Objective To analyze the Aedes surveillance data of dengue fever outbreak in urban Ningbo, Zhejiang province, China, and compare the effects of three vector control measure packages on the density of adult Aedes mosquitoes and Breteau index (BI), and to provide a basis for formulating emergency management of dengue in the locality. Methods Three different comprehensive measure packages were used to control mosquitoes:measure package 1 included ultra-low-volume spraying, thermal fogging, slow-release agent, and environmental management; measure package 2 included ultra-low- volume spraying, residual spraying, slow-release agent, and environmental management; measure package 3 combined the 5 methods mentioned in measure package 1 and 2. The decline rate with net trap index and control effect with BI were compared between the 3 measure packages using ANOVA or rank sum test and curve fitting, respectively. Results There were no significant differences in the decline rate with net trap index between the 3 measure packages on the first day (0.24±0.41, 0.20±0.64, 0.47±0.17; F=1.659, P=0.206) and second day (0.27±0.27, 0.55±0.27, 0.47±0.39; F=2.236, P=0.123); significant difference was found on the third day (0.31±0.57, 0.44±0.46, 0.77±0.27; F=3.397, P=0.046), and measure package 3 showed the highest decline rate. Time to safety threshold of BI (decrease to less than 5) for the 3 measure packages were 3.58, 3.36, and 2.62 d, respectively, with the shortest time for measure package 3. Conclusion Combination of ultra-low-volume spraying, thermal fogging, residual spraying, slow-release agent, and environmental management works for Aedes control in the emergency response of the dengue fever outbreak.

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 investigate the density and seasonal fluctuation trend of Aedes mosquitoes in Ningbo, China, and to provide a reference for the prevention and control of Aedes-borne diseases. Methods From April to November, 2017, the double-layered mosquito net (DLMN) method and the Breteau index (BI) method were used to survey the adults and larvae of Aedes mosquitoes in residential areas, parks, and waste stations in the counties (cities and districts) of Ningbo. And the seasonal fluctuation trends of Aedes mosquitoes were analyzed. Results The mean net trap index of Aedes mosquitoes in Ningbo was 1.18 mosquitoes/net·hour, and the index was highest in September. Among all the above-mentioned habitats, the parks had the highest net trap index (1.23 mosquitoes/net·hour). The mean BI in surveillance area was 15.11, and the BI was highest (23.63) in September. Conclusion The risk of transmission of Aedes-borne diseases in Ningbo is high from June to September. Regarding the Aedes vector surveillance, using both DLMN and BI methods simultaneous can better assess the risk of dengue transmission.

Dengue viruses could be transmitted vertically by vector Aedes mosquitoes, and survive a long time in diapausing eggs and then disseminate with these eggs. Therefore, vertical transmission has been suggested to be a possible mechanism for the persistence of dengue fever viruses during adverse conditions for horizontal transmission. However, it is unclear how widespread it is in nature, and its importance in the epidemiology of this disease is still debated. Here, we review the literature on the relationships of viral vertical transmission and Aedes diapause, to discuss how dengue fever viruses survive during cold winter or inter-epidemic phase and then transit to next epidemic season. This review will provide some references for the research on dengue fever monitoring and controlling.

Objective Master the population composition and seasonal abundance of the flies to provide scientific evidences for formulating vector control strategies by the government. Methods Monitoring the populations of flies from March to December in 2006-2016 in different environments with brown sugar and vinegar, to analyze the density and composition of flies. Results Chrysomya megacephala, Musca domestica, Lucilia sericata, and L. cuprina were the predominant species of flies in Ningbo area, which accounted for 80.71% of the total flies. The active phase of flies was from May to October each year, the peak of fly density occurred in June (23.67 flies/cage), but the peaks in different years were inconsistent and the latest appeared in September. The density of flies decreased obviously from 2012, density of M. domestica exceeded Chrysomya megacephala since 2013. The seasonal abundance of flies showed bimodal distribution in the green belts and residential areas, the peaks appeared in July and September, and in June and September, respectively. The density of flies in external environments associated with food processing facilities presented a unimodal distribution with peak in June. The peak of fly populations in market places was not prominent, density was higher during May to September than other months. Conclusion The density of flies generally showed a decreasing trend, but the control efficacy of house flies was lower than that of other flies. We should pay more attention to technical training of flies control persons, and to advocate integrated management of predominant fly species in key habitats to reduce the occurrence of flies-transmitted diseases.

Objective To explore a new vector control training model suitable to the grassroots, improving the convenience, professionalism and effectiveness of training. Methods According to different training objectives to create knowledge base, using internet technology and Ningbo Vector Management Platform, distance education was achieved for knowledge inquiries, explanations and training effect assessment. Results The establishment of knowledge base provides a reference for solving the daily problems which improves the efficiency of problem solving. This training model has simplified training procedures and improved training results, by separating examination and teaching to ensure a fair assessment. We organized 6 times centralized exams in 2017, with an average score increased from 54 to 73. Conclusion The new training model has realized the distance education and assessment of knowledge which can be trained around the clock, this is a great improvement of professionalism and ability of grass-roots vector control personnel.

Objective Given that an outbreak of dengue was occurring in neighboring city of Ningbo, to reduce the risk of local transmission caused by imported cases, to strengthen monitoring of Aedes albopictus and to provide a basis for the control of dengue vector in Ningbo city. Methods The densities of Ae. albopictus larvae in residential quarters of cities or countryside and nurseries in 11 counties, cities or regions of Ningbo were monitored by Breteau index(BI) method from 2017-09-11 to 2017-11-10, and the relationships between mosquito densities and meteorological factors were analyzed by Spearman correlation analysis and multiple linear regression analysis. Results Almost all the BI was above 5, the Dengue virus trasmission threshold, among the monitoring sites. During most of the monitoring period, the BI was above 20. The BI of later monitoring declined, but still above dangerous threshold. The BI of urban districts(17.88) was significantly lower than that of suburb(31.44); The BI of nurseries(40.25) was higher than that of residential quarters of cities(13.10) or countryside(29.46). Mosquito densities were significantly associated with average temperature(R=0.899, P=0.015), especially average minimum temperature(R=0.943, P=0.005). Conclusion The densities of Ae. albopictus larvae were generally higher above the Dengue virus trasmission threshold, and there were potential risks of dengue epidemic in Ningbo city. The surveillance system should be strengthened, and multi-layered technology of prevention and control should be reserved. Besides, average temperature, especially average minimum temperature, had a significant influence on mosquito densities.

Objective To understand the distribution of vector species in Ningbo area, managing specimens library with internet technology to improve the identification of the vector species. Methods Through the investigation of disease vectors to establish the internet-based electronic specimen library, achieving rapid species comparison and identification. Results The establishment of the internet-based electronic specimen library has improved the convenience and accuracy of identifying vector species. Through the establishment of the main vector distribution map in Ningbo area, the research ability of the vector borne diseases has been enhanced, which promoted the public popular science of vector-borne diseases. Conclusion The internet-based electronic specimen library has carried on the beneficial exploration for informatization construction, provided materials for guiding the vector surveillance and research work.

Objective Based on the development demand of the management of vector monitoring,the vector biology information platform was needed in Ningbo city. Methods The system was established by the computer programming technology. Results The vector biology information platform has been popularized and applied in our city, medical institutions and CDC,which further promoted the construction of media information and adapted to the health of Ningbo media biological management requirements. Conclusion Changing the traditional non-information to the information work mode can greatly improve the work efficiency and quality.

Objective To improve the analysis and utilization of vector surveillance data, and better monitor the risks of vector-borne diseases. Methods Through the development and construction of Ningbo vector surveillance information system, the surveillance data of virus vector in Ningbo area was fully executed; and analyzed based on internet technology. Results The new method improved the accuracy of the surveillance results, the timeliness of the data analysis report and the utilization value of the surveillance data, reduced the cost of human resources and facilitated the vector surveillance work at the grassroots level. Conclusion The new system is of great significance to the informatization process of vector surveillance, and has a good application value.

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 We monitored the adult mosquito densities during 2011 to 2014, in order to provide a reference for preventing and controling outbreaks of the Japanese encephalitis. Methods During April to November of 2011 to 2014, we used light trapping method to monitor adult mosquito density at different geographic locations and the data were analyzed using SPSS software. Results The predominant mosquito species in different habitats were different, Culex tritaeniorhynchus accounted for 91.39% in livestock shed. The predominant mosquito species in other various habitats was C_x. pipiens pallens which accounted for more than 70%. Peak season was in June, July and August. Conclusion The overall mosquito density was low in Ningbo city, we should strengthen the monitoring of mosquito density in livestock shed. We should implement mosquito management tactics in April and May before the onset of the peak mosquito density.

Objective To provide scientific data for vector control after investigating its community structure and seasonal fluctuation in Ningbo, 2014. Methods Mouse trap, light trap, cage trap and glue trap were used to catch rodents, mosquitoes, flies and cockroaches respectively. Results The rodents were identified as 4 species of 3 genera, 1 family and Rattus norvegicus was predominant species and occupied 62.17%. The mosquitoes were identified as 4 species, 3 genera, 1 family and the dominant species, Culex pipiens pallens, occupied 61.54%. The flies belonged to 13 species of 7 genera, 3 families. Musca domestica was predominant species and occupied 24.10%. The cockroach were identified as 3 species of 2 genera, 1 family and Blattella germanica was predominant species and occupied 80.90%. Rodents and cockroaches were active throughout the year and active period was from April to October. Seasonality of mosquitoes and flies was obvious. The active peak of mosquitoes and flies were both on July. Conclusion The community structure and seasonal fluctuation of vector were preliminarily known. It should strengthen monitoring and control of vectors and vector borne diseases in Ningbo.

Objective To understand the potential of malaria by monitoring vectorial capacity of Anopheles sinensis, providing basis for early warning and prevention and control of malaria. Methods An investigation method for capacity of local vector transmission was used for quantitative calculation of An. sinences biting rate, human blood index, man-biting habit and expected life of infectivity, etc, and then the vector capacity and basic reproduction rate of An. sinensis was obtained according to the formula of Garrett-Jones (1964). Results The anopheles population declined year by year,the maximum density of An. sinensis was July, the host of An. sinensis was ubiquitous, the human blood index was 0.097 which was overall high, the peak season of basic reproduction rate was July, all higher than the critical value of 1.0. Conclusion There was a certain trend of malaria transmission, prevention and control task was still demanding, we need to increase mosquito control work of overwintering mosquitoes and the first generation mosquitoes of early spring.

Objective To know the density of flies and their seasonal fluctuation in Minhang district for providing a scientific basis for their control. Methods The cage trap method was used, with one canopy with fresh baits set at each monitoring point for six hours (9：00 to 15：00). The flies caught by cage were collected after killed by ether and classified, and the density calculated. Results The average density of flies was 1.09 flies/cage, and that in green belt, farmers market and residential area was 1.44, 1.15 and 0.95 flies/cage, respectively. The dominant species were Musca domestica, Sericata, Sarcophagidae and Chrysomya megacephal. A bimodal density distribution with seasonal variation was seen with the peak mainly in June and September. Conclusion The density and population of flies vary with the season and breeding environment, with temperature, the breeding environment and the control measures being the major influencing factors. Integrated control measures should be taken with a top priority given to the environment management, plus chemical control to reduce the density of flies and control the prevalence of infectious diseases.

【Abstract】 Objective To study the synthesis control effects of the poison bait and the gel bait to Blattella germanica in the passenger trains.  Methods One percent acephate and 1% Yekang gel bait were applied exclusively or both were jointly used in the passenger trains. The density of B.germanica was monitored before and after treatment respectively. Results There was significant difference between the combined application of poison bait and gel bait and single application of poison bait（χ2＝17.146，P＝0.000）. The combined application of poison bait and gel bait also significantly differed compared to that of the single gel bait（χ2＝15.499，P＝0.000）. Conclusion The combined application of cockroach poison bait and gel bait had a remarkable efficacy to the fast killing of B.germanica and the maintenance of low cockroach density in the passenger trains.

Objective Plague animal material is tested by 4-pair-primer-PCR which is compaired with traditional “4 piece test” to find a quick diagnostic way for plague. Methods Narcotics test and 4-pair-primer-PCR are both done in traditional way. Results 52 positive specimen of 4-pair-primer-PCR are found from 150,and 62 of traditional way are found. Both the ways have no discrepancy( χ ²=1.42, P> 0.05 ). Conclusion 4-pair-primer-PCR is a quick,peculiar,sensitive method for the diagnosis and surveillance of plague.

Objective:To research on the biological and epidemiological characteristics of 115 Y.pestis.Methods:Detection of virulent factors.etc.Result:Isolated from different foci and reservoirs in Northern Hebei and in middle Inner Mongolia,115 strains of Y.pestis have been performed with permentation of alcohol and carbohydrate,nitrate reduction,urea decomposition,indigo formution and virulent factors etc.Conclusion:The results have showed differences of relative stability brom phenotypic charactors because of different natural foci.According to Chinese Y.pestis ecotype,they belong to Erduosi Plateau.