Objective To investigate the resistance status of adults Musca domestica to 6 commonly used insecticides in Zhejiang province, providing scientific basis for its prevention and control. Methods We collected adult M. domestica from 12 monitoring sites in Huzhou, Jiaxing, Shaoxing, Taizhou, Yiwu, Lishui, Zhoushan, Quzhou, Wenzhou, Jinhua, Hangzhou, and Ningbo during May and October in 2017, and brought them back to the insectary. Topical application method was used to determine the resistance of M. domestica to 6 commonly used insecticides in 12 cities of Zhejiang province. Results The LD₅₀ values of the twelve monitoring points to beta-cypermethrin, deltamethrin, permethrin, DDVP, propoxur were 0.003 0-3.281 8, 0.005 1-0.262 6, 0.003 1-0.425 3, 0.010 0-40.409 2, and 0.044 7->160.000 0 μg/♀, and the resistance ratio were 0.8-911.6, 3.6-291.8, 6.3-39.4, 1.4-892.0, and 1.9->538.2 fold. The LD₅₀ values of the Hangzhou population to acetofenate was 1.547 8 μg/♀, the resistance ratio was 7.2 fold. Conclusion The adult M. domestica of most monitoring points have been resistant to commonly used insecticides. In practice, insecticides resistance surveillance should be highlighted, and insecticides should be used scientifically and rationally to prevent and reduce the occurrence and development of resistance.

Objective To analyze the impact of rodent density on the incidence of hemorrhagic fever with renal syndrome (HFRS) in Zhejiang province, and to provide background for the prevention and control of the rodent-borne diseases. Methods The monitoring data of rodent density and the incidence of HFRS were collected from January 2005 to December 2014 in Zhejiang province. Spearman correlation analysis and linear regression method were applied for data analysis. Results The average density of rodents in the last decade was 0.88% in Zhejiang province, and the Rattus norvegicus was the predominant species which accounting for 51.16% of the total number. There was correlation with the rodent density and the incidence of HFRS lagging one month to four months, and the correlation coefficients were 0.247, 0.369, 0.328, and 0.213 respectively (P < 0.05). The linear regression found that the rodent density was significantly associated with the incidence of HFRS lagging one month to four months (R²=0.106, 0.167, 0.134, and 0.067, P < 0.05). Every 1% increase in the rodent density, followed by 0.326, 0.409, 0.367 and 0.258 (/100 000) increase in the HFRS incidence lagging one month to four months respectively. Conclusion Rodent density has certain influence on the incidence of HFRS in Zhejiang province. The density monitoring and rodent control should be carried out on a routine basis.

Objective To understand the epidemic characteristics of endemic typhus nearly 10 years in Zhejiang province, and provide a scientific basis for prevention and control. Methods Through the National Disease Reporting Information system, typhus cases data were collected in Zhejiang province from 2005 to 2014, analyzed by descriptive epidemiological methods. Results In total 39 typhus cases were reported in Zhejiang province from 2005 to 2014, the average annual incidence rate was 0.0086/100000. The incidence of the high risk season was June to September, and the cases were distributed in 6 cities, 18 counties (districts), and mainly in rural areas (87.18%). The male to female ratio was (1.05:1), the median age was 47 years old. The average time of clinical diagnosis and laboratory diagnosis were 10.0 d and 14.5 d, two diagnosis regimens of occupational distribution had statistically significant difference (χ²=7.257, P=0.006); gender constitute no statistical difference (χ²=1.293, P=0.256). Conclusion The key area of prevention and control typhus were rural and rural-urban fringe zone of Zhejiang province, health education in tourists and enhanced detection are warranted and improve the ability to detect.

Objective To investigate the infection state and genotype of Wolbachia from Aedes albopictus in central and eastern Zhejiang province, and to provide a reference for mosquito and mosquito-borne disease control. Methods Light traps and human baits were applied to collect adult female mosquitoes, wsp genes of Wolbachia were tested by PCR and sequenced for phylogenetic analysis. Results In total 192 adult female mosquitoes were captured in six sampling sites: Hangzhou, Ningbo, Shengsi, Yiwu, Lishui and Wenzhou. The positive rate of wsp gene of Wolbachia was between 25.0% and 96.9% among these cities. There were 11 wsp haplotype sequences, of which lengths were between 581 bp and 605 bp, the average content of A, T, G and C was 31.4%, 31.1%, 21.5%, 16.0%, respectively. The homology of the nucleotide sequences of wsp was between 76.5% and 99.8%, and the homology of the amino acid sequences of wsp was between 66.2% and 100%. The 11 wsp haplotype sequences were divided in supergroup A (Wolbachia: wAlbA) and B (Wolbachia: wAlbB) by phylogenetic analysis. Conclusion Infection of Wolbachia in Ae. albopictus mosquitoes are widespread by in central and eastern Zhejiang province, whose genotypes belong to wAlbA and wAlbB.

Objective To explore the relevant meteorological factors influencing mosquito density, and to provide theoretical basis for the prediction of mosquito density. Methods The data of meteorological factors and mosquito density were collected from January 2007 to December 2013 in Hangzhou, Quzhou and Wenzhou city, Zhejiang province, respectively. Pearson correlation analysis and multiple linear regression analysis with stepwise were used to explore the influencing factors. Results The average vapor pressure (P=0.000, 95%CI: 0.004-0.007) is significantly associated with mosquito density in Hangzhou city; the average minimum temperature (P=0.000, 95%CI: 0.027-0.055), the maximum daily precipitation (P=0.001, 95%CI: 0.001-0.005) and the extreme minimum station barometric pressure (P=0.041, 95%CI: 0.001-0.029) are significantly associated with mosquito density in Quzhou city; the average station barometric pressure (P=0.012, 95%CI: -0.029- -0.004) is significantly associated with mosquito density in Wenzhou city. The average station barometric pressure (P=0.000, 95%CI:-0.015- -0.007) and the average temperature (P=0.000, 95%CI: -0.013-0.004) have a lagging effect on the mosquito density in Hangzhou city; the average station barometric pressure (P=0.000, 95%CI: -0.079- -0.034), percentage of sunshine (P=0.017, 95%CI:-0.111- -0.012) and the average vapor pressure (P=0.017, 95%CI: -0.050- -0.005) have a lagging effect on the mosquito density in Quzhou city. Conclusion The average vapor pressure, the average station barometric pressure, the average minimum temperature, the maximum daily precipitation and the extreme minimum station barometric pressure may be the main meteorological factors that affect mosquito density. The average station barometric pressure, the average temperature, percentage of sunshine, the average vapor pressure may have a lagging effect on the mosquito density.

Objective To identify the species compositions, densities and seasonal fluctuation of vectors in Zhejiang province from 2011 to 2013, the aim is to provide scientific and technical support for the prevention and control of vectors. Methods Mosquitoes, flies, rodents and cockroaches were monitored with mosquito lamps, cage traps, traps set at night and glue traps. Results From 2011 to 2013, the mosquito density was 1.52, 1.33 and 1.62 per lamp-hour, respectively, with the highest density found in livestock pens, and the dominant species were Culex pipiens pallen (sure not Cx. quinquefasciatus), accounting for 57.44%. Mosquitoes appeared from April and peak in June through August. The fly density was 8.77, 5.67 and 3.47 per cage, respectively, with the dominant species were Chrysomya megacephala from 2011 to 2012, which became Musca domestica in 2013. The rodent density was 0.89%, 0.81% and 0.78%, respectively, with the dominant species were Rattus norvegicus, accounting for 57.70%. Rodents were observed throughout the whole year. The cockroach density was 0.54, 0.37 and 0.35 per glue trap, respectively, with the dominant species were Blattella germanica, accounting for 88.42% . Conclusion Species compositions, densities and seasonal fluctuation of vectors in Zhejiang province were analyzed through 3-year surveillance, mitigation measures should be taken accordingly to control vectors.

Objective To get epidemiological data on plague hosts and vectors in the history of plague epidemic in Zhejiang province, and providing scientific basis for the prevention and control in the province. Methods The rodents were captured in the 20 surveillance sites in the province by trapping, then calculated the rodent density, flea index, flea infected rates, SPSS 17.0 software was applied for statistical analysis of the data; The animal livers and spleens were collected for Yersinia pestis culture and used for indirect hemagglutination assay (IHA) detection F1 antibody of Y. pestis. Results The average indoor and outdoor rodent was 4.19% and 4.47%, there is a considerable difference between the rat density in different regions. The capture was 50 680 rodents, belong to 3 orders, 5 families, 9 genera and 16 species (Subfamily). There were 32 482 rodents and 1062 that were processed. Average flea infected rate was 3.27%, the flea infected rate were different among species, with statistical significance (χ²=3723.567, P=0.000). The fleas are 7 species from 3 genera and 3 families, among different areas there were significant differences (F=5.659, P=0.000). No plague were cultured or detected in 46 881 rodent samples and 49 327 serum samples. Conclusion The composition of plague hosts and vectors is stable, no mouse and human plague epidemic, however plague surveillance standardize should strengthen to be prepared for emergency and plague resurgence.