Surveillance Distribution Of Vectors And Chemical Resistance Of Aedes Albopictus In Pingshan District Of Shenzhen City 2014

Backgroud:Mice, mosquitoes, flies, and cockroaches are the main vector organisms in china, they can Propagate disease by biting, contaminated food and carrying pathogenic bacteria, which will bring great damge to human health and country.At present, there are 185 kinds of mouses, 3300 kinds of mosquitoes,3730 kinds of flies and 200 kinds of cockroaches in our country, which can spread a serious of vector biological disease such as plague,hemorrhagic fever of renal syndrome(HFRS), brain leptospirosis, epidemic hepatitis b,yellow fever, filariasis, dengue fever, chikungunya, malaria, dysentery, typhoid, cholera and so on. It pose a serious threat to human health and economic burden to the country.At the same time, the chemical prevention and control has become a domestic and important means of vector biology. However, the frequent, irregular and unreasonable use of chemical pesticides has led to various degrees of insecticide resistance in vector organisms.Resistance has become an important factor in effective control of vector obstacle. Aedes albopictus, as the most important mosquito vectors, which accelerated the outbreak or prevalence of dengue fever. However, resistance problems seriously restricting the effective prevention and control of Aedes albopictus, so understanding and grasping the situation of insecticide resistance of Aedes albopictus is particularly important.Objective:1. To establish the vector biological basis database, for effectively control vector and vector biological diseases.Using surveillances methods to grasp the basic situation, population density, distribution and seasonal fluctuation of vector organisms of Pingshan district in Shenzhen city.2. Understanding Aedes albopictus resistant to commonly used insecticides for the effective and rational use of pesticides to control dengue media provide a scientific basis.Mehods:1. Monitoring the dynamic of main vector biological of Pingshan district in shenzhen by referece to the “National vector biological monitoring program(Trial) ”and the “Density of vector biological monitoring method”. Rat cage method was used for the surveillance of rats, flies using cage-traps, using the ultraviolet lamp and mosq-ovitrap trapping mosquito,cockroaches using sticky trapmethod. Classification and identification of vector biology were conducted after trap, provide advice on the prevention and control by the analysis results of species composition, density, distribution and seasonal variation situation.2. In order to grasp the situation of Aedes albopictus resistance. Selecting 5 locations in the east, west, south and north of Ping shan district in the mosquito density peak(March- June)collected aedes albopictus larva to lab and feed after mixed.The larvae dipping method was carried out on the F1 generation of aedes albopictus larva in commonly used insecticide resistance test.Results:1. Rattus norvegicus is the main rodent species in Pingshan district, which accounting for90.65% and the average density of Rattus(2.37%) is higher than the national standard. The difference of the rattus density among the main community in Pingshan district has not statistical significant; Residential rat density is higher than that of special industries, the difference has statistical significance( c 2=4.72,P=0.03); The growth and decline of the rat density seasons throughout the year is a multi-peak curve.There are a total of 10 genera and16 species of flies were captured. Chrysomyia megacephala as the dominant species,accounting for 74.16%, the annual average density of flies was 96.51 individual per cage;The difference of the flies density among the main community in Pingshan district has statistical significant(F=3.41, P=0.03).The difference of the chrysomyia megacephala distrubution in the environments of residential communities, farmers’ market, hospital and park has statistical significance(F=3.47,P=0.02); The growth and decline of the season throughout the year is a three peak curve, the peak in April, June, and November,respectively. 4529 mosquitos were captured in 2014 and the average density of mosquito is15.10 individual per lamp. Culex Pipciens quinquefasciatus is the dominant specie of mosquitoes, account for 90.97%, following is Armigeres subalbatus and Aedes albopictus;The difference of mosquitoe density among the main community in Pingshan district has not statistical significance. The density of mosquitoes in resident communities is higher than hospital and parks. The growth and decline of the season throughout the year is a double peak curve;The average annual ovitrap positive rate is 9.33%, and the difference of ovitrap positive rate among different environment in Pingshan has not statistical significance. The growth and decline of the season throughout the year is a unimodal curve,reaching the highest(33.10%) in September. A total of 663 cockroaches were captured throughout the year and the annual average density of cockroaches was 0.45 individual per cage. Blattella germanica is the dominant specie of mosquitoes, account for 90.95%. The difference of cockroaches density among the main community in Pingshan district has not statistical significance. The density of Blattella germanica in catering environment is higher than farmers’ market and residential communities. The growth and decline of the season throughout the year is a multi-peak curve.2.Aedes albopictus from Pingshan district of Shenzhen was sensitive to propoxur, and the resistant index was 1.45; Aedes albopictu had low resistance to DDVP, Deltamethrin and Permethrin, the resistant index was 2.14, 2.27 and 4.17, respectively. Aedes albopictus had high resistance to beta-cypermethrin and temephos, the resistant index were 22.84 and21.91, respectively..Conclusions:1. The main vector organisms population of Pingshan district is Rattus norvegicus, Culex Pipiens quinquefasciatus, chrysomyia megacephala and Blattella germanica, respectively;The average density of rattus and ovitrap positive rate were were higher than the national standard, prompting the government should focus on the prevention and control of vector organisms and be ware of the corresponding infectious disease.2.Aedes albopictus from Pingshan district of Shenzhen had different degree resistance on commonly used chemical insecticides, with the highest insecticides resistance are beta-cypermethrin and temephos. The government of Pingshan district should reasonably choice insecticides which can effectively prevent and reduce the occurrence and development of resistance.