accounting for 25.00%, and 6 were undetected, accounting for 2.83%. The coincidence of microscopic examination between the report hospitals and the centers for disease control and prevention at district/county level was 78.16%, and the coincidence between centers for disease control and prevention at district/county level and municipal level was 93.20%. The utilization rate of RDT in the laboratory of district/county level was 73.58%. The coincidence of RDT tests between those domestic and imported was 93.59%. Compared with the detection results by municipal center for disease control and prevention, 37 samples were misjudged by the laboratories of district/county level. Almost all (99.37%) of the confirmed malaria cases were imported overseas, including Africa (85.44%), Asia (13.92%) and America (0.63%)., Conclusions: The surveillance after malaria elimination in Shanghai should be carried out by combining with different detection methods and resource integration.

Objective: To introduce the application of the network training on clinicians' knowledge of malaria diagnosis and treatment in Yunnan Province, and evaluate its effect., Methods: Through the platform Yiboshi (www.yiboshi.com), the medical and health personnel at the units of provincial, prefectural, county levels and 25 townships of 25 border counties were trained on the knowledge of malaria diagnosis, treatment, prevention and control, and the effects were evaluated by examinations, questionnaires and interviews., Results: Totally 7 152 participants were trained, the average participation, completion and pass rates of the training were 95.26%, 98.55% and 97.30%, respectively. The trainees mainly learned malaria control knowledge from 3 aspects, namely policy of malaria elimination, malaria epidemiology, malaria diagnosis and treatment. The questionnaires showed that 95.94% of the participants considered that their theoretical and technical levels improved, 97.30% were interested in the training content, 93.24% recognized the arrangement of the training time was reasonable, and 91.89% were satisfied with the service of the platform., Conclusions: The network training on knowledge of malaria diagnosis and treatment in Yunnan Province has achieved good effect. The network training meets the need of training a large number of clinicians in the malaria elimination and post-elimination stage.

Objective: To understand the quality of malaria blood examinations in township-level hospitals, so as to provide the evidence for continuing the malaria blood examinations in the stage of post-malaria elimination., Methods: A total of 64 township hospitals were investigated and 640 negative malaria blood slides were scored individually according to 10 indicators in "Malaria Elimination Technical Scheme" in 2013 and 2014. The single and multiple indicators were calculated, and the work of blood examinations and situation of technicians were investigated. The data of malaria blood examinations and patient discovery in township hospitals of Nantong City were collected and analyzed during the period of 2011-2014., Results: For the single indicator, 29.5% of the thick blood films did not reach the standard, and 35.8% of thin blood films did not reach the standard. For the multiple indicators, blood slides with more than 4 indicators below the standard (poor quality) accounted for 32.5%. From malaria blood examinations and malaria situation, the number of slides was 194 635 during the period of 2011-2014, and there were no local vivax malaria casesin 4 consecutive years from 2011 to 2014, and local malaria has been effectively controlled in Nantong City. For health facilities where malaria patients initially presented, the township and village level accounted for 16.3%, and county and higher level accounted for 83.7%., Conclusions: The quality of malaria blood examinations in township level hospitals of Nantong City is not high and the microscopic examination has a relatively low efficiency in the discovery of malaria cases. A new model for malaria blood examinations needs to be further explored.

Objective: To investigate and analyze the capabilities of Plasmodium microscopic examinations in medical and health organizations in Dongxihu District, Wuhan City, so as to provide evidences for achieving the standard of malaria elimination and malaria control in the future., Methods: The basic information of the laboratorians and the hardware facilities in 15 microscopic examination stations of Plasmodium were collected and analyzed from 2010 to 2015. Meanwhile, the quality of making, dyeing, cleanliness of all the negatives blood smears were evaluated, and all the positive smears were re-checked in the district during the period above mentioned., Results: Totally, there were 28 laboratorians and 9 qualified microscopes in 15 microscopy stations in Dongxihu District. The age of the laboratorians in the first-level and third-level organizations was mainly from 40 to 50 years old, but the age of those in the second-level organizations was from 20 to 30 years old. The years for microscopic examination working of most of the laboratorians in the first-level and third-level organizations were more than 15 years, while the working years of those in the second-level organizations were mainly less than 10 years. The education level of the laboratorians in the first-level organization was mainly (50.00%) junior college, while the education levels of those in the second and third organizations were mainly bachelor. From 2010 to 2015, 8 561 blood smears were produced and 539 of them were reviewed, the coincidence rates of review were all 100%, and the average qualified rates of making, dyeing, and cleanliness of the negative blood smears were 82.08%, 79.92% and 83.33%, respectively. All the rates mentioned above in 2015 were higher than those in 2010 ( χ 2 = 26.45, 16.85, 13.93, all P ＜ 0.01)., Conclusions: The capability of microscopic examinations of Plasmodium has improved obviously in Dongxihu District, but the human resources construction and hardware input in this district should be improved, meanwhile, the check on the quality control of microscopic examinations of Plasmodium should be continued, so as to guarantee the sustainable and healthy development of malaria control work in this district.

Objective: To investigate the execution and effect of the prevention and control system for malaria eliminating in Huai'an City from 2010 to 2015, so as to provide the evidence for formulating and adjusting the strategy and measures for malaria elimination., Methods: The data of network malaria reports, blood tests of feverish patients, epidemiology investigation forms of case study of malaria patients in the report system, and the investigation and disposition forms of epidemic foci were collected and analyzed statistically., Results: From 2010 to 2015, there were 267 malaria cases in total in Huai'an City. Totally 303 016 feverish patients had blood tests, and 231 of them showed positive and the positive rate was 0.08%. The epidemiological case studies showed that all the patients were foreign imported cases except 22 local infected vivax malaria cases in 2010 and 2011. All the malaria cases were reported after diagnosis within 24 hours through the directly reported network, and the implementation rate was 100%. All the malaria cases had an epidemiological investigation within 3 days with 100% implementation rate, in which 261 (97.95%) cases were investigated within 2 days. All the cases had an epidemical investigation and disposition within 7 days with 100% implementation rate, in which 252 (94.38%) cases were completed within 5 days., Conclusions: The implementation rate of malaria elimination work mode has reached 100% in Huai'an City from 2010 to 2015, and there are no local infected cases in recent four years.

Objective: To further identify the high-risk population at malaria elimination phase, and to provide the scientific evident for targeted prevention and control measures, we compared the demographical feature and its change trend for malaria cases between malaria control stage and elimination stage in China., Methods: The data of individual case (probable and confirmed) and population during 2007-2014 were collected from China National Notifiable Infectious Disease Reporting Information System, and the data of epidemiological investigation for malaria case (imported and indigenous) during 2011-2014 were collected from China Parasite Disease Prevention and Control Information System. All of the data didn't include China's Hongkong, Macao, Taiwan and foreign cases. We described the demographic features of malaria cases, e.g. sex, age, occupation and mobility, to compare the differences of cases between malaria control stage (2007-2010) and the elimination phase (2011-2014)., Results: From 2007 to 2014, a total of 108 076 malaria cases were reported nationwide, which 13 355 cases were reported at the elimination stage. The proportion of male cases considerably increased from 65.1% (6 1625 cases) at the control stage to 91.4% (12 209 cases) at the elimination phase, with the cases aged 15-64 years among male cases dramatically rose from 74.3% (45 793 cases) to 97.2% (11 870 cases). In terms of occupation, the proportion of children and students decreased from 17.8% (16 891 cases) to 2.7% (356 cases), while the percentage of migrant workers, workers and other professional cases increased from 8.5% (8 031 cases), 3.5% (3 319 cases) and 3.6% (3 435 cases) to 13.1% (1 757 cases), 11.5% (1 534 cases) and 11.4% (1 517 cases), respectively. During the elimination stage,P. faliparium cases have higher proportion of male (96.4%, 7 179 cases) and adult aged 15-64 year (99.4%, 7 399 cases) than that of P. vivax cases , 83.9% (4 344 cases) and 90.3% (4 679 cases), respectively. Moreover, the proportion of imported cases rose from 63.6% (2 599 cases) in 2011 to 97.7% (2 854 cases) in 2014, and the proportion of the migrants in indigenous cases also showed an increasing trend from 13.5% (201 cases) in 2011 to 28.4% (19 cases) in 2014., Conclusion: Compared with the control stage, great changes of demographical characteristics of malaria cases occurred at the elimination stage. Male adults aged 15-64 year-old, imported cases and domestic migrants were the high-risk population for targeted control and prevention at the malaria elimination stage.

Objective: To evaluate the Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan -pLDH) for detecting Plasmodium ovale and analyze the influence of parasitaemia, concentration and polymorphism of pLDH on the performances., Methods: A total of 100 blood samples from P. ovale patients confirmed by PCR were detected with the Wondfo Rapid Diagnostic Kit according to the manufacturers'instructions. The parasitaemia was determined by the microscopic examination. The concentration of pLDH was measured by ELISA tests. The LDH gene of P. ovale was amplified by PCR and sequenced. The influence of these three factors on the positive rate was analyzed., Results: The overall positive rate of Wondfo Rapid Diagnostic Kit was 70.0% (70/100). The positive rate was 27.3% for the samples with parasitaemia ≤ 500 parasites/μl and reached 75.0%-75.4% when parasitaemia > 500 parasites/μl. The positive rate was 6.7% for samples with a low pLDH concentration ( A values ≤ 0.100) and reached 95.1%-100% at a high pLDH concentration ( A values > 0.100). The results of sequence analysis indicated that all the samples could be divided into 2 types, P. o. curtisi and P. o. wallikeri . The gene homology of LDH between 2 types was 97%. There were 24 single nucleotide polymorphism (s) (SNPs) between 2 types, while only 3 SNPs were non-synonymous mutations. The homology of LDH amino acid sequences between 2 types was 99%; only 3 amino acids were different. The positive rates for P. o. curtisi and P. o. wallikeri were 73.1% (38/52) and 66.7% (32/48) respectively; there was no statistically significant difference ( P > 0.05)., Conclusions: The Wondfo Rapid Diagnostic Kit (Pf-LDH/Pan-pLDH) performs better than most of the similar products for the detection of P. ovale , and the positive rates are closely related to the parasitaemia and concentration of pLDH, while no related to the polymorphism of pLDH gene.

Objective: To grasp the malaria epidemic situation in Changzhou City from 2010 to 2014, so as to provide the evidence for formulating and adjusting malaria control strategies and measures., Methods: The epidemiological data of malaria cases in the special report system from 2010 to 2014 were collected, and the malaria epidemic situation and the diagnosis and treatment of malaria patients were analyzed., Results: There were 132 malaria cases reported in Changzhou City from 2010 to 2014, with a decrease of 27.47% compared to 182 cases from 2005 to 2009. Among the 132 cases, 2 cases were local infected cases and the remaining 130 cases were imported cases. Four cases were clinically diagnosed and 128 cases were laboratory confirmed, with 97 cases of malignant malaria, 14 cases of vivax malaria, 13 cases of ovale malaria, and 4 cases of quartan malaria. The 132 cases were distributed in five districts：56 cases in Jintan City, 51 cases in Liyang City, 19 cases in Tianning District, 3 cases in Wujin District, and 3 cases in Xinbei District. The median duration between the onset and treatment of the disease was 2 days, and the median duration between the diagnosis and treatment was 1 day. The diagnosing units were concentrated on the county-level disease control agencies, and medical institutions at county and municipal levels, accounting for 92.42% (122/132). From 2011 to 2014, there were no local malaria cases., Conclusions: From 2012 to 2014, there have been no local malaria cases in Changzhou City, and the goal of eliminating malaria has been achieved basically. However, there are still many imported malaria cases, and the infected species are diverse. Therefore, imported malaria is still the key of malaria prevention and control.

Objective: To diagnose the first imported case of Plasmodium ovale infection by laboratory detection., Methods: The epidemiological data and blood samples of the case were collected, and the samples were detected by the microscopic examination, rapid diagnostic test (RDT) and nested PCR., Results: The patient was a construction worker backing from Congo, Africa. He experienced the symptoms of irregular fever and weakness one month after returning in Lingyang Town, Junxian County. The results of RDT only suggested no- Plasmodium falciparum infection. Under the microscope, it was seen that the infected RBC were obviously disfigured and in irregular shape, the ring forms were thick and big, and also thick granulas in big trophozoite stage and schizont stage were found. The results of PCR showed that the size of amplified product was about 800 bp, which was conformed to that of P. ovale ., Conclusions: Though microscopic examination is the golden standard for malaria diagnosis, as P. ovale is difficult to be identified under microscope, the microscopic method combined with PCR test can be used for definite diagnosis.

Objective: To understand the epidemic situation and influencing factors of malaria in Jiangsu Province and grasp the regularity and trend of the epidemic., Methods: According to the provincial malaria transmission situation and characteristics, Sihong County of Suqian City, which had more original cases, and Baoying County of Yangzhou City, which had more import cases, were chosen as the malaria surveillance sentinels at the state level; six counties, Yixing County of Wuxi City, Suining County of Xuzhou City, Wujin District of Changzhou City, Haian county of Nantong City, Ganyu County of Lianyugang City, and Xuyi county of Huaian City were chosen as the malaria surveillance sentinels at the provincial level. The data of basic status, blood tests of feverish patients, case studies of malaria patients, investigations and disposals of epidemic focuses and others were collected and analyzed., Results: There were 92,484 blood test samples from feverish patients in the eight surveillance sentinels in 2014, and the average rate of blood tests was 1.15%. Totally 61 cases were plasmodium positive, and the positive rata was 0.07%. All of the 61 cases were foreign imported patients diagnosed by laboratory. After the direct network reporting, the review of the blood slides and epidemiological individual surveys were finished in 3 days, and the investigations and disposals of epidemic focuses were finished in 7 days. The epidemiological individual surveys of these 61 cases showed that 37.70% (23/61) of the first-time consultancy was mainly in the county level CDC, and 50.82% (31/61) in county level medical organizations. The making definite diagnosis of malaria also focused on the county level, 45.90% (28/61) in county level CDC and 47.10% (29/61) in county level medical organizations. The definite diagnostic rate of fist-time consultancy was 90.16% (55/61). Totally 48 malaria patients had been sent to abroad by their companies, and 34 had fellow crew., Conclusions: The malaria surveillance sentinels in Jiangsu Province play a good role on the surveillance function of malaria, and effectively promote the elimination of malaria in whole province. In the future, the malaria surveillance should establish a multi-sectoral cooperation and investigation mechanism, and strengthen the screening of the high-risk population and health education.

Objective: To analyze the surveillance data of malaria in Tengchong County of Yunnan Province in 2013, so as to provide the evidence for carrying out the malaria elimination in the future., Methods: The data of epidemic situation and surveillance of malaria in Tengchong County in 2013 were collected and analyzed for the prevalence state as well as and the monitoring indicators including the blood examination of fever patients of unknown origin, initiative detection of cases, under-reporting survey, sentinel surveillance and species and density investigation of Anopheles mosquitoes., Results: Totally 138 malaria cases were reported in Tengchong County in 2013, among which 118 cases were infected with Plasmodium vivax and 20 cases with P. falciparum, and all the reported cases were imported. The completion rates of blood examinations, case reports and case investigations all reached 100%. A total of 57 cases were involved in initiative detection, but no positive cases were found. The twice under-reporting of malaria case surveys were conducted and 1 case had been under-reported. The sentinel surveillance was carried out both in the domestic and overseas sites at the same time to detect the suspected malaria cases, 172 cases were screened totally, and 15 ones were detected as positives. Totally 528 returnees were screened, and there were no positive case found. A. sinensis and A. liangshanensis were the dominant species, followed by A. minimus, A. maculatus and others., Conclusions: The malaria epidemic situation is stable in Tengchong County in 2013, and all the work in surveillance has been conducted successfully, but there still exist some difficulties in the process of malaria elimination. The local health departments should further strengthen the surveillance on imported cases and the management on migrant population as well as the capability building for health workers in malaria control in the future.

Objective: To analyze the regular surveillance and evaluate its effect during the elimination stage of malaria in Jiangsu Province from 2012 to 2014 and discuss the best way for surveillance and management, so as to provide the evidence for formulating and adjusting the strategy and methods for malaria elimination., Method: The data of network malaria reports, blood tests of feverish patients, epidemiology investigation forms of case study of malaria patients in the report system, and investigation and disposition forms of epidemic regions were collected and analyzed statistically., Results: From 2012 to 2014, there were 894 malaria cases in total. Totally 1 625 034 feverish patients had blood tests, and 892 of them showed positive and the positive rate was 0.05%. The epidemiological case study showed that all the patients were foreign infection import patients except one was foreign import cases by blood transfusion. These cases were mainly distributed in Nantong City (125 cases), Yangzhou City (123 cases), Huai'an City (112 cases), Lianyungang City (111 cases) and Taizhou City (88 cases), and the total cases of the five cities accounted for 62.53% (559/894) of total cases of entire province. These cases were mainly diagnosed in country level CDC and medical organizations, and city level medical organizations. These units accounted for 87.02% of all the diagnostic organizations (778/894)., Conclusions: From 2012 to 2014, there are no reports of local malaria infection cases in Jiangsu Province, meaning the preliminary realization of eliminating malaria. However, we still should strengthen the regular surveillance and treatment of import malaria cases.

Objective: To understand the malaria epidemic situation in Huai'an City in 2014, so as to provide the evidence for formulating and adjusting effective strategies and measures to eliminate malaria., Methods: The reported malaria cases from the Internet Reporting System and the epidemiological data of malaria of Huai'an City in 2014 were collected and analyzed statistically., Results: A total of 56 malaria cases were reported in Huai'an City in 2014 with the incidence of 0.12/10,000, and 43.59% of increasing rate compared with the previous year (39 cases). All these cases were imported from African countries. There were 50 cases of falciparum malaria, 4 cases of ovale malaria, 1 case of quartan malaria and 1 case of mixed infections. All the patients were male and aged 24-59 years. Totally 96.43% of the patients (54 cases) were peasants and 69.64% of them (39 cases) only received junior high school education. The malaria cases were mainly distributed in Huai'an District (32 cases), Xuyi County (8 cases) and Huaiyin District (6 cases), totally accounting for 82.14%. There was no significant seasonal variation in the reporting time of the cases. The median time from onset to seeing a doctor was 2 days and the median time from seeing a doctor to being diagnosed was 1 day. Totally 16.67% of the patients (8 cases) were misdiagnosed when they first visited a doctor. All the patients were laboratory confirmed and all of them received the standard treatment after diagnosis., Conclusions: There have been no local malaria cases reported from Huai'an City in the last three years. However, the situation of imported malaria is more serious and the species of infected Plasmodium are more diverse. Therefore, to accomplish the aim of malaria elimination in the whole city, it is necessary to further strengthen the multi-sectoral cooperation, health education, malaria screening and professional training to control the imported malaria.

Objective: To standardize the malaria smear preparations of febrile patients in Chenzhou Prefecture, Hunan Province, so as to provide the technical support for malaria elimination., Methods: According to the Technical Solutions to Eliminate Malaria (2011 edition) , the blood smear preparations of febrile patients from each county, included more than 3% negatives and all positives, were reviewed monthly in 2014. The quality of blood smear manufacture, dyeing, cleanliness and results was reviewed by malaria microscopic examination experts. The data were analyzed with the descriptive epidemiological methods., Results: Totally 231 blood smears were reviewed in 2014 with a reviewed rate of 6.91%. The blood smear production qualified rate was 80.52%, the dyeing pass rate was 84.42%, the cleanliness pass rate was 86.58%, and there were no false detections and no leak detections. The highest blood smear production qualified rate, dyeing pass rate and cleanliness pass rate were found in Guiyang County and Linwu County, with all the rates of 100% respectively. The lowest blood smear production qualified rate and cleanliness pass rate were found in Yizhang County, with the rates of 52.94 % and 70.59% respectively. The lowest blood smear dyeing pass rate was found in Yongxing County with the rate of 63.64%. There were statistically significant differences between Guiyang County and Yizhang County in the production qualified rates and cleanliness pass rates (χ2 = 18.60, 9.73, both P < 0.01). There was a statistically significant difference between Guiyang County and Yongxing County in the dyeing pass rates (χ2 = 11.43, P < 0.01)., Conclusion: Through the review of blood smears, the problems will be timely discovered. Therefore, the blood smear quality should improve, which is helpful for achieving the goal of malaria elimination.

Objective: To develop a method for DNA extraction from malaria parasites on preserved blood smears, to provide basis for research on malaria genetic traceability., Methods: The improved DNA extraction kit (QIAamp DNA Mini Kit) was used to extract plasmodium DNA from 41 giemsa-stained blood smears, and the extraction was compared with that using the Chelex-100 and Na(2)HPO(4) methods. Nested PCR was used to amplify small subunit ribosomal RNA to identify Plasmodium parasite. The PCR products underwent sequencing and sequence alignment, to analyze the difference in PCR positive rates between blood smears prepared in the 1980s and in recent 10 years, between blood smears with and without deoil/decoloration, and between blood smears with different qualities., Results: The total PCR positive rate for the improved kit method was 70.7% (29/41). The PCR positive rate for blood smears prepared in the 1980s and in recent 10 years was 78.6% (11/14) and 66.7% (18/27) respectively, with no significant difference (W=0.63, P>0.05). The PCR positive rate for blood smears with and with- out deoil/decoloration was 62.5% (15/24) and 82.4% (14/17) respectively, also with no significant difference (χ(2)= 1.89, P>0.05). However, the PCR positive rate was significantly higher in blood smears with high quality [93.3% (28/30)] than those with low quality [9.1%(1/1l)](=27.59, P<0.01). Sequence alignment showed that the PCR products were consistent with the target DNA fragments. However, DNA extracted using the Chelex-100 and Na(2)HPO(4) methods showed negative PCR results., Conclusions: DNA extracted from blood smears prepared in the 1980s using the improved Kit (QIAamp DNA Mini Kit) shows a high PCR positive rate. Besides, blood smear staining and use of oil for microscopic examination do not affect DNA extraction.