Objective To analyze the epidemiological characteristics of Japanese encephalitis (JE) in Jinhua, China from 2007 to 2012 and to provide the foundation for prevention and control of JE. Methods The data on JE was collected from the reporting system for JE, and the epidemiological characteristics of JE in Jinhua during 2007-2012 were analyzed by descriptive epidemiology. Results From 2007 to 2012, a total of 33 cases of JE were reported in Jinhua, and 1 case was fatal; the average incidence rate was 0.11/100 000. The cases were mainly distributed in cities of Yiwu, Dongyang and Yongkang. Thirty-two (96.97%) of all cases were aged under 15 years. The migrant population from other provinces accounted for 72.73% of all cases. The peak season was during July to August. No history of immunization was found in 84.85% of all patients. According to the vector surveillance, Culex pipiens pallens was the dominant species of mosquitoes, accounting for 63.73%. Conclusion From 2007 to 2012, the migrant children from other province, who had no history of immunization with JE, constituted a large proportion of JE cases in Jinhua. Therefore, effective JE control measures should be taken to reinforce the vaccination among migrant children and strengthen the personal protection against mosquitoes in migrant population. Meanwhile, the surveillance of mosquito vectors and reservoir hosts should be conducted.

Objective To determine the insecticide resistance of Culex pipiens pallens from different regions of Zhejiang province, China, to analyze the resistance phenotypes and genotypes of Cx. pipiens pallens and their association, and to provide a baseline data for the mosquito control in Zhejiang. Methods The larva dipping method was used to determine the insecticide resistance of Cx. pipiens pallens from four regions of Zhejiang province, and the genotypes were studied by PCR amplification and sequencing. Results The insecticide resistance of Cx. pipiens pallens varied greatly across different regions of Zhejiang, and beta-cypermethrin, deltamethrin, allethrin, DDVP, acetofenate, or propoxur had a median lethal concentration difference of 2.1 to 42.8 times, with the greatest variations in beta-cypermethrin. The Zhoushan strain had a significantly higher pyrethroid resistance than the strains from other regions. The pyrethroid resistance-associated vssc gene of Zhoushan strain had high polymorphism, and some samples had three neighboring fragment deletions (20 bp, 53 bp, and 40 bp) in the intron region of vssc gene. Conclusion The insecticide resistance phenotype varies greatly in Cx. pipiens pallens from different regions of Zhejiang. The kdr gene of Zhoushan strain has complex polymorphism, further study is warranted to determine whether it is the immediate cause of the change in resistance phenotype.

【Abstract】 Objective To grasp the population density and its seasonal fluctuation of primary vectors in Jinhua city，and to provide the scientific basis for the control of vector. Methods The light-trapping and cage-trapping were conducted to monitor the density of mosquitoes and flies respectively, as well as the night trapping and cockroach paste for rats and cockroaches. Results The average density of mosquitoes in Jinhua city was 12.47/(man·hour) from 2005 to 2007, of which, Culex pipiens pallens was the dominant specie, accounting for 94.46%, followed by Armigeres subalbatus (3.65%) and Anopheles sinensis (1.16%). Flies density index was 50.03/cage and Chrysomya megacephala and Lucilia sericata were the dominant species, which accounted for 36.05% and 24.56% respectively. The density of cockroaches was 126.74/100 nights·pages, and the dominant specie was Blattella germanica (97.95%). There were 135 rats caught and the rats density was 0.33%. Of which, the dominant specie was Rattus norvegicus (51.85%). Conclusion The main control targets  were Cx.pipiens pallens, Cx.megacephala, L.sericata, B.germanica as well as R.norvegicus in Jinhua city, so it should take the integrated measures to reduce the density of main vectors by firstly managing environment according to the characteristics of its breeding, habits and seasonal fluctuation.