ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Malaria is a serious and fatal global vector-borne disease. It is one of the three major infectious diseases of the Millennium Development Goals(MDGs)of United Nations which urgently need to control. Malaria, HIV/AIDS, and tuberculosis are three major global public health threats and cause substantial morbidity, mortality, negative socioeconomic impact，and human suffering. This paper mainly summarized global and China’s epidemic situation of malaria，the major malaria vector anopheles species and their distribution characteristics in China, and described the background of malaria elimination, the contents and methods of malaria control. The authors emphasized that the monitoring and control of the vector anopheles is irreplaceable and necessary tools for malaria elimination and reviewed the main problems, challenges and future research directions on vector anopheles surveillance and control for the ongoing malaria elimination in China.
Objective To determine the status quo of West Nile virus (WNV) infections in animals in Ili, Sinkiang, providing the relevant data for WNV prevention and control in China. Methods One-step real time quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect the WNV envelope protein gene from the brain tissues of 70 donkeys and 100 shepherd dogs collected in Ili, Sinkiang. Results Of the brain samples of 70 donkeys and 100 shepherd dogs, 2 were suspected positive for WNV envelope protein gene fragments. However, they were excluded through 3% gel electrophoresis revalidation. Therefore, all tested samples were negative for the WNV envelope protein gene. Conclusion WNV infection is not found in brain tissues of donkeys and shepherd dogs in Ili, Sinkiang.
Objective To determine the population dynamics of mosquitoes and midges before and after sunset. Methods Net traps were set along certain locations at varying heights to capture the insects before and after sunset. Results Most of the captures were midges, amounting to 1039 of 7 genera, dominated by the genus Culicoides. The collected mosquitoes were of 2 species under 2 genera, totaling 53. The activity peak of the insects was approximately 1 hour after sunset. Conclusion The species composition and dynamics of mosquitoes and midges around the residential areas of Weng’ang village before and after sunset were generally clarified.
Objective To identify the dominance and diversity of species collected outdoors using CO2 mosquito traps at different places and times in a military camp. Methods Insects captured using CO2 mosquito traps were analyzed for the species and individual statistics to calculate the dominance, Shannon-Weiner diversity index and evenness. Results Among the collected blood-sucking dipteran insects there were mosquitoes, midges and horseflies. Mosquitoes and midges had higher degrees of dominance. The highest dominance of blood-sucking dipteran insects was up to 1.00, and the lowest 0.57. The higher degree of the environmental complexity, the richer diversity of species was seen. Human and climatic factors also exerted noticeable impact on the dominance, diversity and evenness. Conclusion CO2 mosquito traps have high specificity for mosquitoes and midges. Species diversity is closely related to the environment.
Objective To provide an overview of such dynamics as the population distribution and seasonal variation of mosquitoes in Zhejiang province, which gives the basis for prevention of mosquito-borne diseases. Methods Mosquito light traps produced by one manufacturer, Wuhan Jixing Environmental Protection Technology Co., Ltd, were used to collect the insects. Results Culex pipiens pallens mosquitoes were the predominant species in most areas of Zhejiang province, while Cx. tritaeniorhynchus mosquitoes were predominant in Ningbo and Lishui areas, and Aedes albopictus were distributed in most parts of the province. Mosquito activities peaked from June to September, as the number of mosquitoes captured in this period accounted for 79.80% of the total in a year. Of the 5 different habitats, stockyards contained the most mosquitoes, accounting for 46.03%. Conclusion Zhejiang’s geographical environment and climatic conditions are favorable to the growth of a variety of mosquitoes, making the prevention and control of mosquito-borne diseases and reduction of mosquito density essential in all areas of the province.
Objective Specific traps were designed to improve the efficiency of capturing Aedes albopictus to facilitate the surveillance of the prevalence of dengue fever. Methods Effective Ae. albopictus traps were designed according to the ecological characteristics of this species based on the design of ovitraps of the U.S. Center for Disease Control and Prevention and Lifeng Lin’s devices. The efficiency of the traps was preliminarily verified both in laboratory and on site. Results Both trapped mosquitoes and ovipositions using the device were higher than those using ovitraps in laboratory (Z＝-2.178, P＝0.029; Z＝-2.021, P＝0.043). As for residential areas, both the mosquito enticing index (MEI) and oviposition enticing index (OEI) were higher in the Ae. albopictus trap group than in the control group〔MEIAedes (Z＝-7.529, P＝0.000), OEIAedes(Z＝-6.058, P＝0.000) and MEICulex (Z＝ -2.484, P＝0.013)〕; MEIAedes (rp＝0.244, P＝0.000) and OEIAedes(rp＝0.256, P＝0.000) of the trap group were positively correlated with the Breteau index in the correspondingly investigated residential areas. (rp＝0.256, P＝0.000). Conclusion Ae. albopictus traps are efficient in enticing mosquitoes and ovipositions with satisfactory sensitivity and stability, which can be used for dengue vector surveillance.
Objective To identify the faunal distribution and species diversity of mosquitoes and their relationship in the residential areas of Lincang city, Yunnan province. Methods The survey was conducted in the residential areas of 13 villages (towns) of the 5 counties in Lincang: Gengma, Cangyuan, Zhenkang, Yongde and Yunxian (563-2038 m above sea level). Light traps were used to capture nocturnally active adult mosquitoes overnight. The collected insects were classified, counted and statistically analyzed. Results A total of 29 621 mosquitoes were captured, belonging to 49 species in 6 genera of 2 subfamilies, including 15 species of the genera Culex, 17 species of the genera Anopheles, 10 species of the genera Aedes, 4 species of the genera Armigeres, 2 species of the genera Mansonia and 1 species of the genera Coquillettidia. Among these mosquitoes, Cx. tritaeniorhynchus (69.17%) and An. sinensis (19.47%) were not the dominant species in terms of their counts but also the most widely distributed. The other 47 species (which together accounted for 11.36%) were relatively fewer with a narrower distribution. The statistics showed that the species diversity index (2.2808) and evenness index (0.7000) were highest in Yunxian, where the constituent ratio (29.47%) of the dominant species, Cx. tritaeniorhynchus, and the mosquito density (287.10 per trap·night) were the lowest. In contrast, Gengma county had the lowest mosquito species diversity (0.4096) and evenness index (0.1229), despite the highest constituent ratio (91.53%) of Cx. tritaeniorhynchus and mosquito density (1435.70 per trap·night). This suggested that the mosquito species diversity and evenness were negatively correlated with the mosquito density and abundance of dominant species, while the mosquito density was significantly positively correlated with the abundance of dominant species. Conclusion Featuring large number and wide distribution, Cx. tritaeniorhynchus and An. sinensis are the dominant species in the local residential areas. The abundance of Cx. tritaeniorhynchus led the changing trends of the local mosquito density and species diversity.
Objective To determine the resistance of Culex pipiens pallens larvae to commonly used insecticides in parts of Jiangsu province, providing the guidance on proper administration of mosquito control agents. Methods Using 7 common chemical pesticides, the resistance of Cx. pipiens pallens larvae in Nanjing, Nantong and Huaian regions of Jiangsu province was measured by larval impregnation. Results Compared with the laboratory susceptible strain, the Cx. pipiens pallens larvae from Nanjing, Nantong and Huaian each had the highest resistance to dichlorvos, while the populations from Nantong and Huaian had the lowest resistance to permethrin. The Nanjing population had the lowest resistance to bioallethrin, and similar resistance to permethrin. Conclusion Suitable insecticides should be used for prevention and control of mosquito larvae, taking into account the regional resistance. To properly apply insecticides, dichlorvos, propoxur, and temephos which mosquitoes are highly resistant to should be gradually replaced by pyrethroids.
Objective To evaluate the resistance of Culex pipiens pallens to commonly used chemical insecticides in Shandong province, providing the basis for proper and efficient administration of insecticidal chemicals. Methods The WHO bioassay was used to test the resistance of susceptible strains and field populations of Cx. pipiens pallens to 5 kinds of insecticide. Results Of 6 field populations of Cx. pipiens pallens, the resistance indices for DDT, DDVP, malathion, propoxur and deltamethrin were 1.59-28.48, 2.22-15.72, 2.36-5.50, 3.40-6.33 and 8.50-36.00. Conclusion Cx. pipiens pallens in Shandong province has generated different degrees of resistance to the 5 commonly used chemical pesticides. Therefore, appropriate measures should be taken to prevent or delay the emergence and development of insecticidal resistance in mosquitoes.
Objective To study the taxonomy of Lispini in Fujian province. Methods Morphological taxonomy of the insects was conducted. Results There were 7 species of 2 genera of Lispini found in Fujian province. New records in this province included the genus Xenolispa, together with Lispe pacifica, Lispe bivittata, Xenolispa binotata, and Xenolispa kowarzi. Notes on Xenolispa binotata were renewed. Additionally, a list of and a key to Lispini were established. Conclusion The faunal composition of Lispini in Fujian is enriched.
Objective To describe the invasion of exotic species into the composition of fly fauna in China and the significance of human-induced invasion of fly vectors. Methods The disaggregated data on Muscidae, Calliphoridae and Sarcophagidae in China were analyzed. Results Among all the fly vectors of Fanniidae, Muscidae, Calliphoridae and Sarcophagidae in China, 78 species were distributed in the China-North America, China-Africa, China-Australia, China-Europe-South America, China-Australia-Africa, China-North America-South America, China-Europe-Australia and China-Africa-America ecozones as well as the worldwide ecozone, accounting for about 5.0% of all known species in China. A total of 84 species of 4 families were distributed in China-Europe-North America, accounting for 5.3% of the known species. Those distributed in China-Europe, China-Asia-Australia and China-Europe-Africa amounted up to 233 species, accounting for 15.0% of all known species. The larvae of these cosmopolitan species were either coprophilous or saprophytic, and most of the adult flies lived in the same living environment as human beings or domestic animals. Of the 35 major polluting fly species living in residential or semi-residential areas settlements in China, 22 showed disjunctive or global distributions in the worldwide ecozone, and the other 4 were widely distributed in the Palaearctic, Oriental and Australia regions. Conclusion Many a species of the fly vectors in China was introduced from abroad through human activities. Human activities constituted a leading cause for the invasion of flies.
Objective To explore the test methods for ant bites and to determine the killing effect of imidacloprid baits against Monomorrium pharaonis. Methods Laboratory test, simulated field test and field test were carried out. Results The LT50 value of 0.03% imidacloprid baits for M. pharaonis was 21.10 h, with a 7 d mortality of 100%. In the simulated field test, all of 4 queen ants were killed at day 5, while 100% of ergates died at day 6. In the field test, the density of M. pharaonis reduced to 98.42% at the 14 day. Conclusion Using M. pharaonis as the subject, the laboratory and simulated field test were applicable for ant baits, and 0.03% imidacloprid baits had favorable killing effect against M. pharaonis, which could be used for residential termite control.
Objective To establish a sensitive and accurate analytical chemistry method as an alternative to biological tests for determination of degradation dynamics of a molluscicide, Luomiecide (50% wettable powder of niclosamide ethanolamine salt), in laboratory and in water bodies. Methods High performance liquid chromatography (HPLC) was performed using a C18 column and a mobile phase of methanol-0.01 mol/L sodium acetate (87∶13) with the theoretical plate number ＞3000; a 100 μl, UV detection wavelength of 330 nm was chosen. Laboratory simulation of degradation was conducted, where vials of luomiecide solutions were placed in the sun for 6 times of sampling in 10 d; a parallel couple of samples were either directly filtered or solubilized with organic solvents, and measured. Another 6 samples were collected on the spot of molluscicidal application, treated and detected following the same procedures. Results The minimum detectable concentration by HPLC was 0.007 mg/L, the linear range 0.01-2.42 mg/L (r＝0.9999, n＝12) and the separation between main peaks and impurities ＞1.5. In laboratory simulation, the original drug concentration dropped rapidly within the first 3 d, with a decrease of 83% on day 10 compared with that on day 0, and the measured concentration on day 7 reduced to the minimum effective level. The bottoming flocculi were identified as niclosamide. As for on-site application, the measured concentration on day 2 was already lower than the minimum effective level, which might be due to the scarce representativeness of the used samples. Conclusion The laboratory study revealed that the decreasing molluscicidal effect of the agent in water with time was a result of the gradual degradation of the agent to niclosamide monomers in water, which again accumulated to form insoluble flocculi and led to concentration decrease, other than chemical degradation of niclosamide. Analytical chemistry methods were not applicable for on-site monitoring of large water bodies.
Objective To identify dead birds infected with bird flu virus in Macao and monitor for potential outbreaks of Avian Influenza, providing the basis for development of Avian Influenza prevention and control in this region. Methods Throat and anal swabs of dead birds in Macao were collected from November 2005 to December 2006 for detection of bird flu using the real-time fluorescent reverse transcription polymerase chain reaction (RT-PCR) diagnostic kit for H5 subtype Avian Influenza virus. Results Of the 866 dead birds picked up in Macao, 296 birds were identified as belonging to 61 species, 28 families, and 11 orders. Resident birds, winter birds and summer birds accounted for 59.3% , 18.5% and 5.6% of the total species number, respectively; travelers, vagrant birds, together with other migratory birds amounted to about 16.7%. Wetland birds accounted for 25.9% , and forest birds for 74.1% . Despite varying number of dead birds found among each month, the difference was not statistically significant (F13，28＝0.598，P＝0.825). Furthermore, all the dead birds were negative for detection of bird flu virus. Conclusion None of the dead birds detected in Macao from November 2005 to December 2006 died from infections of the highly pathogenic H5 subtype Avian Influenza virus. Their death was likely natural.
Objective To investigate the rat density in different habitats and the prevalence of major rodent-borne diseases in Nanchang, and to assess the risks of occurrence of rodent-borne diseases. Methods The rodent species was measured using night traps, and data on major rodent-borne diseases were retrieved from the information reporting system for infectious diseases. Risk assessment was completed using the risk assessment matrix. Results From 2006 to 2008, the average density of rats was 1.03% in Nanchang. Rattus norvegicus was the predominant species, accounting for 52.55%, followed by Mus musculus and R. tanezumi, accounting for 18.88% and 17.35%, respectively. The highest rat density, 1.83%, was observed in natural villages of rural areas among the 3 habitats, followed by that in special sectors, 0.89%; and the lowest, 0.56%, was in residential lots. The average incidence of hemorrhagic fever with renal syndrome (HFRS) was 0.68/105 in Nanchang from 2006 to 2008, without human or rodent plague outbreaks in 3 consecutive years. As for the future risk, HFRS occurrence was highly likely in Nanchang, and plague occurrence was possible. Conclusion A scientific risk assessment system may help to predict the risk of disease occurrence.
Objective To provide the basis for early detection and control of plague in the Three Gorges Reservoir through monitoring of the host animals, insects and plagues in this region. Methods Night traps were used to measure the rat density. Live rodents were captured using cage traps to collect serum samples for detection of plague F1 antibody and determination of parasitic fleas on the rodent body. Animals which died of unknown causes were recorded, and plague monitoring was carried out. Results The average rodent density was 1.49% in Chongqing area of the Three Gorges Reservoir from 2007 to 2008. The indoor density was 1.50%, the outdoor 1.48%. Rattus norvegicus, Mus musculus, R. tanezumi and Anourosorex squamipes were the dominant species. The average flea-carrying rate was 4.03%, and the total flea index was 0.13. The parasitic fleas found on those rats included Monopsyllus anisus (0.12%), Leptopsylla segnis (77.88%), Palaeopsylla remota (14.39%) and Xenopsylla cheopis (7.61%). For the 6549 surveyed live rats, the serological test was all negative for plague. There was neither a large number of dead animals of unexplained causes nor plague cases. Conclusion Plague was not found in Chongqing area of the Three Gorges Reservoir, though the vectors and host animals exist.
Objective To determine the infection status and dynamics in vivo and ex vivo of Escherichia coli O157∶ H7-EDL933 in the infected Musca domestica. Methods In vitro topical application of strains was employed to quantitatively infect the experimental flies, 1 μl apiece (the concentration of bacterial suspension was 8.0×105～1.9×107 cfu/ml). Each fly was bred in one test tube for observation. Results The M. domestica infected In vitro carried the bacteria both in vivo and ex vivo. The median bacteria-carrying duration ex vivo was (96.0±15.3) h (95％CI: 66.0-126.0 h), and the median bacteria-carrying duration in vivo was (144.0 ±17.3) h (95%CI: 110.2-177.8 h). There was no significant difference between the bacteria-carrying dynamics in vivo and ex vivo ( χ2＝0.74，P＝0.388). The longest bacteria-carrying duration of M. domestica was at least 216 h (9 d). Conclusion M. domestica was not only the probable vector of E. coli O157∶H7, but also a potential reservoir host for human infection thereof.
Objective To provide the basis for development of the prevention and control strategies of Japanese encephalitis (JE) by analysis of the comprehensive monitoring data on this condition in Henan province. Methods Excel 2003, SPSS 12.0 and Epi Info 2000 were used to analyze the encephalitic cases in Henan from 1995 to 2008 and the monitoring data on vectors and host animals at Tanghe and Xixian counties, state-level monitoring sites. ELISA assay was conducted for detection of serum JE IgG antibody in the host animals. Results The incidence of JE was downward mobile with periodic fluctuation from 1995 to 2008. 91.75% of the cases were found during July to September, and 79.80% were distributed in the south and southeast regions: Xinyang, Nanyang, Zhumadian, Zhoukou and Luoyang. Children aged 0 to 14 years were the primarily affected group in the province (85.01%), though a noticeably increased portion of those who were ≥15 of age (56.84%) was observed in Luoyang city. 87.31% of the cases had not received vaccination or obscure immunity history. The antibody positive conversion rate reached 50% in pigs one month earlier before the onset peak in humans, and the mosquito density peak was present a fortnight ahead of the onset peak. Conclusion The JE epidemic in Henan may be reduced by strengthening the monitoring of vectors and host animals, improving JE vaccination coverage and carrying out specific control measures for children in the prevalent areas as well as the older group in Luoyang city.
Objective To analyze the correlation between the mosquito density dynamics and prevalence with the incidence of Japanese encephalitis (JE), providing the basis for prediction and prevention of this disease. Methods The monitoring was conducted in four villages, each randomly selected from a township in the east, west, south and north parts of Guiping city apiece. Mosquitoes were captured at residential rooms, pigpens and cowsheds using the same type of lamp trap at the same time of each year. The correlation between the incidence of JE and the mosquito species, density and dynamics was then analyzed. Results Mosquitoes of 7 species in 4 genera were collected in Guiping from 2003 to 2008. These species were: Culex tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. pipiens quinquefasciatus, Anopheles sinensis, An. minimus, Aedes albopictus and Armigeres subalbatus. The dominant species was Cx. tritaeniorhynchus. The mosquito density peaked in April each year, with an average of above 40 / (trap·h); and maintained high from May to September at 60-500 / (trap·h), followed by a decline after October, which was consistent with the time distribution of JE incidence. Conclusion Guiping city has a high density of mosquitoes. Cx. tritaeniorhynchus is the dominant species of JE vector. The density dynamics of mosquitoes were closely correlated with the incidence of JE. Hence, the prevention and control of mosquitoes such as Cx. tritaeniorhynchus should be strengthend.
Objective To study the family Ceratopogonidae of the order Diptera in Xinjiang Uygur Autonomous Region. Methods Traps, nets, animal baits and light traps were used to capture the relevant species; and related literature was reviewed. Results Notes on the family Ceratopogonidae of the order Diptera in Xinjiang was published, with statement of 106 species, 10 genera and 4 subfamilies of Diptera, Ceratopogonidae. The notes covered 1 genus (Leptoconops Skuse) of the subfamily Leptoconopinae, with 17 species; 1 genus (Dasyhelea Kieffer) of the subfamily Dasyheleinae, with 16 species; 3 genera of the subfamily Forcipomyiinae, comprising 1 species under the genus Atrichopogon Kieffer, 8 species under the genus Forcipomyia Meigen and 2 species under the genus Lasiohelea Kieffer; 4 genera of the subfamily Ceratopogoninae, comprising 48 species under the genus Culicoides Latreille, 4 species under the genus Brachypogon Kieffer, 8 species under the genus Bezzia Kieffer and 1 species under the genera Palpomyia Meigen and Mallochohelea Wirth for each. Conclusion The notes provide scientific basis for further prevention and control of Diptera, Ceratopogonidae in Xinjiang.
Objective To provide an overview of the research advancement in Muscina (Robineau-Desvoidy, 1830) in China. Methods The relevant specimens were collected and identified in conjunction with literature review. Results In addition to the new species, Muscina longifascis (Feng, sp. nov.), 15 species of the genus Muscina are known in the world. Seven of them are distributed in China, of which 2 species are unique to China and 5 present in multiple areas. This paper outlines the identification features of this genus, presenting a basic understanding of its ecological behaviors. A key to the known species in China is also established. Conclusion The number of species of the genus Muscina is relatively small, despite the vast species distribution. Record of the species should be carried on. The type species of the new record is reserved in the Insect Museum of Shanghai Institute of Plant Physiology and Ecology.
Objective A computer program was formulated on the internationally recognized platform of statistics analysis system (SAS) for rapid screening of pesticide toxicity. Methods Two insecticides, A and B, were tested for the toxicity against Blattella germanica using indoor fumigation. The resulting data were subject to computation by this program to fit a weighted probit regression line. The LC50 and 95% confidence interval (95%CI) of both agents were then calculated and compared in pair with the slope of the toxicity regression line. Results The toxicity regression lines of the two agents were Y(probit)＝ -3.193＋5.005×Log10 (dose) and Y(probit)＝-2.498＋2.696×Log10 (dose). The Wald test showed both P values were ＜0.01, while the goodness-of-fit test showed both P values were ＞0.05. The LC50 values for the two pesticides were 4.35 g/m3 (95%CI: 3.17-5.29 g/m3) and 8.44 g/m3 (95%CI: 6.07-10.66 g/m3), respectively; the slopes of the two regression lines were 5.005 and 2.696, respectively. Comparison between the LC50 values showed: u＝3.415, P＜0.001; and that between slopes revealed: t＝2.028, P＜ 0.05. These results suggested that agent A was stronger than B in both toxicity and sensitivity. Conclusion Through dual verification, the established method and computer program proved to be accurate, reliable, and simple and fast for rapid screening of insecticidal toxicity.
Objective To establish a mathematical model of dengue fever based on the Newton model of the transmission of dengue fever and the SIR compartment for in-depth study of the epidemiological characteristics of imported dengue fever and of the effects of different control measures. Methods A model of the transmission of dengue fever, consistent with the actual situation of the dengue fever outbreak in Cixi city, Zhejiang province in 2004, was established to simulate and study the scenario. Results According to the model, the total mosquito density threshold per capita was 2.4. Thus, an epidemic outbreak of dengue fever would not be possibly avoided following import of pathogens unless the antibody level among the population was ＞67.8%. Conclusion The simulation results derived from the mathematical model was close to that of field investigation, which was particularly consistent with the mid-to late-period of the outbreak. Hence, the application of mathematical model may practically facilitate field control of epidemic diseases.
Objective To investigate the species, density and distribution of vectors in Longgang district, Shenzhen, providing the basis for vector prevention and control in the region. Methods Vector monitoring was conducted in 4 streets (Pinghu, Buji, Bantian, Pingshan) of Longgang district from March to June, 2009. Rodents were captured by night traps, mosquitoes by lamps, flies by glue boards and cockroaches by roach motels. Results As for Pinghu, Buji, Bantian and Pingshan, the rodent densities were 4.21%, 0, 12.09% and 13.75%, respectively; mosquito densities were 2.04, 0.84, 3.13 and 0.66/h, respectively; fly densities were 2.02, 1.43, 1.19 and 0.66/(board·day), respectively; and cockroach densities were 1.04, 1.80, 1.03 and 1.91/ instrument, respectively. Conclusion The general characteristics of vectors in Longgang district were identified, which would serve as the basis for development of corresponding vector control strategies.
Objective To identify the species composition and seasonal succession of vectors in Shenyang city, providing the technical ground for prevention and control of vector-borne diseases. Methods Night traps, lamp traps, cage traps and glue traps were used to monitoring the dynamics of rodents, mosquitoes, flies and cockroaches, respectively. Results Of the captured animals and insects, there were rodents of 3 species in 3 genera, 2 families with the dominant species of Rattus norvegicus; mosquitoes of 5 species in 3 genera with the dominant species of Culex pipiens pallens, Anopheles sinensis and Aedes vexans; flies of 12 species in 12 genera, 3 families with the dominant species of Lucilia sericata, Muscina stabulans and Musca domestica; and only 1 species of cockroach, Blattella germanica, was found. Conclusion The species composition and seasonal succession of biological vectors in Shenyang were generally identified.
Objective To investigate the population composition and seasonal succession of biological vectors in Cixi city, 2008, providing the basis for implementation of vector prevention and control. Methods Rodents, mosquitoes, flies and cockroaches were monitored using night traps, light traps, cage traps and paste baits, respectively. Results Rattus norvegicus was the dominant species of rodents, accounting for 72.22% of the total captured mice; Culex pipiens pallens was the dominant species of mosquitoes, accounting for 49.81%; Musca domestica and Chrysomya megacephala were the dominant species of flies, accounting for 24.64% and 27.87% of the total, respectively; Blattella germanica was the dominant species of cockroaches, accounting for 81.20%. Rodent activities peaked in spring and fall, while those of mosquitoes, flies and cockroaches topped from July to September. Conclusion The population composition and seasonal dynamics of vectors are basically clarified.
Objective To determine the susceptibility of Culex pipiens pallens to commonly used insecticides in urban areas of Ningbo city, providing the basis for better administration of pesticidal agents. Methods LC50 was calculated using the impregnation method. Results The resistance indices of Cx. pipiens pallens were between 2.00 to 5.09 times in regard to permethrin, deltamethrin and beta-cypermethrin, and up to 1.11 to 2.04 and 1.36 to 2.88 times against dichlorvos and propoxur, respectively. The resistance index of Baoshijie pesticide diffusing agents against the larvae was up to 1.28 times, and the resistance indices of Abate 1% granules against the larvae and pupae were 1.19 and 1.37 times, respectively; for Feibiao 5% insecticidal granules, these indices were 1.64 and 1.07 times, respectively. Conclusion Cx. pipiens pallens mosquitoes were lowly resistant to permethrin, deltamethrin and beta-cypermethrin, yet sensitive to dichlorvos and propoxur in urban areas of Ningbo city. Baoshijie pesticide diffusing agents, Abate 1% granules and Feibiao 5% insecticidal granules were effective in larval control, though the first two were not as powerful against pupae. Monitoring of resistance in mosquitoes should be further strengthened for scientific, proper application of pesticides in future.
Objective To determine the distribution of the foci of Angiostrongyliasis in parts of Yunnan province, providing the basis for prevention and control of its infection. Methods The investigation was conducted in accordance with the requirements of the survey program on Angiostrongylus cantonensis issued by the Ministry of Health. Results A total of 7 intermediate hosts of A. cantonensis were found at the sampling sites. Pomacea canaliculata was distributed in 13 of the 19 surveyed counties, accounting for 68.42%. Of the 3874 captured snails, P. canaliculata accounted for 51.83% and Achatina fulica accounted for 6.56%. The positive infection rates of 3rd instar larvae of A. cantonensis found in Jinghong and Mengla counties were 0.56% and 0.26%, respectively. Conclusion The natural foci of Angiostrongyliasis are present in Yunnan.
Objective To analyze the epidemic dynamics of hemorrhagic fever with renal syndrome (HFRS) in Cangzhou city from 1986 to 2008, and to evaluate the effect of prevention and control measures. Methods Descriptive approaches were employed to analyze the epidemic dynamics, epidemiological characteristics and relevant monitoring results of HFRS. Results HFRS in the city was characterized by low incidence and frequent fluctuation. The first case was reported in 1986, followed by two incidence peaks in 1999 and 2002, with the incidence rates of 14.78/105 and 14.51/105. 89% of counties (cities) had the incidence above the intermediate standard, ranging from 6.93 to 42.02 per 105. The sex ratio was 2.07∶1, with the age of onset extending to both ends of younger and older ages. Most patients were 15 to 64 years of age, accounting for 91.37%. The average antibody positive rate of the surveyed population was 8.69%. The average rat density was 2.20%, and averagely 8.61% of rats were carrying the virus. Conclusion Though the implementation of“Attaching Equal Importance to Rodent Control and Immunization Coverage”strategy in conjunction with strengthened monitoring and early warning, as well as publicized health education and other comprehensive measures, HFRS has been effectively controlled in the city with the incidence of less than 1/105 since 2006.
Objective To analyze the results of malaria surveillance in Wuxing district, Zhejiang province from 2004 to 2008, providing the basis for timely amendments to the prevention and control strategies. Methods Blood tests and case study were conducted based on the epidemic survey reports and case information in Wuxing district from 2004 to 2008. Results A total of 6142 patients with clinically diagnosed, suspected malaria or fever due to unknown causes were subject to blood tests in Wuxing from 2004 to 2008; and 26 malaria patients were found, mostly imported cases. These cases were monthly present from April to November, though relatively concentrated in July, August and October. Most patients were from Zhili Town and Daochang village where floating population was relatively large. The sex ratio was 2.25∶1, and age of onset ranged from 7 to 74 years. Conclusion Blood tests, active search for the three kinds of patient and health education should be specifically carried out among floating population, and the span of routine malaria monitoring should be extended to improve the detection rate and consolidate the current control effect.
Banna virus was first isolated in 1987, from cerebrospinal fluids and serum samples of fever and encephalitic patients in Xishuangbanna, Yunnan province of China. It is a model virus of Seadornavirus, a newly recorded viral genus of the Reoviridae family. As a newly isolated virus that is closely associated with human diseases, Banna virus has attracted wide concern from the related academic realm. This paper reviews the advances in etiologic characteristics, geographic distribution, vectors, human and animal infections, and other issues of Banna virus.
Carrying the identification characteristics, the biological specimen of specific vectors is an important basis for a border port to correctly identify the vector in intercepted subjects. With the help of computer and network technology, biological samples of vectors can be digitalized, based on which a database with quick inquiry functions may be created to facilitate vector identification. This paper presents the importance of vector samples digitalization and summarizes the advances in digital biological specimens and related researches at home and abroad, indicating that collection of digital biological samples should include both text and image data of the specimen. The workflow suitable for vector sample digitalization is also discussed.
Snails are the intermediate host of schistosomiasis. Their survival is dependent on the ecological environment. This paper reviews the research on molluscicidal plants at home and abroad in recent years, and describes the impacts of these plants on snails’living environment, and the toxicity and mechanisms of plant-derived molluscicides. Using the molluscicidal ecological measures from these plants may effectively reduce environmental pollution by other chemical agents, and decrease snail control costs, which is conducive to blocking the spread of schistosomiasis.
Angiostrongylus cantonensis is an animal parasite that also invades the human body. Living in the central nervous system, it may cause eosinophilic meningoencephalitis (eosinophilic meningoencephalitis due to A. cantonensis). At present, the disease is mainly seen in the Asia - Pacific region, particularly Southeast Asian countries and China’s southern provinces. Pomacea canaliculata is a major intermediate host of A. cantonensis. In recent years, outbreaks of eosinophilic meningoencephalitis due to A. cantonensis in Wenzhou city, Zhejiang province and Changle city, Fujian province were wholly caused by consumption of P. canaliculata. However, prevention and control of P. canaliculata is currently limited to simple physical, agriculture and chemical means, and an effective system of integrated control techniques has yet to be founded. This paper mainly introduces the domestic and foreign advances in prevention and treatment of P. canaliculata in recent years.
Earthquakes occur frequently around the world in recent years. Large earthquakes may cause heavy casualties, with the dead bodies buried under the ruins. In such a disaster, the survivors are deprived of clothing, food, shelter and other basic material conditions of life; hygienic facilities such as wells, kitchens, bathrooms, toilets and trash boxes are severely damaged; water and power supply are off, traffic paralyzed and communication interrupted; multiple sources of infection are formed out of sewage, feces and garbage after the water drainage system is destroyed; a surge of refugees become homeless and sleep in the open or temporary quake-proof shelters, their normal routines disordered and the body immunity declined. Such post-earthquake sequelae precipitate the outbreaks, spread and prevalence of infectious diseases. Therefore, to avoid post-disaster major epidemics and prevent the occurrence and spread of infectious diseases, medical contingency plans should be immediately initiated in conjunction with epidemic prevention mechanisms to minimize the seismic hazards.
Objective To explore the training for professionals in medical vector laboratories at border ports. Methods The essence of staff training was investigated through analysis of the current situation and existing problems in laboratory construction. Results Training for the professionals of medical vector laboratories should be targeted with stress on cooperation and exchanges, as well as increased efforts to attract and retain talents. Conclusion An important component of the public health system at border ports, medical vector laboratories play a significant role in preventing the invasion of alien vectors and controlling borne infectious diseases. Great importance should be attached to personnel training which is key to the laboratory construction.
