Objective To analyze the molecular genetic characteristics of Hantavirus strain DX1101 isolated from the imported Rattus norvegicus. Methods We separated the rat lung, extracted virus RNA, and then used codehop RT-PCR to amplify L gene segment of Hantavirus and nested RT-PCR for M gene segment. The obtained products were then sequenced and analysed by phylogenetic tree. Results Homological and phylogenetic analysis of the two gene amplification products showed that the Hantavirus strain belongs to genetic subtype SEOV. The phylogenetic tree of M gene showed that the strain is genetically closest to the strain IR461 found in England. Conclusion This study identified Hantavirus in R. norvegicus seized from inboard containers. Therefore, it is of great significance to enhance the quarantine of inboard containers.

Objective To explore the drawing method of a statistical map based on statistics analysis system(SAS)and its application in the surveillance of exotic medical vectors and risk analysis in entry-exit inspection and quarantine system. Methods The statistical map method based on SAS program was applied for the classification statistics and data analysis of exotic medical vectors, with real-time, dynamic and automatic marking on the world map actualized. Results A world map was automatically drawn by computer and the related data and messages were labelled real-timely, dynamically and automatically on the world map in different colours. The locations of the twenty countries covered in this study were marked as asterisk in the map based on the longitude and latitude degree values of the capitals in those countries. Blue, yellow, orange and red colours were used to represent the different numerical levels of captured medical vectors. The numbers of vectors from Panama, Brazil and Thailand were marked by a blue asterisk indicating a relatively small number, while those from Korea South and South Africa were marked by red asterisk indicating a relatively large number. Conclusion The statistical map gives an intuitive, simple and dynamic illustration of the distribution of exotic medical vectors from different countries, contributing to inspection and quarantine authorities making timely, accurate and reasonable distribution of forces and strengthening quarantine supervision of what is imported from the countries as sources of relatively large number of exotic medical vectors.

Objective To design a computer program for risk analysis and assessment of import and export containers based on the statistical analysis system (SAS). Methods The feasibility of developing a container risk analysis system for inspection and quarantine (CRASIQ) based on SAS was analyzed by means of applicability assessment, analysis of procedures and software. Typical modules of the program were demonstrated. Results The SAS software was suitable for research and development of CRASIQ. The system included parallel data management and core application layers, as well as six sub-modules, which would provide fifteen functions. Conclusion The SAS - based CRASIQ may enhance the inspection, quarantine and supervision for import and export containers to support intellectual decision for prevention and control of exotic epidemic cases or toxic and harmful substances.

Objective To determine the deratting and disinsecting effects of sulfuryl fluoride (≥99.8%) and their relationship with the dose and exposure time. Methods Rats and cockroaches were divided and fumigated with sulfuryl fluoride at 4, 8, 12, 16, 20 g/m³. The death time of SD rats and Periplaneta americana was recorded. Results were simulated and predicted using the response-surface model. Results All groups of subjects were killed at different concentrations of sulfuryl fluoride. The average time to death ranged from 43 to 381 minutes for SD rats and from 97 to 387 minutes for P. americana. The response-surface model for SD rats was established as:Y＝1.57－1.16X₁－0.37X₂＋0.05X₁²＋0.22X₁X₂＋0.01X₂² and that for P. americana: Y＝6.92－2.15X₁－0.89X₂＋0.15X₁²＋0.18X₁X₂＋0.02X₂². Conclusion Desired killing effect resulted from sulfuryl fluoride at 4 g/m³ to 20 g/m³, concentration was negatively correlated with the exposure time (i.e. the time to death increased as the concentration dropped). Time and decrease of concentration. P. americana demonstrated stronger resistance to the agent compared with SD rats.

Objective To explore the frontier quarantine strategies for prevention and control of exotic vectors. Methods Exotic vectors first intercepted at Ningbo port from 2004 to 2009 were analyzed along with the case study of hazards brought by exotic vectors. Results With many years of strict frontier quarantine on international sailing ships, containers and cargos, 39 exotic vectors of 3 species, Supella supellectilium, Cochliomyia macellaria and Panchlora nivea were captured for the first time from 10 batches, as well as 9 species from 12 batches, which were sparsely distributed in a handful of provinces other than Zhejiang province. Hence, hazardous exotic vectors were effectively prevented from invading or spreading in China. Conclusion Frontier quarantine is irreplaceably essential to preventing the import of exotic hazardous vectors.

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 A computer program was developed based on the internationally recognized statistics analysis system(SAS) to rapidly screen for the optimal synergistic formula for pesticide formulations. Methods Agents A and B were combined in a certain ratio and subject to the determination of toxicity against Tetranychus cinnabarinus and the computer program calculations for fitting the polynomial mathematical model of the co-toxicity coefficient (CTC), the arcsine transformation of the mass fraction. The derivative of the model curve was calculated and the maximum CTC and the optimal formulation ratio were computed. Results The polynomial mathematical model was statistically significant (F＝20.76, P＜0.05), the total coefficient of determination (R2)＝0.9540; the model equation was: CTC＝-2.021 499X2＋222.543 940X－5951.467 969; the derivation of the curve revealed the best extreme value X＝55.04, with the corresponding maximum CTC of 173.42 and the optimal formulation ratio of 2∶1. Conclusion Upon dual verification using program calculations, the established screening method proved to be an accurate, reliable, rapid and user-friendly approach to screen for the optimal synergistic formula.

Objective The  optimal  dose?duration  relationship  of  a  broad?spectrum  fumigant?sulfuryl  fluoride, was analyzed in this study. Methods Each group of Blattella germanica was fumigated to reach static inhalation of the agent through the respiratory tract. Poisoning symptoms and death counts were observed, and a quadratic response surface regression model was established to fit and predict the experimental data, which were then verified under simulated scenes. Results The analysis of variance showed statistical significance of the response surface model (F＝75.12, P＜0.0001), the total coefficient of determination R²＝0.7848. The simple, quadratic and cross terms of the model were all statistically significant, their coefficients of determination being 0.1493, 0.1902 and 0.4453, respectively. The on?site simulation experiment demonstrated a 100% cockroach kill rate based on the dose and fumigation duration predicted by the model using sulfuryl fluoride. Conclusion The optimal dose?duration of sulfuryl fluoride fumigation for cockroach control was basically identified through this study, providing the basis for determination of proper dose and duration in the future container fumigation.

【Abstract】 Objective To explore risk factors associated with introduction of exotic medical vectors by international navigation ships. Methods A frequency?matched design of epidemiological study was applied in this study. A total of 170 vessels in which medical vectors were detected and 680 controls randomly selected among all of the vessels arriving at Ningbo port in 2007 were investigated, and vector risk factors were screen out by unconditioned logistic multivariate regression. Results Six risk factors included: gross tonnage (OR＝0.711, 95%CI:0.497-1.016), arriving season (OR sp vs.wi＝3.413, OR su vs.wi＝3.328), cargoes varieties (OR＝3.541, 95%CI:1.495-8.383), vector?positive records (OR＝31.213, 95%CI:8.250-118.093), nationality of crews (OR＝0.402, 95%CI:0.173-0.938), issuance date of Deratting exemption certificate (OR＝1.372, 95%CI:1.117-1.684). Conclusion Six risk factors were screened out by multivariate quantitative techniques, which would provide theoretic basis for the construction of Risk Assessment and Early Warning System.

【Abstract】 Objective To explore a new kind of technique and method for the monitoring of pathogens carried by rats. Methods According to the verification standard stipulated by sampler, use mathematic formula to count based on the statistics verification principle with the increase of surveillance samples. Draw the line of monitoring data on the graph. Distinguish quickly whether the carrying rate of pathogen exceeded the permission criteria or not, according to the relationship of monitoring line and up and down limitation.  Results Take the surveillance of Hantaan virus (HV) carried by rats as example, the guard-line of virus carried by rat was assumed to  be 30%. The virus carrying rate of rats was periodically monitored by sequential sampling method. If the monitoring line was above the up limitation, suggesting that the level of HV carried by about 95% rats reached or exceeded 30%. Conclusion The Sequential sampling method could make a relatively rapid and credible conclusion on the monitoring of pathogen carrier for its avoidance of blindness work and cost waste during the surveillance.

Objective To explore a new scientific method of medical-vector management, and grasp effectively the change of epidemic situation in time to provide a early warning. Methods The values of ,Rs,UWL,LWL,UCL,LCL were calculated by the method of quality control chart(QCC), and then X-R _s chart was drawn. Results According to the data in 2006, the analytical QCC was drawn to find that the interception rate of medical pest exceeded the UCL in June of 2006. After elimination abnormal points, it was found that the interception rate in April 2007 exceeded obviously standard value compared to that of January to May 2007 analyzed by the management QCC. It suggested that the CIQ Institution should enhance the inspection and quarantine to the disembarkation containers to prevent the introduction of vector. Conclusion The QCC can make precaution to epidemic situation captured from entry containers and help to CIQ Institution enhancing the inspection and quarantine to containers in the ports.

Objective To explore a standard method of integrated evaluation on the levels of medical-vector capture in entry-exit inspection and quarantine system.Methods The fundamental technique of order preference by similarity to ideal solution(TOPSIS) method was applied.Seven indexes including total vectors,messages and so on were treated by Grey methods and the optimal or tenth-rate projects were also defined.All objects were synthetically ranked by their distances to the optimal project.Results The ranks of the six objects as followed: Dept.A>Dept.B>Dept.E>Dept.C>Dept.D>Dept.F according to the integrated evaluation on the seven indexes.Conclusion TOPSIS method has the properties of veracity and practicability in the integrated evaluation on the levels of medical-vector capture in entry-exit inspection and quarantine system.And it is also a scientific and objective evaluating method.

Objective To study the relationship between proper dosage exposure time and deratting effect of sulfuryl fluoride in containers.Methods All groups of rats were fumigated using the method of static respiratory tract inhalation.Symptoms of intoxication and death conditions were recorded.The experimental data were simulated and predicted using response surface model and also verified by field studies.Results The response surface model was highly significant in statistics( P<0.0001),total R ² equaled to 0.884;All of the deratting rates attained 100% in field studies using the dosage and exposure time predicted according to the model mentioned above.Conclusion The relationship between dosage and exposure time of sulfuryl fluoride in deratting is determined,which offers a scientific proof for the fumigation later.

Objective The morbidity analysis and trend prediction of malaria in China using the Grey Model method.Methods The morbidities of all kinds of malaria were analyzed according to “National Data of Class A and B Infectious Diseases” during 1994 to 2001,and trends of morbidity in 2003 were predicted using the GM(1,1)method.Results The morbidities of all kinds of malaria declined continuously in the recent eight years.According to the prediction of the Grey Model,the morbidities of all kinds of malaria were predicted as 15.4,11.5,2.8,1.32 per 100 000 in 2003,respectively.Conclusion The morbidities of malaria in China have declined continuously in total,but its monitoring and prediction are still of sanitary importance as an important vector-borne disease hazardous to the health of citizens.