ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To investigate the taxonomy and distribution of Apodemus species in China, and to provide supportive data for prevention and control of rodent borne disease. Methods DNA barcoding was employed to identify Apodemus samples collected from 22 provincial areas in China. Genomic DNA was extracted from tissue samples for PCR amplification of the mitochondrial cytochrome C oxidase subunitⅠ (COⅠ) gene, followed by sequencing. The obtained sequences were compared with the related sequences in GenBank. Then a phylogenetic tree was constructed. Results COⅠ gene fragment were amplified from 119 Apodemus samples, and they were sorted into eight branches through phylogenetic reconstruction. Compared with the data in the GenBank, the collected samples were identified as eight independent species: Ap. agrarius, Ap. chevrieri, Ap. peninsulae, Ap. latronum, Ap. ilex, Ap. draco, Ap. uralensis and an undefined species. Conclusion The accurate distribution of Apodemus species in China can be determined by effective identification of samples through DNA barcoding. In addition, the results revised the Apodemus species distribution based on the morphological identification.
Objective To identify rodent species in Zhejiang port and analyze the sequence characteristics. Methods The livers were obtained from rodents captured during April to October in 2015. The cytochrome C oxidase subunitⅠ(COⅠ) and 16S rRNA gene sequences of rodents were amplified. The species were confirmed and the phylogenetic trees were constructed. Results There were two species, Rattus norvegicus and Mus musculus in Zhejiang port. The mutation rate of COⅠgene was greater than that of 16S rRNA gene. Most of the mutation was transition and synonymous mutation. Conclusion Both COⅠ gene and 16S rRNA gene, as molecular markers, could be applied to identify rodent species.
Objective To test the resistance to pyriproxyfen in dengue vectors Aedes aegypti and Ae. albopictus and observe the mortality pattern of mosquitoes at various concentrations in Jinghong city, Yunnan province, so as to provide evidence for dengue vectors control and resistance management. Methods Aedes larvae were collected from Dengue epidemic areas in Jinghong from October to November, 2015. WHO recommended methods for insect growth regulators was carried out on the 3rd instar larvae collected. The resistance ratio (RR) was calculated by comparing half inhibition of emergence concentration (IE50) of the tested wild population with the susceptible reference strain. Additionally, the mortality pattern of dengue vectors exposed to pyriproxyfen was analyzed by observing daily stage-specific mortality at various concentrations. Results The IE50s of Ae. aegypti and Ae. albopictus in Jinghong city were 0.024 47 (0.022 09-0.027 07) and 0.135 20 (0.117 10-0.156 60) μg/L. There was 13.44-fold resistance in Ae. albopictus and 0.85-fold resistance in Ae. aegypti to pyriproxyfen compared with the susceptible strains respectively. Aedes albopictus was also 5.53-fold more tolerant to pyriproxyfen than Ae. aegypti in Jinghong city. For the dead individuals, most of them died at 4-6 d after exposure to pyriproxyfen, and the peak of death for susceptible Ae. aegypti and Ae. albopictus were at 4-5 d and 4 d respectively. A wider range of death peak was observed for Jinghong population of Ae. aegypti and Ae. albopictus, which was at 4-6 d. At low concentrations, most of the dead were deformed adults and mosquitoes not completely separated from the pupae. For the susceptible reference strain, dead pupae began to occur steadily when the mortality was over 60%, and the proportion increased as the concentration went up. However, the mortality of pupae was fluctuating in Jinghong population. Conclusion In Jinghong city, Ae. aegypti larvae was susceptible to pyriproxyfen. Considering this species is preferentially found in urban areas, pyriproxyfen is recommended to use in urban areas. Although Ae. albopictus larvae have developed moderate resistance to pyriproxyfen, this larvicide still can be used in alternatery with other insecticides to delay the resistance development. It proves that pyriproxyfen is highly efficient for mosquito control and resistance management in Jinghong city. Periodic resistance monitoring must be conducted to learn the variations of resistance level timely.
Objective To investigate Liaoning virus(LNV) in mosquitoes in Chaoyang district, Beijing. Methods According to the Surveillance for Vector Density-Mosquito (GB/T 23797-2009), mosquitoes were collected by CO2 traps in 2014 and 2015. Reverse transcription-polymerase chain reaction was used to detect LNV. Molecular characteristics were carried out by Mega 6.0. Results A total of 9 811 mosquitoes were collected and Culex pipiens pallens (8 968/9 811, 91.41%) was the main species. The sample BJCY14007 was positive for LNV. LNV has two branches (serotypeⅠand serotypeⅡ) based on the molecular characteristics of the segment 10. BJCY14007 was more related to NE97-12 (representative strain, serotypeⅠ). Conclusion The LNV was firstly detected in Beijing. It deserves further investigation LNV prevalence in mosquito, human population and other hosts for risk assessment.
Objective To investigate the infection and genotype of Wolbachia from Culex modestus at Alataw port, China-Kazakhstan border. Methods Sweeping Netting and Light Trapping were utilized to collect adult mosquitoes at the Yiqu, Erqu and Aibi Lake, wsp genes of Wolbachia were detected by polymerase chain reaction (PCR), the sequence analysis by Blast and phylogenetic analysis by Mega 6.0. Results The positive rate of wsp gene of Wolbachia was 3.33% (2/60) at Alataw port. The wsp haplotype sequences were divided in Supergroup A (wAlbA) and B (wAlbB) by phylogenetic analysis. Conclusion The wAlbA and wAlbB Wolbachia exists in Cx. modestusat Alataw China-Kazakhstan port.
Objective Provision of advices to safe use of aerosol insecticide products for residents. Methods The risk for the residents under the extreme usage of aerosol insecticide products was assessed through the space spraying model from US-EPA to compute the extreme usage of the ten most popular prodicts in the market. Results For the sprayers (adult), ten kinds of extreme use of pesticides were 285.94, 268.80, 52.36, 193.75, 566.14, 937.60, 147.69, 230.40, 222.66 and 814.86 g/d. For the adult residents, ten kinds of extreme use of pesticides were 83.40, 78.40, 15.27, 56.51, 165.12, 273.47, 43.08, 67.20, 64.94 and 237.67 g/d. For the juvenile residents, ten kinds of extreme use of pesticides were 20.10, 18.90, 3.68, 13.62, 39.81, 65.93, 10.38, 16.20, 15.66 and 57.29 g/d. Conclusion Safe use of aerosol insecticide products not only can prevent resistance development, but also can minimize risk of professional and environmental exposure.
Objective Establishment of an economic, efficient, accurate and convenient detection method for the bacteria carried by medical vector with the high-throughput sequencing platform(NGS). Methods Optimizing the pretreatment method of the samples, and then sequencing with the NGS techniques through the Illumina high-throughput sequencing platform, detecting the V3 variable regions of 16S rRNA to study bacteria carried by Chrysomya megacephala. Results Ninty-five bacteria carried by C. megacephala were identified to species and 235 species were identified to genus with the improved method, which exceeded the bacteria species identified in the previous studies with the traditional methods. Conclusion The methods of sample collection, pretreatment, and PCR conditions established in this study, sequencing with the Illumina high-throughput sequencing platform were effective and trustworthy, identification of bacteria pathogens carried by medical vector with this method is feasible.
Objective To investagate the horizontal transmission of Beauveria bassiana CF08 strain in population of Musca domestica adults under the laboratory and field conditions. Methods After spraying spores or introducing infected houseflies to healthy houseflies, the prevalence of infection was recorded. Results The pathogenicity of B. bassiana CF08 strain between female and male houseflies had no significant difference (t=1.220, P=0.240). Under laboratory conditions, with the increasing proportion of infected houseflies in population, the infection rate of healthy houseflies increased up to 80%. But in the fields, the infection rate of healthy houseflies only to 12%. Conclusion Beauveria bassiana CF08 strain could horizontally transmit in house flies populations under laboratory conditions, but was not suitable for control wild house flies in the fields.
Objective To study the effects of the branch powder of Rhododendron micranthum Turcz on the oviposition, growth and development of Musca domestica. Methods Rearing media with added branch powder of Rh. micranthum Turcz was used to feed M. domestica and observed in the laboratory. Results The minimum effective concentration of the branch powder of Rh. micranthum Turcz inhibited the oviposition of M. domestica was 4%,effective for up to 60 h. The concentration of 5% the branches powder caused a sluggish development and prolonged larval stage of M. domestica, delaying development for 0.8 d. The test material had no obvious effects on the pupation of M. domestica. Conclusion The branche powder of Rh. micranthum Turcz influences the oviposition, growth, and development of M. domestica, reducing the experimental populations.
Objective To survey the species distribution, community composition, and the blood-sucking rate of the main hematophagous midges of Suiyang county of Guizhou province, China. Methods The light (photocatalytic UV trap lamp) trap was used to capture blood sucking midges in different livestock sheds, which were then classified and identified. Results We obtained 31 167 blood sucking midges in Suiyang belonging to 2 genera 18 species, of which 15 species belonged to Culicoides, 3 species belonged to Lasiohelea. There were 10 new recorded species in Guizhou province, C. gymnopterus, C. kinabaluensis, C. mcdonaldi, C. nipponensis, C. orientalis, C. qianweiensis, C. tentorius, La. lushana, La. relicta, and La. ripa. The predominant species was C. orientalis (72.08%). The main species composition of the blood sucking midges varied among different livestock sheds. The total blood sucking rate of three main species was 40.12%, in which C. punctatus had the highest (56.41%) and C. orientalis had the lowest (36.88%) blood sucking rate. The three main hematophagous midge species had a different blood sucking rate in different livestock sheds. Conclusion The hematophagous midge species and blood sucking rate varied in different livestock sheds in Suiyang, which provides a basic data for the prevention and control of blood sucking midges and the species diversity research in Guizhou province.
Objective To investigate the resistance status of Aedes albopictus to used insecticides in the late stage of dengue fever emergency control of Guangdong province in 2014, and learn how to prevent the development of resistance. Methods From the end of October to the beginning of November 2014, larve of Ae. albopictus were collected in epidemic regions in Haizhu and Baiyun district of Guangzhou city, Chancheng and Nanhai district of Foshan city, Chaoyang district of Shantou city, Chao'an district of Chaozhou and Rongcheng district of Jieyang city, and were reared about 1 to 2 generations in the lab, then were tested along with the susceptible larvae according to the methods of national standard “Test Methods of mosquito resistance to insecticides-bioassay methods”(GB/T 26347-2010) to calculate LC50 and resistance index. Results Aedes albopictus of all tested regions had low resistance to temephos and propoxur, the resistant index was 4.92-8.33 and 2.35-6.23 fold respectively. The resistantce to permethrin, beta cypermethrin, deltamethrin resistance were 3.53-31.29 fold, 8.35-38.69 fold, and 2.63-37.04 fold respectively. Of pyrethroid insecticides, Guangzhou city have reached the high level resistance mostly, Foshan city, Chaozhou city mostly low level of resistance, Jieyang city for low level of resistance, Shantou city mostly above the moderate level of resistance against cypermethrin. Aedes albopictus from some cities also have developed resistance to other insecticides in different levels. Conclusion Resistance of Ae. albopictus in the dengue epidemic cities in Guangdong increased very quick to the used insecticides. The control of Ae. albopictus should adhere to the principle of sustainable and integrated management to prevent or delay the development of resistance.
Objective To decide the predominant mosquito species in Yongcheng city, and their natural occurrence, density, seasonal fluctuation, and habitat distribution. The results will guide the vector management in this area. Methods Light-trapped method was used twice a month in three towns which lies in different direction in Yongcheng area. Dwellings, houses premises, and livestocks were selected as the surveillance sites in each town. Excel 2007 and SPSS 20.0 were used for data analysis. Results The total mosquito number obtained in 2010 were 20 684 with the average density 34.08/(trap·night). Culex tritaeniorhynchus took up to 54.12%, which was the predominent species. The mosquito density in livestocks was 50.58/(trap·night) which was the highest; the mosquito density around dwellings and their premises had no significant difference. Mosquito density showed statistical significance in 3 surveillance habitats (F=74.450, P<0.01). Mosquito density began to increase in July, reach a small peak activity in late July, and reached the highest peak activity in September, followed a decline in October. The mosquito density in Renhu and Mengzhuang villages reached the peak in early September, showed a unimodal peak activity. Renhu had the highest mosquito density. Three towns showed statistically significant differences in mosquito species and their density (χ2=2 033.097, P<0.01). Conclusion The distribution of mosquitoes in Yongcheng city varied according to habitat and village characteristics, then the mosquito prevention and control work should be based on the mosquito distribution in different habit, different village, and seasonal performance by species in this area.
Objective To investigate mosquito composition,distribution and habitats in Chuxiong prefecture of Yunnan province and provide evidences to prevent local arboviral infectious diseases. Methods Three counties were choosen and then two natural villages in each county were selected randomly from July to August in 2014. Adult mosquitoes were collected by overnight trapping with light trap and double-bednets. Larvaes were collected in different breeding sites around villages. Results A total of 12 711 adult mosquitoes from 23 species of 6 genera in 2 subfamily were collected. Among them, 12 384 adult mosquitoes from 15 species in 4 genera were collected by overnight trapping with light trap and the maximal amount species were Culex tritaeniorhynchus (59.95%). The average population density of adults mosquitoes were 344.00 of each light trap with overnight trap. Besides, a total of 327 individuals were collected from 11 species in 4 genera by double-bednets, of those Aedes albopictus as dengue vector were local predominant species (19.88%). The average population density of adult mosquitoes was 5.90 per labor hour by double-bednets. A total of 8 586 larvae were collected from 22 species of 6 genera in 2 subfamilies, of those Cx. tritaeniorhynchus was the most (27.50%). Conclusion The species richness was high in 3 counties of Chuxiong prefecture and different mosquito species with different habitats. The predominant species were Cx. tritaeniorhynchus. Other four species including Cx. pipiens quinguefasciatus, Anopheles sinensis, An. minimus, and Ae. albopictus were sub-dominant species. Afore mentioned five mosquitoes specises are wild spread with large populations and deserve our attentions.
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 research the serial toxic effects of 0.05% fipronil cockroach gel bait on adults and nymphs of Blattella germanica. Methods This experiment used pipette to offer insecticide in the first efficacy experiment; and the serial toxic effect experiment was conducted using the dead insect of last serial toxic effect experiment to feed the cockroach. Results The first to fourth secondary effects of tested insecticide on adults reached 100%, the fifth secondary effects from the remains amounted to 78.3%. Against nymphs, however, only the first two secondary effects reached 100%, the third and fourth mortality were only 48.3% and 15.0%. The results indicated that 0.05% fipronil cockroach gel bait can continuously controlB. germanica effectively and it was more effectively on adults than on nymphs. Conclusion Fipronil has a good serial toxic effect on B. germanica.
Objective To study the efficacy against fleas and mites on rodents with Baishajing-aerosol product. Methods Dermatophagoides farina and Xenopsylla cheopis were selected as test subjects, an ultrafine atomizer was used to spray Baishajing-aerosol agent into simulated site to evaluate the efficacy of this product against fleas and mites. Sulphuryl fluoride and Baishajing-aerosol agents were further sprayed into the container respectively to compare the killing effect against fleas and mites. Results Fleas (24 h) and mites (48 h) mortality caused by Baishajing-aerosol agents were 100% in simulated field. In 33.28 m3 (5.90 m×2.35 m×2.40 m) and 67.68 m3 (12.00 m×2.35 m×2.40 m) heavy container field sites, X. cheopis (24 h) mortality in Baishajing-aerosol agents and Sulphuryl fluoride groups were 100%, but there was significant difference in mortality of D. farina (48 h) in Baishajing-aerosol agents and sulphuryl fluoride groups (χ2=842.418, 690.344,P<0.001). Sulphuryl fluoride group had no obvious acaricidal effect. Conclusion Baishajing-aerosol agent has a remarkable control effects against fleas and mites, and it is worthy of further research and application.
Objective Three suspected brucellosis cases were investigated in Suizhou city of Hubei province, and three suspected Brucella strains were identified. Methods Field investigation was applied to finish Brucella epidemiological survey, used Brucella conventional appraisal classification method and the phage cracking test for testing. BCSP31-PCR method (Based on Brucella genus specific gene BCSP31 target gene detection method), AMOS-PCR (based on electrophoresis banding identify B. abortus biovar 1, 2, 4 of Brucella, B. melitensis, B. ovis and B. suis biovar 1) and Real-time PCR, three molecular classification method were compared. Results Three patients were infected by close contact with sick animals and their meat, conventional identification and a variety of polymerase chain reaction (PCR) had the same results, B. melitensis biovar 3. Conclusion Brucella melitensis biovar 3 was identified as the pathogen of the three cases from Suizhou city and cases were mainly caused by direct contact with sick animals and their meat.
Objective To explore the main risk factors related to the incidence of Japanese encephalitis (JE), and to provide evidence for the prevention and control of JE.Methods We collected the data about case information by searching PubMed, China National Knowledge Infrastructure (CNKI), China Biology Medicine Disc (CBM), Wanfang Database, and database for Chinese Technical Periodicals (VIP) from 1995 to 2015, and we applied Stata 12.0 software for the Meta-analysis. Results Totally 7 case-control studies were selected (including 412 cases and 763 controls).The results of Meta-analysis showed that the factors of raising swines, house location, immunization history, and using screen windows were influential factors, and the OR value (95%CI) were 2.87(2.01-4.10), 2.46(1.55-3.89), 0.12(0.04-0.37), and 0.37(0.17-0.83), respectively. Conclusion Raising swines and living in the peripheral villages were risk factors of JE, and JE vaccination and using screen windows were protective factors.
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 To study rodent-harborage pathogens in Inner Mongolia Manchuria port during 2013-2015, in order to provide basic information for surveillance. Methods To detect 12 pathogens in rodents by using nucleic acid detection method. Results There are more types of rodents in Manchuria port area,and the main pathogens were Bartonella and Hantavirus (HV), Bartonella detection rate was 9.09% in 2013, HV detection rate was 2.34% in 2014. Conclusion Bartonella and HV were the main pathogens transmitting among rodents in Inner Mongolia Manchuria port, the detection of these 2 pathogens should be strengthened to prevent the occurrence of the diseases.
Objective To understand the mutations of Yersinia pestis, all of strains isolated in Tibet during 2009 to 2011 were selected to identify the biochemical features of the pathogen. Methods Traditional methods like glycerol fermentation, glucose metabolism and nitrate reduction were carried out. Tested strains isolated from Tibet during the year of 2009 and 2011, were incubated in biochemical action tubes made recently in 28℃ for 14 d, and the color of every tubes was observed and recorded each day. Results All of 111 tested strains were able to reduce nitrate and ferment glycerol, but unable to catabolize rhamnose; Nine of tested strains were capable of catabolizing arabinose, six of them isolated from Naqu and the other three from southern valley of the Qinghai-Tibet Plateau; The results of arabinose metabolism of the other 102 strains were all negative. Conclusion It was suggested that all tested strains belong to Biovar Antiqua. Those Y. pestis strains isolated from Naqu located in the northern Tibet were Qinghai-Tibet Plateau Ecotype, and most strains isolated from southern valley of the Qinghai-Tibet Plateau were Gangdise Mountain Ecotype except only three strains, which had the same biochemical features as the strains of Qinghai-Tibet Plateau Ecotype. It needs to utilize molecular methods through analyzing genetic markers to type the three special Y. pestis strains.
Objective To investigate the distribution and species of ticks and rodents that were involved in the transmission of severe fever with thrombocytopenia syndrome(SFTS). Methods SFTS that occurred at Yaoshang village, Guangfu town, Wuzhong district of Suzhou city was investigated. The free ranging ticks were collected by flagging and the parasitic ticks were collected off the hosts by hand from June 14th to 18th in 2016. Small mammals were captured by cage-trapping. The specimens of serum,heart, liver, spleen, lung, and kidney were collected with sterile operations. The severe fever with thrombocytopenia syndrome virus(SFTSV)nucleic acid in the viscera of small animals and in the ticks were detected by real-time PCR. Results A total of 100 ticks were collected, consisting of 4 species, including 37.00% Haemaphysalis sinensis, 29.00% H. flava and 26.00% H. longicornis, separately, which composed the predominant species in Suzhou city. The total number of captured small animals was 17, including 3 species rodents, 1 species Erinaceidae and 1 species insectivora. The results were negative in RNA detection of SFTSV in the specimens of ticks and small animals by real-time PCR. Conclusion The tick vectors and the host animals of SFTSV were found in Suzhou city, but the transmission mechanism between the vectors and the possible hosts need further studies.
Objective To analyze the epidemiological characteristics of the first dengue fever outbreak as well as the density and seasonal fluctuation of Aedes mosquitoes. Methods The reported cases and epidemiological data of dengue fever and mosquito vectors in Yunfu city were analyzed statistically and described. The density of Aedes larvae was monitored by Bretu index method, and that of adult mosquito populations by mosq-ovitrap method. Results There was 22 cases of dengue fever in Yunfu city in 2014, the incidence was 0.91/100 000, including 10 imported case and 12 local cases. Monitoring the mosquito vectors density in 10 sites during July through November in 2014, Aedes Breteau index fluctuated between 3.46-6.58, Mosq-ovitrap average index was 3.39. Conclusion The prevention and control of dengue fever in Yunfu city warrants more attention, low risk does exist for local outbreaks of dengue fever, suggesting to strengthen mosquito-borne disease surveillance, as well as studies on relevant natural and social factors.
Objective To monitor the resistance status of Culex pipiens pallens to commonly used insecticides in Hohhot city and the surrounding areas for management of insecticide resistance development. Methods The susceptibility of larvae to five commonly used insecticides was tested by WHO larval immersion method to determine the median lethal concentration (LC50) and 95% confidence intervals (95%CI). Results In Hohhot city, Qingshuihe, Wuchuan, Tuoketuo, Helingeer county, and Tumed Left Banner, the resistance ratios of Cx. pipiens pallens for deltamethrin were 1.09, 0.05, 0.77, 0.09, 0.87, and 0.09 fold; for permethrin were 0.97, 0.09, 0.63, 0.11, 1.16, and 0.07 fold; for beta cypermethrin were 1.18, 0.08, 0.19, 0.01, 0.08, and 0.06 fold; for parathion were 1.22, 0.73, 7.96, 0.68, 1.21, and 1.37 fold; for DDVP were 5.02, 0.89, 0.01, 0.09, 1.06, and 0.17 fold, respectively. Conclusion Culex pipiens pallens in Hohhot city and the surrounding areas is overall susceptible to above five commonly used insecticides, except that Cx. pipiens pallens in Wuchuan country and Hohhot city have low resistance to parathion and DDVP, respectively.
Objective To investigate the resistance of Aedes albopictus to five insecticides and provide evidence for rational application of insecticides.Methods WHO-recommended larva dipping method was used to test medium lethal concentration of the larvae at their fourth instar in this test, exposed to the five commonly used inseticides and to assess the levels of resistance in Ae. albopictus. Results The LC50 of abate, deltamethrin, betacypermethri, and fenobucarb was 0.001 3, 0.001 4, 0.005 1, and 1.568 5 mg/L. The average resistance was 4.3, 1.4, 2.4, and 1.0 fold. Resistance to acetofenat was so high, beyond the test range. Conclusion In Wuhan city, the field monitoring of Ae. albopictus on insecticide resistance is crucial for the prevention and control of dengue fever. It was necessary to apply integrated measures and use insecticides scientifically in controlling Ae. albopictus.
Objective To compare field rodent control efficacy using various methods and provide scientific data for deratization in the future. Methods To observe the change of rat density before and after deratizatio at the experimental animal center from September to November 2015. Glue rat board was continuously used in the finished feed warehouse, using bromadiolone baits in raw material storehouse, production workshop using the mousetrap method, the conventional animals feeding chamber by cage-trap. Results A total of 122 rats were captured in 18 d, after deratization average rat density dropped to 6.8% from 59.1% prior to the deratization; corrected deratization rate was 79.2%. Peak was in first day by three physical deratization methods, after a downward trend, the rat density were significantly lower after deratization, but did not reach the standard (≤3%). Dead rats were found after 3 d using bromadiolone baits, 5-6 d to peak, rat density decreased to 0 after deratization. Conclusion Various methods used for prevention and control of rodents obviously reduced the density of rodents. The deratization methods which fit different environments were screened according to the feeding habit, in order to choose rodent bait and control devices efficiently.
Objective According to the analysis of the strategies, measures and achievements of the vector control in old communities in Haidian district, to provide experiences and models for large-scale vector control activities in the future. Methods According to the sanitary condition in the old communities, integrative control measures were implemented. Based on the environmental management, proper chemical controls were conducted in different environments, such as space spraying, residual spraying and so on. The effect was evaluated by density estimation. Results The control was conducted in 124 communities. Compared with the same period of the previous year, mosquito density decreased by 95.03% and house fly density decreased by 91.53%. Conclusion A new vector prevention and control was achieved during this activity, which effectively mitigated the impact caused by vectors in such communities. The efficacy meets the national standard. In addition, these achievements attracted the attention, support as well as welcome from the general publics.
The main factors that influence the density of mosquitoes include meteorological, geographical landscape and environmental factors. The geographical landscape is closely related to mosquito density. At present, most of the studies in China and abroad are based on the application of geographic information system (GIS) and remote sensing to analyze the influence of geographical landscape factors on mosquito density in large scales. The original research on regional geographical landscape and mosquito breeding mainly concentrated in rural areas where the density of mosquito is higher. However, simple statistics are made in urban areas. With the accelerated urbanization, the domestic and foreign scholars are studying the relationship between mosquito density and geographical landscape factors in the process of urbanization. This article mainly summarizes the influence of geographical landscape factors on mosquito density from three aspects of land use, water distribution and spatial distribution of vegetation, and the current research progress and future development direction of the field are briefly described.
