ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To study the flight range of Anopheles sinensis and provide evidence for the development of control measures for malaria elimination in China. Methods The mark-release-recapture technique was used to preliminarily study the flight range of An. sinensis. The 3000 wild An. sinensis were captured and marked with green fluorescent powder and released at the specific site of Yongcheng city. Subjects were recaptured for ten successive days using light traps and fluorescent detection. Results Twenty-five of the 3000 released An. sinensis were recaptured, resulting in a recapture rate of 0.83%. The number of recaptured An. sinensis varied over time; one on day 0 (the day of release), fourteen on day 1, eight on day 2, one on day 3, and one on day 6. No marked An. sinensis were recaptured on the other days. The number of recaptured An. sinensis also varied by location; the number of recaptured An. sinensis was significantly higher to the east and south of the village than to the west and north. Eighty percent of the marked An. sinensis were recaptured within 100 m of the initial release site with a maximum flight distance of 400 m. Conclusion This is the first study of An. sinensis flight-range patterns using the mark-release-recapture technique in China. In this study, the recapture rate was low, and most marked An. sinensis were recaptured within a 100 m radius of the release site with a maximum flight distance was 400 m. Given preliminary data on An. sinensis flight patterns, the management area of disease control efforts in future malaria epidemics should cover a radius up to 500 m from an epidemic focal point, with most resources concentrated within a 100 m radius.
Objective To identify anopheline mosquitoes in Hainan province based on morphological and molecular characteristics. Methods Anopheline adults and larval specimens were collected from four different geographic locations in Hainan province. The adults were morphologically identified, and the rDNA-ITS2 and 28S-D3 fragments of selected adults and larvae were amplified and sequenced for molecular identification. Results The morphological identification of 336 anopheline adults revealed nine species, predominantly Anopheles vagus, which comprised 81.55%. Thirty-seven ITS2 and 41 D3 sequences were amplified. Blast results were consistent with morphological identification; excluding one An. aconitus identified as An. minimus. Molecular identification verified An. sinensis, An. vagus, An. kochi and other anopheline species (highly homogeneous with An. sundaicus and An. subpictus). Double peaks of one (G/A) and two (A/T) bases were found within the ITS2 sequences of An. vagus and An. minimus and three (G/A) and one (G/A) bases were observed within the D3 sequences of An. vagus and An. kochi. Conclusion The morphological and molecular identification of anopheline mosquitoes is reliable and feasible but suggests ongoing cryptic speciation in An. vagus, An. minimus and An. kochi.
Objective To develop standard laboratory rearing techniques for Aedes albopictus in order to provide consistent, quality, standardized testing insects for use in pesticide experiments. Methods Using standard rearing techniques, the mosquitoes were bred under controlled rearing conditions. The reliability of multiregional rearing was examined based on the weight of female adults 3 days after eclosion from three batches of mosquitoes. Results All three batches resulting from standard rearing techniques yielded qualified Ae. albopictus based on the average weight, with high repeatability and low relative deviation (8.28%) of weights. As shown from the average weights of mosquitoes bred using different dietary formulas, all three approaches were applicable to different regions and the relative deviation was low (7.69%). Conclusion The rearing technique was repeatable and effective in developing weight-uniform Ae. albopictus for pesticide experiments.
Objective To measure the sex-specific flight behavior of Musca domestica for the formulation of prevention and control strategies. Methods The tethered flight of female and male adults of M. domestica aged 1, 5, 9, 13, 17, 21 and 25 days were measured. Flight behaviors including; longest distance, longest duration and average speed in the longest journey of a single flight, were compared between sexes. Results Significantly different flight capacities were seen between male and female adult flies. Newly eclosed males were far behind the females of the same age in this regard. The highest flight capacity occurred at different ages between sexes. In female flies, the highest flight capacity occurred on day 9, with a distance and duration of 438.72 m and 818.01 s, respectively. In contrast, two days of high flight capacity were observed in male flies, on days 9 and 17. The highest flight capacity in males was on day 17, with a distance and duration of 642.91 m and 1385.21 s, respectively. As for the average speed in a single farthest flight, the male flies recorded the highest value on day 9 with a rate of 0.66 m/s while females presented with two peaks on day 9 and day 17, with a rate of 0.58 m/s on day 17. Conclusion The flight capacities of M. domestica are significantly different between sexes.
Objective To explore the on-site fly control effects of a new biological agent, Echo, in animal farms. Methods Echo, chlorbenzuron, pyriproxyfen, a mixture of Echo with chlorbenzuron, and a blank control were sprayed at the same concentration onto feces in a laboratory simulation and in the field. Results After treatment with Echo for 12 days, compared to the control group, the emergence rate of flies from the feces exposed at 24 h, 48 h and 72 h, decreased by 96.2%, 64.4% and 86.7%, respectively. After treatment with Echo and the mixture of Echo and chlorbenzuron for 7 days and 12 days in the field, the density of fly larvae decreased by 56.2% and 65.5%, respectively. After treatment with Echo for 12 days, fly density decreased by 71.2% compared to the control. After treatment with the Echo and chlorbenzuron mixture for 12 days, fly density decreased by 55.2% compared to the control. Fly density also decreased by 74.5% after treatment with Echo for 6 h in the field. Conclusion The Results show that Echo was effective in deodorization, inhibition of fly breeding and reduction of fly density.
Objective To develop environment-friendly ricin-based rodenticides and determine their effects. Methods Methods for extracting ricin from castor seeds were examined. Ricin-based agents were combined with different baits and attractants according to the food consumption behaviors of mice. Their effects were then compared in terms of formula, shape and size. Results Rodenticides with rice flour and glutinous rice flour baits were attractive to mice, and the effects were statistically similar. Baits of glucose and peanut powder were strong attractants, while formulations with black sesame powder were ineffective; the associated feeding coefficients were 7.40±0.70, 2.96±0.03 and 1.10±0.01, respectively. Mice appear to be indifferent to bait shape, as their consumption of cubicle, spherical and cylindrical baits were statistically similar. However, differences were shown in the consumption of baits of different sizes. Baits 8 to 9 mm in diameter were most preferable with a consumption rate of 40.08%±0.80%. Rodenticides using ricin extracted from degreased seeds with petroleum ether, ethyl acetate and chloroform were refused by subjects. In contrast, ricin extracted with normal saline solution yielded a favorable response. Bait containing ricin at 0.91%, 0.71% and 0.53%, resulted in an average death time of 37.17 h±7.41 h, 68.00 h±18.07 h and 82.17 h±14.30 h, respectively. Conclusion The most effective rodenticide studied was composed of ricin extracted from degreased seeds with normal saline, rice flour/glutinous rice flour, contained a glucose attractant (mass fraction 3%), and had a diameter of 8 to 9 mm.
Objective To study the overwintering of Phlebotomus wui in artificial conditions. Methods Group A: larvae overwintered in the breeding dish at a temperature of 10-18 ℃ and relative humidity of 30%-45%. Group B: larvae overwintered in the breeding dish at a temperature of 1-13 ℃ and relative humidity of 45%-70%. Group C: larvae overwintered in an oviposit pot at a temperature of 1-13 ℃ and relative humidity 45%-70%. Results The average overall pupation rate was 52.6%. The highest pupation rate was seen in Group C, followed by Group B and A. In Group A, B, and C, the eclosion rates were 15.1%, 64.3% and 70.6%, the overall adult survivals 7.2%, 32.7% and 41.7%, and the effective accumulated temperature 3000 day·℃, 2975 day·℃ and 2960 day·℃, respectively. The time and extent of pupation and eclosion were scattered in Group A yet clearly concentrated in Group B and C. Conclusion The environmental temperature has a significant effect on overwintering of P. wui, which requires an effective accumulated temperature of 2978 day·℃. The higher the temperature, the shorter the duration of diapause, resulting in earlier eclosion and abbreviated overwintering. Thus, the mating and blood-feeding period of P. wui commences earlier. In contrast, normal mating and blood feeding requires an average temperature lower than 11 ℃ and a diapause duration longer than 9 months. Humidity is also a significant factor because most larvae will not survive when the humidity remains below 75%.
Objective To determine the prevalence of Anaplasma phagocytophilum in goats and oxen in Zhejiang province. Methods Five goats and five oxen were randomly surveyed in each househould based on registration information. Venous blood samples of 5 ml were collected from each subject, and the separated serum was tested for IgG antibodies against A. phagocytophilum using immunofluorescence assay (mIFA) as recommended by the WHO. The blood cells were used for DNA extraction, which was then amplified for the 16S rRNA genes of A. phagocytophilum. The PCR products were sequenced and analyzed for homology and genetic variation. Results A high carrying rate (39.42%) was found in the local livestock, particularly in Tiantai county. Considerable variation in the 16S rRNA genes was found in the prevalent strains. In addition to 15 independent variations in the nucleic acid sequences, at least five strains with variation in the dominant sequences were found. Conclusion Most domestic animals in Zhejiang province carry A. phagocytophilum warranting the survey and molecular epidemiological investigation of this pathogen in humans.
Objective To analyze the epidemiological characteristics of rabies in Guangzhou from 1980 to 2010. Methods A retrospective analysis was conducted using rabies epidemic data and case reports. Canine brain samples from endemic areas were also collected for antigen detection using immunofluorescence assay (IFA) and RT-PCR. Results From 1980 to 2010, 655 human rabies cases were reported in Guangzhou, including 597 cases from 1980 through 1989, which accounted for 91.15%; and 45 cases from 2005 to 2010, accounting for 6.87%. These data show two epidemic peaks in the past thirty years. Male patients outnumbered females; most were aged 10 to 55 years and were students, migrant workers or farmers. Eighty-six dogs were captured in the epidemic areas. However, no viral antigens were detected in the brain tissues using immunofluorescence and RT-PCR. Conclusion Two epidemic peaks of rabies in humans were observed in the past thirty years in Guangzhou. In the 1980s, morbidity rose quickly after exposure due to low vaccination rates in both dogs and humans. After 2005, as a result of increasing numbers of domestic dogs, decreasing public awareness of rabies, absence of proper wound treatment and post-exposure immunization, rabies incidence increased. However, negative findings in the 86 dogs studied suggest low prevalence of rabies virus in domestic dogs in Guangzhou.
Objective To determine the population composition of rodents and fleas and investigate plague in the natural foci in Longlin county, Guangxi Zhuang Autonomous Region for formulation of prevention and control strategies. Methods The flea-carrying rate and flea index of rodents were calculated based on the number of fleas collected from caged rodents. The free flea index was calculated according to the number of indoor fleas captured on sticky paper. The mammals were then subject to etiological and serological tests to determine the infection rate. Results Rodents of eleven species (3 families with 2 orders) and fleas (6 species) predominantly Rattus tanezumi and Xenopsylla cheopis were found in the foci. The average rodent density, flea-carrying rate, flea index and index of X. cheopis were 3.24%, 27.09%, 0.95 and 0.74, respectively. The indoor free flea index was 0.046. Among 5398 cultured rodent specimens, 10 strains of Yersinia pestis were isolated; two positive sera and 24 indicative sera were detected via indirect hemorrhagic assay (IHA). Conclusion The optimum period for rodent control is April and October and the key period for plague monitoring is from February to October in the natural foci of R. tanezumi plague in Longlin county.
Objective To compare the effectiveness of indirect immunfluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA) and western blot (WB) in serologic diagnosis of Lyme disease. Methods Serum samples, epidemiological data and clinical information of potential Lyme disease patients were collected. Serum antibodies (IgM, IgG) against Borrelia burgdorferi were detected by IFA, ELISA and WB. Results were interpreted based on clinical manifestations and epidemiological data. Results Of the 398 serum samples collected from suspected patients, 86 were ELISA-positive (21.61%), including 27 IgM positives and 59 IgG positives; 82 were IFA-positive (20.60%), including 26 IgM positives and 56 IgG positives; and 83 were WB-positive (20.85%), including 31 IgM positives and 52 IgG positives. The positive rate of WB for the diagnosis of patients with erythema migrans (EM) was significantly higher than that of ELISA and IFA (χ2＝6.34, P＜0.05）. Conclusion The combination of IFA, ELISA and WB may improve the sensitivity and specificity of the laboratory diagnosis of Lyme disease. WB has a lower false positive rate than ELISA and IFA.
Objective To determine the prevalence of hantavirus in rodents based on surveillance data in residential areas of Huludao for the formulation of preventive and control strategies in humans. Methods Rodent cages were used to capture small mammals. Lung samples of the subjects were then taken for detection of Hantavirus antigens using indirect immunofluorescence assay (IFA). Genotyping was conducted using RT-PCR. Results In 2005 and 2006, 254 Rattus norvegicus, 17 Mus musculus and 5 Apodemus agrarius were captured in nine residential areas and two wild fields in Huludao. The virus-carrying rates were 4.72% in R. norvegicus and 5.88% in M. musculus, respectively. Nine strains of Hantavirus were amplified using the RNA derived from the positive lung tissues of R. norvegicus. According to genotyping results, all were identified as Seoul virus (SEOV). A strain of SEOV was also isolated. Hantavirus was not detected from M. musculus and A. agrarius. Conclusion R. norvegicus was the primary host of Hantavirus in residential areas of Huludao and all rodent-carrying Hantavirus strains were identified as SEOV.
Objective To determine the seasonal trends of the morbidity and mortality of Japanese encephalitis(JE) in China from 2004 to 2010. Methods Circular distribution analysis was conducted based on JE morbidity and mortality data in China from 2004 to 2010. Results Seasonal concentration of JE morbidity and mortality was observed (P＜0.05). The highest morbidity was observed on August 11 and the highest mortality on August 10, with peak periods from July 8 to September 13 and July 7 to September 14. Conclusion This study provides insight for the seasonal characteristics of JE in China for disease prevention and control.
Objective To determine the antibacterial activity of propolis from Henan province against Bacillus anthracis. Methods The agar diffusion method was used to test for antibacterial activity. Antibacterial effects were measured after exposure to seven formulations of 31% propolis at pH ranging from 5.5-8.5 （5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5）. Additionally, ten dilutions of propolis from 31% to 0.06%（1∶512）, including a 0 control, at pH 5.5 and a dose of 7 μl were examined in triplicate. Results The diameters (mm) of the zones of inhibition in each pH group, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0 and 8.5, were as follows: 19.16±0.29, 17.67±0.29, 14.67±0.58, 13.67±0.29, 14.00±0.00, 13.33±1.15 and 12.00±0.00 mm, respectively. The diameters in each concentration group, 15.50%, 7.75%, 3.88%, 1.94%, 0.97%, 0.48%, 0.24%, 0.12% and 0.06%, and the control group were: 19.50±1.80, 19.67±1.04, 17.75±0.35, 15.67±0.58, 14.00±2.29, 13.17±1.04, 11.83±1.53, 10.83±1.26, 9.00±0.00 and 0.00±0.00 mm, respectively. Conclusion Propolis from Henan province had antibacterial activity against B. anthracis, which declined with increasing pH or decreasing concentration.
Objective To analyze the epidemiological characteristics of hemorrhagic fever with renal syndrome(HFRS) in China from 1999 to 2009 using the GM(1,1) model for evaluation of its application in similar analyses. Methods The analysis was based on the GM(1,1) model created using nationwide incidence data of HFRS from 1999 to 2009. Results Despite slowly decreasing morbidity, the mortality of HFRS remained stable in recent years, making the disease an ongoing public health threat in China. The predicted values based on GM(1,1) were consistent with the actual incidence rates from 1999 to 2009. The predicted incidence rates in 2010 and 2011 were 0.61/105, 0.51/105, respectively. Conclusion The GM(1,1) model has a good fit, accurate prediction, and can be used for analysis of HFRS incidence.
Objective To determine expression and DNA-binding activity of the recombinant CRP (cyclic AMP receptor protein) in Yersinia pestis, Vibrio parahaemolyticus and Klebsiella pneumoniae for the study of transcriptional interregulation. Methods The coding region of the crp gene of Y. pestis, V. parahaemolyticus and K. pneumoniae was amplified by PCR, and cloned into the BamHⅠ and Hind Ⅲ sites of a pET28a vector. The recombinant plasmid pET28a-crp was inducted into BL21λDE3. Over-expression of His-CRP in the LB medium was induced by adding 1 mmol/L IPTG (isopropyl-b-D-thiogalactoside). The over-expressed protein was purified under native conditions with nickel loaded HiTrap Chelating Sepharose columns (Amersham). Electrophoretic mobility shift assay (EMSA) and DNase I footprinting experiments were carried out to analyze the DNA-binding activity of the three CRP proteins in vitro. Results All three purified His-CRP proteins were able to bind to the upstream DNA regions of Y. pestis (psaA), V. parahaemolyticus (toxR), and K. pneumoniae (kfuA). Conclusion Recombinant CRP proteins of Y. pestis, V. parahaemolyticus and K. pneumoniae were expressed and purified, suggesting their inter-regulatory effect on the transcription of key virulence genes of the three pathogens.
Objective To determine the species distribution and taxonomy of Culicoides (Sinocoides) in China. Methods Bed nets, light traps and insect nets were used to collect the subjects. Results Eight species of Culicoides (Sinocoides) have been recorded in China, including Culicoides (Sinocoides) malipoensis Liu et Ren, sp. nov. and Culicoides (Sinocoides) nanniwanensis Liu et Wang, sp. nov. The distribution of the known species in China and measurements of the main differential characteristics were described to compile a key list of species. Conclusion The investigation clarified the distribution and composition of Culicoides (Sinocoides) in China.
Culicoides (Sinocoides) malipoensis Liu et Ren, sp. nov. is alike to Culicoides subpalpifier Wirth et Hubert, 1989. The latter is noticeably distinguishable by contiguous eyes, palpal ratio (PR) of 2.5 and unequal spermathecae of 3. Culicoides (Sinocoides) nanniwanensis Liu et Wang, sp. nov. is alike to Culicoides opertus Liu et Yu, 1990, but the latter is distinctly characterized by the absence of sensory pits on the third palpus, absence of sensilla coeloconica in the 15th antenna segment, and wings with two pale spots. The type specimens are preserved in the Center for Disease Control and Prevention of Shenyang PLA Command, Shenyang 110034, China.
Objective To compare the attracting effects of carbon dioxide (CO2) traps with ultraviolet (UV) light traps on mosquitoes in field settings. Methods Both approaches were used within a 2-hour window before and after sunset, three times monthly, for six consecutive months. Results A total of 2483 mosquitoes were captured, of which 1544 were attracted by CO2 traps and 939 by UV light. The density of mosquitoes captured by CO2 traps (11.20/lamp·hour) was significantly higher than by UV light traps (6.87/light·hour). Conclusion The attracting effect of carbon dioxide traps was better than that of UV light traps. CO2 traps can be used to effectively monitor mosquito density.
Objective To determine the density of primary vector species and their seasonal fluctuation in Pan’an county for improvement of prevention and control strategies. Methods Light traps, cage traps, roach pastes and night traps were used to capture mosquitoes, flies, cockroaches and rodents, respectively, for density calculations. Results From 2005 to 2010, the average density of mosquitoes in Pan’an county was 2.04 per lamp-hour, with the prominent species being Culex pipiens pallens / Cx. pipiens quinquefasciatus accounting for 71.81%. The average density of flies was 1.83 per cage with Chrysomya megacephala and Musca domestica as the predominant species, which accounted for 52.62% and 37.81%, respectively. The density of cockroaches was 0.91 per paste, with Blattella germanica as the predominant species (92.10%). The rodent density was 0.89% with Niviventer fulvescens as the predominant species (37.60%). Most mosquitoes and flies appeared in May; the former became most active in July and the latter in June through August. Cockroaches and rats were observed throughout the year with relatively high roach density from March to October and generally peak rodent density in September. Conclusion The population composition and seasonal fluctuation of primary vectors in Pan’an county are clarified.
Objective To explore the species and other information of Calyptratae in Daxiangling. Methods Mist nets were used to capture the subjects in different habitats. The specimens were then classified using stereomicroscopy. Specimens of significance were carefully preserved and new species were morphologically described, illustrated and published. Results A total of 136 species of Calyptratae under 53 genera, 17 subfamilies of 7 families were found. This included 48 new (endemic) species, mostly from the Oriental region, which accounted for 35.29% of known species in this investigation.Conclusion Tremendous biodiversity of Calyptratae was found in Daxiangling region warranting further study.
Objective To collect data on from previous practices for sustainable rodent control and monitoring of potential rodent infestation. Methods Rodent and flea control measures were implemented for five consecutive years in urban, rural and wild locations since 2005. Bromadiolone baits were deployed in urban areas and the pests were manually captured, holes blocked, aluminium phosphide applied and isolation belts made up of bromadiolone bait sentinels built in the suburb and field areas. Rodent infestation monitoring Results before, during and after the five-year control period were compared. Results The rodent density in the urban area dropped to 0.2% in 2009 from 9.0% five years ago, the Rattus norvegicus density to 0 from 20.0%, the flea infestation rate to 0 from 93.3%, and the index of Xenopsylla cheopis to 0 from 16.27. The previously dominant species disappeared including the vector Xe. cheopis. The rodent density hit a record low this year, since the opening of Alataw Pass with a decrease to 3.0% from 6.0% in the rural controlled area. Meanwhile, the Rhombomys opimus density decreased to 2.3/hm2 from 9.0/hm2 in positive field spots. Conclusion The current rodent control strategies have effectively eliminated the potential risk of human plague at Alataw Pass. The establishment of a quintuple anti-rodent guard system is discussed for sustainable rodent control and monitoring for potential infestations.
Objective To evaluate the killing effect of aluminum phosphide and bromadiolone bait on Spermophilus dauricus, and compare the two agents in terms of their killing effect on rodents. Methods All rat holes in the experimental area were plugged before the experiment. Based on calculation of the effective holes the next day, rodentcidal agents were put in the holes, with protection zones set up between and around each of the plots. Results The killing effect of aluminum phosphide was good each month of the study, with maximum corrected efficacy rate greater than 90%. The killing effect of 0.005% bromadiolone bait was better in May to June than in July to September, with the corrected efficacy rates being more than 90% and less than 75%, respectively. Conclusion Aluminum phosphide has a strong killing effect on S. dauricus the entire active season, while 0.005% bromadiolone bait shows good efficacy against the rodent only in May and June.
Objective To investigate the population composition and seasonal variation of cockroaches in libraries of Wuhu city, Anhui province for the development of effective control strategies. Methods The pests in libraries were studied using capture boxes from January to December 2008. Results A total of 1080 cockroaches, 4 species in 2 genera, 2 families, were captured, namely Periplaneta americana, P. fuliginosa, P. australariae, and Blattella germanica. Among them, B. germanica was the predominant species, accounting for 51.85％. The average year-round infestation rate was 53.32%, with an average density of 2.56 pests per room. The reading rooms were the worst affected. The reading rooms were most badly affected. The peak breeding season was in August, and the density variation was highly temperature-dependent (r＝0.954, P＜0.01). Conclusion Libraries in Wuhu city were highly roach-infested demanding immediate and effective control measures.
Objective To identify the factors driving rebound epidemic of rabies and formulate specific control measures based on analysis of the epidemiological characteristics of this disease in Jinhua, Zhejiang from 1950 to 2010. Methods Descriptive epidemiological analysis was performed using epidemic data from 1950 to 2010 and case investigations after 2005. Results A total of 174 rabies cases were reported from 1950 to 2010, including 30 in the 1970s and 107 in the 80s, suggesting prevalence in Zhejiang province in that period. After a 13-year period of zero case report from 1992 through 2004, 32 cases were reported from 2005 to 2010. In Jinhua, high incidence rates of rabies were observed in summer and autumn, with 64.94% of cases occuring from July to November. Since 2005, most cases were farmers without proper post-exposure treatment and immunization. Conclusion Increased numbers of dogs, poor public awareness of prevention, lack of prompt, proper post-exposure treatment and immunization, and oppresive costs of vaccines and immune globulins have contributed to the rebound of rabies epidemics. Therefore, governmental support for management and immunization strategies, promotion of public education and inclusion of vaccines in rural medical care coverage is crucial for future prevention and control.
Objective To analyze prevalence trends and epidemiological factors of hemorrhagic fever with renal syndrome (HFRS) in Chaoyang city from 1999 to 2009, in order to clarify causal correlations, better understand the epidemiology of the disease and improve prevention and control measures. Methods Statistical analyses were performed based on the HFRS data stratified by age, sex, occupation, season, annual rainfall amount, and annual output of major agricultural products (sorghum, corn and millet) in Chaoyang from 1999 to 2009. Results During the past decade, male patients accounted for 75.48% (782/1036) of the total number of HFRS patients; patients aged 20 to 50 years accounted for 79.92% (828/1036) and farmers accounted for 71.72% (743/1036). These Results indicate that males, aged 20 to 50 years old, and farmers were the highest risk population. Futher, spring was the peak season of transmission. As for environmental factors, changes in the annual rainfall amount did not affect the prevalence of HFRS (r＝0.182, P＝0.593). However, the annual millet output was correlated with the incidence (r＝0.694, P＝0.018) rather than sorghum (r＝0.475, P＝0.140) or corn (r＝0.481, P＝0.134). Conclusion The spatial, temporal and population distribution of HFRS was consistent with epidemiological characteristics of the disease. The annual millet output was positively correlated with HFRS incidence. These Results can inform prevention and control programs for HFRS.
Objective To examine vector prevention and control practices for large-scale events in China by describing vector monitoring and control as a part of pest control operations (PCO) in the 2008 Beijing Olypmic Games. Methods Candidate PCO companies were first screened, and eligible bid winners were then trained and tested, during which the services provided were supervised and inspected by the government designated agency. Results The PCO companies achieved satisfying vector control rates during the 2008 Olympic Games. Conclusion A government-funded pest control model for large-scale events has been established, which utilizes well-trained PCO companies under the management, coordination and supervision of health care administrators knowledgable of technical protocols formulated by the disease prevention and control system.
In October 2010, China's first community-based chikungunya fever (CHIK) outbreak occurred in Dongguan, Guangdong, a deviation from the long-term predominance of sporadic imported cases. CHIK is an acute infectious disease caused by chikungunya virus (CHIKV) and mainly transmitted by Aedes aegypti and Ae. albopictus, which are widely distributed in China. A CHIK outbreak may occur following the invasion of CHIKV. Hence, it is urgent to formulate control measures to prevent further spread of this disease. This study gives an overview of the pathogenic and epidemiological characteristics of CHIK to promote understanding of this disease and improve surveillance, prevention and control programs.
From 1964 to 2006, ten GETV were isolated in China, including M1, HB0215-3, HB0234, SH05-6, SH05-15, SH05-16, SH05-17, YN0540, YN0542, and GS10-2. This paper reviews the isolation, identification, distribution and molecular biology of those strains in comparison with the molecular biology of the foreign GETV and SAGV.
Yersinia pestis bacteriophage, a strongly specific bacterial virus, is commonly used for identification of the plague pathogen. Early research on this bacteriophage has focused mainly on the natural isolation, biological characteristics, and diagnostic or therapeutic applications. In recent years, advances in microbial genomics and proteomics have shed light on the role of this bacteriophage in the evolution of Y. pestis. This paper summarizes recent progress in Y. pestis bacteriophage research regarding genome structure and related pathogenicity and immunology, for the development of new molecular-based diagnostic modalities and medicines.
