ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To investigate the distribution patterns of mosquitoes and mosquito-borne viruses in Yunnan province to provide evidence for prevention and control of mosquito-borne diseases. Methods In 2009, mosquito samples were collected from 6 counties of Yunnan province. Mosquitoes were first classified, followed by cell culturing for viral isolation for molecular identification. Positive isolates were identified using SDS-PAGE and RT-PCR. The genomes of isolates were also, sequenced for phylogenetic analysis. Results A total of 18 562 mosquitos of 4 genera (Culex, Anopheles, Armigeres, Aedes) and 24 species were collected. Cx. tritaeniorhynchus and An. sinensis were the major species, comprising 58.37% and 28.45% of the total population, respectively. Fifteen strains of viruses were isolated from the mosquito pools. RT-PCR and phylogenetic analysis revealed two viral strains from Cx. tritaeniorhynchus, identified as Japanese encephalitis virus (JEV, GenotypeⅠ). One strain isolated from An. sinensis was identified as Banna virus. Twelve vrial strains were identified as Cx. pipiens pallens densovirus (CppDNV), of these, nine strains were isolated from Cx. tritaeniorhynchus, and three strains from An. sinensis. Conclusion Cx. tritaeniorhynchus and An. sinensis were the predominant species in the investigated areas. JEV, Banna virus and CppDNV were isolated. In northeast Yunnan, JEV was isolated for the first time.
Objective To determine the changes of carboxylesterase (CarE) activity in Culex pipiens quinqusfasciatus treated with cypermethrin and propoxur at sublethal doses. Methods The enzyme activities were measured in vitro with an ultraviolet-visible spectrophotometer. Results After 24 h treatment, the enzymatic activity of resistant strains was 1.19 times that of sensitive strains. Significant inhibition was noted in all treatment groups after 48 h. Compared with the 24 h treatment group, the enzymatic activity of the control group, propoxur at LC20, propoxur at LC40, cypermethrin at LC20, and cypermethrin at LC40 decreased by 24.71%, 38.42%, 97.42%, 90.77% and 95.76%, respectively. The decreases in all treated groups were more significant than in the control group. Activities in resistant strains treated with cypermethrin and propoxur at sublethal doses for 48 h were significantly different from the control group, except for the group treated with LC20 propoxur. Compared with the control group, the specific activity was 11.6254 nmol/(mgpro·min) in the group treated with LC40 of propoxur, indicating significant inhibitory effect. In the groups treated with LC20 and LC40 of cypermethrin, the activity was 55.8868 and 54.5530 nmol/ (mgpro·min), respectively, suggesting significant inductive effects. No difference was noted between the two 24 h and 48 h treatment groups. Compared with the 24 h treatment group, the specific activity of the control group, propoxur (at LC20 and LC40) and cypermethrin (at LC40) treated groups decreased by 60.71% , 59.14% , 23.68% and 47.87% , respectively, whereas the cypermethrin LC20 group increased by 23.89%. The decrease in the control group was lower than those in the treatment groups. Conclusion Different levels of carboxylesterase activity were observed in sensitive and resistant Cx. pipiens quinqusfasciatus when treated with sublethal doses of cypermethrin and propoxur. Thus, indicating their different inhibitory effects and that a single insecticidal agent could have different levels of activity in different populations.
Objective To evaluate alluring effects of monitoring devices on spawning mosquitoes under simulated and field settings. Methods Alluring effects were recorded for 12 h (overnight) in laboratory stimulated and field environments with ecological water (from the field habitats) and dechlorinated tap water as the baits. Results In the stimulated scenario, the trapping rate was 56.5% for female mosquitoes, and in a 50/50 subject group 40.0% and 4.0% for female and male mosquitoes, respectively. In the field, obvious alluring effects were noted in buildings and crowded areas, as well as remarkable selective trapping effects on female mosquiotes in grassy and sparsely populated areas (t＝4.916, P＜0.05). The trapping effect of ecological water was better than dechlorinated tap water. Conclusion The alluring effect of monitoring devices on spawning mosquitoes was observed in both the stimulated and field setting. The selective trapping effect on female mosquiotoes in the field was dependent on habitat, meteorological
Objective To compare mosquito densities using the black box method and the carbon dioxide method and explore the application of the black box approach. Methods The black box method and the carbon dioxide method were used to measure mosquito density and composition at seven locations in two districts of Shanghai. Correlations between species composition, sex ratios and seasonal variation were compared using the two Methods. Results The average mosquito density using the black box method (25.63 mosquitoes/box) was 3.50 times higher than the carbon dioxide method (7.32 mosquitoes/ device), and the average density of female mosquitoes using the black box method (14.65 mosquitoes/box) was 2.35 times higher than the carbon dioxide method (6.23 mosquitoes/device), densities were significantly different. The density indices of the two approaches were not correlated. The species composition recorded by the black box method was: Culex pipiens pallens (94.97%), Aedes albopictus (4.97%), Cx. tritaeriorhynchus (0.03%), and Anopheles sinensis (0.03%). The species composition recorded by the carbon dioxide method was: Cx. pipiens pallens (79.26%), Ae. albopictus (18.27%), Cx. tritaeriorhynchus (2.10%) and An. sinensis (0.37%). The differences in composition were also statistically significant. Conclusion As compared to the carbon dioxide method, the black box method is readily applicable, simple, affordable and can be used in most locations, particularly habitats dominated by Cx. pipiens pallens. The carbon dioxide method can be used for the monitoring of both Cx. pipiens pallens and Ae. albopictus.
Objective To select a primer set for sex identification of Marmota himalayana from the sry and smcY primers used in ground squirrels. Methods One pair of sry primers and four smcY primers (used in 3 different combinations) were used to amplify the genomes of 10 M. himalayana of known sexes. One pair of microsatellite primers were used to verify the method. Results The sry primers amplified several bands from 100 bp to 1000 bp, but no male-specific bands were found. Combination 1 of smcY primers amplified a bright band of about 100 bp only in males, but a weak band of about 600 bp was also amplified in some females. Using smcY primer combination 2 yielded no amplified bands. Combination 3 amplified a bright band of about 250 bp in all males, but no band was observed in females. Conclusion The gender selectivity of smcY primer combination 3 means it could be used for sex identification of M. himalayana.
Objective To analyze the species diversity and faunal composition of Calyptratae in Emeishan area of Sichuan province. Methods Faunal analysis and biodiversity analysis were employed, using Shannon-Wiener index and Berger Paeker index as indicators for diversity and dominance. Results In the study area 224 species, 81 genera and 7 families of Calyptratae were recorded. Muscidae and Anthomyiidae were predominant at the genera and species levels, accounting for 24.69% and 22.22% of all known Calyptratae genera respectively, and 30.80% and 31.25% of the species in the region, respectively. Sixty-two endemic species accounted for 27.68% of the total. Fifty-nine Oriental realm species and 67 Palaeoarctic and Oriental realm species, accounted for 26.34% and 29.91%, respectively. The diversity indexes at the genera and species levels were 1.72 and 1.64, respectively. Conclusion The Emeishan area of Sichuan province has high Calyptratae species diversity and was characterized by endemic elements, Oriental realm elements, Palaeoarctic and Oriental realm elements and other coexisting elements.
Objective To compare the efficacy of three kinds of baits (rotten fish, rotten eggs and brown sugar-vinegar) against flies to offer the ideal option for vector monitoring. Methods Fly traps with different baits were deployed simultaneously in five experimental sites. The captured flies were identified in the laboratory. Results No significant differences in the captured species was found between the baits. Flies captured by the rotten fish, rotten eggs and brown sugar-vinegar accounted for 66.99%, 32.07% and 0.94%, respectively. Chrysomya megacephala and Musca domestica were the dominant species in the rotten fish group. Lucilia cuprina was more easily attracted by sugar-vinegar baits. Rotten eggs were more attractive to C. megacephala and Hemipyrellia ligurriens. Calliphoridae and Muscidae were more easily attracted by rotten fish, while Sarcophagidae, Calliphoridae and Anthomyiidae preferred rotten eggs. Conclusion Sugar-vinegar baits did not reflect seasonal changes as they attracted a very small number of flies. Rotten fish attracted a large number of flies from only a few species. Rotten eggs could attract a proper number of flies from a balanced collection of species, and thus could be used for fly monitoring.
Objective To determine the susceptibility of Culex pipiens pallens and Musca domestica to common insecticides in Henan province. Methods The dipping method and the topical application method were used to measure the susceptibility of Cx. pipiens pallens and M. domestica to commonly used insecticides. Results In Zhumadian city, the resistance ratio of Cx. pipiens pallens to common insecticides was 1.36-67.37, and Cx. pipiens pallens had the highest resistance to deltamethrin. The resistance ratio of M. domestica was 6.36 to greater than 443.39, and M. domestica had the highest resistance to propoxur. In Nanyang city, the resistance ratio of Cx. pipiens pallens was 1.33-40.26, and Cx. pipiens pallens had the highest resistance to beta-cypermethrin. The resistance ratio of M. domestica was 6.34 to greater than 443.39, and M. domestica had the highest resistance to propoxur. Conclusion Cx. pipiens pallens populations in investigated cities were still sensitive to temephos and fenobucarb but resistant to deltamethrin and beta-cypermethrin. M. domastica had developed different resistances to all insecticides. It is important to use insecticides appropriately to prevent the development of resistance in mosquitoes and houseflies.
Objective To develop a rapid detection kit for resistance level and target resistance to organophosphate insecticides in Culex pipiens complex field populations. Methods Strains with different resistance levels were established according to biochemical and molecular resistance mechanisms in mosquitoes. to reflect the correlation between typical acetylcholinesterase (AChE) staining and the resistance staining. The relationship between target resistance and chromogenic reactions was determined according to the inhibitory effects of propoxur at different concentrations on insensitive AChE 1 induced by a G119S mutation. Results A set of coloration cards made from AChE filter paper were developed to describe different organophosphate resistance ratios, which could be used for rapid and simple detection of the resistance level in the field. A chromogenic system was established to visualize the presence of target resistance and the relevant genotypes in the population. Conclusion This study introduces a simple and effective tool for detection and monitoring of mosquito resistance.
Objective To evaluate the residual efficacy of bifenthrin against Aedes albopictus on washed mosquito nets. Methods The knockout and fatality rates of mosquito nets after several WHO standard washing procedures were determined using forced exposure tests. Residues were measured using gas chromatography. Results The knockout and fatality rates decreased sharply as the number of washing increased. At the 15th and 20th wash, the average knockout rate decreased by 39.4% and 70.0% respectively, and the average fatality rate dropped 25.0% and 69.7%, respectively, indicating a significant impact of washing on the effect of agent-treated nets. The residue and degradation of bifenthrin conformed to the first-order kinetics equation: C＝137.3746e-0.0696t, T1/2＝9.97 times, R2＝0.9868. Conclusion After washing, mosquito nets were no longer effective when residual bifenthrin content was lower than 28.15 mg/m2. A final content of more than 42.99 mg/m2 should be ensured to maintain noticeable mosquito control efficacy.
Objective To measure Culex pipiens pallens larval sensitivity to common insecticides and the effects after combined with S1 and MGK264 in order to provide evidence of the development of resistance. Methods WHO-recommended bioassays were employed to calculate the LC50,regression equation and synergistic coefficients. Results Lakefront Cx. pipiens pallens had varying degrees of resistant to five insecticides．The synergistic coefficients of DDVP, propoxur and cypermethrin were 3.10-6.17, 3.98-7.74, 6.48-9.91, respectively, and after combination with S1 and MGK264 1.08-1.90, 1.63-2.37, 3.93-4.33, respectively. Reported synergistic coefficients show satisfying synergetic effects. Conclusion The combination of synergistic insecticides may result in a good killing effect for resistant Cx. pipiens pallens．
Objective To identify the molluscicidal effect and mechanism of Melia azedarach L. leaves against Oncomelania hupensis. Methods Different polar parts of M. azedarach L. leaves were isolated to screen for active compounds. The molluscicidal effects of M. azedarach L. leaves at different concentrations were detected using the laboratory screening Methods recommended by WHO. The glycogen and protein contents of O. hupensis treated with light petroleum extract of M. azedarach L. leaves were determined by Anthrone and Coomassie reactions, respectively. Acute toxicity on non-target organisms was determined using Zebrafish as a bioindicator. Results The light petroleum extract of M. azedarach L. leaves was the most active component with snail-killing effects. The LC50 values of the light petroleum extract was 101.6 mg/L after 72 h treatment. The snail glycogen content decreased remarkably (by 75.61%) after treatment with the light petroleum extract. The LC50 value of the zebrafish extract was as small as 285.6 mg/L after 72 h treatment. Conclusion M. azedarach L. leaves may contain safe and effective molluscicidal ingredients.
Objective To establish a set of standard laboratory techniques for effective feeding and breeding of ticks. Methods Under experimental conditions, Hyalomma anatolicum anatolicum ticks were fed New Zealand rabbits or sheep, and incubated at 28 ℃ with 80%-85% relative humidity. Results H. a. anatolicum had a three-host life cycle of 84-159 d (mean 121.5 d) when fed on sheep, and a two-host life cycle of 77-140 d (mean 108.5 d) when fed on rabbits. Conclusion The Results offered essential evidence for the development of prevention and control strategies for ticks and guidance on the preservation and breeding of ticks under laboratory settings.
Objective To measure the risk of vectors may pose on naval vessels and provide evidence for the development of risk management strategies. Methods A risk assessment system and relevant indicators were established to measure the risk of vectors on naval vessels. Results Twenty-four factors were found to play a role in the transmission of vector-borne diseases, including biological, geographical and administrative factors. Qualitative analysis showed different degrees of risks associated with all the vectors in this environment, particularly parasitic fleas and mites on rodents. Conclusion Risks can be reduced by improving risk management and control regulations and standards, establishing a technical support platform, and improving comprehensive control Methods.
Objective To describe the fungal species Batkoa apiculata found in adult Musca domestica. Methods After aceto-orcein staining, the diameters of conidia, conidiophores and rhizoids of B. apiculata were measured and photographed. Results Cultured at high humidity for 12 hours, conidiophores and conidia of the fungus emerged from the head, thorax and intersegmental membranes of the abdomen of the fly specimen. Primary conidia were spherical with a papilla basad, unitunicate, multinucleate (more than 13), (36.2±2.0)μm×(29.3±2.5)μm〔(31.9-45.6)μm×(23.9-40.3)μm〕, L/D 1.2±0.1 (1.1-1.5). Secondary conidia were small, similar to primary conidia, (27.8±1.9)μm×(24.1±1.5)μm〔(23.9-31.8)μm×(19.3-26.2)μm〕, L/D 1.2±0.1 (1.0-1.4). Conidiophores were club-shaped and unbranched, (14.2±1.5) μm (11.8-18.6 μm). Rhizoids were monohyphal with a disc-like structure at apex. Pseudocytidia and resting spores were not found. Conclusion B. apiculata collected from M. domestica is new to China. The fungus may serve as a potential agent for the control M. domestica.
Objective To develop a quantitative detection method using loop-mediated isothermal amplification (LAMP) to detect Plasmodium falciparum, P. vivax, P. malariae, and P. ovale. Methods Based on the conserved nucleotide of the four species and the mechanism LAMP, a LAMP reaction system containing six primers was designed for genus detection and quantitation. LAMP products were stained by SYBR Green and analyzed by electrophoresis. The specificity of LAMP was evaluated by detection of Plasmodium spp. and twelve species of related parasites. The sensitivity of LAMP was evaluated in comparison with the PCR sensitivity, and the feasibility of quantitative LAMP was evaluated by detection of recombinant plasmids. Results After staining, LAMP products with Plasmodium DNA turned green while the color of the negative control and other parasites remained unchanged. Electrophoresis showed that LAMP products had characteristic ladders, which was not present in the negative control and other parasites. At a template concentration of 1.42×104-1.42×109 copies per microlitre, the standard curve established by recombinant plasmids showed a fine linear relationship between threshold cycle (Ct) and template concentration, with a correlation coefficient of 0.9995. The LAMP assay was found to have a detectability of 1.42×101 copies/μl, a 10-fold increase in sensitivity compared with traditional PCR. Conclusion The detection system had high specificity and sensitivity, which could be used for the prevention and control of malaria．
Objective To predict the 2010 incidence of hemorrhagic fever with renal syndrome (HFRS) based on a seasonal trend model with the reported data from 2005 to 2009 in China. Methods SPSS 15.0 and Excel were used for data analysis, and a seasonal trend model was designed. Results Since 2005, reported cases of HFRS have gradually declined. The regression equation for this data model was statistically significant (F＝25.449, P＜0.000). The model predicted 4933 reported cases in 2010, including 533, 361, 452, and 497 from January to April, respectively, with the relative errors of 5.82%, 2.22%, 10.18%, and 13.08%. The average error was only 7.82%. Conclusion The seasonal trend model can be used to fit epidemic data that describe a long-term trend and seasonal characteristics, and to predict the short-term dynamics.
Objective To study the taxonomy of the genus Portschinskia in Beijing. Methods Morphological taxonomy of insects, comparative morphology and biological drawing were conducted. Results New records in Beijing included the genus Portschinskia, together with P. magnifica and P. przewalskyi. Notes on P. magnifica were renewed. Additionally, a list and key to the genus Portschinskia in Beijing were provided. Conclusion The faunal composition of the genus Portschinskia has been enriched.
A new species of the genus Culicoides, C. heiheensis sp. nov. was described in Heihe, Heilongjiang, China. The new species was closely allied to male C. longlinensis (Yu, 1982), but distinctly different in the number of pale spots in its wing cell M1 and cell A. The ninth sternum had wide caudomdian excavation, its ninth tergum had no apical lobes, and the parameres shape was different from male C. longlinensis (Yu, 1982). The type specimen was deposited in the Entomology Collection Gallery of Heilongjiang Entry-Exit Inspection and Quarantine Bureau, Harbin 150001,China.
In October 2009, approximately 170 midegs (including specimens of the genera Alluaudomyia, Culicoides, Dasyhelea, Forcipomyia, and Stilobezzia) were collected in Jinggangshan, Jiangxi province. Among them, a new species of Alluaudomyia was found and named A. haiyingi. The specimens of the new species were deposited in the Medical Entomology Collection Gallery, Academy of Military Medical Sciences, Beijing, China (20 Dongda Jie, Fengtai, Beijing 100071).
Objective To determine the impact of temperature and relative humidity on sulfuryl fluoride fumigation against rats. Methods The study was conducted in a simulated fumigation container in order to determine the impact of temperature, humidity and sulfuryl fluoride doses on the fumigation against rats. Results Univariate analysis showed that sulfuryl fluoride efficacy was affected by dose and temperature. As the dose increased from 0.750 g/m3 to 0.892 g/m3, the mortality of rat increased from 30% to 70%. There was no significant difference in the mortality among different humidity groups (25%-85%). Multivariate analysis revealed that relative humidity and dose were correlated with the mortality. The quadratic regression equation with the mortality rate of mice as the dependent variable, and temperature and humidity as the other variables was: P＝-0.008 39H＋ 1.036 77D. Conclusion The fumigation dosage of sulfuryl fluoride should be adjusted based on humidity and temperature.
Objective To identify local rodent species and distribution in farmland of Yunnan province. Methods We studied monitoring data from 15 stations during 1994 to 2009 in order to determine the annual density change of mixed population in field. Student's t test was used to analyze changes in density and monthly changes are presented with diagrams. Results The distribution of rodent infestation could be divided into six areas by agriculture industry type. Although the rodent density did not change significantly during a years time, a bimodal pattern of the monthly change in the species and number was noted with two peaks during April to June and September to November. Six species were identified as the major causes of infestation, accounting for 88.32% of the total captured rodents. Conclusion Further research using national monitoring data from sentinel stations in Yunnan province is needed. Species diversity, activity distribution and infestation of out-of-field rodents and their relationship with in-field population are areas of concern.
Objective To study the impact of farmland climate factors on the rodent community. Methods From 1978 to 1993, canonical correlation analysis of the farmland rodent density and climate factors in Kaijiang county, Sichuan province was conducted. Results In the period, the overall farmland rodent density was 5.58%-26.57% ; Apodemus agrarius density 1.91%-18.41% , Rattus norvegicus density 0.68%-10.86% , and Anourosorex squamipes density 0.47%-9.50% . Among the canonical correlation coefficients between 12 climate factors including temperature, humidity, rainfall and sunshine, and four variables (overall rodent density, Ap. agrarius density, R. norvegicu density, An. squamipes density), the first couple (correlation coefficient r＝1.0000) was statistically significant (χ2＝248.7032,P＜0.01). The largest coefficient of the rodent density was noted in the overall rodent density (4.7748), and the largest coefficient of the climate factors was the average sunshine from July to August (-3.1532), followed by average humidity from July to August (-1.6177) and then average rainfall from July to August (-1.4652). All were negatively correlated. Conclusion Farmland rodent quantity was mainly affected by average sunshine, humidity and rainfall from July to August.
Objective To determine the species composition and distribution of small nocturnal rodents in a natural plague focus in Hebei province. Methods The 5 m trap line method was used to capture small nocturnal rodents in different habitats every month. Samples collected from the rodents were cultured for bacterial growth and serological detection. Results A total of 969 nocturnal rodents of 8 species were captured, which belonged to 5 genera of 3 families. The average density was 1.17%. The dominant species were Cricetulus barabensis and Phodopus sungorus. A bimodal density pattern was seen throughout the year with two peaks in April to July and December to Feburary. Conclusion The small nocturnal rodents were widely distributed in all habitats except mountain slopes. Monitoring of these animals would be epidemiological significant for the prevention and control of animal plague.
Objective To identify the population composition, distribution and biology of mosquitoes in Anhui province as evidence for the development of control strategies against mosquito-borne diseases. Methods Mosquito were captured or collected by the man-hour or light trap Methods. Results From August to September 2009, 2086 mosquitoes were captured, which belonged to 10 species, 5 subgenera, 4 genera and 2 subfamily. The dominant species was Culex tritaeniorhynchus (67.79%), and Cx. pipiens pallens (12.03%), Cx. bitaeniorhynchus (11.79%), Armigeres subalbatus (5.03%) and Anopheles sinensis (1.58%) were commonly seen in summer. The mosquito populations varied in different habitats. Conclusion The mosquito population composition was dependent on habitat type, breeding resources, climate and geographic factors. Hence, effective mosquito control strategies should be tailored to local mosquito population structures.
Objective To evaluate effect of control measures on mosquito and fly populationsin urban Quzhou based on the monitoring of their species and density. Methods The mosquito and fly density was monitored using lamp traps and cage traps, respectively. Results There were 4 species and 3 genera of mosquitoes in urban areas, predominated by Culex pipiens pallens, which accounted for 96.82% of the total population. The anual average adult density was 5.28 per lamp-hour, which peaked from June to August. There were 6 genera and 4 families of flies in this area, predominated by Lucilia and Musca, which accounted for 68.22% and 23.82%, respectively. The annual average adult density was 39.74 per cage, which peaked from June to August. Conclusion As a result of comprehensive control strategies, diminishing breeding grounds in the city have lead to a significant decrease in mosquito and fly population densities.
Objective To determine current resistance to commonly used insecticides in the natural population of Musca domestica in Ordos city, in order to evidence for proper application of insecticides for fly control. Methods Topical application method was used in the study. Results The natural populations of M. domestica in Ordos city had developed various degrees of resistances to dichlorovos, deltamethrin and beta-cypermethrin, with resistance ratios of 19.39, 48.05, and 407.69, respectively. Propoxur resulted in low fatality in M. domestica. Conclusion The natural populations of M. domestica in Ordos city had low resistance to dichlorovos and high resistance to deltamethrin and beta-cypermethrin. Propoxur had a low lethality rate in the flies.
Objective To investigate the incidence of insect-borne diseases before and after the May 12 Earthquake in Longnan, Gansu province, and to analyze role of disinfection on insect-borne diseases after the earthquake. Methods From 2005 to 2009, data on Japanese encephalitis (JE), kala-azar and malaria in the area were collected to determine the incidence and analyze the epidemiological characteristics of the insect-borne diseases before and after the earthquake. Results From 2005 to 2008, a total of 164 JE cases were reported with an average incidence rate of 1.20/105. No significant difference between the JE incidence in 2008 and that from 2005 to 2007 (P≥0.05). From 2005 to 2009, 501 kala-azar cases were reported with an annual incidence rate of 3.68/105. More cases were observed in men than in women (P＜0.001). No significant difference was noted between the incidence in 2009 and incidences in 2007 and 2009 (P≥0.05). From 2005 to 2008, seven cases of malaria were reported with an annual incidence rate of 0.06/105. Wudu district and Wenxian county were worst affected by insect-borne diseases. Conclusion JE and kala-azar were historically common insect-borne infectious diseases in Longnan. After the earthquake, the incidence of these diseases did not increase compared to the previous years. The reason may be closely related to insect disinfection work after the earthquake.
Objective To discuss the feasibility of lipL32-PCR for detecting Leptospira interrogans. Methods The specificity and sensitivity of primers based on the lipL32 gene were compared with the recommended standard G1/G2 primers. Using these gene-based primers, a PCR assay was conducted for detection of L. interrogans in kidney samples from frogs and rats in Changshan county. PCR identification was performed on isolates taken from Zhejiang in 2008. Results The lipL32-PCR was specific and sensitive to L. interrogans. The PCR identification result for 2008 isolates was consistent with serological testing. A consistency of 95.0% was noted between lipL32-PCR and the assay based on the standard G1/G2 primer. The positive rate was 10.0% for lipL32-PCR and 5.0% for G1/G2-PCR. No significant difference between the two positive rates was shown by Fisher's exact probability test (P＝0.25). Conclusion The lipL32-PCR was specific and sensitive in the detection of L. interrogans and can effectively reflect the carrier rate in animals, thus, providing evidence for the control of leptospirosis.
Objective To investigate the characteristics of the hosts of hemorrhagic fever with renal syndrome (HFRS) at high altitude and determine the types of natural focus and epidemiological patterns. Methods In and out-door monitoring was performed with iron rat traps and nut baits deployed in the evening and collected in the morning. Rat blood and lungs were collected for indirect immunofluorescent detection of related antigens and antibodies. Results A total of 40 480 deployments in the 10 years resulted in 4621 collected rats that belonged to 8 species, 7 genera, 3 families and 2 orders. Most carriers were Rattus norvegicus, R. tanezumi, Mus musculus, Niviventer excelsior, and Apodemus chevrieri. Conclusion Yanyuan county was a HFRS-prelevant area with multiple species of host animals. N. excelsior was one of the host animal at high altitude.
Objective To monitor rodent carriers of Hantan virus, the pathogen of hemorrhagic fever with renal syndrome (HFRS), and related ectozoan vectors in Shanghai coastal harbors. Methods From 2008 to 2009, quarterly surveys of the rodent carriers were performed in Shanghai coastal harbors of Chongming, Jinshan and Zhapu. The rodents were collected using rat cages and clamps. Blood and lung samples were taken for HFRS viral testingand ectoparasites were collected for laboratory identification. The HFRS-IgG and HFRS-IgM antibodies were detected by ELISA, and MacELISA, respectively. HFRS Hantan virus antigens in lung tissue samples were detected by direct immune florescence technique. Hantan virus genotype was analyzed using RT-PCR. Results A total of 232 rodents and 3 birds were captured, including 4 species of 4 genera of Rodentia and 2 species of 2 genera of Insectivora. None of the samples tested positive for HFRS Hantan virus. Conclusion No Hantan virus positive samples were isolated from the captured rodents in the Shanghai coastal harbors, and only a very small amount of ectoparasites were collected from the animals. Crocidura lasiura was the most common animal in these harbors, and Laelaps jettmari huaihoensis comb.n. collected from Apodemus agrarius was a new record in Shanghai.
Mosquito-borne diseases such as dengue fever, St. Louis encephalitis and Japanese encephalitis are serious threats to human health. Climate change, such as changes in temperature and precipitation, may altermosquito distribution, growth, development and viral production. Changes in these factors will also impact disease prevalence and transmission. This study introduces the latest research on the impact of climate change on mosquito-borne viral diseases, epidemiological characteristics of these diseases, and potential changes in mosquito-borne disease epidemiology under climate change.
Timely and accurate knowledge of mosquito insecticide resistance is crucial to understanding current resistance levels and resistance mechanisms, in order to control resistance, extend the service life of new insecticides and improve the environment. This article introduces available assays for detecting insecticide resistance in mosquitoes.
The development of enzymology has improved the classification of Oncomelania hupensis, enhanced research on the compatibility between O. hupensis and Schistosoma, increased knowledge of mechanisms of ecological restrictions on snails and chemical and plant molluscicides. This paper reviews the development of O. hupensis enzymological study Methods, summarizes current research Methods, and describes the distribution of enzymes in O. hupensis. It also compares the advantages and limitations of different detection Methods. Further studies should be conducted to increase understanding and visualization of these enzymes.
Objective To discuss the ecological prevention measures against bird hazards in Fuyang Airport and to provide an ecological perspective on the causes and patterns of bird strikes. Methods From September 2008 to August 2009 a study of the local ecology and bird populations at Fuyang Airport was conducted using the line intercept method. Results Bird strikes are a major threat to any airport. Analysis of the relationship between the community structures and bird habitats revealed that location and availability of food sources, water sources and hiding places were the key factors in bird population diversity at Fuyang Airport and surrounding areas. Conclusion Ecological control is fundamental for the prevention of bird strikes. Ecological control works by minimizing environmental factors that attract birds, thereby reducing bird populations, diversity, and the risk of bird strikes.
