Objective To investigate the emergence of Aedes albopictus in mosquito-positive small water containers in surveillance sites for dengue fever vector Aedes in Hebei province, China, and to provide scientific data for prevention and control of dengue vector Aedes. Methods Two villages were randomly sampled from the surveillance sites for dengue vector Aedes, one in Mancheng district in Baoding and the other in Yutian county in Tangshan. Four streets in different directions were selected to record mosquito breeding status and their larvae condition in all mosquito-positive small water containers inside and outside the rooms. The mosquito larvae were collected and taken back to the laboratory to be fed for observing and recording the emergence of Ae. albopictus, and analyses were performed on factors that may affect the emergence probability of Ae. albopictus. Results The positive rate of Ae. albopictus in mosquito-positive small water containers was 100% in peak seasons for Ae. albopictus activities in the surveillance sites for dengue vector Aedes in Hebei province, and the constituent ratio was 71.67% for containers containing Ae. albopictus larvae only. There were significant differences in the constituent ratio of mosquito-positive small water containers containing Ae. albopictus only between containers of different characteristics ( P<0.05). The probability of larvae emergence into Ae. albopictus was 66.57% for larvae in mosquito-positive containers, but there were no significant differences in the probability of larvae emergence into adult Ae. albopictus between mosquito-positive water containers of different characteristics ( P>0.05). Conclusion Aedes albopictus larvae breeding is observed in mosquito-positive water containers of different characteristics in the residential areas in Hebei province, which demonstrates equivalent infestation. Water containers of different characteristics in the pre-warning areas of dengue risk should be completely disposed. The Breteau index and the data on probability of larvae emergence into Ae. albopictus in mosquito-positive water containers can be referred to during prevention and control of dengue vector Aedes to comprehensively evaluate the risk of dengue vector-borne diseases.

Objective To calculate the weights of quality assessment indicators of vector density surveillance in Hebei province, China by the analytic hierarchy process (AHP), and to rank those indicators in the order of their influence on quality of surveillance. Methods Based on the achievement data on density surveillance and quality control of four vectors in both cities and counties of Hebei province from 2014 to 2015, AHP was applied to construct a judgment matrix and calculate the weights of assessment indicators. Results The main influencing indicators of quality of rodent surveillance were coincidence rate of distribution of surveillance points, coincidence rate of selection of surveillance points, and coincidence rate of species of specimens, with the weights of 0.197 0, 0.197 0, and 0.175 6, respectively. The main influencing indicators of quality of mosquito surveillance were coincidence rate of surveillance time, coincidence rate of distribution of surveillance points, coincidence rate of selection of surveillance points, coincidence rate of quantity of specimens, and coincidence rate of species of specimens, with the weights of 0.204 5, 0.136 4, 0.136 4, 0.136 4, and 0.136 4, respectively. The main influencing indicators of quality of fly surveillance were coincidence rate of species of specimens, coincidence rate of distribution of surveillance points, and coincidence rate of selection of surveillance points, with the weights of 0.235 1, 0.156 7, and 0.156 7, respectively. The main influencing indicators of quality of cockroach surveillance were coincidence rate of quantity of specimens, coincidence rate of distribution of surveillance points, and coincidence rate of selection of surveillance points, with the weights of 0.235 1, 0.156 7, and 0.156 7, respectively. Conclusion AHP can be used to assess the quality of vector density surveillance. The weights of indicators can reflect the relative importance of different indicators in the quality of density surveillance of four vectors. It can provide a reference for the quality control of vector density surveillance.

Objective To expound the application of Bayes analysis in the relationship between Japanese encephalitis (JE) and multiple seasonal autoregressive integrated moving average model (ARIMA) in Hebei province, meanwhile, to evaluate the effect of the multiple seasonal ARIMA model in the prediction of monthly mosquito density and JE prediction. Methods We collected the incidence data of the JE and mosquito population density data. A mathematic model was constructed using SPSS 21.0 and used to predict the situation, discuss the application of Bayes analysis in the relationship between JE and multiple seasonal ARIMA model of total mosquito density. Results ARIMA (0,1, 1)×(0, 1, 1) ₁₂ model best fitted the incidence of mosquito density from 2009 to 2016. The incidence of JE disease was correlated with mosquito population densities ( r=0.101, P=0.043). Bayes analysis indicated that 63.16% subjects were correctly discriminated among samples of mosquito density and Bayes analysis got a result that the coincidence rate was 100% among the prediction of mosquito density and true ones in JE prediction. Conclusion Bayes analysis verified that the multiple seasonal ARIMA model in the prediction of monthly mosquito density can be used to predict the JE. ARIMA model fits well in the prediction of mosquito density, and applies to the information system of vector monitoring, and to early warn the unusual mosquito density and control mosquito-borne infectious diseases.

Objective A software for information management system of vector surveillance has been developed and used for the storage, management and query of the vector surveillance data of disease control and prevention at provincial, municipal and county levels in Hebei province. Methods The system is based on Eclipse development platform, and uses MySQL database and related development tools to build the software interface based on Windows operating system, and allows the inputs of field surveillance data and information to the database. Results The software can realize the functions of information input, retrieval query, statistics and user management. The vector surveillance data of disease control and prevention institutions at provincial, municipal and county levels of the system can be automatically collected, counted and displayed, a dynamic management process can be implemented. Conclusion The development of the software can realize the collection, management, analysis and quality control of surveillance data, plays a positive role in improving vector surveillance work efficiency and quality, and providing supportive information for vector control and the health administrative authorities.

Objective The activities of acetylcholinesterase, multifunctional oxidase, carboxylesterase and glutathione-S-transferase in the field populations and susceptible populations of Blattella germanica were determined. Correlation coefficient and path coefficient were used to explain the relationship between enzyme activity and resistance levels of different insecticides. To explore the resistance mechanism of field populations of B. germanica in Hebei province. Methods During 2014-2015, adults and nymphs of B. germanica. were collected in 8 cities of Hebei province, 2-3 weeks old adults were reared indoors. The activities of enzyme activities were measured by physiological and biochemical methods, and the relationship between enzyme activity and resistance level was analyzed by correlation and path analysis. Results The resistance level of Chengde B. germanica populations to chlorpyrifos was the highest, the resistance index was 25.32 times. The resistance of level to cypermethrin and the beta-cyfluthrin in the B. germanica populations of Thangshan was the highest, with the resistance index of 37.45 and 23.92 times respectively. The activity of CarE and MFO-oxygen-demethylation in the wild populations were significantly higher than that in susceptible populations, and activity of AChE and GSTs were different. The relationship between resistance level and enzyme activity of path analysis showed that CarE activity had a major enhancement effect on the resistance level of chlorpyrifos, and the decision coefficient was 0.122 8. The MFO activity has a major contribution in the resistance level to beta-cyfluthrin and cypermethrin. The decision coefficient was 0.283 8 and 0.512 1 respectively. Conclusion Carboxylesterase was related to chlorpyrifos resistance in field populations of B. germanica. Acetylcholinesterase was associated with resistance to chlorpyrifos and cypermethrin. Multifunctional oxidase was associated with resistance to cypermethrin and beta-cyfluthrin. Glutathione-S-transferase had little effect on the resistance level of the three insecticides in field populations of B. germanica in our province.

Objective To monitor the resistance level of Musca domestica to different types of insecticides in Hebei province, China, understand the resistance characteristics and development trend. The changes of resistance to different insecticides were compared in the laboratory without selection pressure, to provide reference for effective chemical control. Methods During 2012-2016 in Hebei province, 83 sampling sites, such as garbage site, farmers market and other breeding sites were selected in 11 cities (districts). Adult houseflies were collected by net trapping, and reared for 1-2 generations in the laboratory, 3-5 days old female adults were used for assay. The resistance level to different types of insecticides was determined by the method of drip method, and the trend of resistance of M. domestica was analyzed by comparing the historical data. Results Musca domestica in Hebei province showed moderate to high levels of resistance to pyrethroid, the degree of resistance varied with organophosphorus, carbamate, and organochlorine. In comparison with the historical data, it was found that the resistance to DDVP declined, then gradually, steadily and slightly increased. Resistance to permethrin significantly increased. The average decline of resistance to permethrin, beta-cypermethrin and DDVP was 90.39%, 89.23%, and 80.41%, after 59 generations in the laboratory in the absence of pesticide selection. Conclusion Musca domestica in Hebei province had different degrees of resistance to four types of insecticides, and the resistance levels to permethrin, cypermethrin, and DDVP declined at varied magnitudes.

Objective To evaluate the application of the autoregressive integrated moving average (ARIMA) model in the prediction of monthly rodent density. Methods The database of monthly rodent density in Hebei province from 2008 to 2014 was constructed with SPSS 21.0 software. A mathematic model was constructed using ARIMA model of 21.0 and used to predict the situation in 2015. Results The main rodents were Rattus norvegicus and Mus musculus in Hebei province. The rodent density presented seasonal periodicity during 2008 to 2014 in Hebei province and the seasonal distribution of R. norvegicus and M. musculus was the same. ARIMA (3, 1, 0)×(0, 1, 1)12 model best fitted the incidence of rodent density from January 2008 to December 2014. The actual average of rodent density in 2015 fell within the 95% confidence interval of prediction. Conclusion ARIMA model fits well in the prediction of rodent density, and can be applied to the information system of vector surveillance to predict the unusual rodent density.

Objective Mosquito collection was carried out in Chengde of Hebei province to explore the effects of altitudes, habitat types and investigation methods for adults and larvae on mosquito species investigation,so as to provide reference for an efficient survey, and prevention and control mosquito-borne infectious diseases. Methods Research sites were selected within three habitat types in Chengde at different altitudes in July to August of 2015. Light-trapping method, mosquito habitat capture method for adults and the pipette method, scoop dipping method for larvae were used. The influencing factors were analyzed using multinomial logistic regression. Results The mosquitoes that were collected in this study included Anopheles sinensis(45.12%), Culex pipiens pallens(27.44%), Armigeres subalbatus(11.03%), Aedes koreicus(6.90%), Cx. vegans(6.23%), Ae. vexans(2.44%), An. messese(0.42%), and Ae. chemulpoensis(0.42%). Anopheles messese was a new record in Hebei province. The influencing factors of mosquito species investigation included altitudes, habitat types and investigation methods for adults and larvae. With the reference category of Cx. pipiens pallens, Cx. vegans, An. sinensis, Ae. koreicus, and Ae. vexans had a higher appearing rate at high altitude, and to the contrary with Ar. subalbatus. Anopheles sinensis, Ar. subalbatus, and Ae. koreicus had a higher appearing rate in breeding and growing areas, An. sinensis had a higher appearing rate in rural residential areas, and to the contrary with Ae. koreicus. Culex vegans, Ar. subalbatus, Ae. chemulpoensis, and Ae. koreicus had a higher capture rate with investigation methods for larvae. Conclusion The population and density of An. sinensis at high altitude areas, and the breeding and growing areas and rural residential areas in Chengde should be particularly concerned. Appropriate mosquito-control measures should be taken at areas likely to appear An. sinensis, so as to prevent and control malaria and other infectious diseases by vector mosquitoes.

Objective The resistance level of nine local strains of Blattella germanica was divided into regions by clustering in Hebei province, providing the basis for regional control of B. germanica. Methods The method of contact with chemical cover was used in this study. The resistance ratios in different populations were categorized by clustering analysis. Results According to the theory of cluster analysis processing, the data of resistance levels were clustered to four categories to 4 groups. The first category is Shijiazhuang and Qinhuangdao strains: low to medium resistance to beta-cypermethrin low resistance to propoxur, high resistance to acephate and permethrin, medium to high resistance to deltamethrin; the second category was Baoding and Handan strains: low to medium resistance to beta-cypermethrin, acephate and deltamethrin, and low resistance to permethrin and propoxur; the third category was Zhangjiakou strain: high resistance to permethrin and acephate, medium resistance to beta-cypermethrin and deltamethrin, low resistance to propoxur; the fourth category was Cangzhou, Xingtai, Chengde, Tangshan strains: medium to high resistance to beta-cypermethrin, low to medium resistance to acephate, high resistance to permethrin: medium resistance to deltamethrin, and low resistance to propoxur. Conclusion Clustering analysis can be satisfactory tool to classify resistance levels in different regions.

Objective To analyze the association between the seasonal fluctuation of mosquito density and mosquito-borne diseases in Hebei province. Methods We collected the incidence data of the mosquito-borne diseases and the monitoring data about seasonality of mosquito population density in Hebei province during the period of 2013-2015, and then all the data were analyzed by using SPSS 21.0 software. Results The total of mosquito-borne diseases in Hebei province during the period of 2013-2015 were 467 cases. The main mosquito-borne diseases were epidemic encephalitis, malaria and dengue fever. The number of cases are 264, 178 and 25 cases respectively. In total, 71 916 mosquitoes were captured during the period of 2013-2015 in Hebei province and the monthly average mosquito density was 1.368 per mosquito-lured lamp. Culex pipiens pallens(1 515), Cx. tritaeniorhynchus(208), Aedes albopictus(150)and Anopheles sinensis(10)were common in Hebei province, the population density of Cx. pipiens pallens was the highest, accounted for 97.38% of the total mosquitoes. The incidence of mosquito-borne diseases was correlated with mosquito population densities during 2013-2015 (r=0.145, P=0.041). Conclusion The results suggest that there are many kinds of mosquitoes in Hebei province and there are complex links between mosquito population densities and mosquito-borne diseases.

Objective To investigate the resistance of Culex pipiens pallens to five commonly used insecticides in Hebei province, China. Methods The susceptibility of Cx. pipiens pallens larvae to commonly used insecticides was determined by WHO larval immersion method. Insecticide resistance was evaluated and compared based on median lethal concentration (LC₅₀) and 95% confidence interval (95%CI). Results The LC₅₀ values of beta-cypermethrin, permethrin, deltamethrin, fenobucarb, and DDVP for 11 field populations of Cx. pipiens pallens were 0.0008-0.1664, 0.0159-0.2280, 0.0006-0.0148, 0.0800-0.6138, and 0.1783-0.5000 μg/ml, respectively. As compared with the previously reported results (1991-1994), Cx. pipiens pallens showed increased resistance to permethrin and slightly decreased resistance to DDVP and deltamethrin. Conclusion The 11 field populations of Cx. pipiens pallens have developed different levels of insecticide resistance. The surveillance of insecticide resistance should be strengthened to provide guidance for the proper application of insecticides.

Objective To investigate the resistance of Culex pipiens pallens to five commonly used insecticides in Hebei province, China. Methods The susceptibility of Cx. pipiens pallens larvae to commonly used insecticides was determined by WHO larval immersion method. Insecticide resistance was evaluated and compared based on median lethal concentration (LC50) and 95% confidence interval (95% CI). Results The LC50 values of beta-cypermethrin, permethrin, deltamethrin, fenobucarb, and DDVP for 11 field populations of Cx. pipiens pallens were 0.0008-0.1664, 0.0159-0.2280, 0.0006-0.0148, 0.0800-0.6138, and 0.1783-0.5000 μg/ml, respectively. As compared with the previously reported results (1991-1994), Cx. pipiens pallens showed increased resistance to permethrin and slightly decreased resistance to DDVP and deltamethrin. Conclusion The 11 field populations of Cx. pipiens pallens have developed different levels of insecticide resistance. The surveillance of insecticide resistance should be strengthened to provide guidance for the proper application of insecticides.

Objective To compare 11 municipal centers for disease control in Hebei province, China in terms of their vector surveillance work, and to explore the method for assessing the vector surveillance capability. Methods The indices for surveillance work were decomposed and quantified. The obtained quantitative results were analyzed by robust statistics (Z-score), and the statistical results were demonstrated by histograms. Results The scoring results (2010- 2011) showed that the municipal centers for disease control had similar surveillance capabilities, but there was significant difference in 2-year mean score between the centers with the highest and lowest scores. Conclusion The method for assessment is effective and reasonable in evaluating the vector surveillance capabilities of municipal centers for disease control, and it can help them identify problems and improve surveillance capability.

【Abstract】 Objective To monitor the population density and seasonal fluctuation of mosquitoes in different areas in Hebei, and to provide the science basis for the reasonable control of mosquitoes. Methods Mosquitoes were collected by light trap method and landing count method. Results There were six species caught, belonging to 3 genera. Culex pipiens pallens was the dominant specie, accounting for 85.34%. Cx.pipiens pallens was caught in the residential areas and park, Cx.tritaeniorhynchus and Anopheles sinensis in stable. The mosquitoes density was monitored by light trap method and landing count method, and its peaks lasted from July to September, but the peak was in August. The mosquito density was 10.33 individuals/lamp·h and 16.06 individuals/man·h  respectively.  Conclusion It  should  put  the emphasis on the control of Cx.pipiens pallens, Aedes albopictus, Cx.tritaeniorhynchus and An.sinensis.

【Abstract】 Objective To monitor the population density and seasonal fluctuation of flies at different areas of Hebei, and compare the trapping efficacy of different baits. Methods Cage trapping method was used in this study. Results A total of 19 species were caught, belonging to 4 families, 14 genera. Musca domestica was dominant specie. Muscidae were mainly trapped with putrid fish, accounting for 54.22% of the total. Muscidae and Calliphoridae were mostly caught with a mixture of brown sugar and vinegar, accounting for 39.17% and 36.08%, respectively. The season fluctuation tendency of flies caught with two baits was similar, and the peak was all in August.  Conclusion According  to  the  surveillance  data,  the  species  controlled  mainly are M.domestica, Chrysomya megacephala, Lucilia sericata, Boettcherisca peregrine and M.stabulans. Environment improvement and the reduction of bleeding sites are the basic measures to control fly density. The putrid fish is worthy to be recommended as a surveillance method of flies density.

【Abstract】 Objective To monitor the population density and seasonal fluctuation of rodents in different residential areas of Hebei province. Methods The night trapping method and powder trace method were used in this study. Results There were 6 species caught, belonging to 2 families 4 genera. Rattus norvegicus was the dominant species (60.99%). Mus musculus, Apodemus agrarius, Tscherskia triton and Cricetulus barabensis followed with it, accounting for 25.30%, 9.38%, 2.89% and 0.48% respectively. The dominant species were different in different districts. The results showed that the peaks of population density were in April and October.  Different surveillance methods were used in Langfang, and the average population density of rodents was 0.87%  by night trapping method, but it was only 3.36% by powder trace method. It was 0.83% and 0.67% in Tangshan and Shijiazhuang, respectively. The population density in the country was higher than that in the town. Conclusion R.norvegicus is the main control target in Hebei province.

Objective In order to obtain basic information of distribution of Dengue viruses vector mosquitoes: Aedes albopictus in north and northwest of Hebei province. Methods Investigation of mosquito larvae adopted small containers method; investigation of mosquito adults adopted mosq-ovitrap, mosq-lamp trap, electro-suction catch method. Results Ae.albopictus was discovered at Shexian county, container index(CI)=34.41, house index(HI)=25.27, breteau index(BI)=4.96. Conclusion Ae.albopictus was discovered at Shexian which is in southwest Hebei province, Ae.albopictus was not found in the city of Chengde in north of Hebei province and the city of Zhangjiakou in northwest of Hebei province.

species of plants were collected mainly in Hebei province for selection of botanical insecticides. These plants were air-dried and ground, then extracted by acetone in a ratio of acetone/plant powder=6/1. In the tests of soaking 3-4 instar larvae of Culex pipiens pallens with 30-fold diluents of the plant extractions, 44 species of plants caused at least 50% mortality of the larvae. Treated with 100-fold diluents, 7 plants extractions caused more than 95% mortality of the larvae, and 2 of those, Memtha haplocalyx and Artemisia capillaris caused 100% mortality. In conclusion, some plants, such as Tribulus terresteis, Memtha haplocalyx, Artemisia capillaris, Eupatorium fortunei, Datura stramouium and Humulus scamdens, have value of development.

This paper reports the sensitivity of B.germanica from five Hebei cities to deltamethrin, cypermethrin,permethrin,propoxur and DDVp. These pesticides are commonly used in the Province. The WHO-suggested pesticide membrane method was applied in the investigation. The results show that B.germanica in the Province had resistance to all five pesticides in varying degrees. The sensitivity order is: deltamethrin>propoxur>cypermethrin>permethrin>DDVp.

The parasites and HBsAg carried on the surface of cockroach in Hebei cities were investigated .The lotion washed the surface of cockroach were examined under the microscope and by PCR.There were 4 kinds of parasites suspended in the solution. The HBsAg carriage on surface of cockroach was negative. It was also discussed in the paper that cockroach transmitted pathogens with mechanical or biological mechanism.

This paper reports a comprehensive method on pest prevention and control. Chemical smoke and spray were used as the major means; the soil was disinfected; and some heavily attacked materials were burned. All these measures were employed for a rapid control on R.( F.) speratus in the reservoir area. DDVP smoke killed 97% of R.( F.) speratus. Boron-Phenol solution killed 100% of R.( F.) speratus in stepping logs and mats within 14 days. Soil disinfection could prevent the spread of R.( F.) speratus.The burning to some heavily attacked materials can eradicate completely the occurrence of breeding R.( F.) speratus in the nest year.

This paper reports the survey on seasonal fluctuation and active rule of cockroach in five Hebei cities. The relationships between meteorological factors and seasonal fluctuation of B.germanica were analysed in this paper. And the grey relative analysis was employed.The active peak of B.germanica of Hebei was in May and September . The importance of meteorological factors were ranked:humidity>temperature>rainfall. B.germanica activated from 21∶00 in the night to 6∶00 in the next morning and there were two active peaks at 23∶00 and 3∶00.

The bacteria carried on the surface of cockroach in Hebei province was investigated. The cockroach captured in 5 cities was washed with 1% peptone solution. The solution was subsequently inoculated into 4 bacteria reproductive solutions. The bacteria were identified routinely. The results showed that 96.77% of cockroaches carried bacteria. Forty-nine strains of pathogenic or opportunistic pathogens were found. These results verified that cockroaches are of high bacteria positive rate on its surface. Its role on the disease transmission should not be ignored.

This paper reports the categories of cockroaches from Hebei cities and their regional distribution. From 1996 to 1998, we trapped cockroaches with wide-mouth flasks in 11 cities under the jurisdiction of provincial government. There were 8 species belonged to 4 genera of 4 families. B.germanica was the first predominated species, and the next was P.japonica. The cockroahes in cities had the characteristics of block distribution and spot distribution.