Chinese Journal of Vector Biology and Control 2016 Vol.27

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Development of a TaqMan Real-time PCR assay for detection of Batai virus
CAO Yu-xi, HE Xiao-xia, FU Shi-hong, LI Hao, LIANG Guo-dong, WANG Huan-yu
Abstract278)      PDF (723KB)(1039)      

Objective To develop a rapid and sensitive detection method for Batai virus (BATV) based on TaqMan Real-time PCR. Methods Based on the BATV NS gene sequences of S segment published in GenBank, BATV specific primers and probe were designed. The specificity and stability of the system were evaluated. Quantitative standard curve of BATV TaqMan Real-time PCR was established. Results The specificity and stability test showed that the system is specific and the coefficient variables were all less than 2.50%. Quantitative standard curve based on the genomic copy was drawn, and the lowest detectable limit (LOD) of system is 10 copies/μl. Conclusion TaqMan Real-time PCR for BATV detection has been developed, which is more sensitive and more efficient than the general PCR.

2016, 27 (1): 1-4.    doi: 10.11853/j.issn.1003.4692.2016.01.001
Surveillance and control of imported dengue cases in Yunnan from 2004 to 2014
JIANG Jin-yong, GUO Xiao-fang, TANG Ye-rong, YANG Ming-dong, WEI Chun, ZHOU Hong-ning
Abstract514)      PDF (1256KB)(1472)      

Objective To understand the epidemiological characteristics of imported dengue cases in Yunnan during 2004-2014, and provide the scientific information for the effective strategies of dengue control and prevention. Methods The data of imported dengue cases were collected from China Information System for Diseases Control and Prevention during 2004 to 2014. A database was established to analyze the epidemiological characteristics with method of descriptive epidemiology; dengue serotype was detected by RT-PCR.Results From 2004 to 2014, a total of imported cases were 629 (629/2 192, 28.70%) in Yunnan; The imported cases of dengue were mainly reported in Dehong Prefecture (341 cases), Xishuangbanna Prefecture (159 cases) and Kunming city (108 cases); The cases were reported every month, but 85.37% (537/629) of the cases were imported between August and November. Male cases were much more than female, 419 and 210 cases respectively. The occupations of cases mainly were business service people (165 cases), farmers (134 cases) and students (72 cases). Most cases were imported from Myanmar (403 cases) and Laos (132 cases). Four (4) dengue serotypes were found from imported cases; of those DEN-3 was the major type in those from Laos, and DEN-1 in those from Myanmar. Conclusion The imported dengue cases have been on rise in Yunnan, and their major concerns are the border areas with Laos and Myanmar. The above results suggested that colloborative efforts from various agencies should be strengthened to monitor border imported dengue cases in case of dengue outbreak.

2016, 27 (1): 5-8.    doi: 10.11853/j.issn.1003.4692.2016.01.002
Analysis of surveillance and control implications on schistosomiasis endemics in Zhejiang province from 2012 to 2014
ZHANG Jian-feng, YAN Xiao-lan, DU Hai-juan, YU Li-ling, SUN Feng, LIN Li-jun, WEN Li-yong
Abstract331)      PDF (356KB)(821)      

Objective To understand the endemic situation of schistosomiasis in surveillance sites, and to provide scientific reference for schistosomiasis control during the "Thirteenth Five-Year Plan" in Zhejiang province. Methods According to the scheme of Zhejiang provincial schistosomiasis surveillance (revised in 2012), 11 provincial schistosomiasis surveillance sites which represented for water network endemic regions and hilly endemic regions were selected and evaluated. The morbidity of the infection, snail distribution and relevant factors were investigated. The 5 meter-synchronously systematic samplings combined with the environmental samplings were used for snail survey. Indirect hemagglutination assay (IHA) combined with miracidium hatching method were used to evaluate morbidity in humas. Results The residual snails area were 12 100 m2 in the 6 surveillance sites from 2012 to 2014. The area with Oncomelania snails,the rate of living snails frame and the mean densities of living snails in 2014 were reduced by 76.22%,53.04% and 73.91% when comparing to those in 2012, and no imported and infective snails were found. There were no local schistosomiasis cases, but 4 advanced schistosomiasis cases and 16 imported schistosomiasis cases were found in the surveillance sites. Conclusion The results of surveillance showed the current stable schistosomiasis endemics and the need of proper control measures in Zhejiang province. There are some residual snail populations and imported schistosomiasis cases in the surveillance sites, thus there is still a risk of re-emergence of schistosomiasis. To achieve the goal of schistosomiasis eradication, we must emphosize comprehensive prevention and control strategy with given priority to the surveillance of residual snails and imported schistosomiasis.

2016, 27 (1): 9-13.    doi: 10.11853/j.issn.1003.4692.2016.01.003
Survey on mosquito species in different indoor resting habitats in Hubei, China
YAO Xuan, XIONG Jin-feng, GUAN Xu-hua
Abstract310)      PDF (302KB)(775)      

Objective To investigate indoor mosquito species distribution in different geographical locations and ecological environments in Hubei province. Methods Mosquitoes were captured from May to September in 2014, species and sex composition were analyzed with statistical tests. Results Five species including Culex pipiens quinquefasciatus, Cx. tritaeniorhynchus, Armigeres subalbatus, Anopheles sinensis and Aedes albopictus were captured, accounted for 46.37%, 25.99%, 15.37%, 12.14% and 0.13%, respectively. From different topographologic types, Cx. pipiens quinquefasciatus and Cx. tritaeniorhynchus were predominant in plains, Cx. pipiens quinquefasciatus, Ar. subalbatus and Cx. tritaeniorhynchus were predominant in hilly areas. From different host types, Cx. tritaeniorhynchus and Ar. subalbatus were predominant in stables, Cx. pipiens quinquefasciatus was common in birdhouses and human dwellings. Females of 5 species were captured, but males from only two species were captured including Cx. pipiens quinquefasciatus and Ar. subalbatus. Conclusion Predominant species and sex composition show significant difference among different topographical environments and host types.

2016, 27 (1): 14-16.    doi: 10.11853/j.issn.1003.4692.2016.01.004
DNA barcoding identification of Mus cervicolor, a non recorded mouse species in China
SHAN Zhen-ju, LIU De-xing, YUE Qiao-yun, WEI Xiao-ya
Abstract311)      PDF (1336KB)(927)      

Objective DNA barcoding techniques were employed to identify the unknown mouse species intercepted from the dry cassava imported from Cambodia at Zhongshan port, whose morphology was damaged too badly to be identified. Methods Genomic DNA was extracted from the intercepted mouse. Target fragments were amplified with the universal primers LCO1490 and HCO2198 for the metazoan mitochondrial cytochrome oxidaseⅠ (COⅠ), PCR products were sequenced. The sequences were blasted in the NCBI. Results The sequence homology of the DNA barcode fragment between these two samples were 99.8%, and was more than 98.5% identical to the sequence of Mus cervicolor published in NCBI. Mus cervicolor is never recorded in China before, and it was the first time to intercept this species at the Chinese port according to the references. Conclusion The intercepted mouse was M. cervicolor identified with DNA barcodes, a non-recorded species in China. DNA barcoding techniques could break the restrictions of traditional species identification depending on undamaged morphological characteristics, can improve the ability to identify the exotic species, overcome the difficult in lack of identification references and experts.

2016, 27 (1): 17-20.    doi: 10.11853/j.issn.1003.4692.2016.01.005
Hard tick species identification and distribution in Aibi Lake located at China-Kazakhstan border
XU Jun, WANG An-dong, XIAO Yun-xia, XU Xin-long, DAI Li, DU Jing-yun, WANG Li-na, ZHANG Ke, LUO Dan, MU Lu-meng, ZHANG Ya-li, XING Jian-xin, WANG Yuan-zhi
Abstract362)      PDF (1025KB)(983)      

Objective To investigate tick species and abundance in different sampling seasons, and explore the ticks' molecular characteristics in Aibi Lake, Alashankou Pass, Xinjiang Uygur Autonomous Region for providing the reference for the tick classification as well as prevention and control of tick-borne diseases. Methods During April to August in 2014, questing ticks were collected by dragging-flag method, and blood feeding ticks were collected from wild and domestic animals at Hejiaoke, Wulandabusen and the naturally preserve of Aibi Lake, Xinjiang, Northwest of China. The morphological and 16S rDNA identification were carried out based on representative ticks. Results We collected 434 ticks including 392 questing ticks and 42 blood feeding ticks, which including Hyalomma asiaticum, Dermacentor marginatus, D. niveus, Rhipicephalus sanguineus, Rh. turanicus, Rh. bursa and Haemaphysalis erinacei. The predominant tick species of Aibi Lake are H. asiaticum and D. marginatus. Their peak seasons were in May (Dermacentor) and June (Hyalomma). Blast analysis of 16S rDNA indicated that D. marginatus had 96%-100% identities compared with that of the ticks from Shihezi (KF547986), and that H. asiaticum was 98%-99% identical to Yili (KF527439), while Rh. sanguineus possessed 93%-94% identities with Israel (KF219732). Conclusion Rhipicephalus turanicus and Rh. bursa for the first time were found in Aibi Lake. 16S rDNA sequence of H. erinacei was reported for the first time, and was 91% identical to H. cretica. 16S rDNA of D. marginatus, H. asiaticum and Rh. sanguineus showed genetic divergence in Aibi Lake, which conveyed us that these tick species originated from different lineages.

2016, 27 (1): 21-24.    doi: 10.11853/j.issn.1003.4692.2016.01.006
Infestation of Neoseiulus barkeri in bedroom storage
TAO Ning, SUN En-tao, ZHAN Xiao-dong, LI Chao-pin
Abstract275)      PDF (515KB)(831)      

Objective To study the structure and feeding habits of Neoseiulus barkeri. Methods After oscillating and washing, the mite was killed with heated alcohol, then placed in the preservation solution. Mounting medium zishi was applied to the slide in the amount of 2-3 drops, and a cover glass was placed after adjusted mite posture with hair needle. The specimens were dried for identification under light microscope. Results Length of N. barkeri male body is about 310-350 μm, with light gray or light brown in color. Corniculus is long and slender, aggregated to center. The fixed digit, which has three tines, and movable digit, which has one denticulation, are approximately equal in length. The spermatodactyl is shap of "T". There are 17 pair setae on the back, all equal length except Z5 which with comb shape and slightly longer. Outer edge hair r3 and R1 are located on the back. Besides anal seta there have other 4 pair setae. The female body length is about 370-390 μm. Color and shape is similar to those in male. The chelicerae is bigger than male's but the anal plate is smaller than male's. The egg is colorless and transparent, with oval shape, and size of (80-85) μm×(60-65) μm. Each female mite preyed Caloglyphus berlesei at an average of (12.80±1.47) per day and C. berlesei eggs with an average of (17.70±1.86) per day. When prey was absence, there was a tendency of self-mutilation. Conclusion We gained certain understanding of the morphology and feeding of N. barkeri, which provide a foundation for the further study.

2016, 27 (1): 25-27.    doi: 10.11853/j.issn.1003.4692.2016.01.007
Effects of Ricin on reproductive system in experimental mice
HE Feng-qin
Abstract279)      PDF (1068KB)(652)      

Objective In order to provide a foundation for the formulation of botanical rodenticide, we compared the effect of different concentrations of ricin extracts of castor beans mixed in rabbit chow on the reproductive function of the mice. Methods Healthy mature male and female mice were fed with rabbit chow that was mixed with extracts of castor beans. The palatability, ovarian and testis organ coefficients were evaluated. Testicular and ovarian histological sections were produced, the latency of birth and number of offspring was compared after experimental and control groups were paired with sexually mature males and females. Results Compared with the control group, the palatability had no statistical significance to the experiment group (♂: t=1.360, P=0.227; ♀: t=1.170, P=0.449). The testis organ coefficient of the experimental group was 4.118×10-3, the testis organ coefficient of the control group was 7.398×10-3, the coefficient of the experiment group was reduced significantly reduced (t=2.740, P=0.013). The thickness of the germinal epithelium in the experimental group was (26.55±6.11) μm, the control group was (54.35±7.14) μm, the germinal epithelium was significantly thinner as compared with the control group (t=3.160, P=0.011). The latency of birth was (7.50±0.71) d and the number of offspring was (3.80±5.22) in the experimental group 1, the latency of birth was (10.00±0.00) d and the number of offspring was (0.40±0.89) in the experimental group 3. However, the latency of birth was (2.20±1.30) d and the number of offspring was (13.50±2.97) in the control group, the latency of birth was significantly delayed (Z=1.954, P=0.049; Z=3.485, P=0.002) and the number of offspring was significantly reduced(Z=2.550, P=0.011; Z=3.424, P=0.004) in experimental group 1 and 3. The female ovarian organ coefficient was 2.218×10-3 in experimental group but 4.621×10-3, in control group. The coefficient of the experiment group was significantly reduced (t=3.980, P=0.001). The luteal maximum cross-section of the experimental group was (12 347.50±2 359.28) μm2, the control group was (19 625.47±6 612.40) μm2, the difference was significant (t=2.750, P=0.013). The latency of birth was (12.00±0.00) d and the number of offspring was (1.80±4.02) in the experimental group 2, the latency of birth was significantly delayed (Z=4.485,P=0.001)and the number of offspring was significantly reduced (Z=2.703, P=0.007) in the experimental group 2.Conclusion The antifertility effect was the most profound and palatability was satisfactory for the mice when consuming the rabbit chow that was mixed with ricin extracts of castor beans. However, further studies are warranted to address the application of castor bean extract as environmentally friendly rodenticide on farmland and woodland.

2016, 27 (1): 28-31.    doi: 10.11853/j.issn.1003.4692.2016.01.008
Population density and insecticide resistance of Culex pipiens quinquefasciatus in Wuhan, 2014
XIONG Jin-feng, TIAN Jun-hua, YAO Xuan, TAN Liang-fei, YANG Rui, PENG Qing-hua
Abstract277)      PDF (644KB)(805)      

Objective In this study, we investigated the population densities and resistance to commonly used insecticides of Culex pipiens quinquefasciatus in Wuhan, Hubei province. Our results can provide new insights into field mosquito control operations. Methods According to GB/T 23797-2009, lamp traps were used to caputre mosquitoes during March to November in 2014. The larve impregnation method which is recommended by WHO, was used to determine the susceptibility of larve (LC50 with 95%CI) to deltamethrin, DDVP, DDT, propoxur and temephos. Results The population densities of Cx. pipiens quinquefasciatus throughout the year showed a single peak between May and June, the average density in stables was significantly higher than any other habitats. The LC50 values of deltamethrin, DDVP, DDT, propoxur and temephos of Cx. pipiens quinquefasciatus were 0.071 7, 0.469 9, 0.766 0, 0.941 0 and 0.000 78 mg/L, and the resistance ratio were 358.50, 151.14, 42.56,9.72 and 1.30, respectively. Conclusion Our data showed that the peak population densities of adult Cx. pipiens quinquefasciatus was between May and June in Wuhan, it is also the key month for mosquito control. Considering the prevalence of resistance to chemical insecticides among mosquitoes, integrated management should be promoted to delay the development of resistance.

2016, 27 (1): 32-34.    doi: 10.11853/j.issn.1003.4692.2016.01.009
Investigation on mosquito density, species, and seasonality in Weishan lakes area, Shandong province in 2014
LI Yu-ting, HAO Xue-an, ZHANG Shu-ling, LIU Shuo, SHEN Yan
Abstract364)      PDF (722KB)(712)      

Objective To investigate the mosquito species, density, and seasonality in Weishan lakes area for local mosquito and diseases control. Methods The surveillance was carried out from April to October in 2014. The adult mosquito density was monitored using carbon dioxide mosquito lamp and mosquito-oviposition trap. While the larval mosquito density was monitored by spoon method for large bodies of water and pipette method for small volumes of water (in containers). Results In total, 10 972 mosquitoes were captured in Weishan lakes area in 2014. The predominant species were Culex pipiens pallens. accounting for 78.45%, followed by Aedes albopictus and Cx. tritaeniorhynchus; Seasonal fluctuations were indicated with one peak in July. The adult mosquito density was the highest in the barn. The positive rate of mosquito larvae was the highest in residential areas. Conclusion The mosquito population was high in Weishan lakes area. The surveillance findings of mosquito density and its seasonal fluctuation can provide guidance for the prevention and control of mosquitoes and mosquito-borne diseases in local area.

2016, 27 (1): 35-37.    doi: 10.11853/j.issn.1003.4692.2016.01.010
Detection of Orientia tsutsugamushi in Panzhihua city by SN-PCR and sequence analysis
LIAO Hong-yu, JIANG De-yong, MU Yong-gui, YANG Xiao-rong
Abstract250)      PDF (495KB)(859)      

Objective To detect Orientia tsutsugamushi in the blood specimens from suspect patients and get a clear understanding of the infection status in Panzhihua, Sichuan province. Methods The whole bacterial genomic DNA were extracted from 48 patients' blood specimens, which were collected from the city of Panzhihua during July to October in 2013. The sta-58 gene of O. tsutsugamushi was detected by the nested PCR (SN-PCR). The partial sta56 genes were amplified, sequenced and analyzed from two cases of SN-PCR positive specimens selected randomly. Results There were 18 SN-PCR positive specimens deteced from 48 blood specimens. The partial sta56 genes were amplified successfully from two specimens and the sequences homology was 96%. Phylogenetic analysis showed that the Panzhihua43, Panzhihua45 and some Taiwan O. tsutsugamushi Strains were in the same branch, meanwhile, in the same branch with the O. tsutsugamushi Karp as well. Conclusion We have firstly detected the O. tsutsugamushi in the blood specimens by SN-PCR in Sichuan province. The existing infection of O. tsutsugamushi in Panzhihua was confirmed by the laboratory detection. Our study indicated that part of O. tsutsugamushi disease patients in Panzhihua were infected by Karp serotype, and the O. tsutsugamushi were closely related to some Taiwan O. tsutsugamushi Strains in genetic evolution.

2016, 27 (1): 38-41.    doi: 10.11853/j.issn.1003.4692.2016.01.011
Fannia immaculata Malloch, 1924-New records in China (Diptera: Fanniidae)
TIAN Jun, WANG Ming-fu, WANG Jing
Abstract317)      PDF (346KB)(904)      

This article created the first record of Fannia immaculata in Jingyuan Region of Ningxia, China. The species is currently known only distributed its type locality namely Quebec, Canada. This paper describes the morphological characteristics of this species and male genitalia drawn diagram for identification.

2016, 27 (1): 42-43.    doi: 10.11853/j.issn.1003.4692.2016.01.012
A new species of genus Dasyhelea Kieffer (Diptera: Ceratopogonidae) collected on an entry ship
NIE Wei-zhong, BO Jing-xin, YU Yi-xin
Abstract285)      PDF (516KB)(765)      

A new species, Dasyhelea kwangyangi Nie, Yu et Bo sp. nov., was recorded, which was captured in an entry ship came from Korea at the anchorage of Qinhuangdao port. The aedeagus and parameres of the new species are closely allied to Dasyhelea nachitai Yu et Liu, 2005, but the latter is distinctly characterized by short aedeagus and apical dilation of parameres. The new species is also closely allied to Dasyhelea faciigera Kieffer, 1924, but no crena on the apical dilation of the median apophysis of parameres of the latter is significantly different from that of the new species. The type specimens are preserved in the medical insect specimens Museum, Fengtai East Street No. 20, Beijing 100071, China.

2016, 27 (1): 44-45.    doi: 10.11853/j.issn.1003.4692.2016.01.013
Fauna and a new species of bloodsucking midges in Hongxing volcano lava area, Heilongjiang province
YANG Jun, LIU Guo-ping, YANG Fang
Abstract353)      PDF (502KB)(871)      

The paper reports 1 genera and 19 species of bloodsucking midges in Hongxing volcano lava area, Heilongjiang province. A new species Culioides hongxingensis Yang et Liu sp. nov. is described. This new species is closely allied to C. pallidulus Yu, 1982, but is distinctly different from the eyes with interfacetal hairs, eyes are separated by width of 3.5 facet of female C. pallidulus Yu, 1982. The new species is also similar to C. subcircumscriptus Yu, 1991, but is distinctly different from the middle of pale spot over x-vein with small dark spot, cell M1 and cell M2 without pale spot of C. subcircumscriptus Yu, 1991. Culicoides donggangensis Liu, Zhou et Wu, 2007 is recorded for the first time in Heilongjiang province. The type specimens are deposited in the Shenyang Command Center for Disease Control and Prevention (Shenyang 110034, China).

2016, 27 (1): 46-47.    doi: 10.11853/j.issn.1003.4692.2016.02.014
A new species of Phaonia minuticornis-group (Diptera: Muscidae, Phaonia)
WU Chuan-gang, LI Tao, DONG Jun-ming, WEI Lian-meng
Abstract253)      PDF (386KB)(883)      

The paper reports and describes one new species Phaonia anshunensis sp. nov., which was collected from Guizhou, China and assigned to the Phaonia minuticornis-group. The type specimen of the new species was collected from Guizhou, China and is deposited in Wei Lian-meng High-Skilled Talent Innovation Studio of Anshun Center for Disease Control and Prevention, Anshun 561000, Guizhou, China.

2016, 27 (1): 48-49.    doi: 10.11853/j.issn.1003.4692.2016.01.015
Quality evaluation system of Aedes albopictus population in the laboratory
HUANG Yan-hui, LUO Yong, ZHANG Li-ping
Abstract267)      PDF (531KB)(1053)      

Objective To establish a quality evaluation system of Aedes albopictus population in the laboratory. Methods A u test method was used to evaluate the quality of laboratory rearing Ae. albopictus. Results A specific quality evaluation system for Ae. albopictus has been established, which includes sample collection, wet weights data collection and processing, statistical inference. Conclusion This system can effectively evaluate the quality of Ae. albopictus, and it is of great significance to repellents' laboratory efficacy tests.

2016, 27 (1): 50-51.    doi: 10.11853/j.issn.1003.4692.2016.01.016
Analysis of malaria surveillance of Yuanjiang county of Yunnan from 1995 to 2014
YANG Ji-qing, YANG Tai-zhuan, YANG Zhong-qiang, LI Wen-qiang, ZHOU Yan-hua, LI Shao-you, ZHOU Hong-ning
Abstract305)      PDF (533KB)(684)      

Objective To analyze malaria surveillance data of Yuanjiang county of Yunnan from 1995 to 2012. Methods Data were collected from Yuanjiang county during 1995 to 2014, including malaria cases, number of resident and mobile population febrile patient blood screening, resident malaria parasitic rate, vector population density and the other data;of those malaria case was identified by tradition microscope method, malaria vector density was investigated by human hour collection mosquito in resident houses or animal shelters, and human infected malaria antibody level was tested by indirect fluorescence antibody test. Results During 1995 to 2014, total of 6 986 malaria cases were reported, in those years the highest malaria morbidity were in 1995 (84.07/10 000, 1 531 cases) and the lowest in 2012 (0 cases); total of 209 824 febrile resident patient bloods were screened, its malaria positive rate was 3.41%; total of 26 373 mobile population febrile patient bloods were tested, its malaria positive rate was 7.65%; total of 51 540 healthy residents were investigated for malaria parasite, its positive rate was 1.56%; the indirect fluorescent antibody positive rate of malaria was 39.34%(769/1 955)in 1997 but 0(0/320) in 2012; Anopheles minimus population density declined rapidly from 1995 to 2014, in consistence with annual malaria morbidity, while that of An. sinensis declined during 1995 to 2002, but increased gradually since 2002. Conclusion Above malaria monitor results suggested that imported malaria case management of mobile population and vector monitor were needed to strengthen, in order to avoid local transmissions causing by imported cases.

2016, 27 (1): 52-54.    doi: 10.11853/j.issn.1003.4692.2016.01.017
Epidemical analysis of human plague in Yushu Tibetan Autonomous Prefecture from 1990-2014
LOU Zhi-ming, WEI Bai-qing, WU Shu-sheng, XIONG Hao-ming, QI Mei-ying, JIN Juan, WANG Xue, ZHAO Xiao-long, WANG Zu-yun
Abstract352)      PDF (419KB)(807)      

Objective To explore the plague epidemiological trend of the nearly 25 years in Yushu Tibetan Autonomous Prefecture, Qinghai province, and to provide basis for implementation of the prevention and control measures. Methods Analyze the data of the human plague cases, plague surveillance and the plague foci research from 1990 to 2014 with the Excel software. Results There were 17 human plague outbreaks in 11 years out of 25 years from 1990 to 2014, 54 cases were reported, including 22 fatalities, the mortality was 40.74% (22/54). The patients were mainly distributed in the following 5 counties: Yushu, Nangqian, Qumalai, Chenduo and Zhiduo. Human plague cases occurred from May to October, the peak at July to October. The majority clinical cases were pneumonic plague (34/54, 62.96%). In 2004, pneumonic plague outbreaked in local area. Conclusion The plague epidemic situation in Yushu Tibetan Autonomous Prefecture, Qinghai province is still at high risk, the human plague in some area outbrook occasionally. So as to reduce human plague occurrence risk, while conducting the Marmot plague monitoring, the monitoring of Tibetan sheep plague should also be strengthened, and the comprehensive measures of plague prevention and control should be carried out.

2016, 27 (1): 55-57.    doi: 10.11853/j.issn.1003.4692.2016.01.018
Serological investigation of vector born rickettsioses in agrarian children in Yili prefecture, Xinjiang Uygur Autonomous Region
XU Qi-yi, LI Hong-ying, LI Fei, YANG Guo-feng, ZHANG Li-juan
Abstract246)      PDF (318KB)(871)      

Objective To better understand the situation of rickettsiae infection in agrarian children in Yili prefecture, Xinjiang Uygur Autonomous Region. Methods A total of 1 722 serum samples were collected from children aged from 6-12 years old in rural areas of Yining city, Gongliu county and Zhaosu county from August to November, 2011. Indirect immunofluorescencs antibody assay proposed by WHO was used to detect tick born Rickettsia sibirica, Ehrlichua chaffeensis, Anaplasma phagocytophilum, Coxiella burnetii and flea born Rickettsia typhi, Bartonella henselae and mite born Orientia tsutsugamushi respectively. Results A high prevalence of tick borne rickettsiae including R. sibirica, E. chaffeensis, A. phagocytophilum and C. burnetiiwere detected in 37.4% (92/246) and 29.3% (72/246), 15.4% (38/246) and 12.6% (31/246), respectively. A significant seroprevalence were detected in 15.8% (39/246) of B. henselae, 5.7% (14/246) of R. typhi, and 11.8% (29/246) of O. tsutsugamushi, respectively. Conclusion A highly seroprevalences of vector-born rickettsiae were demonstrated in agrarian children in Yili prefecture, Xinjiang Uygur Autonomous Region. Differential diagnoses of patients with unknown febrile diseases and empirical anti-rickettsia antibiotics treatment of patients with suspected rickettsia infection were needed in the local areas.

2016, 27 (1): 58-60.    doi: 10.11853/j.issn.1003.4692.2016.01.019
Study of distribution and similarity about Ceratopogonidae in three National Nature Reserves in the west of Zhejiang province
HAN Xiao-jing, JIANG Xiao-hong, HOU Xiao-hui
Abstract317)      PDF (365KB)(748)      

Objective To determine the species diversity and similarity analysis of Ceratopogonidae in Tianmushan, Jiulongshan, Qingliangfeng National Nature Reserve of Zhejiang province. Methods The insect net capture, Malaise capture and light trap were used to capture biting midges. The similarity analysis of biting midges was clustered by the Jaccard bivariate similar coefficient. Results In the three National Nature Reserve, 56 species of 9 genera belonging to 3 subfamilies of Ceratopogonidae were found, including 52 new record species. The similarity analysis indicates that the similarity coefficient between Tianmushan and Qingliangfeng Reserve is the highest (SI=0.24); between Jiulongshan and Tianmushan Reserve is the lower (SI=0.21); between Jiulongshan and Qingliangfeng Reserve is the lowest (SI=0.20). Conclusion This study provides reference data for species diversity of Ceratopogonidae, control of bloodsucking midge and midge-borne viral diseases. The clustering analysis indicates that the similarity coefficient is mainly related to the factors of geographic locations, weather conditions, and human activities.

2016, 27 (1): 61-64.    doi: 10.11853/j.issn.1003.4692.2016.01.020
A preliminary analysis of a large number rat fleas ( Xenopsylla cheopis) on Asian house rats ( Rattus tanezumi) in Jinghong, Yunnan
WU Ai-guo, LIN Gong-hua, LI Yu-qiong, TAO Ji-hong, ZHAO Chun-hua, ZHENG You-chun, LI Bao-hua
Abstract282)      PDF (333KB)(902)      

Objective To investigate the aggregation characteristics of rat fleas (Xenopsylla cheopis) on Asian house rats (Rattus tanezumi) and to provide scientific basis for plague control. Methods We collected fleas from live-trapped rats and calculated two infestation indices: flea prevalence and average flea abundance. Results A total of 73 rats were trapped from four survey sites along the Lancang River in Jinghong, Yunnan, and from these rats we collected 1 169 rat fleas. There were 1 056 fleas in a single survey site called Manfeilong Reservoir Fish Fry Field, with a flea prevalence of 95.45% and an overall average flea abundance of 48.00, showing an unusually super parasitic phenomenon. Moreover, we also found that the sex ratio of the fleas in this study was male-predominant, very different from previous reports (from either field surveys or lab breeding populations). Conclusion Since high densities of rat (R. tanezumi) and flea (X. cheopis) represent an increased risk in zoonotic plague prevalence, we suggest that there is a considerable high probability in causing the human plague in Jinghong, and local government and disease control department should be highly cautious about it.

2016, 27 (1): 65-67.    doi: 10.11853/j.issn.1003.4692.2016.01.021
Rodent charateristic changes in the Three Gorges Reservoir before and after the water storage
MAO De-qiang, LI Hong, ZHANG Chun-hua, SHEN Zhuo-zhi
Abstract291)      PDF (312KB)(749)      

Objective To investigate the change of the characteristics of rodents before and after the water storage in the Three Gorges Reservoir. Methods Mouse traps and cages were used to detect the density of rodents in different periods of the Water Storage. Results The indoor density of rodents before water storage was 4.14%. While it was 1.67% after water storage; the outdoor density of rodents before water storage was 4.29%, and it was 1.44% after water storage. The former was higher. The indoors densities of Rattus tanezumi in recent two years were much higher than before, it was 0.84% in 2011 and was 0.77% in 2012. Conclusion The densities of rodents significantly decreased after the second water storage in the Three Gorges Reservoir. But the indoors densities of R. tanezumi in recent two years were much higher than before. Continuous monitoring of rodent populations is warranted.

2016, 27 (1): 68-70.    doi: 10.11853/j.issn.1003.4692.2016.01.022
The population density analysis of adult mosquitoes in Ningbo city, China during 2011 to 2014
WANG Gui-an, XU Rong, MA Xiao, ZHU Guang-feng, ZHANG Chao-yang, LIN Yin-jun
Abstract281)      PDF (802KB)(794)      

Objective We monitored the adult mosquito densities during 2011 to 2014, in order to provide a reference for preventing and controling outbreaks of the Japanese encephalitis. Methods During April to November of 2011 to 2014, we used light trapping method to monitor adult mosquito density at different geographic locations and the data were analyzed using SPSS software. Results The predominant mosquito species in different habitats were different, Culex tritaeniorhynchus accounted for 91.39% in livestock shed. The predominant mosquito species in other various habitats was Cx. pipiens pallens which accounted for more than 70%. Peak season was in June, July and August. Conclusion The overall mosquito density was low in Ningbo city, we should strengthen the monitoring of mosquito density in livestock shed. We should implement mosquito management tactics in April and May before the onset of the peak mosquito density.

2016, 27 (1): 71-74.    doi: 10.11853/j.issn.1003.4692.2016.01.023
Investigation on resistance of Blattella germanica against five insecticides in Wuhan
ZHOU Liang-cai, LIU Xiao-quan, BAO Ji-yong, CHEN Xiao-min, ZHU Jun-sheng
Abstract304)      PDF (302KB)(726)      

Objective To investigate the resistance of Blattella germanica against five insecticides and customize future application of insecticides.Methods The B. germanica used in this study were the first filial generation (F1 generation 1). The insecticide film method recommended by the World Health Organization was used to determine the median knock-down time (KT50) and the corresponding 95% confidence interval (95%CI), knock-down rate, and mortality rate of B. germanica exposed to the five commonly used insecticides and to assess the levels of resistance of B. germanica. Results The average resistance of B. germanica strains from Hankou, Hanyang and Wuchang against propoxur, ehlorpyrifos, betacypermethri and azamethiphos was 1.4-2.2, 1.5-1.7, 2.8-3.1, 2.5-2.9 fold. Its resistance against tetramethrin was beyond the test range. Conclusion It was advised to apply integrated control measures and use insecticides strategically in controlling B. germanica.

2016, 27 (1): 75-76.    doi: 10.11853/j.issn.1003.4692.2016.01.024
Resistance of Culex pipiens quinquefasciatus larvae to commonly used insecticides in Panzhihua city, Sichuan
CHEN Zu-hua, PAN Hong-yu, TANG Gang, HUANG Jin, HUANG Xing-hui, SHEN Lai-hong, YAN Shu-li, LIU Yu
Abstract261)      PDF (371KB)(813)      

Objective To investigate the resistance of Culex pipiens quinquefasciatus larvae to six insecticides and direct future application of insecticides. Methods Mosquito larvae were collected in 2014 from 5 counties (districts) of Panzhihua city, and tested by WHO recommended larval dipping method for medium lethal concentration. Results Culex pipiens quinquefasciatus larvae collected from Panzhihua city were susceptible to fenobucarb (R/S<1), but showed various degrees of resistance to cypermethrin, permethrin and deltamethrin. The resistance ratio of Cx. pipiens quinquefasciatus larvae was 75.00 fold to beta cypermethrin, 12.40 fold to permethrin 2.50 fold to deltamethrin. Slight tolerance was indicated to temephos and DDVP where resistance ratios were 1.67 and 1.65 respectively. Conclusion It was necessary to apply integrated measures and use insecticides strategically in controlling mosquitoes.

2016, 27 (1): 77-79.    doi: 10.11853/j.issn.1003.4692.2016.01.025
Investigation and response of the dengue outbreak on a construction site in Guangdong province
LIU Jie, WU Jun-qiu, LI Jian-sen, KE Yi-wu, GUAN Da-wei, WU Su-mei, CHEN Chuang-bin, PENG Zhi-qiang
Abstract273)      PDF (618KB)(767)      

Objective Investigation of epidemiological characteristics of one dengue outbreak in a construction site in Jieyang city, Guangdong province, and evaluation of response outcome. Methods Investigate all cases in the site by epidemiology survey methods, collect blood samples from the workers for antibody detection and nucleic acid test, and survey the density of mosquito larvae by Breteau index. Results The 22 cases in total happened within 16 d, the first case on 26th September and the last case on 12th October with a morbidity of 14.7% (22/150) on this construction site. The mosquito density was decreased after the implement of control measures and the dengue outbreak was effectively contained. The isolates of dengue virus from cases had high similarity with the isolates from Guangzhou cases by Dengue virus phylogenetic analysis. Conclusion The outbreak was caused by dengue virus type 1. The source of infection might have come from Guangzhou. Early cases were not recognized in time due to misdiagnosis which led to the spread of dengue on a construction site. The key point for the successful prevention and control of dengue fever was the timely response of governmental departments and the effective implementation of mosquito control measures.

2016, 27 (1): 80-83.    doi: 10.11853/j.issn.1003.4692.2016.01.026
A group of emerging and reemerging pathogens: Bartonella spp.
LI Dong-mei
Abstract377)      PDF (1729KB)(944)      

Bartonella spp. are fastidious, gram-negative and facultative intracellular bacteria that are mainly transmitted by hematophagous arthropods and known to be involved in various zoonosis. In order to understand the research advances in genus Bartonella, we analyzed literatures of Bartonella spp. temporally, spatially and by authorship using GoPubMed, and brought together knowledge of new species and genomic characteristics that were gained in recent years. This review aims to provide information for further understanding and research on Bartonella spp.

2016, 27 (1): 84-88.    doi: 10.11853/j.issn.1003.4692.2016.01.027
The application of the tandem repeats in the Yersinia pestis genotyping
WANG Hai-feng, LIU He-zhi, YANG Shun-lin, ZHOU Song, BAI Xue-wei, YANG Xiao-yan, ZHANG Yi-hui, CHEN Kai-le, LIANG Ying, SHI Xian-ming
Abstract245)      PDF (365KB)(991)      

The plague is categorized as a Class A infectious disease in China. Plague foci are widely distributed, and strains have different features and varied virulence in China. It is of great significance for deducing the sudden outbreak of plague and terrorist attack detection, with the strains of different foci for genotyping. The choice of tandem repeats loci is the key of the multiple loci vntr analysis (MLVA) classification results. This assay mainly introduces tandem repeats in Yersinia pestis genotyping in application progress, and provides a reference for other workers in genotyping.

2016, 27 (1): 89-91.    doi: 10.11853/j.issn.1003.4692.2016.01.028
Prospects on Zika virus vector control measures and strategy
LIU Qi-yong
Abstract415)      PDF (1763KB)(1524)      

Zika virus (ZIKV) disease is a mosquito-borne disease transmitted by Aedes mosquitoes. At present, the epidemic scope and magnitude of ZIKV and its vectors are extending constantly and have already constituted the focus of international communities. This article reviews the Zika epidemic situation, its main vectors, sustainable vector management and implication of dengue fever-based control strategies and relevant measures, the specific measures of vector control adopted by WHO memberships, and provides commendations for the prevention and control of ZIKV scientifically and effectively in future.

2016, 27 (2): 93-98.    doi: 10.11853/j.issn.1003.8280.2016.02.001
Relationship between mosquito density and land cover types in Guangzhou, China
YUE Yu-juan, LU Liang, LIU Qi-yong
Abstract319)      PDF (1409KB)(1050)      

Objective To explore the relationships between mosquito density and land cover types. Methods Mosquito data in Guangzhou city were extracted from 1st-30th September 2014. Land cover types in towns of Guangzhou city were extracted based on geographical information system and remote sensing. The relationships between mosquito density and land cover types were explored based on epidemiological statistical method. The differences of mosquito density among towns were explored. Results Coverage ratios of irrigated croplands, water bodies and closed to open (>15%) grassland or woody vegetation on regularly flooded or waterlogged soil-fresh, brackish or saline water in towns with Breteau index (BI)>20, were 1.4%-35.7%, 0.1%-23.1% and 0-3.4%, respectively. These coverage ratios were higher than those in towns with BI≤5, amounting to 0-0.7%, 0-5.1% and 0, for the coverage types described previously. Compared with land cover types in adjacent towns with BI≤5, coverage ratios of irrigated croplands, water bodies and cropland/vegetation were higher and coverage ratio of rainfed croplands was even higher in towns with BI>20. Conclusion Mosquito density was closely related to irrigated croplands, water bodies and closed to open (>15%) grassland or woody vegetation on regularly flooded or waterlogged soil-Fresh, brackish or saline water.

2016, 27 (2): 99-102.    doi: 10.11853/j.issn.1003.8280.2016.02.002
Comparison of biochemical characteristics of carboxylesterase between pyriproxyfen resistant and susceptible populations of Culex pipiens pallens
LIU Hong-xia, XU Jin-qiu, LIU Yao, LENG Pei-en
Abstract301)      PDF (661KB)(846)      

Objective To preliminarily explore biochemical resistance mechanism by comparison the biochemical characteristic of carboxylesterase in pyriproxyfen-resistantand susceptible population of Culex pipiens pallens. Methods The activity of carboxylesteres (CarE) was determined by van Aspern(1962). Results The tendency of CarE activity change in hydrolyzing α-naphthyl acetate (α-NA) or β-naphthyl acetate (β-NA) depended on substrate concentration. The hydrolyzing activity was significantly higher in resistant population than in susceptible population with α-NA and β-NA as substrates within the certain concentration range. When substrate was β-NA, the Kinetic parameters (Km) and Vmax of CarE were 27.20×10-5 mol/L and 115.00×10-5 A/(mg·pro·min) in resistance population respectively, and that of CarE in susceptible population were 104.00×10-5 mol/L and 207.00×10-5 A/(mg·pro·min). Difference between them was significant (tb=2.74, tc=3.16). When substrate was α-NA, there was no significant difference between Km (131.00×10-5 mol/L) in resistance population and Km (75.20×10-5 mol/L) in susceptible population; but difference was significant between Vmax of them. The CarE from resistant population was more sensitive to DDVP (dichlorvos) and propoxur than that from susceptible population. Conclusion Enhanced CarE activity maybe attributable to the resistance of Cx. pipiens pallens to pyriproxyfen.

2016, 27 (2): 103-106.    doi: 10.11853/j.issn.1003.8280.2016.02.003
Zoogeographical analysis of Culex pipiens pallens/ Cx. pipiens quinquefasciatus in China, 2014
LU Run-ze, LIU Qi-yong, WU Hai-xia, GUO Yu-hong
Abstract403)      PDF (959KB)(1249)      

Objective Based on zoogeographical division of China, we analyzed the population characteristics of Culex pipiens pallens/Cx. pipiens quinquefasciatus including its composition, density, seasonal fluctuation and the distribution in different circumstances, it will be supportive for mosquito surveillance and control program. Methods The mosquito surveillance data based on light traps were extracted from the National Vectors Surveillance Networks in China. The data werer analyzed in accordance with the zoogeographical division of China respectively to obtain the species composition and distribution, the population density, the seasonal fluctuation by each zoological division. Results In 2014, the annual average density of Cx. pipiens pallens/Cx. pipiens quinquefasciatus was 1.20 mosquito/(trap·h). It was relatively low in January, February, November and December, and reaches the peak in July [3.45 mosquito/(trap·h)]. It was the predominant species both in the Southern [1.58 mosquito/(trap·h), 64.37%] and the Northern [2.31 mosquito/(trap·h), 81.97%] region of China. There was no record of Cx. pipiens pallens/Cx. pipiens quinquefasciatus in Mongolia-Xinjiang Region. The annual average mosquito density had significance variation (F=3.977, P=0.004) in different zoogeographical division, and the differences in the seasonal mosquito fluctuation were statistically significant (F=2.484, P=0.013). The mosquito density distribution of different habitats also showed with significance variation (F=4.569, P=0.001). Among them, the mosquito density of livestock sheds was relatively high [1.92 mosquito/(trap·h)]. Conclusion The Cx. pipiens pallens/Cx. pipiens quinquefasciatus' composition, density, and seasonal fluctuation showed difference with different zoogeographical distribution. The result is another evidence for the zoogeographical division of China, and the result might be a good example for analysis of mosquito surveillance. It may also serve as a basis for making the control decision in different zoogeographical divisions.

2016, 27 (2): 107-111.    doi: 10.11853/j.issn.1003.8280.2016.02.004
The relationship between the distribution of small mammals, vectors and plague in different landscapes in Southwest Yunnan
HUANG Tao-hua, LIU Lin, DU Chun-hong, HONG Mei, LIU Zheng-xiang, GAO Zi-hou
Abstract274)      PDF (881KB)(1069)      

Objective To investigate the distribution features and laws of small mammals and ectoparasitic fleas in different landscapes in domestic rat plague foci in Southwest Yunnan and their relationship with plague prevalence. Methods Yunxian, Yongde, Jinggu, Ninger, Menghai and Mengla were sampling area of our research. The systematic investigation on small mammals and their ectoparasitic fleas distributed in different landscape ecosystem were carried out. The characteristics of the spatial distribution of diversity of small mammals and their ectoparasitic fleas were analyzed using community ecological indexes. Results There were 719 small mammals captured, which belonged to 19 species (subspecies), 12 genera, 6 families and 3 orders. Rattus tanezumi (55.77%) were dominant species. A total of 229 fleas were captured, and they were classified into 14 species (subspecies) of 11 genera in 5 families. Xenopsylla cheopis (57.21%) and Ctenophtha lmus lushuiensis (17.03%) were dominated species. Diversity index and evenness index of small mammals and ectoparasitic fleas in different landscapes was, in descending order, forest area> agricultural area> residential area. But the order of dominance index was opposite. Shannon-Wienne's diversity index(H') of small mammals captured in forest area, agricultural area and residential area was 2.28, 1.60 and 0.16 respectively, and that index of ectoparasitic fleas was 1.97, 1.75 and 0.15 respectively. Conclusion Landscape played a dominant role in community structure of host animals and fleas. Forest area helped to keep natural focus in domestic rat plague foci. Residential area was an important environment of plague prevalence. Agricultural area might be an important channel of transmission and prevalence of plague. Agricultural area played a pivotal role in long-term preservation, prevalence and diffusion of domestic rat plague foci.

2016, 27 (2): 112-116.    doi: 10.11853/j.issn.1003.8280.2016.02.005
The population dynamics of small mammals in Three Gorges Reservoir hydro-fluctuation area, 2010-2014
CHANG Zhao-rui, LU Liang, GUO Yu-hong, MAO De-qiang, ZHAO Xin, LIU Jing-li, YANG Wei-zhong, ZHANG Jing
Abstract290)      PDF (382KB)(691)      

Objective To understand the distribution of rodents, dynamics of rodent density and composition in hydro-fluctuation area of Three Gorges Reservoir after experimental storage, and provide evidence for the risk prediction and control of rodent-borne diseases. Methods Four surveillance sites were set in upper, middle and down reaches of the Three Gorges Reservoir and surveillance were carried out twice after water drainage and before water storage every year. The small mammal density and the species composition in different regions, altitude and periods were analyzed. Results During 2010-2014, a total of 116 small mammals were captured and the average capture rate was 1.10% and on the decline overall. The captured small mammals were classified into six species. Apodemus agrarius was the predominant species accounting for 46.55% and Anourosorex squamipes was next with 25.86%. The average capture rate after water drainage (1.23%) was higher than that before water storage (0.90%). All captured small mammals distributed in all three altitude and the composition decreased from high to low latitude. The predominant species was different in three altitude. The predominant species in 166-175 m altitude was A. squamipes accounting for 44.45%, followed by Rattus tanezumi (18.52% ); In 145-155 m and 156-165 m altitude, Ap. agrarius was predominant species accounting for 84.00% and 72.97%, respectively. Conclusion The average capture rate was low and there was various species of rodent in hydro-fluctuation area. The density and species composition of small mammals varies with different regions, altitude and monitoring time. The host animals of hemorrhagic fever of renal syndrome, Leptospinosis and commensal rodent plague may be of risks in hydro-fluctuation area of Three Gorges Reservoir. It should be strengthened to monitor the host animals and take the corresponding control measures in the area based on the risk assessment.

2016, 27 (2): 117-120.    doi: 10.11853/j.issn.1003.8280.2016.02.006
Functional expression of NADPH-cytochrome P450 reductase of the house fly ( Musca domestica) in Escherichia coli
FENG Jing, TIAN Kai, HOU Xin, QIU Xing-hui
Abstract402)      PDF (370KB)(789)      

Objective House fly (Musca domestica) is a mechanical vector of many diseases which can cause severe consequences for human and animal health. Cytochrome P450 monooxygenases play an important role in resistance to many insecticides in the house fly. Establishment of functional expression system of NADPH-cytochrome P450 reductase will be helpful for the characterization of P450 mediated insecticide resistance. Methods In this study, we cloned the open reading frame of MdCPR gene into the expression vector pB508. The constructed plasmid MdCPR-pB508 was transformed into Escherichia coli (DH5α). The production of MdCPR protein in E. coli was induced by isopropyl β-thiogalactoside (IPTG). Results MdCPR was expressed in E. coli with an expected molecule weight of around 76×103. The E. coli-produced MdCPR protein was mainly present in the membrane fraction, showing the catalytic activity of NADPH-dependent reduction of cytochrome C. Conclusion The successful functional expression of MdCPR can facilitate further investigation of the role of various cytochrome P450s in insecticide resistance in house flies.

2016, 27 (2): 121-123.    doi: 10.11853/j.issn.1003.8280.2016.02.007
Spatial-temporal characteristics of hemorrhagic fever with renal syndrome in mainland China, 2004 to 2013
GUAN Peng, WU Wei, HUANG De-sheng, NIE Xiao-nan, GUO Hai-qiang
Abstract282)      PDF (1797KB)(817)      

Objective To explore the spatial-temporal characteristics of hemorrhagic fever with renal syndrome (HFRS) in mainland China. Methods Demographic information and the annual number of incident HFRS cases in mainland China from 2004 to 2013 were collected. Retrospective time-space analysis (based on discrete poisson model) was conducted to detect the spatial and spatio-temporal clusters of HFRS cases in SaTScan (Version 9.1.1) after geographical information system database constructed via ArcGIS software (Version 9.3). Gravity centers of HFRS cases were calculated and depicted with bubble charts in Excel 2010. Results The number of HFRS cases decreased from 2004 to 2009 and increased with a gravity center northeast to that of population. The gravity center of HFRS cases in 2013 moved to southwest for 307.87 km compared to that of 2004 with the directional angle as 241.69 degree. The distance in longitude was 119.52 km and 282.61 km in latitude. The most likely cluster was in Heilongjiang, Jilin and Liaoning during 2004 to 2008 with the relative risk 9.22. The secondary cluster included four geographical areas, Shaanxi area (2008-2012), Shandong, Tianjin and Hebei area (2004-2005), Zhejiang province (2004-2007) and Jiangxi (2011-2013), the relative risks varied from 1.32 to 6.33. Conclusion There are significant spatio-temporal cluster pattern for the distribution of HFRS cases in mainland China, the epidemic status showed a weakening trend and the gravity center moved from northeastern part to northern China.

2016, 27 (2): 124-127.    doi: 10.11853/j.issn.1003.8280.2016.02.008
Analysis on spatiotemporal patterns and driving factors of Japanese encephalitis in Henan province
JIANG Hong-yue, LI Hai-rong, YANG Lin-sheng, WANG Juan-le
Abstract263)      PDF (1629KB)(823)      

Objective This paper was intended to analyze the spatiotemporal patterns of the Japanese encephalitis (JE) in Henan province from 2006 to 2010, and explore the connection between JE incidence and the geographical environmental driving factors. Methods The JE incidence from 2006 to 2010 in Henan was analyzed with epidemiological research, spatial autocorrelation, and correlation method. The multiple linear regression model was also built to identify the impact of meteorological, surficial and socio-economic factors on JE. Results The total number of JE case is 2 729 with yearly incidence of 0.547 4 per 100 thousand people and the overall death case was 119 with mortality rate of 4.36%. The incidence outbreak from July to September, accounting for 97.08% of the whole year cases and the annual incidence declined in 2008 and then fluctuated until 2010. JE cases were mainly concentrated in the southwest area, and "hot spots" agglomeration was significant in Luoyang, Nanyang, and northern Xinyang city. In terms of the meteorological driving factors, rainfall, the number of rainy days, >80% humidity days and >25℃ cumulated temperature promoted the outbreak of JE, while >30℃ cumulated days and the maximum above 30℃ cumulated temperature would reduce the incidence. For the surficial factors, watershed density and cultivated area illustrated the significant correlation with incidence of 99% confidence. With the increase of income per capita in farmers and total number of health technical staff, the possibility of an outbreak of JE also decreased. The overall predicted R2 of regression model was 0.643 with the adjusted R2 of 0.414. Conclusion The southwest area in Henan province is the key area for JE management. Research on the geographical driving factors of JE disease, will have a significant effect on the prevention and control of JE incidence.

2016, 27 (2): 128-132.    doi: 10.11853/j.issn.1003.8280.2016.02.009
Epidemic characteristics of endemic typhus in 2005-2014, Zhejiang province, China
ZHANG Rong, SUN Ji-min, LU Qun-ying, LU Miao-gui, SHI Xu-guang, REN Jiang-ping, GONG Zhen-yu
Abstract319)      PDF (1277KB)(934)      

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.

2016, 27 (2): 133-136.    doi: 10.11853/j.issn.1003.8280.2016.02.010
Investigation of Yersinia pestis and Hantavirus carried by small mammal hosts at Guangdong entry-exit ports
GAO Yun-xia, LI Xiao-bo, FANG Sheng-fan, YAN Jie, HUANG Li, ZHANG Xian-guang, FANG Shu-chun, DENG Jing, DING Guo-yun, HUANG Ji-cheng
Abstract302)      PDF (395KB)(893)      

Objective To investigate the species of small mammal hosts, ectoparasites, and infection of Yersinia pestis and Hantavirus at Guangdong 27 frontier ports, and to provide scientific evidence for implementing prevention and control interventions. Methods Small mammal hosts were captured by rat cages from May 2014 to April 2015. Lung specimens were collected, and followed by pathogen detection using PCR technique. Rodent borne disease was monitored in small mammal populations at frontier ports. Results In total 885 small mammal hosts were captured, the average density of small mammal hosts was 0.58%. The predominant species were Suncus murinus (47.68%) and Rattus norvegicus (33.67%). Xenopsylla cheopisi was collected. The flea-carrying rate was 0.79% and the flea index was 0.03. A total of 839 lung specimens were collected and SEO-type Hantavirus were positive in 10 entry-exit ports (positive rate: 2.74% ). The Hantavirus-carrying rate in R. tanezumi was the highest (7.45%). There were no significant differences of virus-carrying rate in four types of frontier ports. No Y. pestis was found. Conclusion The average density of small mammals was lower than control threshold and no plague infection was found among small mammals, but there were R. tanezumi and X. cheopisi, and high Hantavirus-carrying rate were found in several entry-exit ports. Prevention measures should be taken into consideration to prevent the rodent-borne diseases.

2016, 27 (2): 137-140.    doi: 10.11853/j.issn.1003.8280.2016.02.011
The application of tandem repeat in genetic typing Yersinia pestis of Hebei province
WANG Hai-feng, YANG Shun-lin, ZHOU Song, BAI Xue-wei, ZHANG Yi-hui, YANG Xiao-yan, NIU Yan-fen, LIU He-zhi, DU Guo-yi, SHI Xian-ming
Abstract272)      PDF (474KB)(736)      

Objective To study the genotype of Yersinia pestis in Hebei plague foci by variable number of tandem repeat (VNTR). Methods Primers were designed according to the confirmed 14+12 VNTR, to genotype the 116 Y. pestis DNA of Hebei province. Results All of the strains showed one genetype, but they were different from CO92 and EV. Conclusion There is only one genetype of plague, indicating a genetic stability in Y. pestis in Hebei province.

2016, 27 (2): 141-144.    doi: 10.11853/j.issn.1003.8280.2016.02.012
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