Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
An analysis of surveillance results of small mammals and body surface fleas in the Chongqing section of the Three Gorges Reservoir Region, China, 2019-2021
WANG Ling, HE Ya-ming, JI Heng-qing, LI Zhi-feng, ZHAO Ting, HUANG Wei, XIAO Han-sen
Abstract48)   HTML    PDF (741KB)(331)      
Objective To analyze the surveillance results of small mammals and their body surface flea vectors in the Chongqing section of the Three Gorges Reservoir Region, China, ao as to provide basic data and scientific guidance for the prevention and control of rodent-borne diseases. Methods The surveillance data of small mammals and their body surface flea vectors in the Chongqing section of the Three Gorges Reservoir Region from 2019 to 2021 were collected to analyze the changes in the species composition, density, flea infestation rate, and flea index of small mammals. The Chi-squared test was performed for analysis of data using SPSS 25.0. Results A total of 2 860 small mammals of 10 species were found in the Chongqing section of the Three Gorges Reservoir Region, with a mean density of small mammals of 1.67%. In residential areas, the mean small mammal density was 2.74%; the density showed a decreasing trend over the years ( χ 2=22.493, P<0.001); and the dominant species were Rattus tanezumi, R. norvegicus, and Mus musculus. In cropland, the mean density of small mammals was 0.60%; the density of small mammals fluctuated at relatively low levels, with a statistical difference between the years ( χ 2=41.953, P<0.001); and the dominant species were R. tanezumi, Anourosorex squamipes, and Leopoldamys edwardsi. There was a statistical difference in the composition ratio of small mammals between residential areas and cropland areas ( χ 2=1 003.754, P<0.001). The flea infestation rate of the small mammals was 18.67%, and the total flea index was 0.70. The dominant flea species was Leptopsylla segnis. Serum antibody against plague was not detected. Conclusions The species and density of small mammals in the Chongqing section of the Three Gorges Reservoir Region during 2019 to 2021 have changed significantly as compared with the completion of the Three Gorges Reservoir. R. tanezumi is the dominant rodent species, and its indoor density is much higher than the national plague control standard limit. The flea species include L. segnis and Xenopsylla cheopis. Great attention should be paid to strengthening plague monitoring and timely rodent and flea control.
2023, 34 (5): 642-647.    doi: 10.11853/j.issn.1003.8280.2023.05.011
Surveillance results of rodent-borne pathogens in Chongqing, China, 2021-2022
XIAO Han-sen, HE Ya-ming, TU Tao-tian, ZHANG Ying, WANG Zheng, JI Heng-qing
Abstract89)   HTML    PDF (580KB)(421)      
Objective To monitor five common pathogens carried by small mammals in key areas of Chongqing, China, so as to provide a scientific basis for the prevention and control of local rodent-borne diseases. Methods From 2021 to 2022, small mammals were collected using cage traps at night at three surveillance sites in the central urban area, Wanzhou District, and Fuling District of Chongqing. The liver, spleen, lung, and kidney tissues were collected to extract nucleic acids for detection of Leptospira interrogans, Rickettsia mooseri, and Bartonella by quantitative real-time PCR (qPCR) as well as Hantavirus and Dabie bandavirus by reverse transcription qPCR. Excel 2010 was used to sort and arrange the data. The SPSS 22.0 software performed statistical analysis on the experimental data. The species composition ratio and pathogen infection rate of rodents were compared by the Chi-squared test. Results A total of 1 188 small mammals were collected, among which Rattus norvegicus accounted for 33.50%, R. tanezumi accounted for 26.77%, Anourosorex squamipes accounted for 26.01%, and Mus musculus accounted for 9.85%, in addition to Leopoldamys edwardsi, R. nitidus, N. confucianus, Apodemus agrarius, and Crocidura attenuata, with a total of nine species. There was a significant difference in the species composition of small mammals between different surveillance sites ( χ 2=714.786, P<0.001). Four samples were positive for Seoul Hantavirus, 24 for L. interrogans, and 8 for Bartonella; the remaining samples were negative. A total of 33 small mammals were found positive, including 2 R. tanezumi and 1 R. norvegicus carrying both L. interrogns and Seoul Hantavirus. The overall infection rate was 2.78% for all pathogens, 0.34% for Hantavirus, 2.02% for L. interrogans, and 0.67% for Bartonella. There was a significant difference in the infection rates of the three pathogens ( χ 2=18.857, P<0.001). Conclusions L. interrogans, Bartonella, and Hantavirus were detected in small mammals in Chongqing. These pathogens were most frequently found in R. norvegicus, R tanezumi, and A. squamipes, which were mainly distributed in the key industries of urban Chongqing and the rural residential areas of Wanzhou District, and the authorities of these places should pay more attention to the spread and control of rodent-borne diseases.
2023, 34 (5): 628-632.    doi: 10.11853/j.issn.1003.8280.2023.05.008
An investigation of the insecticide resistance of Aedes vector after emergency control of a dengue fever outbreak in Chongqing, China, 2019
TU Tao-tian, XIAO Han-sen, MENG Feng-xia, LIU Qi-yong, LIU Xiao-bo, HE Ya-ming, JI Heng-qing
Abstract232)      PDF (515KB)(950)      
Objective To investigate the resistance of Aedes albopictus to commonly used insecticides, after control of a dengue fever outbreak in Chongqing, China, 2019, and to provide a basis for controlling mosquito-borne diseases including dengue fever and Aedes vector. Methods From May to October, 2020, Ae. albopictus mosquitoes were collected from parks or waste tire piles in 6 districts (counties) of Chongqing and were reared for 1-2 generations in laboratory, and the larval dipping method and the adult exposure tube method were used for insecticide resistance surveillance. Results Ae. albopictus larvae from each investigation site of Chongqing had varying degrees of sensitivity to commonly used insecticides, with a resistance ratio of 0.46-7.32. The resistance ratio was 0.46-4.92 for temephos and 0.82-7.32 for propoxur. Adult Ae. albopictus mosquitoes from each investigation site of Chongqing developed varying degrees of resistance to deltamethrin, permethrin, beta-cypermethrin, and lambda-cyhalothrin, with a 24-hour death rate of 5.88%-78.22%. The adult Ae. albopictus mosquitoes in the field of Wanzhou district developed suspected resistance to bendiocarb and fenitrothion, and those in the field of Dazu district developed suspected resistance to chlorpyrifos; the adult Ae. albopictus mosquitoes in the field of the remaining investigation sites were sensitive to propoxur, bendiocarb, malathion, fenitrothion, and chlorpyrifos. Conclusion Ae. albopictus adult mosquitoes from each investigation site of Chongqing develop resistance to pyrethroids, and Ae. albopictus larvae from some investigation sites develop a low level of resistance to temephos and propoxur. It is recommended to regularly monitor the resistance level and changing trend of Ae. albopictus and to select corresponding insecticide use strategies according to the insecticide resistance of Ae. albopictus at different developmental stages.
2022, 33 (1): 44-47.   doi: 10.11853/j.issn.1003.8280.2022.01.008
Advances in research and application of cockroach-killing baits
XIAO Han-sen, HE Ya-ming, JI Heng-qing
Abstract341)      PDF (549KB)(835)      
Cockroaches are of common hygiene pest worldwide that seriously threatens human health. Because they like to hide in the dark environment, placing baits has become an important way to kill cockroaches indoors. However, the long-term use of conventional chemical insecticides is harmful to the human body and the indoor environment, and also leads to the development of insecticide resistance in cockroaches. Therefore, it is particularly important to develop safe and effective cockroach-killing baits. This article summarized the current advances in the research and application of cockroach-killing baits, in order to facilitate the exploration of new methods to prevent and control cockroaches in the future.
2021, 32 (5): 642-646.    doi: 10.11853/j.issn.1003.8280.2021.05.027
Efficacy of Metarhizium anisopliae CQMa421 bait against cockroaches: A laboratory and field study
HE Ya-ming, JI Heng-qing, PENG Guo-xiong, XIAO Han-sen, TU Tao-tian, ZHANG Ying, YU Zhan, LIU Zong-ling, WANG Xiu-juan, LI Ming
Abstract416)      PDF (527KB)(933)      
Objective To evaluate the effects of the Metarhizium anisopliae CQMa421 bait in controlling Blattella germanica in both laboratory and field settings, and to provide a reference for the application of fungal insecticides in the control of hygiene pests. Methods The M. anisopliae CQMa421 baits at different concentrations were prepared, and their effects on the population density of B. germanica were measured in the laboratory and field settings. SPSS 25.0 software was used to analyze mortality, median lethal time (LT 50), median lethal concentration (LC 50), and 90% lethal concentration (LC 90) to evaluate the cockroach-killing effects of the M. anisopliae CQMa421 baits. The chi-square test was used to compare mortality between groups. Results The laboratory test showed that after feeding B. germanica for 12 days with the M. anisopliae CQMa421 bait at 1×10 8 spores/g, LT 50was (6.85±0.24) days. In the field test, after placing the M. anisopliae CQMa421 bait at 1×10 8 spores/g (1 box/per 2.5 m 2) for 30 days, the relative density of B. germanica decreased by 93.22%. Conclusion The M. anisopliae CQMa421 bait at 1×10 8 spores/g can effectively control the population density of B. germanica.
2021, 32 (5): 633-636.    doi: 10.11853/j.issn.1003.8280.2021.05.025
A study of the population distribution and density changes of mouse-like rodents in the Chongqing section of the Three Gorges Reservoir Area,China
HE Ya-ming, MAO De-qiang, JI Heng-qing, LI Hong, ZHANG Chun-hua, XU Jie, LYU Xiao-yan
Abstract305)      PDF (3013KB)(901)      
Objective To investigate the population distribution and density changes of mouse-like rodents in the Chongqing section of the Three Gorges Reservoir Area, China, and analyze the ecological influence of the Three Gorges Project on rodents, for an understanding of the potential spreading risk of rodent-borne diseases. Methods The surveillance data of mouse-like rodents in the Chongqing section of the Three Gorges Reservoir Area from 2005 to 2018 were collected for descriptive and linear regression analyses by Excel 2010 and SPSS 25.0 softwares, respectively. Results Thirteen species of mouse-like rodents were found in the Chongqing section of the Three Gorges Reservoir Area, with a total density of 1.68%. In residential areas, the density was 2.01%, and the dominant species were Rattus tanezumi,R. norvegicus, and Mus musculus. In cropland, the density was 1.37%, and the dominant species were Insectivora, R. tanezumi, and R. norvegicus. The density of mouse-like rodents in cropland showed a decreasing trend along the flow of the Yangtze river. The total density tended to increase with years, and reached its peak in March throughout the year. The density of R. tanezumi increased significantly with years, especially in residential areas. Conclusion The population distribution and density of mouse-like rodents have changed significantly after the completion of the Three Gorges Reservoir, and there is a risk of occurrence and spread of rodent-borne diseases. Surveillance and control of mouse-like rodents should be strengthened.
2020, 31 (5): 580-586.    doi: 10.11853/j.issn.1003.8280.2020.05.016
An analysis of emergency surveillance results of Aedes vector before mosquito control in the epidemic areas of dengue fever outbreak in Chongqing, China, 2019
XIAO Han-sen, HE Ya-ming, SHEN Tian-zhanhong, WANG Yi-qi, YANG Xue-fan, TU Tao-tian, JI Heng-qing
Abstract312)      PDF (723KB)(930)      
Objective To investigate the results of emergency surveillance of Aedes vector before mosquito control after the occurrence of the index case of dengue fever in the epidemic areas of Chongqing, China, and to provide a basis for future surveillance of Aedes vector and early warning research on the risk of local transmission of dengue fever. Methods The surveillance data of Aedes vector were collected after the first cases of dengue fever were reported and before the mosquito control measures were adopted in each epidemic area of Chongqing, including Breteau index (BI) and double mosquito net index (DMNI), and SPSS 25.0 software was used for data description and linear regression analysis. Results The average BI for the first-time emergency surveillance in all epidemic areas was 11.01, and the average was 5.10 mosquitoes/net·hour, with a positive correlation between the two indices ( r=0.517, P<0.05). The bivariate linear regression analysis was used to establish the regression equation of BI and DMNI: y (BI)=7.07+0.82 x ( F=61.232, P<0.005), and the early warning of dengue fever risk in Chongqing was stratified into four levels based on this equation. Conclusion Graded assessment of BI and DMNI acts as an indicator for the early warning of dengue fever risk. For Chongqing, BI controlled below 7 and DMNI controlled below 3 mosquitoes/net·hour may reduce the risk of local outbreak of dengue fever.
2020, 31 (3): 268-271.    doi: 10.11853/j.issn.1003.8280.2020.03.005
An analysis of rodent surveillance results at national-level surveillance sites in Chongqing, China, 2018
TU Tao-tian, FENG Shao-quan, HE Ya-ming, YANG Xue-fan, XIAO Han-sen, JI Heng-qing
Abstract304)      PDF (401KB)(773)      
Objective To investigate the community structure, density, and seasonal variation of rodents at national-level surveillance sites in Chongqing, China, and to provide a basis for the prevention and control of rodent-borne diseases. Methods From January to November, 2018, the trap-at-night method and the route index method were used at four national-level surveillance sites in Chongqing. SPSS 25.0 software was used for statistical analysis, and the chi-square test was used for comparison of constituent ratio. Results In 2018, the density of rodents was 0.98% in urban surveillance sites and 0.73% in rural surveillance sites, with a mean density of 1.15% indoors and outdoors, and the highest density was observed in special industries (1.74%). The mean route index of rodents was 1.81/km in the external environment of various places, and the highest index was observed in waste transfer stations and public toilets (2.86/km). The dominant species was Mus musculus in both urban and rural areas, and there was a significant difference in the composition of rodent species between different habitats ( χ 2=32.814, P<0.001). Conclusion This study provides preliminary results of the rodents in Chongqing, and reasonable prevention and control measures should be adopted based on surveillance results in districts and counties.
2019, 30 (6): 711-712.    doi: 10.11853/j.issn.1003.8280.2019.06.028
An investigation of the distribution of mosquito populations in Chongqing, China, 2018
HE Ya-ming, TU Tao-tian, SHEN Tian-zhanhong, XIAO Han-sen, FENG Shao-quan, YANG Xue-fan, YE Sheng, YU Zhen, CHEN Shuang, WANG Yi-qi, TANG Yun, LUO Fei, JI Heng-qing, LIU Qi-yong
Abstract335)      PDF (3826KB)(853)      
Objective To investigate the distribution of mosquito populations in Chongqing, China, and to provide a basis for the development of mosquito control measures. Methods From August to October, 2018, eight districts/counties in Chongqing were selected according to their geographical locations for field investigation in both urban and rural areas. Mosquitoes were captured by trapping lamps, mosquito data were collected and descriptively analyzed by Excel 2010 and ArcGIS 10.60 softwares, and the rank sum test was used by SPSS 25.0 software for different mosquito species density in urban and rural areas. Results A total of 5 species of mosquitoes in 4 genera were collected, and the total mosquito density was 14.83 only/(lamp·hour). The urban mosquito density was 0.67 only/(lamp·hour), and the dominant species were Culex pipiens quinquefasciatus and Aedes albopictus; the rural mosquito density was 18.69 only/(lamp·hour), and the dominant species were Cx. tritaeniorhynchus and Armigeres subalbatus. Rongchang area had the highest total mosquito density, and the density of Cx. tritaeniorhynchus in rural areas was higher than that in urban areas (Z=-3.019, P=0.003). Conclusion The total mosquito density is relatively high in Chongqing, and appropriate mosquito control measures should be taken according to local conditions to prevent and control the occurrence of mosquito-borne diseases.
2019, 30 (5): 570-573.    doi: 10.11853/j.issn.1003.8280.2019.05.022
An investigation of potential plague foci in Yunyang county, Chongqing, China, in 2018
HE Ya-ming, LI Hong, JI Heng-qing, ZHANG Lin, ZHANG Xing, GAN Peng
Abstract287)      PDF (563KB)(819)      
Objective To investigate the populations and carried pathogens of plague-related host animals and vector fleas in Yunyang county of the Three Gorges Reservoir Area, and to understand the potential risk of plague occurrence in this region. Methods In April 2018, an investigation was conducted in the cultivated land and residential areas of Yunyang county, Chongqing. Rodents were captured by cage trapping method. Rodents and parasitic fleas collected by comb inspection were identified. Rodent blood was collected for serological testing. Results A total of 8 species of rodents were captured, the total rodent density was 2.52%, capture rate. The indoor and outdoor dominant species were Rattus tanezumi and Apodemus agrarius, respectively. The flea-carrying rate was 50.46% and the total flea index was 4.24, with the dominant flea species Leptopsylla segnis. The free flea index was 0.001. The plague serum antibody was not detected. Conclusion There might be a risk of local epizootic risk with imported plague in Yunyang county of the Three Gorges Reservoir Area, since there exists plague host animal and vector fleas. It implies the need for epizootic plague surveillance program in the county.
2019, 30 (3): 327-330.    doi: 10.11853/j.issn.1003.8280.2019.03.023
Interpretation of the group standard in Procedures for assessment of pest control service quality
JI Heng-qing
Abstract399)      PDF (568KB)(916)      
Objective To help the readers better understand and apply the group standard in Procedures for assessment of pest control service quality (T/CPCACN0001-2018). Methods We evaluated and analyzed the current status of pest control operation (PCO) in China according to the information obtained during development of this standard. Results We discussed the background and process of the development of the standard, the contents of the standard, and the potential problems and prospects of its implementation. Conclusion Although there are various problems and difficulties during the implementation of this standard, the quality assessment of pest control service will be performed widely with social and economic development and the continuous standardization of PCO. The release and implementation of this standard will play a leading role in the quality assessment of pest control service.
2019, 30 (3): 317-319.    doi: 10.11853/j.issn.1003.8280.2019.03.020
Resistance of Blattella germanica to commonly used insecticides in Chongqing
TU Tao-tian, JI Heng-qing, TAO Xiao-ying, LUO Chao, YANG Xue-fan, SHAO Zheng-rong, LIU Yi-ping, FENG Shao-quan, HE Ya-ming
Abstract374)      PDF (407KB)(752)      
Objective To investigate the susceptibility of Blattella germanica to commonly used insecticides and optimize future application of insecticides. Methods The surface contact method was used, calculating the medium knock-down time(KT 50) and obtaining resistance ratios by comparing with susceptible strain from 2015 to 2016. Results The resistance index of field-collected strains of B. germanica to beta-cypermethrin, deltamethrin, cypermethrin, acephate, DDVP, ehlorpyrifos, and propoxur were 13.76-32.93, 5.26-15.25, 4.81-21.02, 1.01-2.11, 1.05-7.38, 1.00-1.20, and 1.02-2.12. The average mortality of B. germanica in different areas of Chongqing after 72 h of contacting to acephate, ehlorpyrifos, DDVP, deltamethrin, cypermethrin, propoxur, and beta-cypermethrin were 100%, 100%, 94.0%, 92.0%, 81.0%, 79.0% and 78.0%. Conclusion Field collected strains of B. germanica in Chongqing have already developed different resistance to seven kinds of insecticides. Insecticides should be applied strategically to manage the insecticide resistance of B. germanica effectively.
2017, 28 (3): 226-229.    doi: 10.11853/j.issn.1003.8280.2017.03.007
A survey on susceptibility of Aedes albopictus larvae to four insecticides in some areas of Chongqing
TU Tao-tian, JI Heng-qing, FENG Shao-quan, YANG Xue-fan, HE Ya-ming, LUO Chao, RAN Zhen-wei, LIU Chun-hua, LIU Yi-ping
Abstract302)      PDF (299KB)(671)      

Objective To investigate the susceptibility of Aedes albopictus larvae to four insecticides in some areas of Chongqing. Methods To determine the median lethal concentration (LC50) of the field population of Ae. albopictus larvae of Yuzhong district and Wanzhou district located in the hinterland of the Three Gorges Reservoir, by immersing them with pesticide in 2014-2015. Results In comparison with the susceptible strain, the resistance ratios of Ae. albopictus larvae to beta-cypermethrin, deltamethrin, permethrin, and temephos were 7.59-, 4.50-, 9.88-, and 3.18-fold respectively in Yuzhong district, and 12.82-, 7.50-, 13.29-, and 2.00-fold respectively in Wanzhou. Conclusion Aedes albopictus larvae of Yuzhong had a low level resistance to beta-cypermethrin, deltamethrin, permethrin, and temephos; that of Wanzhou had a moderate resistance to beta-cypermethrin and permethrin, but a low level resistance to deltamethrin. Therefore, it is important to rotate pesticides and choose appropriate doses in mosquito control.

2016, 27 (5): 506-507.    doi: 10.11853/j.issn.1003.8280.2016.05.024
Study on murine-like animals and their parasitical fleas in Chongqing Reservoir Area of the Three Gorges
JI Heng-qing, FENG Lian-gui, DING Xian-bin, MAO De-qiang, LI Hong, TU Tao-tian
Abstract663)      PDF (886KB)(768)      
Objective To investigate the species composition and density of the murine-like animals and their parasitical fleas in Chongqing Reservoir Area of the Three Gorges and provide a scientific basis for preventing and controlling the diseases transmitted by the murine - like animals and fleas. Methods The night trap method was used to investigate the species composition and density of the murine-like animals. Live murine-like animals were captured by cage-trap and anaesthetized for collecting the parasitic fleas to investigate the flea species and the infection rate and index. Results The average density of the murine-like animals was 1.58% with a density of 1.56% in the rooms from 2009 to 2010, which was a little lower than that in outdoors(1.60%). A total of 11 species, 2315 murine-like animals belonging to 2 orders and 2 families were captured, of which Anourosorex squamipes, Mus musculus and Rattus norvegicus were the dominant species with the constituent ratio being 38.75%, 25.14% and 19.27%, respectively. The average rate of the murine-like animals infected with fleas and the total flea index were 6.74% and 0.29, respectively. Five species of parasitic fleas were collected including Leptopsylla segnis(79.16%), Xenopsylla cheopis(1.08%), Monopsyllus anisus(2.54%), Palaeopsylla remota(8.90%)and Ctenocephalides felis(8.32%). Conclusion There exist important reservoir host of plague, Leptospinosis and hemorrhagic fever with renal syndrome and X. cheopis which is an important vector of plague in the Three Gorges Reservoir. There are abundant species of the murine - like animals with relatively low density, low flea infection rate and low total flea index.
2012, 23 (4): 317-319.
Results of plague surveillance in Chongqing area of the Three Gorges Reservoir in 2007-2008
JI Heng-qing, WANG Xin-li, MAO De-qiang, SU Pei-xue, LI Hong, ZHANG Chu-hua, JIAO Yan
Abstract1578)      PDF (1016KB)(835)      

Objective To provide the basis for early detection and control of plague in the Three Gorges Reservoir through monitoring of the host animals, insects and plagues in this region. Methods Night traps were used to measure the rat density. Live rodents were captured using cage traps to collect serum samples for detection of plague F1 antibody and determination of parasitic fleas on the rodent body. Animals which died of unknown causes were recorded, and plague monitoring was carried out. Results The average rodent density was 1.49% in Chongqing area of the Three Gorges Reservoir from 2007 to 2008. The indoor density was 1.50%, the outdoor 1.48%. Rattus norvegicus, Mus musculus, R. tanezumi and Anourosorex squamipes were the dominant species. The average flea-carrying rate was 4.03%, and the total flea index was 0.13. The parasitic fleas found on those rats included Monopsyllus anisus (0.12%), Leptopsylla segnis (77.88%), Palaeopsylla remota (14.39%) and Xenopsylla cheopis (7.61%). For the 6549 surveyed live rats, the serological test was all negative for plague. There was neither a large number of dead animals of unexplained causes nor plague cases. Conclusion Plague was not found in Chongqing area of the Three Gorges Reservoir, though the vectors and host animals exist.

2010, 21 (5): 454-457.
Investigation on breeding situation of mosquitoes in various plashes in urban areas of Chongqing
JI Heng-Qing, ZHENG Fa-Wen, FAN Hong-Lian
Abstract1460)      PDF (271KB)(1010)      

【Abstract】 Objective To investigate the breeding situation of mosquitoes in various plashes in urban areas of Chongqing and provide scientific evidence for mosquitoes control. Methods Direct observational method was used to investigate the breeding of mosquitoes in small?sized containers such as miniascape, crock, kettle and tyre, but direct observational method and scoop sampling method used in the  large and medium?sized waters like water pool and lake. The proportion of breeding was recorded. Some larvae were collected and taken back to the laboratory to  be classified. Results Mosquito larvae were found in all kinds of plashes except for fishing pond and lake. The average positive rate in small container was 10.65% (1.45%-91.11%), while it was 18.42% in the large and medium?sized waters. The dominant species were Aedes albopictus and Culex pipiens quinquefasciatus, accounting for 58.18% and 29.56% respectively. Conclusion The management of plashes mosquito should not be neglected in the mosquito control.

2009, 20 (5): 477-478.
Studies on the early-warning of plague in the Three Gorges Reservoir region in Chongqing
JI Heng-qing; JIA Qing-liang; WANG Xin-li; SU Pei-xue; WU Guo-hui; MAO De-qiang; ZHANG Chun-hua
Abstract1121)      PDF (238KB)(785)      
Objective To explore main plague hosts, vectors and plague foci in the second phase water line of the Three Gorges project in Chongqing, and provide scientific basis for plague early warning and control. Methods Investigate the density of rat-shape animals inside and outside of home. The rat-shape animals were anaesthetized to investigate the varieties of parasitical fleas and the infected rate after captured by cage-trap. Identify the captured rat-shape animals and know their population and distribution. Plague F1 antibody was tested in serum samples separated from the blood of anaesthetized rat-shape animals. Search for the dead animals without specific death causes and monitor the plague epidemic situation, and acquire the information about the natural foci and epidemic situation. Results 3 order, 8 families and 27 species of rat-shape animals were found in this area. Among them, Rattus norvegicus, Mus musculus, Rattus flavipectus and Anourosorex squamipes were the dominant species. The average density of rat-shape animals was 1.57%, and the density of them was 1.64% in the room that was a little higher than that of outside(1.51%). 10 340 serum samples of rat-shape animals were tested and no positive results were obtained. 6 species of parasitical fleas such as Xenopsylla cheopis, Monopsyllus anisus, Leptopsylla segnis, Ctenocephalides felis, Palaeopsylla remota and Neopsylla specialis were found. The average rate of rat-shape animals infected with fleas and the total flea index were 6.51% and 0.15, respectively. The results of epidemiology survey and epidemic situation monitoring indicated that there were no plague in mice or human population in the region. Conclusion No plague was found so far in the Three Gorges Reservoir region in Chongqing, but R.flavipectus and X.cheopis were widely distributed in this region. Once the infection sources were introduced, the outbreak of plague would be possible. So there was potential risk for plague in this region, we should pay more attention to it.
The results and analysis of plague surveillance in Three Gorges in Chongqing,2005
WANG Xin-li; JI Heng-qing; ZHANG Chun-hua; SU Pei-xue; CHEN Ya-lin; MAO De-qiang; JIAO Yan
Abstract1043)      PDF (309KB)(700)      
Objective To monitor rodents and vector fleas in Three Gorges,to find plague earlier and take prevention and control measures immediately. Methods Use clamp-trap method to monitor rodent density in residential areas and out of side. Use cage-trap method to capture live rodents to extract serum for detecting F1 antibody. Hocus the living rodents and collect their parasitical fleas. Results 87 327 clamps were placed in 2005,of which 84 146 clamps were valid,1278 rodents were obtained,the total rodents density was 1.52%,and the density in room was 1.67%,which was higher than that of outside (1.41%). The dection of all serum for F1 antibody was negative. 326 of 4114 rodents were found infecting with flea. Total 853 fleas were collected,which needed further identification. The rate of rodents with fleas was 7.92%,total index of flea was 0.207. Conclusion There has been no plague in Three Gorges in Chongqing area.