Objective To investigate the species distribution and breeding habitats of sandflies, and to provide a scientific basis for the risk assessment of sandflies and the formulation of prevention and control strategies for kala-azar. Methods Light traps were used to collect sandflies in different habitats of Sanmenxia, Henan province, China from July to August in 2018. The collected sandflies were frozen before sorting, putting into tubes, and marking. Then fresh samples were randomly selected and dissected for species identification. SPSS 22.0 software was used for statistical analysis. The chi-square test was used to compare the sandfly distribution between groups. Results All counties (cities, districts) in Sanmenxia had kala-azar vector sandflies, and a total of 1 369 sandflies (38.03 sandflies/lamp·night) were collected using the light traps. There was a statistical difference in sandfly distribution between different areas and habitats ( χ ²=571.957, P<0.001). There was also a statistical difference in sandfly distribution between the three types of habitats (cave dwellings, tile-roofed adobe house, and brick house) ( χ ²=341.209, P<0.001). The overall sex ratio of sandflies was 2.05:1, with a statistical difference between five habitats ( χ ²=262.201, P<0.001). Specifically, females accounted for relatively high proportions in human settlements, pigpens, sheepfolds, followed by cowsheds, while males accounted for a relatively high proportion in chicken coop. Via molecular identification, the sandfly species were identified as Phlebotomus chinensis, Sergentomyia khawi, and Se. squamirostris. Conclusion Sandflies are widely distributed in specific rural environment of Sanmenxia. Preventing imported cases and controlling internal vectors, strengthening the comprehensive control in barns, and targeted monitoring and early warning of sandflies in tourism and canine habitats may effectively prevent the recurrence and transmission of kala-azar.

Objective To investigate the breeding of Aedes on rooftops of residential buildings in the core area of dengue hotspots in Yuexiu district of Guangzhou, China, and to provide a basis for scientific surveillance and control of Aedes vector. Methods From January 2018 to August 2019, an investigation was performed for the general information and breeding of Aedes on rooftops of residential buildings in the core area of dengue hotspots in Yuexiu district. EpiData 3.0 software was used for data entry, and SPSS 21.0 software was used for statistical analysis. The chi-square test was used for comparison of the positive breeding rate of Aedes between different rooftops, and a logistic regression analysis was used to identify the influencing factors for the positive breeding rate of Aedes on rooftops. Results Among the 414 rooftops inspected, 154 (37.20%) were positive for Aedes, with a container index of 34.27% (439/1 281). There was no significant difference in the positive breeding rate of Aedes on rooftops between high buildings and low buildings ( χ ²=0.839, P=0.360). Rooftops used for other purposes had a significantly higher positive breeding rate of Aedes than those not used for other purposes[41.36% (122/295) vs 26.89% (32/119), χ ²=7.595, P=0.006]. Cultivation of flowers or vegetables, enclosure for living, and storage of sundries increased the risk of breeding of Aedes. Positive breeding was mainly observed in water containers or idle containers, accounting for 47.61% (209/439), followed by water plants (107/439, 24.37%), rubbish (84/439, 19.13%), and other things (39/439, 8.88%). Conclusion Rooftops are important breeding sites for Aedes and are often neglected. The breeding of Aedes on rooftops should be taken seriously when developing the measures for mosquito control and effectiveness evaluation.

Objective To investigate the mosquito infestation in the mouths of manholes under the municipal administration networks in Shenzhen, Guangdong province, China, and to provide a basis for the prevention and control of mosquito-borne diseases in urban areas. Methods The ponding status, mosquito infestation rate, and mosquito density were investigated in the mouths of manholes under the municipal administration networks of representative subdistricts in the new town areas, old town areas, and urban villages in Shenzhen. The larvae were captured with a 500-ml larva sampling spoon for density (larvae/spoon) calculation. Results A total of 508 mouths of manholes under the municipal administration networks were investigated in November 2017; the mean positive rate of mosquito infestation was 4.7% (including a mean positive rate of Aedes infestation of 3.3%). The mounting rate and maintenance rate of Mosquito Proof Set (the four types of mosquito proof facilities, including mosquito repellent sticks, mosquito proof sluices and nets) were 27.4% and 76.3%, respectively. Of the mouths of positive manholes, 83.3% were not equipped with Mosquito Proof Set. The highest and lowest densities of larvae in the positive manholes were 43 larvae/spoon and 1 larva/spoon, respectively. Relatively high positive rates were observed in water supply manholes (5.9%), sediment manholes (5.7%), and municipal sewage manholes (5.5%). The sediment manholes, municipal sewage manholes, and municipal rainwater manholes had a relatively high constituent ratio both in the overall manholes investigated (84.8%) and in the positive manholes (87.5%). No mosquito infestation was found in the mouths of gas, communication, and power supply manholes. Conclusion The Mosquito Proof Sets are conducive to reducing mosquito infestation in the sewers. Places most seriously infested with mosquitoes are sediment manholes, municipal sewage manholes, and municipal rainwater manholes under the municipal administration networks. The Mosquito Proof Sets can effectively reduce mosquito infestation.

Objective To investigate the drug resistance of Xenopsylla cheopis to pyrethroids in the area of intensified flea control in Baise, Guangxi Zhuang Autonomous Region, China. Methods The insecticide resistance of X. cheopis was determined by residual film. The LC ₅₀ and 95% confidence interval of insecticide were calculated by SPSS 13.0 software. Results Compared with the control area (Youjiang district), fleas in the intensified control area (i.e., Longlin county and Xilin county) showed significantly decreased sensitivity to pyrethroids such as deltamethrin, beta-cyhalothrin, and cypermethrin as the LC ₅₀ of these insecticides increased susceptibility. The relative resistance ratios of X. cheopis to the three pyrethroid insecticides were 6.22, 7.69, and 5.69, respectively, in Longlin county, while those were 5.29, 6.03, and 4.82, respectively, in Xilin county. Conclusion Fleas in the intensified flea control area showed increasing resistance to pyrethroids. Therefore, surveillance of insecticide resistance should be highlighted for rational use of insecticides.

Objective To provide a reference for the monitoring, early warning and prevention and control of vector borne diseases, by researching the population distribution and density fluctuation of vectors and their significance in vector-borne diseases and by summarizing the temporal-spatial distribution characteristics of hemorrhagic fever with renal syndrome (HFRS), Scrub Typhus and intestinal infectious diseases for coastal beach area of Yancheng city. Methods To collect and process network-based report data of HFRS, Scrub Typhus and intestinal infectious diseases, human population information in the coastal beach area of Yancheng city; the vector population distribution, density fluctuation were monitored in coastal beach area from 2011 April to 2013 December. The pathogen were detected with fluorescent quantitative RT-PCR and RT-PCR in small mammal tissues and their ectoparasites, mosquitoes and ticks. All data was analyzed by Excel 2003 and SPSS 16.0. Results (1) The rodent density was 3.60%, it was higher than that of the coastal areas of Jiangsu province and the rodent density in Jiangsu province. The rodent density in the field is higher than that of town (residential area). The rodent density appeared two peaks in winter and summer at 2011-2013, the winter peak was in January and the summer peak during May to August. Apodemus agrarius was the predominant species in the coastal area, the constituent ratio of 89.19%. (2) The mosquito densities (per light-trap hour) was 0.51. There was a peak of the mosquito density from May to October every year. The predominant species was Culex pipiens pallens which constituent ratio was 88.84%. (3) The fly densities (per cage) was 46.57. The predominant species were Chrysomyia megacephala, Musca domestica which constituent ratio were 45.17%, 25.70% respectively. (4) The cockroach's densities (per net) was 0.01, and the infestation rate was 0.30%. The predominant species was Blattella germanica. The tick index of Hedgehog was 7.75, and the density of free tick (per flag-hour) was 37.00. In the emergency monitoring at August 2015, the density of the tick (per flag-hour) was 0.25, the tick index of parasitic ticks in sheep, dog, hedgehogs, and weasel were 1.80, 0.02, 8.33, 10.00 respectively. Capture ticks are Haema-physalis longicornis, The Gamasid index was 0.26, and the Chigger index was 0.24 in Ap. agrarius surface. (5) The incidence of intestinal infectious diseases, Scrub Typhus were intermittent gradually increased, and HFRS increased sharply in 2010-2014. There was the winter peak of HFRS, the highest incidence in December, and the autumn peak of Scrub typhus in November. There were two peaks of intestinal infectious diseases in May and November. Two SFTS epidemic occurred for the first time in Dongtai area in 2015, and related to the history of fishing in the coastal beach and a clear history of tick bites. (6) In small mammal tissues, SFTS total antibody was positive only in 1 of hedgehog serum, and SFTSV nucleic acid was positive in the capture of free ticks. However, Hantavirus, Rickettsial and other pathogens were negative. Conclusion There were vectors such as rodents, mosquitoes, flies, cockroaches, ticks, fleas, and mites in Yancheng city coastal areas, and posed risk of vector borne diseases, which occurred from time to time. It should take effective measures to prevent and control outbreak.

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.

Objective To observe the molluscicidal effect of a novel molluscicide, 10% wettable powder of quinoid-2′,5-dichloro-4′-nitrosalicylanilide (LDS), on Oncomelania hupensis from the mountainous areas in Zhejiang province, China in the laboratory and field and to provide a scientific basis for the application of LDS in the field. Methods O. hupensis was immersed in 0.1, 0.2, 0.4, 0.6, or 0.8 mg/L LDS in the laboratory and field; 0.2, 0.4, 0.6, 0.8, or 1.0 g/m2 LDS was sprayed onto O. hupensis in the laboratory and field, or powder form of LDS was scattered onto O. hupensis in the field. Meanwhile, 50% wettable powder of niclosamide ethanolamine salt (WPN) and clean water were used as controls. The molluscicidal effects were evaluated. Results O. hupensis had mortality rates of 100% and over 95% after being immersed in 0.1 mg/L LDS for one day in the laboratory and field, respectively, with no significant differences compared without O. hupensis treated with WPN (P＞0.05). O. hupensis had a mortality of over 95% after being sprayed with 0.8 g/m2 LDS for one day in the laboratory, a mortality of over 85% after being sprayed with 0.2 g/m2 LDS for three days in the field, and a mortality of over 85% after being scattered with 0.4 g/m2 LDS powder for one day in the field. The mortality of O. hupensis increased as the concentration of LDS rose and the exposure to LDS was prolonged. Conclusion LDS (10%) has a good molluscicidal effect on O. hupensis from mountainous areas of Zhejiang province in the laboratory and field.

Objective To analyze the imported chikungunya fever cases detected at the frontier ports of Guangdong Entry-Exit Inspection and Quarantine Bureau and to provide a basis for control of imported infectious diseases. Methods Surveillance was conducted in the entry passengers at the frontier ports of Guangdong Entry-Exit Inspection and Quarantine Bureau from 2008 to 2011, and epidemiological investigation was carried out in the feverish passengers from the epidemic area of chikungunya fever. The blood samples of suspected cases were collected for laboratory test, and the information of positive cases were analyzed. Results Eleven cases of chikungunya fever, all from the epidemic area of chikungunya fever, were detected; of these imported cases, 9 were in the period of disease while passing the frontier ports, and the other 2 were in incubation period and had an onset in the observation period after entry. The mean age of the 11 cases was 40.2 years; most of them were young and middle-aged males. The primary detection method was fever surveillance. There were no secondary cases. Conclusion Control measures against chikungunya fever are properly taken by Guangdong Entry-Exit Inspection and Surveillance Bureau at frontier ports, thus effectively preventing the transmission of chikungunya virus through frontier ports.

Objective To investigate the prevalence and genotypes of Hantavirus among the rodents in Xinjiang Uyghur Autonomous Region, China. Methods Total RNA was extracted from the lung of rodents (gerbil, vole, and Rattus norvegicus) captured from 3 areas (Alashankou, Shihezi, and Urumqi) of Xinjiang in 2010, and then the Hantavirus M gene was amplified by RT-PCR. The amplified gene fragments were cloned and then sequenced to identify their genotypes. Results No target fragment was detected in 312 gerbil lung samples and 31 vole lung samples. Of the 72 R. norvegicus lung samples, 11 (15.28%) were positive with Hantavirus M gene, all belonging to SEOV genotype. Conclusion It is the first time to find the Hantavirus (SEOV) carried by R. norvegicus in Urumqi, Xinjiang. More measures should be taken to monitor and control hemorrhagic fever with renal syndrome in this area.

Objective To investigate the prevalence of Anaplasma phagocytophilum infection among the sheep in Shihezi, Xinjiang Uyghur Autonomous Region, China and to analyze the 16S rRNA gene sequences of An. phagocytophilum. Methods Blood samples were collected from the sheep in Shihezi; total DNA was extracted from these blood samples; the target 16S rRNA gene fragments of An. phagocytophilum were amplified by nest PCR. The sequences of 16S rRNA gene fragments from positive samples were compared with the corresponding gene sequences deposited in GenBank. Results Of the 109 blood samples, 37 (33.94% ) were positive with the target gene fragments. The detected 16S rRNA (524 bp) gene sequences had a sequence homology up to 99% with some 16S rRNA gene sequences of An. phagocytophilum in GenBank. Conclusion The infection with An. phagocytophilum exists among the sheep in Shihezi, Xinjiang Uyghur Autonomous Region, China.

Objective To determine the resistance of Musca domestica to commonly used insecticides to inform proper application of chemical killing agents. Methods The median lethal dose (LD₅₀) for M. domestica was determined by the dripping method. Results The LD₅₀ values of beta-cypermethrin, deltamethrin, and dichlorvos for M. domestica were 0.064, 0.010, and 0.037 μg/♀, respectively, and the corresponding resistance coefficients of M. domestica were 9.14, 50.00 and 61.67, respectively. M. domestica showed low resistance to beta - cypermethrin and high resistance to deltamethrin and dichlorvos. Conclusion For effective control of M. domestica, comprehensive control strategies shall be employed, such as eliminating breeding places and physical management, chemical control and regular resistance monitoring, along with appropriate application of pesticides.

Objective To determine the presence and virulence genes of enterohemorrhagic Escherichia coli(EHEC) O157∶H7 in diarrhea patients and host animals in Henan province in order to identify the cause and related risk factors. Methods Suspicious samples collected at surveillance sites from 2005 to 2009 were subjected to serological detection and PCR, and tested for stx1, stx2, eaeA, hlyA virulence genes. Results Of the 10 732 serum samples, 255 (2.38%) were positive for O157∶H7 strains. The detection rate in animal stool samples was 6.31% (8.04% for sheep and 7.20% for cows). Different detection rates were observed in different years. Most EHEC O157∶H7 strains were from sheep, cattle and chicken feces. A combination of virulence genes stx2, eaeA, hlyA was predominant. Conclusion EHEC O157∶H7 existed in the population and various animals in Henan province. The most important animal hosts were sheep and cows. Contaminated food during processing was a possible cause and might lead to potential outbreaks.

Objective To determine the population composition of rodents and fleas and investigate plague in the natural foci in Longlin county, Guangxi Zhuang Autonomous Region for formulation of prevention and control strategies. Methods The flea-carrying rate and flea index of rodents were calculated based on the number of fleas collected from caged rodents. The free flea index was calculated according to the number of indoor fleas captured on sticky paper. The mammals were then subject to etiological and serological tests to determine the infection rate. Results Rodents of eleven species (3 families with 2 orders) and fleas (6 species) predominantly Rattus tanezumi and Xenopsylla cheopis were found in the foci. The average rodent density, flea-carrying rate, flea index and index of X. cheopis were 3.24%, 27.09%, 0.95 and 0.74, respectively. The indoor free flea index was 0.046. Among 5398 cultured rodent specimens, 10 strains of Yersinia pestis were isolated; two positive sera and 24 indicative sera were detected via indirect hemorrhagic assay (IHA). Conclusion The optimum period for rodent control is April and October and the key period for plague monitoring is from February to October in the natural foci of R. tanezumi plague in Longlin county.

Objective To verify the on-site molluscicidal activity of carbamide in hilly areas, providing the basis for promotion of this agent. Methods The experiment was performed in hilly areas invested with seedling fields and ditches using a 40 g/m² carbamide group, a 2 g/m² niclosamide group and a control group. Molluscicides were applied with turfs shoveled and buried in soil in spring and autumn, and the effect was evaluated in the next spring. Results The presence rate, average density and area of live snails were 59.27%, 5.66/0.1 m² and 20 630 m² in the carbaimide group before application of molluscicides, and became 0.44%, 0.005/0.1 m² and 280 m² one year after snail control, which was statistically different from the results before molluscicidal use and the control group (P＜0.01), but not different from the niclosamide group (P＞0.05). Conclusion Under pretreated dry environmental conditions, carbamide of 40 g/m² has satisfactory molluscicidal effects and is worth promoting.

The mite?borne hemorrhagic fever with renal syndrome (HFRS) has been attracting domestic and foreign controversies in recent years. Based on a large number of field investigation and experimental studies, Chinese scholars have proved the existence of the mite vector of HFRS and its possible role. This paper reviews the epidemiologic, experimental and molecular biologic basis of the HFRS of Apodemus type and Rattus type transmitted by gamasid mites, as well as the research advance in the animal hosts.

Objective The study was conducted to establish a molluscicide with strong snail?killing effects and low toxicity to aquatic organisms. Methods Immersion tests using 100, 200, 400 and 800 mg/L carbamide and spraying tests using 15, 20, 25 and 30 g/m² carbamide were conducted under laboratory conditions to measure the molluscicidal effects, respectively, which were then compared to the effect using 2 g/m² niclosamide. Results The Oncomelania hupensis mortality rates ranged from 3% to 6% after carbamide immersion at the concentration of 100-800 mg/L, suggesting no statistical difference from those in the control group (P＞0.05). The 1, 3 and 5 d O. hupensis mortality rates in laboratory spraying tests reached 91%, 90% and 95% in the 30 g/m² group, while those in the 2 g/m² niclosamide group were 97%, 96% and 98%, indicating no statistically significant difference (P＞0.05). Conclusion Under laboratory conditions, carbamide immersion was ineffective in killing snails, whereas carbamide spraying had the same molluscicidal effects as niclosamide did.

Objective To analyze the dietary composition of Bandicota indica to unearth the seasonal and annual patterns of the food structure, providing theoretical foundation for the development of scientific control countermeasures and sustainable management. Methods The contents of rat stomachs were analyzed in conjunction with field observation. Results Fibers accounted for (68.68±5.17)% in the gastric contents of the rats, while starch food (23.06±4.32)% and animal food (8.26±1.43)%, respectively. Significant differences were found in the gastric contents of subjects of different age, sex and in different seasons and years (P＜0.01). The proportion of starch and animal food in females was significantly greater than that in males. No significant differences were found in starch and fiber food consumed by the juvenile versus that by the sub-adults and adults, though the juvenile had higher intake of such kind of food (P＞0.05). However, the proportion of animal food consumption in adults was significantly higher than that in sub-adults and juvenile (P＜0.01). Considerable seasonal disparity in the food structure, characterized by higher amount of starch and animal food in summer and autumn and higher amount of fiber food in winter and spring, was also shown in B. indica. Conclusion B. indica were mainly fed on fiber food, as well as starch and animal food, under natural conditions. Diversity of food structure was associated with the reproduction and population growth, growth season of crops and vegetation types of the habitat.

【Abstract】 Objective To investigate the geographical distribution, habitat, dominant hosts and population spatial distribution patterns of Ornithonyssus bacoti in Yunnan province.  Methods   A total of 28 counties in five zoogeographical sub?regions were chosen as the investigated sites. Each investigated site was divided into two habitats (indoors and outdoors) and then small mammal hosts were randomly captured by mouse traps. All the gamasid mites from the body surface of the hosts were collected and preserved in 70% ethanol. Hoyer’s medium was used to mount the mites onto glass slides and each mite specimen was finally identified by microscope. The spatial pattern of the mite was analyzed by K?value of negative binomial distribution, patchiness index, Taylor’s power function and Iwao’s model.  Results A total of 3339 O. bacoti were collected from 11 560 captured  small  mammal  hosts  which belonged to 3 orders 4 families 8 genera  and  15  species.  Of  the  investigated 28 counties, O. bacoti was found in 21 counties and the mites were collected from 15 species of small mammal hosts. O.bacoti mainly distributed in Southwest region (accounted for 90% of the total), and the quantity of O. bacoti in indoors (2914, 87.27%) were obviously higher than that in outdoors (425, 12.73%).  90% mites mainly parasitized on the body surface of Rattus norvegicus and R. tanezumi which were  the  dominant  host  of  mites.  The  results  showed  that  the  spatial  pattern  of  O. bacoti  was  an  aggregated  distribution. Conclusion O. bacoti  widely  distributes  in  Yunnan  province  and  mainly  parasitizes  on  the  body surface of R. norvegicus and R. tanezumi. It is of aggregated distribution among its main hosts.

【Abstract】 A supplemental description on larvae and pupa of Simulium (Odagmia) emeinesis ［An, Xue and Song （1991）］ is given based on the specimens collected from Emei Mountain and Bifeng gorge of Sichuan province, China. The pupa and larva stage have previously been unknown and are only described in the type specimen. This species is classified into the ornatum species of subgenus Simulium according to hair of pleural membrane.

【Abstract】 Objective To improve the traditional preparation of the polytene chromosomes of blackflies and observe chromosomes abstracted. Methods Mature larvae of blackflies were selected, dissected and shelled out salivary glands. The traditional method was improved, and the clear polytene chromosomes slices were prepared after the use of new staining fluid, flush fluid and cleaning fluid. Results The improved method made chromosomes clearly and wholly in microscope. Conclusion The improved technique succeeded in the preparation of chromosome specimens of blackfly salivary gland, which was convenient for the observation of chromosomes shape and chromosomes variation in the laboratory.

【Abstract】 Objective To study the effect of meteorological factors on rats density by Response surface methodology（RSM） based on correlation and regression analysis. Methods The meteorological factors and rats density were monitored continuously. A response surface model was made by the correlation and regression analysis of them. Results Linear regression analysis（P＜0.030）indicated that monthly average minimum temperature， sunshine time and precipitation were the main influence factors， and the multiple correlation coefficient was 0.716. However， RSM suggested that monthly average minimum temperature（P＝0.003）, precipitation square（P＝0.059）， interaction of monthly minimum temperature and sunshine（P＝0.027） affected mostly the density of rats， and its multiple correlation coefficient was 0.761. Conclusion The effect of meteorological factors on the rats density could be evaluated by RSM model.  This model was superior to linear regression model. The effect of meteorological factors on rats density was resulted from multiple factors and their interaction.

Objective To study efficacy of the mixture including pyrethroid, avermectin and tebuconazol to hygiene pest. Methods Efficacy of this mixture was evaluated with KT ₅₀ and LC ₅₀ of them to hygiene pest. Results This mixture had better efficacy than other mixtures composed of part elements to mosquito, housefly and cockroach( P<0.001). The rate of knockdown and the mortality of the mixture to Mulex pipiens pallens, Musca domestica or Blattella germanica were all 100% after treated for 1 h and 24 h, respectively. The LC ₅₀ value of it to the larvae of C.pipiens pallens and M.domestica were 0.025 μg/ml and 0.41 μg/ml, respectively. The oothecae hatchability of B.germanica and Periplaneta americana decreased to 94% and 76%, respectively. The knockdown rate of the mixture to C.pipiens pallens, M.domestica, B.germanica and P.americana were all 100% after 1 h treated in analogous site. The 24 h mortality to C.pipiens pallens, M.domestica or B.germanica was 100% and the 48 h mortality to P.americana also reached 100%. According to GB/T 17322.1, the control efficacy of the mixture achieved A degree. Conclusion This mixture had good control effect on common hygiene pest, and also provided new method for the control of agriculture pest and hygiene pest.

Objective To explore the factors causing the mainly clinical symptoms of fever,headache,swelling of lymph gland and tetter from unknown causation in Henan province.Methods An epidemiological investigation was carried out in Huaibin county of Henan.Serological method was used to determine antibodies titer and serological type.Specific gene fragments of Orientia tsutsugamushi(Ot) were detected by nested PCR.Results 32 suspicious patients were found in the rural.Blood samples were taken from 20 of 32 cases,positive rate of those was 100% for Oxk by Weil-Felix reaction.And the Oxk reaction titers were four times rise among 11 of 2 ^nd blood samples.IgM and IgG antibodies to Ot were detected by IFA as positive in all 20 cases.And the highest titer was 1∶2560.Of serological typing of 20 cases,4 were identified as Gilliam,6 as Karp and 8 as Kato.Specific DNA bands of Ot were observed by nested PCR for the DNA extraction from the blood clot of 3 patients.Conclusion Infection of tsutsugamushi disease was discovered for the first time in Henan province.

Objective To investigate and estimate the distribution of the ticks in Jinhua,Zhejiang province to find out the reason of the suspected Ehrlichiosis happened in this area. Methods Investigate species and Observe amount peaks of the ticks parasitizing on domestic and wild animals caught from mountain areas and sold in the farm produces fair in the edge of Jinhua in which a suspected case had been found on 10,20 and 30 of each month in 2005. Results The results indicated that total 6 genus,6 species of ticks were found on these animals. Of them,rabbit tick Ixodes sinensis showed the double amount peaks in the year,one peak appeared from February to April and the other from October to December; Amblyomma testudinarium appeared later and also showed the double peaks,one peak from March to May and the other from August to October; Haemaphysalis longicornis only appeared in hot summer from June to September. Conclusion Amblyomma testudinarium which had been found infected with human Granulocytic Ehrlichiae in previous investigation,was found in this investigation. And it together with I. sinensis,seems to be dominant tick species in this area,risk of tick borne diseases such as Lyme diseases and Ehrlichiosis should be paid attention to.

Objective To present a method for forecasting popalation dynamics of Rattus rattoides in the Pearl River Delta. Methods Model of multiple seasonal,model of addition seasonal and ARIMA model were used to simulate the temporal variation dynamics of Rattus rattoides population and the corresponding model were established for the middle-term and long-term prediction. Results Model of multiple seasonal,model of addition seasonal and ARIMA model were satisfying to simulate the accumulation and disappearance tendency of Rattus rattoides population. Based on the models,the average errors of forecasting Rattus rattoides population were ( 6.43± 1.87 ),( 10.34± 2.56 ) and ( 11.48± 2.78 ),respectively,and the accuracy rate of the emergence grade forecast were 91.67 ,83.33 and 66.67 ,respectively. Conclusion Model of multiple seasonal and model of addition seasonal could be used to forecast the emergence dynamics of Rattus rattoides population with the predicted model of X( t)=5.158 393 29-0.015 772 24 t)γ _T+t and X( t)= 5.181 308 46-0.008 617 24 t+ d _T+t.

Objective:To study on the mixture insecticide efficacy against Culex pipiens quinquefaciatus larva.Method:Determining the LC ₅₀.Result:Cypermethrin and Bacillus thuringensis mixture insecticide to sensitive Culex pipiens quinguefaciatus larva LC ₅₀ was 0.0056mg/L,the guotiety was 0.98,which to resistant Culex pipiens quinquefaciatus larva LC ₅₀ was 0.0545mg/L,the toxicity quotiety was 284.03,they have obvious synergistic action.Concoulion:On the dosage of 2.5mg/L consistancy to sensitive and resistant type,the killing efficiency was over 80% in the laboratory and validity time was 21 days.The efficiency quotiety was longer than that with 0.5mg/L Cypermethrin and 2.0mg/L B.t.I.H-14.But after 21 days,mixture insecticide efficiency quickly decreased.One month later,it was out of action.

The LC ₅₀ Cypermethrina and Bacillus thuringensis mixed insecticide to sensi tivity Culex pipiens quinguefaciatus larve was 0.0056mg/L. Toxicity guotiety was 90.8. Their toxicity showed on additive joint action.The resislante Culex pipiens quinguefaciatus larva's LC ₅₀ was 0.0545mg/L. Common toxicity quotiety was 284.03. They have obvious synergistic joint action. n the scale of 2.5 mg/L consistency to sensitivity and resistance type killing efficiency was greater than 80% in the laboratory and validity time was 21 days. Its efficiecy quotiety was longer than that of 0.5mg/L Cypermethrin or 2.0 mg/L B.t.i H-14. But after 21 days, the mixture efficiecy decreased quickly.

The transmission electron microscopy had been used to visualize the three types of pathogens from the hindgut of the cockroach, Periplaneta fulginosa, The three pathegens were designatd ball shape, short curverods and large rod.At specific areas of the hindgut,pathogens attached to spine-like projections.The short rods had been obsarved to under go fission,Some pathogens invated into submucous membrane of tho gut. The cockroaches transmit ted pathogens with biological mechanism.