Objective To analyze the species composition, distribution, density, and seasonality of mosquitoes in four counties (cities) of the Yellow River irrigation area of Ningxia Hui autonomous region (Ningxia), China, in 2019, and to provide a scientific basis for the prevention and control of mosquitoes and mosquito-borne diseases. Methods The light trapping method was used to carry out mosquito vector monitoring in the urban residential areas, rural houses, livestock sheds, and other habitats of Helan county, Pingluo county, Qingtongxia city, and Zhongning county in the Yellow River irrigation area twice a month during June to September in 2019. Excel 2007 software was used to establish a database, and SPSS 23.0 software was used for statistical analysis of data. The mosquito composition ratio was compared by the chi-square test, and the mosquito density was compared by analysis of variance. Results A total of 34 670 adult mosquitoes were caught from June to September 2019, with an average density of 46.10 mosquitoes/light-trap·night; there was no significant difference in mosquito density between different areas ( F=2.357, P=0.930); Helan county had the highest average mosquito density, which was 252.96 mosquitoes/light-trap night. There was a significant difference in the composition of mosquito species between different areas ( χ ²=3 826.933, P<0.001); the majority of the mosquitoes caught belonged to Culex pipiens pallens and Cx. tritaeniorhynchus, accounting for 55.90% and 43.86%, of the total number of catches, respectively. Among the different habitats, livestock sheds had the highest density of mosquitoes, which was 73.55 mosquitoes/light-tarp·night, and there was a significant difference in the density of mosquitoes between different habitats ( F=433.600, P <0.001). The seasonal fluctuation curve of mosquito density showed an obvious single-peak curve, and the difference of mosquito density in different months was statistically significant ( F=938.159, P<0.001). Conclusion The mosquito density in the Yellow River irrigation area is generally at a relatively high level. Cx. pipiens pallens and Cx. tritaeniorhynchus are the dominant mosquito species in the area, and livestock sheds and rural houses are the places with a high incidence of mosquito infestation.

Objective To investigate the barrier effect of rivers on the spread of rodent plague. Methods The data of the rodent plague foci in Dehong autonomous prefecture of Yunnan province, China, from January 1982 to December 2007 were collected. The numbers of townships and plague foci with rodent plague were recorded in each county (city) and in each of the three regions divided by the Daying River and Longchuan River (national borders-Daying River, Daying River- Longchuan River, and Longchuan River-prefecture borders) in each year. The epidemic intensity values of five counties (cities) and three regions were calculated according to the entropy index and adjusted for area size. The difference in adjusted epidemic intensity between the five counties (cities) or the three regions were analyzed using the Kruskal-Wallis H test. Results During 1982-2007, in Yingjiang, Lianghe, Longchuan, Ruili, and Mangshi, rodent plague was epidemic for 16, 11, 19, 11, and 10 years, respectively, and the numbers of plague foci were 159, 96, 93, 76, and 35, respectively. There was no significant difference in the overall distribution of adjusted epidemic intensity between the five counties ( H=8.277, P=0.082). In the three regions (national borders-Daying River, Daying River-Longchuan River, and Longchuan River-prefecture borders), plague was epidemic for 16, 25, and 10 years, respectively, and the numbers of plague foci were 103, 321, and 35, respectively. There was a significant difference in the overall distribution of adjusted epidemic intensity between the three regions ( H=19.738, P=0.000), and significant differences were also observed between the region from Longchuan River to Daying River and the region from national borders to Daying River or the region from Longchuan River to prefecture borders ( χ ²=18.423, P=0.003; χ ²=26.692, P=0.000). Conclusion Rivers may have a barrier effect on the spread of rodent plague in Dehong prefecture, which may be related to the effects of rivers on the geographical distribution of Yersinia pestis and the community, population and distribution of the host and vector fleas of Y. pestis.

Objective To investigate the prevalence of 6 rodent-borne pathogens, in some suburban areas of Beijing, China. Methods TaqMan fluorescent probe-based quantitative real-time PCR (qPCR) was used for laboratory evaluation. Plasmid standards were prepared and standard curves were plotted. Detection thresholds were determined according to the reevaluated data. From January to June, 2017, the trap-at-night method was used to capture rodents in Chaoyang, Huairou, Mentougou, and Pinggu districts of Beijing, tissue samples were collected to extract nucleic acids, and qPCR was used to detect pathogens. Results A total of 160 rodents were captured, among which there were 59 Rattus norvegicus rodents, 69 Mus musculus rodents, 4 Apodemus peninsulae rodents, 25 Niviventer confucianus, and 3 Sorex spp.. The examination of spleen tissues showed that all rodents except Sorex were infected with Rickettsia typhi (8.1%), Orientia tsutsugamushi (1.3%), Anaplasma phagocytophilum (5.6%), Leptospira interrogans (18.7%), or Bartonella spp. (5.0%). No Francisella tularensis was detected in all rodents. There were co-infections with various pathogens including Leptospira interrogans and A. phagocytophilum in R. norvegicus and M. musculus. Conclusion Rodents in Beijing carry the pathogens of common, emerging and reemerging infectious diseases. The distribution investigation of animal hosts and vectors of these pathogens in these areas and prevention and treatment of related infectious diseases should be strengthened.

Objective To evaluate the effect of rodent control by bromadiolone in the plague epidemic area, provide basic data for rodent control and plague prevention. Methods In Yulong county, Gucheng district,Jianchuan county and Heqing county residential area and cultivated land in two habitats, 0.005% wheat bait was prepared with 0.5% bromadiolone and applied to project area of the plague epidemic area and non-epidemic area of the control during April to May 2017. Results The killing effect of plague epidemic residential area was 77.67%-100%, cultivated land 88.89%-100%; In control of non-epidemic residential area, killing effect was 88.48%-100%, cultivated 85.72%-97.74%. As to the same habitat in epidemic area and non-epidemic area in different counties, there were no statistical differences in the efficacy of different habitats in 4 counties and cities( χ ²=0.800, 0.863, P > 0.05). Two kinds of experimental design methods were used to calculate the effect of residential area and cultivated land, and there was no statistical significance ( χ ²=1.507, 0.050, P > 0.05). Conclusion In Yunnan provincial residential area and wild animal habitats, bromadiolone still has good effect as poison baits. In the process of plague epidemic disposal, the population density of rats can be effectively reduced, and the spread of plague epidemic can be prevented. It can be utilized in control of commensal and wild rodents to prevent the two types of plague epidemics.

Objective To investigate Liaoning virus(LNV) in mosquitoes in Chaoyang district, Beijing. Methods According to the Surveillance for Vector Density-Mosquito (GB/T 23797-2009), mosquitoes were collected by CO₂ traps in 2014 and 2015. Reverse transcription-polymerase chain reaction was used to detect LNV. Molecular characteristics were carried out by Mega 6.0. Results A total of 9 811 mosquitoes were collected and Culex pipiens pallens (8 968/9 811, 91.41%) was the main species. The sample BJCY14007 was positive for LNV. LNV has two branches (serotypeⅠand serotypeⅡ) based on the molecular characteristics of the segment 10. BJCY14007 was more related to NE97-12 (representative strain, serotypeⅠ). Conclusion The LNV was firstly detected in Beijing. It deserves further investigation LNV prevalence in mosquito, human population and other hosts for risk assessment.

Objective To understand distribution and seasonality of Culex tritaeniorhynchus in Chaoyang district, Beijing. Methods According to the Surveillance Methods for Vector Density-Mosquito (GB/T 23797-2009), mosquitoes were collected by the CO₂ traps. To determine the spatial distribution, the two types of sampling sites including park (or green spaces) with waters and human populated area were chosen in different geographical locations, and mosquitoes were trapped from August to September. To find out the seasonality, the mosquitoes were trapped per ten days from May to October in the same place. Results The proportions of sampling sites with Cx. tritaeniorhynchus between 2^nd Ring Road and 3^rd Ring Road, 3^rd Ring Road and 4^th Ring Road, 4^th Ring Road and 5^th Ring Road, outside 5^th Ring Road were 1/2, 3/3, 4/8 and 3/6 respectively, and there were no statistically different in different area subdivided by ring road (P=0.570); the proportions of sampling sites with Cx. tritaeniorhynchus of parks (or green spaces) with waters and human populated areas were 76.92% (10/13) and 16.67% (1/6) respectively, and were statistically different (P=0.020); the Cx. tritaeniorhynchus densities between 2^nd Ring Road and 3^rd Ring Road, 3^rd Ring Road and 4^th Ring Road, 4^th Ring Road and 5^th Ring Road, outside 5^th Ring Road were 0.09, 0.16, 0.31 and 4.97 mosquitoes per trap-hour respectively; the mean (m) and variance (S²) of densities of Cx. tritaeniorhynchus were 1.56 and 24.03, S²/m=15.42>1, which suggested that Cx. tritaeniorhynchus clumped distributed; the first appearance of Cx. tritaeniorhynchus was in the last twenty days of July, then its constituent ratio showed a trend from rise to decline and the peak period of its density was in September. Conclusion Culex tritaeniorhynchus tends to spread from suburb to city with the improvement of water conversation, and clumped distributed in urban area of Chaoyang district. Vigilance is needed to the epidemic risk of Japanese encephalitis, and public health department should strengthen the prevention and control measures.

Objective To provide the basis for plague prevention and control by investigating species composition and infection rate of Yersinia pestis in fleas collected from floor in the plague natural foci of Lijiang in Yunnan province. Methods Investigation was carried out at 8 villages of Yulong county and 5 villages of Gucheng district of Lijiang. Floor fleas were collected by sticky flea paper method. Species was identified based on morphological characteristics. Y. pestis was cultured from fleas in laboratory. Results The sticky flea paper 21 845 copies were collected in the 13 villages. The average flea index of 0.0249. The sex ratio of fleas was 1.95:1. In total, 545 fleas were collected, which belong to 2 families, 3 genera and 3 species, including Ctenocephalides felis felis (69.54% ), Pulex irritants (18.72% ), and Ctenophthalmus quadrarus (11.74%). Infection of Y. pestis was negative for all fleas. Conclusion There are 3 flea species from floor in the plague focus, Ct. felis felis, P. irritant were predominating species. Infection of Y. pestis was not found.

Objective To provide the basis for plague prevention and control by investigating in the flea species from dog and cat and infection rate of Yersinia pestis in the plague natural foci of Lijiang in Yunnan province. Methods Investigation was carried out at 3 villages of Yulong county and 3 villages of Gucheng district of Lijiang. Fleas on dog body and cat body were collected with insecticide bath, and identified based on morphological characteristics. Y. pestis was cultured from fleas in laboratory. Results There 93 dogs were investigated and there were fleas on 74 dogs, with average fleas infection rate is 79.57%, average fleas index is 2.63. Totally 245 fleas were collected from dog, and all are Pulex irritans. The sex ratio of fleas was 2.14:1. There were fleas on 28 of 37 investigated cats, average fleas infection rate is 75.68%, average fleas index is 2.46. Totally 91 fleas were collected, including P. irritans (46.15%), Ctenocephalides felis felis (53.85%). The sex ratio of cat fleas was 3.55:1. Infection of Y. pestis was negative for all fleas. Conclusion The P. irritans were predominat species to dog body fleas, P. irritans and C. felis felis were predominating species to cat body fleas. Infection of Y. pestis was not found.

Objective To analyze the monitoring results of rodents in Qinling Mountains in Baoji, China and investigate the population distribution and virus carriage of rodents in this area, and to provide a basis for the control of rodents and rodent-borne diseases in Baoji. Methods Night trapping method was used to capture rodents in 6 ecological environments in Qinling Mountains, including broad-leaved mixed forest, valley, peach forest, and fallow land. Results A total of 164 wild rodents (9 species) were captured, with different populations in different ecological environments at different altitudes. In the valley and arable land below 1850 m above sea level, Apodemus agrarius was the dominant species, accounting for 54.23% (77/142) of all captured rodents, followed by A. peninsulae, accounting for 16.20% (23/142). In the mixed coniferous and broad-leaved forest with an altitude above 1850 m, A. chevrieri was the dominant species, accounting for 72.73% (16/22) of all captured rodents, followed by A. peninsulae, accounting for 18.18% (4/22). Of all captured rodents, 17.81% carried viruses; among the positive rodents, hemorrhagic fever with renal syndrome (HFRS) virus was first detected from an individual of A. peninsulae besides A. agrarius. Conclusion There are a variety of rodents as vectors in Qinling Mountains in Baoji, with different populations at different altitudes, which is almost in accordance with the incidence of HFRS.

Objective To identify Borrelia burgdorferi sensu lato infection of rodents in Pan’an county, Zhejiang province. Methods The ospA gene specific fragments from 128 mouse liver and spleen samples were detected using the PCR method and the positive samples were sequenced, followed by phylogenetic analysis. Results It was found that there were four ospA gene positive fragments out of the 128 samples, of which 3 fragments were obtained from Rattus losea and the other one was from Apodemus peninsulae. The 4 positive fragments shared high similarity with each other in terms of the sequences and shared high identities with B. valaisiana. Conclusion B. burgdorferi sensu lato can be detected from samples using the ospA gene. There exists B. burgdorfer sensu lato infection in rodents in some mountain areas of Zhejiang province, and B. valaisiana is found to be predominant.

Objective To analyze the species composition, seasonal variation and the diversity of fly at different habitants in Hongkou district, Shanghai from 2006 to 2010 to provide evidence for the prevention and control. Methods Cage traps with sugar and vinegar baits were used to capture flies. Quarterly analysis of biodiversity was performed from March to November each year. Results The flies in this district belonged to 10 species, 7 genera and 3 families. The highest density was noted in Musca domestica (0.62 flies per day for every cage). The density of M. domestica was increased, whereas the density of Lucilia sericata declined each year. The fly densities were 2.52, 1.91, 1.46, 1.12, and 0.70 flies per day for every cage from 2006 to 2010, respectively. The highest density was noted in late April, early May, late June and mid-July from 2006 to 2010. In July, eight species were collected at most. The species diversity index and evenness index were highest in May. Different habitats by fly density in descending in the last five years were: farm trade market ＞ residential area ＞ public green belt ＞ external environment of restaurants. The most abundant species were observed in residential areas (ten species), which had the highest species diversity index and evenness index. Conclusion The fly diversity declined year by year from 2006 to 2010, which had a peak from late April to mid-July each year. The dominant species were M. domestica and L. sericata. The population characteristics could be generally described by the species diversity index and evenness index.

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 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 gain an insight into the mosquito species, their density and their growth and decline with different monitoring methods. To understand their distribution patterns, and the dominat mosquito species obtained with different monitoring methods, in order to provide relatively accurate early warning information for the proper implementation of mosquito density monitoring and effective control and prevention of Japanese encephalitis(JE) and other vector-born diseases. Methods The “National Vector Biological Monitoring Program (trial)” issued by the Ministry of Health of P.R. China was used as a guideline for the investigation and monitoring. Results The Results of mosquito larvae density monitoring showed that the positive rate of the idle containers was highest from July to September every year. Of the idle containers the container index (CI) was 36.83%, the housing index (HI) was 34.86% and breteau index (BI) was 24.14. The light trap method, human induced method and mosquito and oviposition trap method were employed to investigate the prevalence of mosquitoes in Baoji city and some of its urban counties from 2006 to 2009. The findings showed that the mosquitoe species acquired were closely related to the ecological environment where they bred and the monitoring Methods used. The types of mosquitoes acquired with different monitoring Methods and in different ecological environments were different. The largest number and types of mosquitoes was obtained with the light trap method, with Culex pipiens pallens (58.82%) being the dominant species, and the mosquitoes obtained by human induced method were mainly Aedes albopictus (77.09%). Those acquired with the capture method were dominantly Cx. tritaeniorhynchus and Armigeres subalbatus, which accounted for 60.94% and 22.21% respectively. The mosquito Cx. pipiens pallens was dominant in urban, and rural residential areas and farming and aquaculture areas accounting for 90.00%, 40.45% and 70.05% respectively, with the mosquito Ae. albopictus being the major species (36.80%) in special places. In terms of the time distribution, it was in August that the mosquito density reached its peak in Baoji. Conclusion It is seen that the types of mosquitoes acquired with different monitoring Methods are different, indicating that it is advisable that proper choice of the monitoring Methods is exercised to avoid bias in routine monitoring. It is desirable that the anti-mosquito measures be taken in April and May befor the peak mosquito densities, in order to reduce the occurrence of mosquito-borne diseases in Baoji.

Objective To provide a preliminary evaluation of the self?made horseradish peroxidase (HRP) marked Hantavirus (HV) recombinant N protein (rNP) rNP?IgM direct capture ELISA diagnostic kit. Methods Assessment of the specificity and stability of the kit and comparison of clinical results with similar products were performed to evaluate the sensitivity of the kit in the detection of serum anti?HV?IgM. Results (1) The kit was only responsive to anti?HV?IgM positive serum, and irresponsive to anti?varicella?zoster virus?IgM (anti?VZV?IgM), anti?Japanese encephalitis virus?IgM (anti?JEV?IgM), anti?dengue virus?IgM (anti?DV?IgM), anti?hand, foot and mouth EV71 virus?IgM (anti?EV71?IgM) positive sera. No obvious reduction in serum anti?HV?IgM detecting capability was noticed after placement at 37 ℃ for 3 d. (2) In 144 sera samples in 120 patients with suspected hemorrhagic fever with renal syndrome, inconsistency was observed only in the anti?HV?IgM test results in 12 sera of 12 patients between the two kinds of kits, in which 8 primary sera samples were detected positive by the kit and negative by commercial ones (the secondary sera samples were positive for both kits); 3 primary samples (the secondary samples unavailable) were at the critical value for the kit and negative for commercial kits. Meanwhile, one other primary serum sample was positive for the kit and negative for the commercial ones (the secondary and tertiary ones positive for both). Conclusion The laboratory developed capture ELISA anti?HV?IgM diagnostic kits had favorable specificity, stability and sensitivity, suitable for the clinical diagnosis and epidemiological surveillance of HV infections.

【Abstract】 Objective To know the resistance situation and its geographic distribution of German cockroaches (Blattella germanica) in Chaoyang district. Methods German cockroaches were trapped from eight sites belonging to different geographic zone. The insecticides film contact method was used to the detection of resistance. The resistance level of German cockroach from different sites was analyzed by average linkage method. Results There was significant difference among the resistance level  of cockroach to seven insecticides (χ2＝26.880, P＝0.000). It had the highest resistance to organophosphorus insecticides (χ2＝20.494，P＝0.000). The resistance levels of cockroach from 8 sites were also significantly different (χ2＝29.143，P＝0.000), which could be classified into four groups by cluster analysis. Conclusion The resistance of cockroach to insecticides was different in different areas in Chaoyang district, so the same control method.

【Abstract】 Objective To approach the feasibility of FlaB?PCR used for the detection of leptospira. Methods The proper  primer  was  synthesized  according  to  FlaB  gene and its sensitivity and specificity was evaluated compared to the primer G1/G2 recommended by public health industry standard. It was applied to leptospira detection of frog and rats which were from Longyou and Changshan. And it was identified by PCR. Results FlaB?PCR was highly sensitive and specific, and pathogenic leptospira DNA could be specifically amplified with the selected primer. The PCR results on leptospira isolated from Zhejiang province  in  2007 were in accordance with the serology results. The positive rate of the kidneys of rats and frogs was 20.94% by FlaB?PCR. Compared with the primer G1/G2 recommended by public health industry, the coincidence of two methods was 90.54%. Conclusion FlaB?PCR can detect the pathogenicity leptospira specifically and quickly, which can reflect the carrying rate of leptospira in wild animals accurately and efficiently and provide the evidence for leptospira control.

Objective To find out flea population, distribution and its parasitism in historical plague epidemic area in Zhejiang. Methods Set up surveillance sites in the historical plague epidemic area, and identify the flea caught from mice. Results To detect 19 species of 61 859 rat-shape animals and 21 059 fleas were found on 13 species of rat-shape animal surface. The total infected rate was 12.38% and the total flea index was 0.340. The index of Xenopsylla cheopis was 0.032. 21 054 parasitical fleas belonged to 10 species, 9 genera and 4 families. Of which, Leptopsylla segnis accounted for 54.41%, 20.89% for Monopsyllus anisus and 9.50% for X.cheopis There were 13 kinds of parasitical hosts for L.segnis, 10 kinds for M.anisus and 6 kinds for X.cheopis. The main hosts of these three fleas were Rattus norvegicus and R.norvegicus from which L.segnis, M.anisus and X.cheopis were detected, and the proportion of them was 95.60%, 92.79% and 82.31% of total fleas respectively. Conclusion The dominant fleas were L.segnis, M.anisus and X.cheopis in Zhejiang province, and their main hosts were R.norvegicus and R.norvegicus. These fleas distributed widely and mostly in Zhejiang. As the main vector, X.cheopis parasitizes not only in domestic mice, but also in the wild mice such as R.losea and A.agrarius. It suggested that the main vectors such as X.cheopis should be surveyed intensively to understand its distribution and dynamic diversification in order to provide scientific data for plague prevention and control.

Objective To know the distributtion and density of Aedes albopictus in Baoji, Shanxi province. Methods Mosquito lavae were investigated by breeding sites surveying method using container index(CI), house index(HI) and breteau index(BI), adults were collected by mosq-ovitrap, human biting catch, human-baited net trap, light-trap methods for density. Results At 7 kinds of ecological biotopes in Baoji urban areas including 642 various water-holding container, 48.75% was larvae positive, with CI, HI and BI 52.36, 58.12 and 71.73 respectively. For adults survey, 625 mosq-ovitrap were used in successive three months (July to September), the average positive rate was 12.52%, and all the collected mosquitoes were Ae.albopictus. For total 24 times of human-baited net trapping at 17:00 to 19:00, the average mosquitos density was 11.17 mosquitos per human in 1h, with 76.12% Ae.albopictus in most. For light-trap, total 16 lights(times) were investigated and most of mosquitoes captured were Culex pipiens pallens(77.19%), the densities are 1.09 and 0.89 per light-trap in 1h for August and September separately Ae.albopictus was 4.35%. Conclusion Ae.albopictus was ubiquitous in Baoji. Three methods all showed that Ae.albopictus was common species of mosquitoes, with a peak in August, with a very high density, so we should pay more attention to Ae.albopictus control.