Objective To compare the characteristics of dengue fever epidemic between Ruili and Jinghong in Yunnan province, China, and to provide a basis for the precise prevention and control of dengue fever in the two cities. Methods The information about local and imported cases of dengue fever was collected in Ruili and Jinghong, Yunnan province from 2006 to 2018, and SPSS 22.0 and R 3.6.2 softwares were used for statistical analysis. Results From 2006 to 2018, Ruili reported a total of 3 022 cases of dengue fever, of which 59.13% were imported cases (59.00% were imported from abroad) and 40.87% were local cases. Among 3 923 cases in Jinghong, imported cases accounted for 3.08% (3.01% were imported from abroad), and local cases accounted for 96.92%. The number of imported cases in Ruili was 14.77 times that in Jinghong. The imported cases in both cities were mainly 16 to 45 years old, and mostly from Southeast Asian countries, especially Myanmar. There were statistically significant differences in sex, age, occupation, and the interval from disease onset to diagnosis of either imported or local cases between the two cities (χ²=7.529, 14.169, and 201.686, all P<0.05; χ²=18.342, 43.723, and 557.247, all P<0.001; Mann-Whitney U=75 032.500 and 2 116 735.000, both P<0.001). Conclusion Most of cases of dengue fever are imported in Ruili but local in Jinghong. Authorities of the two cities should strengthen the surveillance of cases of dengue fever, promptly detect, isolate, and treat cases, and take measures to deal with the epidemic in time.

Objective To analyze the epidemiological characteristics of Japanese encephalitis (JE) in eight provinces and municipalities of northern China (Gansu, Ningxia Hui Autonomous Region, Shaanxi, Shanxi, Hebei, Beijing, Tianjin, and Liaoning) from 2005 to 2019, to investigate the pattern of the development of JE, and to provide a scientific basis for effective prevention and control of JE. Methods A descriptive epidemiological analysis was performed for JE cases in the above eight northern provinces and municipalities from 2005 to 2019, which were collected through the China Information System for Disease Control and Prevention and JE Surveillance Information Reporting and Management System. Results From 2005 to 2019, the mean annual incidence rate of JE was 0.14/100 000 and there were 390 deaths, with a case fatality rate of 7.25%. The distribution of JE expanded from 157 counties/districts in 2005 to 254 counties/districts in 2018. The number of cases from August to September accounted for 81.26% of all cases, and August and September were the peak periods for the onset of JE. The proportion of patients aged 0-14 years decreased from 54.55% in 2005 to 3.96% in 2019, and the proportion of patients aged ≥ 15 years increased from 45.18% in 2005 to 96.03% in 2019 ( χ ² _trend=998.524, P<0.001). Farmers, preschool and scattered children, and students accounted for 58.76%, 14.81%, and 12.38%, respectively. The proportion of farmers increased from 37.19% in 2005 to 79.21% in 2019. Conclusion The distribution of JE has expanded in the eight provinces and municipalities of northern China, and age distribution tilts toward high age. As for occupational composition, there is an increase in the proportion of farmers.

Objective To survey dynamically the density of vector Aedes in the core area, warning area, and observing area, to evaluate the risk of dengue transmission based on the surveillance results, and to adopt control measures against vector Aedes. Methods From late August to late October, 2018, urban residential areas, rural residential areas, and nurseries or medical institutions were selected as surveillance habitats, and the densities of Aedes larvae in the observing area were surveyed by Breteau index (BI) every ten days; in the core area and warning area, communities with dengue cases received grid management, and the densities of vector Aedes were carried out emergency surveillance by BI and double bed net trap. Results The mean BI of observing area was 23.06. The mean BI varied widely in different counties (cities or districts). Ninghai county had the highest BI of 50.42, whereas Haishu district had the lowest BI of 4.81. The mean BI of urban areas (13.57) was significantly lower than that of suburban areas (33.84). By late October, the mean BI of the whole city declined to 14.09, especially in Haishu district (1.77) and Jiangbei district (3.54) (below the safety threshold, BI<5). The mean BI and bed net trap index in the core area and warning area were 3.27 and 1.02 mosquitoes per net per hour, respectively. Both BI and bed net trap index quickly declined and then leveled off after emergency investigation and settlement, and were below the safety thresholds after 2.61 and 1.57 days. Conclusion Based on the reasonable emergency surveillance of vector, combined with powerful prevention and control measures, the densities of dengue vectors can be effectively reduced to control the risk of dengue transmission.

Objective To understand the present situation and trend of resistance in Musca domestica to four types of insecticides in Dongli district of Tianjin in recent years, and to provide a scientific basis for better use of insecticides. Methods Musca domesticas were collected outdoors in Dongli district during 2014 to 2017, the resistance of M. domestica to β-cypermethrin, deltamethrin, permethrin and propoxur were determined by topical application method, and data were analyzed by SPSS 19.0 software for LD ₅₀ and its confidential intervals ( CI). The regression equation was established to evaluate resistance development trend. Results The resistance ratios of M. domestica in Dongli district during 2014 to 2017 to β-Cypermethrin, deltamethrin, permethrin and propoxur were 1.75-3.75, 1.00-15.00, 36.75-40.00, and 3.41-29.50 fold, respectively. Musca domestica in Dongli district has developed severe resistance to permethrin and propoxur, moderate to deltamethrin, and mild even susceptible to β-Cypermethrin. Conclusion Musca domestica in Dongli district of Tianjin has developed different degrees of resistance to four types of insecticides and the trend was upward. It is suggested that insecticides should be used scientifically based on the susceptibility monitoring, in order to prevent and delay the development of resistance.

Objective To know the habitats and population distribution of the main vectors for the Water Sport Event in the 13 ^th China National Games, to provide basis of making scientific control measures. Methods According to The protocol of vector surveillance in Tianjin, developing the survey of the habitats and population distribution of the main vectors in the Water Sport Event from June to July 2017. Results The main vectors in the Water Sport Event in the 13 ^th National Games were mosquitoes and rodents. There was potential risk of mosquito breeding in river bank, landscape belt and demolition zones. The mosquito densities were 38.50 and 43.96 mosquitoes per light trap per hour. The reed marshes and small-scale pond provided the breeding places for mosquito larvae, the indexes were 12.00 and 9.17 larvae per dip. Rodents prevailed at 2.15% and 1.54% capture rate in the demolition zones. Conclusion The careful surveillance of the main vectors provided basis for making effective integrated control measures, and it is the key factor of successful vector control for the Water Sport Event in the 13 ^th National Games in China.

Objective To identify Plasmodium falciparum chloroquine resistant transporter ( Pfcrt)point mutations and P. falciparum multidrug resistance 1 ( pfmdr1)and their correlation in imported P. falciparum. Methods Blood samples were collected from returnees infected with P. falciparum in endemic areas of Africa and Southeast Asia during 2009-2016 in Wuhan city. The Pfcrt76 gene and pfmdr1 gene were amplified by nested PCR, and the products were digested by restriction endonuclease ApoⅠ, AseⅠ and EcoRv. The mutation rate was analyzed. Results A total of 232 patients with falciparum malaria were involved in the study. The mutation rates for Pfcrt76, pfmdr1 loci 86, 1042, and 1246 were 55.2%, 17.2%, 5.2%, and 8.6% respectively, the total mutation rate for pfmdr1 was 26.3%. The mutation rates for pfmdr1 loci 86, 1042, 1246 and pfmdr1 were 28.6%, 3.8%, 12.4%, and 36.2%, respectively in the samples with mutation in Pfcrt76, but 10.4%, 2.1%, 7.3%, and 17.7%, respectively in the samples without mutation in Pfcrt76 from Africa. The linkage disequilibrium analysis between symptoms and the mutations of Pfcrt76, pfmdr186, 1042, and 1246 were conducted, and the value of D'and r ² were 0.230 and 0.018, 0.290 and 0.004, 0.996 and 0.012, 0.150 and 0.035, respectively, for each mutation. Conclusion The pfmdr1 mutation sites between Africa and Southeast Asia have statistically significant differences. Pfcrt76 was positively correlated with pfmdr1 mutation and pfmdr186 point mutation.

Objective To establish the Ningbo city vector biology information platform based on the geographic information system (GIS). Methods According to the vector surveillance plan of Zhejiang province, the surveillance points were set up and the data were reported. Taking ArcGIS 10.2 as the foundation of the system, based on the Java integrated environment, the GIS module was set up to integrate the control platform system using ArcGIS core components. The data transfer and performance between the GIS component and the database program was achieved by the service function published by ArcGIS. Results The main function of the GIS module includes the establishment and management of the database, the statistical graph, the bidirectional query and retrieval of the graph and attributes data, and the statistical analysis of the data. Conclusion The establishment of the GIS based vector biology information platform in Ningbo city can realize the information management for vector biology, and provide scientific basis for vector-borne disease control.

Objective To investigate hibernating Aedes albopictus in Ningbo city for local mosquito and diseases control. Methods The investigation was carried out from February to March in 2016. Collecting deposition including water and mud from 11 countries, 5 kinds of habitat, 4 kinds of containers and then were incubated in laboratory. Results A total of 1 528 valid samples were collected and the Ae. albopictus positive rate was 23.36%. The Ae. albopictus positive rate of used tire, temporary water container and vegetation water containers were higher than fixed water containers. The Ae. albopictus positive rates of mountains and peninsular were higher than that of plain. By logistic regression analysis, the Ae. albopictus positive rates of tire, temporary water container and vegetation water containers were 2.623 times (95%CI:1.698-4.052), 1.968 times (95%CI:1.280-3.027), and 1.759 times (95%CI:1.046-2.958) higher than fixed water containers, respectively. The Ae. albopictus positive rates of mountains and peninsular were 1.507 times (95%CI:1.034-2.197), and 1.530 times (95%CI:1.015-2.306) higher than plain, respectively. Conclusion The Ae. albopictus positive rate of Ningbo city was high. Doing a good job in eliminating Ae. albopictus larvae and eggs in early spring, actively, can control the mosquito density throughout the year, effectively.

Objective To get an insight into the species of biological vectors and their seasonal fluctuation in Dongli district, Tianjin, providing a scientific basis for the control of the hazards of biological vectors. Methods The national biological vector surveillance program was followed for the selection of the surveillance sites, with the night trapping method, trapping lamp method, cage trap method and adhesive killing method used to investigate the density of the rats, mosquitoes, flies and cockroaches. Results It was found that Rattus norvegicus was the dominant species in Dongli district, accounting for 79.55% of the total, followed by Mus musculus, accounting for 20.45%. The rat density peaked in August, followed in May. The density of mosquitoes varied with different habitats with the highest density seen in the livestock shed accounting for 19.52/(lights·h), followed by farmer houses, green parks, hospitals and residential areas. Musca domestica was the dominant fly species, accounting for 58.40% of the total number of the captured. The brown-tail Boettcherisca peregrina and M. sorbes accounted for 20.41% and 7.13%, respectively, the habitats listed in a descending order in terms of the number of flies captured were farmers’houses> markets>residential>green belt. The dominant species of cockroach was Blattella germanica, accounting for 99.81% of the total number of the captured, with its density and infestation rates highest in the farmers’market. Conclusion Of all the surveillance sites investigated, the highest rat density is seen in catering industry, the highest rat density of mosquitoes in cattle sheds and the highest density of flies and cockroaches in farmers’markets. Prevention and control of the vectors should be taken seriously.

Objective To establish subtracted cDNA libraries using the suppression subtractive hybridization (SSH) technique based on the livers of New Zealand white rabbits infected with Schistosoma japonicum before and after praziquantel treatment, providing the basis for screening the drug-response molecular target during the therapy. Methods New Zealand white rabbits infected with S. japonicum were assigned to two groups to receive praziquantel medication or blank, respectively. The SSH technique was conducted to build the forward and reverse subtracted cDNA libraries using the PCR-Select cDNA Subtraction kit. The differentially expressed ESTs were screened and positive clones were isolated from the libraries for bioinformatic analysis．Results Thirty-nine positive clones were isolated from two subtracted cDNA libraries, including 22 from the forward library and 17 from the reverse library. The analysis revealed that the ESTs were mainly responsible for coding enzymes and proteins associated with protein synthesis and degradation. Conclusion The subtracted cDNA libraries before and after praziquantel treatment for S. japonicum were successfully constructed, laying a solid foundation for further research into the molecular mechanisms of this medication therapy.

【Abstract】 Objective To know the species composition and seasonal change of pest flies in the farm produce trade markets, the external environment of restaurants, the public green belts and the residential areas in Ningbo city, and to provide the theoretical basis for the establishment of flies control strategy. Methods The adult flies were termly captured by cage with attractants and were identified and counted, and then calculating its density and constituent ratio.  Results The dominant species in four kinds of habitats were Musca domestica,  Chrysomyia megacephala  and  Lucilia cuprina,  but  M.domestica, C.megacephala and L.sericata in the farm produce trade markets, C.megacephala, M.domestica and L.sericata in the external environment   of   restaurants,   C.megacephala,   L.cuprina    and   M.domestica   in   the   public  green  belts,  and  M.domestica, C.megacephala and L.cuprina in the residential areas． Among flies captured, the appearance of M.domestica was the earliest, and its disappearance was the latest. However, the activity period of other flies was all less than 8 months each year, and the peak was usually from May to October.  Conclusion In the  control  of  flies,  the  life  habit  and  the  occurrence  rule  of M.domestica, Chrysomyia megacephala, L.sericata, and L.cuprina should be taken into account, and the key control period was from May to October.