Objective To investigate mutations in the voltage-gated sodium channel gene ( VGSC) responsible for knockdown resistance (kdr) in Aedes aegypti and analyze the prevalence characteristics of the VGSC gene in the key areas of Ae. aegypti distribution in Yunnan Province, China. Methods Wild adult or larval Ae. aegypti samples were collected from 7 counties/cities (Yingjiang County, Ruili City, Zhenkang County, Gengma Dai and Va Autonomous County, Menghai County, Jinghong Municipality, and Mengla County) in Yunnan Province. The gene VGSC was amplified by direct sequencing to analyze the point mutation rate and the composition of combined mutations. The Chi-square test was used to compare the differences in the kdr mutation rate of VGSC gene between different loci and between different sexes of Aedes albopictus. Results The DNA was successfully extracted and VGSC gene were sequenced for a total of 561 Ae. aegypti mosquitoes (276 females, 242 males, and 43 larvae) in 7 counties/cities. Four point mutations were found in the VGSC gene. S989P, V1016G, and F1534C mutations were present in every county/city. The S989P mutation rate ranged from 71.43% to 100%, with a mean of 92.51% (95% confidence interval [ CI]: 90.33%- 94.70%). The V1016G mutation rate was 100%. The F1534C mutation rate was 55.81%-100%, with a mean of 85.38% (95% CI: 82.45%-88.32%). The Y1527F mutation was first detected in Ruili Municipality, Gengma and Zhenkang County, and the mutation rate ranged from 0 to 35.45%, with a mean of 8.73% (95% CI: 6.39%-11.08%). There were 4 types of co-occurring mutations: S989P+V1016G, V1016G+F1534C, S989P+V1016G+F1534C, and S989P+V1016G+Y1527F+F1534C. Single point mutations were not found. There were no significant differences in the mutation rates of 989, 1016, 1527, and 1534 loci and the composition ratios of combined mutations in female and male mosquitoes in six counties/cities except Yingjiang County. Conclusions The kdr mutation in the VGSC gene of Ae. aegypti in Yunnan Province is mainly characterized by multiple-point joint mutations, and a new Y1527F mutation appears. Kdr mutations surveillance in Ae. aegypti should be carried out regularly to grasp the changes in its resistance to insecticide targets in time.

Objective In order to understand the insecticide resistance of Musca domestica to five different commonly used insecticides in Huairou district from 2014 and 2016, and provide the basis for scientific and reasonable guidance on the selection of insecticides for its control program. Methods The drug resistance test was carried out using the membrane method, and the experimental data were analyzed by PROBIT model in SPSS(21.0) software. Results In 2014 and 2016, the wild population of M. domestica in Huairou district was susceptible to DDVP, and the resistance were 0.23 and 0.25-fold,respectively. The resistance to Deltamethrin was high, and the resistance were 157.62 and 37.15-fold, respectively; resistance to Beta-cypermethrin were very high in both years, the resistance were 181.64 and 289.06-fold, respectively. In 2016, the resistance level to Propoxur changed from low to high, and increased by 4.15 times compared to 2014; the resistance level to Chlorpyrifos was decreased by 33.58 times from low resistance to being susceptible. Conclusion The M. domestica in Huairou district showed high or extremely high resistance to pyrethroid insecticides. The resistance to DDVP and Chlorpyrifos should be further monitored and determined. Integrated control measures should be taken to control fly species.

Objective To assess the mosquito-killing effect of ultra-low-volume spraying machine during night and day in community and Zhongshan Park at Shaoguan, and provide the scientific basis to choose scientific and effective mosquito-killing technology. Methods Used the large vehicle-mounted ultra-low-volume machine spraying pesticide to kill mosquitoes in Shaoguan communities and park environment, respectively during night and day, then evaluated mosquito-killing effect of applying pesticide spray during night and day by Mosq-ovitrap positive index (MOI) and human-bait of monitoring Aedes density before and after applying pesticide. Results After ultra-low-volume spraying during night and day respectively at villa of Shaoguan Country Garden, human-bait index was reduced by 98.19% and 76.85%, MOI by 81.15% and 43.86%; at park, human-bait fell by 76.47% and 77.78% respectively, and MOI fell by -58.54% and 76.33% respectively. Human-bait relative density index of nighttime, daytime spraying at villa was 3.90 and 14.25 respectively, MOI was 38.48 and 24.47; human-bait relative density index at park was 33.82 and 44.44, MOI was 99.09 and 45.68. Conclusion The ultra-low-volume spraying in Shaoguan community environment at nighttime was significantly better than daytime spraying, but in Zhongshan Park the results were similar. In community environment, nighttime ultra-low-volume spraying, compared with spraying during the day, can effectively kill mosquitoes and keep mosquito-borne diseases at low density level, and has a certain application prospect.

Objective To study the efficacy for mosquito control and residual effect of different pesticides by artificial simulation as barrier spray on vegetation. Methods Using insecticidal barrier spray on vegetation technology, Scheffleraoctophylla were sprayed separately by 2.5% effective chloric fluorine with ester millirod suspending agent (Demand), 10% alpha-cypermethrin (Fendona) and 10.4% chlorine chrysanthemum-allyl chrysanthemum water emulsion (alpha-cypermethrin). Then they were moved to an outdoor tent. A total of 30 female Aedes albopictus were put into every tent weekly. One rat and four mosquito oviposition device were introduced into every tent after 24 h, then collected mosquito eggs after 3 d, and recorded survived mosquitoes. Results 2.5% effective chloric fluorine with ester millirod suspending agent remained effective for more than 21 weeks, 10% alpha-cypermethrin for 9 weeks, and 10.4% chlorine chrysanthemum-allyl chrysanthemum water emulsion had no residual effect. The maximum of weekly counts for survivors was 4, 15 and 21 respectively. The median was 1, 5 and 7. Conclusion Both 2.5% effective chloric fluorine with ester millirod suspending agent and 10% alpha-cypermethrin have good mosquito killing and residual effect by using insecticidal barrier spray on vegetation, 2.5% effective chloric fluorine with ester millirod even better.

Objective Application of insecticidal barrier spray on vegetation for dengue mosquito vector control to explore rapid and long-term effective control means for dengue mosquito vector control in the urban communities. Methods From June to September of 2015, the phoenix garden of Shaoguan city in Guangdong province was selected as the test site, comparing the effectiveness of barrier spray on vegetation technology to kill the dengue vector mosquito with the ultra low volume spraying. Results The insecticidal barrier spray on vegetation showed quick kill effect, and continuous control effect on Aedes albopictus, reducing mosquito lure egg apparatus index (MOI) lure under 5 for 2 to 4 weeks, the duration of the MOI under 10 for 3 to 6 weeks, the duration of the effective control of mosquito density for 6 to 7 weeks. Pesticide resistance was not detected. Conclusion Insecticidal barrier spray on vegetation can effectively control dengue mosquito vector density more than one month. Compared with ultra-low volume spraying, insecticidal barrier spray on vegetation reduced the cost by 37.50%, saved on-site manpower, pesticides and time, had a positive impact on dengue fever outbreak control in urban communities.

Objective To explore the plague epidemiological trend of the nearly 25 years in Yushu Tibetan Autonomous Prefecture, Qinghai province, and to provide basis for implementation of the prevention and control measures. Methods Analyze the data of the human plague cases, plague surveillance and the plague foci research from 1990 to 2014 with the Excel software. Results There were 17 human plague outbreaks in 11 years out of 25 years from 1990 to 2014, 54 cases were reported, including 22 fatalities, the mortality was 40.74% (22/54). The patients were mainly distributed in the following 5 counties: Yushu, Nangqian, Qumalai, Chenduo and Zhiduo. Human plague cases occurred from May to October, the peak at July to October. The majority clinical cases were pneumonic plague (34/54, 62.96%). In 2004, pneumonic plague outbreaked in local area. Conclusion The plague epidemic situation in Yushu Tibetan Autonomous Prefecture, Qinghai province is still at high risk, the human plague in some area outbrook occasionally. So as to reduce human plague occurrence risk, while conducting the Marmot plague monitoring, the monitoring of Tibetan sheep plague should also be strengthened, and the comprehensive measures of plague prevention and control should be carried out.

Objective To understand the situation of people about the plague knowledge and analyze its influencing factors in Yushu after the earthquake, then to provide a reference for Yushu post?disaster plague control and prevention. Methods There were 294 persons consisting of students, cadres, pastoralists and migrant workers from 9 towns of Yushu who were extracted by the method of stratified cluster random sampling. Then the awareness situation of the population about plague was surveyed through the questionnaire and interview. Results The average rate of plague awareness of the respondents was 77.89% (229/294). The awareness rate of the sampled students was 93.81% (91/97), the awareness of the local pastoralists was 80.95% (51/63), the awareness of the local cadres was 74.55% (41/55), the awareness of the migrant workers was 58.23% (46/79). Multiple factors analysis displayed that the age, occupation, cultural level and the source region of the population is the influence factors to their plague awareness situation. Conclusion The plague awareness rate of the migrant workers for post?disaster reconstruction in Yushu is lowest, which increases the risk of plague long distance spread to the world. So the plague propaganda and education of the population for the post?disaster reconstruction in Yushu should be strengthened.

Objective To establish a comprehensive assessment model for plague surveillance for Qinghai province, China, and to evaluate the national-level surveillance stations in the natural focus of Himalayan marmot plague for improvement of performance and quality of plague surveillance. Methods A total of 25 comprehensive assessment indicators reflecting the surveillance quality were selected, which included the population survey of marmots and other small rodents, the flea index and burrow track fleas from the primary host of plague, marmots, and the plague bacteriological and serological measurements. The analytic hierarchy process (AHP) was used to establish a comprehensive assessment model for plague surveillance and to evaluate the plague surveillance in 4 national-level surveillance stations in the natural focus of Himalayan marmot plague in Qinghai. Results According to the scores obtained from the AHP model, the 4 national-level surveillance stations were in the order of Ulam county (1.9286), Gonghe county (1.3174), Golmud city (1.0692), and Yushu Tibetan Autonomous Prefecture (0.9477). Conclusion The results of plague surveillance evaluation based on AHP are reasonable and reliable. It provides strong evidence for the management and improvement of plague surveillance.

Objective To establish a comprehensive assessment model for plague surveillance for Qinghai province, China, and to evaluate the national-level surveillance stations in the natural focus of Himalayan marmot plague for improvement of performance and quality of plague surveillance. Methods A total of 25 comprehensive assessment indicators reflecting the surveillance quality were selected, which included the population survey of marmots and other small rodents, the flea index and burrow track fleas from the primary host of plague, marmots, and the plague bacteriological and serological measurements. The analytic hierarchy process (AHP) was used to establish a comprehensive assessment model for plague surveillance and to evaluate the plague surveillance in 4 national-level surveillance stations in the natural focus of Himalayan marmot plague in Qinghai. Results According to the scores obtained from the AHP model, the 4 national?level surveillance stations were in the order of Ulam county (1.9286), Gonghe county (1.3174), Golmud city (1.0692), and Yushu Tibetan Autonomous Prefecture (0.9477). Conclusion The results of plague surveillance evaluation based on AHP are reasonable and reliable. It provides strong evidence for the management and improvement of plague surveillance.

Objective To investigate the community structure of rodents in different habitats of Ordos sandland. Methods From April to October 2008, the rodent communities in seven types of vegetation in Ordos sandland were investigated by night trapping method. Results The population density and community structure of rodents differed across various habitats. The alfalfa habitat had the most species of rodents (5 species) and the highest diversity index (1.3075). Only Phodopus roborovskii was caught in the habitat of Astragalus adsurgens. P. roborovskii was the dominant species in all habitats, accounting for 65.83% of all rodents, but its population dynamics were different between different habitats. Conclusion Planting different types of vegetation can change the habitat conditions in Ordos sandland, thus leading to changes in the community structure and population size of rodents. Attention should be paid to the interaction between rodents and habitats in the process of sandland use.

Objective To update the information on the species of ectoparasitic fleas on small mammals in Gonghe county, Qinghai province, China. Methods Small mammals were captured by night trapping method, and ectoparasitic fleas were collected from them. The slide specimens of fleas were made, and these fleas were classified and identified based on morphological characteristics. Results A total of 785 ectoparasitic fleas (13 species, 8 genera, 3 families) were collected from small mammals in Gonghe county. Conclusion Neopsylla bidentatiformis (Wagner, 1883) is a new record in Qinghai province.

Objective To investigate mosquito breeding at the victim temporary habitation of Jiuzhou gymnasium,and bring forward the control measure based on the investigation results.Methods Investigate the density of mosquito larva in the river and rice field by lava-spoon method,investigate in the downcomer,lawn,bamboo and wood by the check-container method and investigate the biting of mosquito to victims in the temporary habitation by inquiry method.Results With the coming of summer,the density of mosquito rose gradually,especially in the rice field.The density index was 0.028 lava/spoon on 29 May in east rice field of gymnasium,and 1.830 lava/spoon on 7 June.The density index increased 64 times within 9 days.Conclusion Control mosquito with the integrated management method,improve Jiuzhou gymnasium and circumjacent environments,and eliminate or control larva breeding sites.

Objective To learn the epidemical status of malaria in Weixi county and provide scientific evidence for the establishement of malaria control measure. Methods Collect the epidemic datum of malaria from 1997 to 2007 in Weixi county, carry out the investigation on malaria vector and infectious source, and know the control situation of malaria through discussion with professionals. Results Weixi county was the origin of malaria prevalence at upstream of Lancangjiang-Meigong river and its incidence of malariae reached 50.31 per ten thousand in 1987. It still didn't reach the criterion of malaria control and had the local infection malaria cases and input malaria cases, though malaria incidence fell in recent year. Anopheles kunmingensis, the main vector, accounted for 26.45%. The long-incubation Plasmodium vivax was prevalent, and malaria can exist above 1800 miter elevation. Conclusion Weixi county belongs to unsteady malaria prevalent district. The local malaris patients could not be diagnosed timely and cured early because of the funds shortage, old facilities, professional detection personnel shortage and the lack of management skill of malaria in the field. It suggested that some relevant department should more attention to malaria control in Weixi county, so as to strengthen the capacity of malaria control through taking some measure such as reinforcing technology training, facilities supply and anti-malaria pharmaceuticals.