【Abstract】 Objective To develop a system of stepwise response for risk categories for dengue fever in China. Methods According to ecological features of Aedes albopictus, establish the method of mosquito and oviposition trap and compare the relationship of the mosquito and oviposition positive index （MOI） and the Breteau index （BI） or the Ovitrap index obtained from the traditional dengue fever vectors surveillance. Develop an epidemic forecast and phased response system for dengue fever control and prevention with reference to other correlative grade control system for dengue or other vector?borne disease, combined with the actual application of mosquito and oviposition trap in the vector surveillance. Results The MOI could be classified into 4 levels, below 5, 5-20, 20-40, and ＞40 respectively. Stepwise response for risk categories for dengue fever were divided into 4 levels according to the levels of MOI, seasonal character, virus infection rates in mosquitoes and the result of human cases surveillance. Conclusion The MOI is less than 5, which suggestes the control of dengue fever is very effective. However, the risk categories and its response index still need further study and verify in the practical application.

Objective To investigate the breeding characteristics of Aedes albopictus in urbanization residential area,which should provide the basis for the control of Ae.albopictus. Methods The study was carried out in the village of Jieyang city and high-urbanization downtown of Foshan from March 2004 to November 2005. Water containers were detected in and around one household which was randomly selected every 5 households. The data were analyzed by software SPSS 11.0. Results Of 5635 possible breeding sites in 7470 houses investigated, 502(6.72%) were positive. In the village of Jieyang,the major breeding containers included unused container (jars, bottles and tins, etc.) and water reservoir receptacles with the positive constitute ratio of 64.98% and 18.77% respectively. The positive constitute ratio of unused containers reached the maximum in September every year. But in residential area of Foshan city, the major breeding containers were made up of water vases in which the flowers and plants grow and unused containera, and the positive constitute ratio of them were 45.52% and 33.79% respectively. The positive constitute ratio of unused containers was in the peak from July to September, and that in miniascape and water plant was the highest in 2004 and May 2005 with the value of 75.00%. But the result was zero after May 2005. Conclusion There were different among the breeding sites in different residential area, which varied with season. The breeding containers in increasing urbanization cities were mainly miniascape, water plant and unused containers, but in low urbanization village, the breeding sites were mainly the unused containers and water reservoir receptacle.

Objective To study the sensitive of TaqMan MGB Real-time polymerase chain reaction(PCR) and nested RT-PCR on detecting Dengue virus(DV) from Aedes albopictus and establish a sensitive, specific, and repetitive method for DV diagnosis. Methods Females adults were artificially infected with Den-2 in lab, different infected mosquito concentration (mosquitos/1000 μl) and 50 mosquitos/pool were designed and processed for virus detection by TaqMan MGB Real-time PCR and nested RT-PCR. Fluorescence signal and electrophoresis showed the results. Results For all pool, the lightest concentration that can be detected was 3 mosquitos/1000 μl for two-step TaqMan MGB Real-time PCR, and 5 mosquitos/1000 μl for one-step TaqMan MGB Real-time PCR and nested RT-PCR. Conclusion Two-step TaqMan MGB is more sensitive, specific, scientific and rapid to detect DV than nested RT-PCR, and is a good surveillance method for DV in A.albopictus.

Objective In order to test the efficacy of four kinds of mosquito coils in the field,and to investigate the efficacy tests and evaluation methods for different kinds of mosquito coils.Methods Compare with density reduction by the bite counts based on pre-and post-treatment using human-leg catch technique.Results The main species which was caught in the trial field was Culex pipiens quinquefasciatus and decreased the peak of bites period was from 22:00 to 23:00 in the evening.Coil A and D caused 88.2%,90.5% population,respectively.However,coil B and C led 72.5%,78.1% population reduction,respectively.Conclusion The tests suggested that four coils had a good effect on prevention from the bites of the mosquito,yet,the insecticide efficacies of coil A and D are better than that of coil B and C.Discussion: Pre-trial is very essential for the efficacy tests in the field trial.Simulating field test for indoor insecticidal efficacy should be adopted to correct or reduce the experiment error.

Objective To study the bite rate,epidemiological a village,named T,in Guangdong province distribution,clinical symptoms of the villagers bitten by the red imported fire ants (RIFA) and the environment of to provide evidence for disease control and prevention. Methods Using random sampling method to spot-check households in the village and interview with questionnaires to profile the epidemiological characteristics,clinical manifestations and the treatment of the T villagers bitten by the RIFA. Results During the period of January 1 to June 28,2006,among 60 households surveyed,45 households were bitten by the RIFA. The household bite rate was 75.0%. In the total of 241 people questioned,72 people had been bitten by the RIFA. The bite rate of population was 29.9%(72/241). Among those afflicted people,there was no significant difference between male and female; for villagers more than 40 years old,the bite rate was higher than 50%. In the extremely hot June,the number of villagers bitten by RIFA drastically increased. Workers at farm and/or afforesting belts were much more likely to be bitten by RIFA. The bite rates in farmers and afforesting workers were 42.3% and 28.3% respectively. The proportion of bitten feet was the highest as 65.0%,the next was the hand; The clinical manifestation were mainly including itch- pain(100%),blushes(45.8%),skin rash(78.6%),papule(54.2%),water(pus) blister(33.3%),fever rarely(1.4%) and dizziness(1.4%) and so on 98.6% patients of which were treated by themselves. The nest of RIFA scattered in the village. Conclusion The villagers bitten by RIFA is common in the village in the recent years but with less severe clinical manifestations. We should enhance the health education for the farmer and afforesting workers,and enhance to control RIFA by the scienific ways.

Objective To compare the results and understand relationship between the mosq-ovitrap method and larval survey for detecting the presence of ; Aedes mosquitoes in the field. Methods The study was carried out in the cities of Foshan and Jieyang,Guangdong province,from March 2004 to November 2005. A mosq-ovitrap was set every 5 random households and their premises,or set every 25-50 meters in a hidden and shady place in the surroundings of hospitals,schools,government office buildings,factories and gardens. Larval surveys and mosq-ovitrap method were used simultaneously in the households or in the areas of 5 meters around the trap set in the surroundings. Results In households,hospitals,schools,government office buildings,factories and gardens,14 902 mosq-ovitraps were simultaneously set and 14 648 were collected back. The positive traps for adult mosquitoes was 932. The mosquito and oviposition positive index(MOI) and mosquito-trap density index(MDI) were 6.36 and 1.03± 0.89 respectively. Total 962 Aedes albopictus(99.5)and 5 Culex(0.5) were collected. The maximum of the mosquito adults captured in a single trap was 10. At the same time,8537 water containers in 14 902 households or premises (5 meters in circumference of the mosq-ovitrap) were checked,of which 844 contained the Aedes albopictus larvae. The Breteau Index,House Index and Container Index were 5.66 ,3.87 and 9.89 respectively. The MOI was 1.12 times of the Breteau Index,or 1.64 times of the House Index,or 0.64 times of the Container Index. Conclusion There is a positive relationship between the MOI and the Breteau Index,and the House Index,the container Index respectively. The MOI is particularly approximate to the Breteau Index.

Objective To compare the results between the mosq-ovitrap and the Ovitrap in the field. Methods The trial was carried out in a campus in Guangzhou from August to November 2004,and from February to August 2005. One mosq-ovitraps and one ovitraps at intervals of 1 m were set every 50 m at hidden and shady spot and the positions of two kinds traps were alternated each month. Mosquitoes captured and the egg positive traps were counted and recorded on the 4 ^th day and the 7 ^th day since the installation. Results On the 4 ^th day since installation,the positive indices of mosq-ovitrap and ovitrap were 35.5 and 56.7 respectively; and at 7 ^th days,the positive indices were 53.3 and 71.5 respectively. In total,the oviposition index(OI) of the ovitraps at 7 ^th days was nearly 2 times of the mosquito and oviposition positive index(MOI) of mosq-ovitraps installed for 4 days. 284( 99.3 ) Aedes albopictus,and 2 Culex quinquefasciatus were captured in the 662 mosq-ovitraps installed for 4 days . The mosquito(Aedes)-trap density index(MDI) was 1.21± 1.12 ,the number of caught mosquitoes ranged from 0 to 8 in all the mosq-ovitraps. The results of the surveillance in each month indicated that there was positive correlation between the MOIs of the mosq-ovitraps set for 4 days and the OIs of the ovitraps set for 7 days ( r=0.838 , P=0.001, y=25.548+1.312 x). Conclusion When the mosq-ovitraps were applied for 4 days,the MOI could reflect the population seasonal dynamic of mosquito. There was positive correlation between the MOIs of the mosq-ovitraps and the OIs of the ovitraps.

Objective To study the resistance development of anticoagulant rodenticide in commensal rodents. Methods Tests was carried out without selectivity by rodents based on the method of National Rodenticide Resistance Monitoring Co-worker Group. Results 769 Rattus flavipectus and 303 Rattus norvegicus were caught in five cities of Guangdong were tested. The resistance rate differs from 1.69 to 12.21 the average dosage taken differs from 10.36 mg/kg to 131.96 mg/kg . The result showed that Rattus flavipectus and Rattus norvegicus had become individual resistance to the resistance rodenticide Ⅰ. Conclusion The anticoagulant rodenticide Ⅱ should be used in the areas gathered with Rattus flavipectus. The anticoagulant rodenticide Ⅰ can be still used but should be used scientifically and properly with careful tests of sensitivity.

Objective To study the sensitivity of TaqMan MGB Real-time Polymerase Chain Reaction (PCR) on detecting Dengue virus (DV) from Aedes albopictus and to develop a sensitive,specific,and repetitive assay method for DV diagnosis. Methods Females A.albopictus were artificially infected with Den-2 in lab,different concentration for infecting mosquito (mosquitos/ 500 μl or mosquitoes/ 1 000 μl) and different pools (0,10,25,50 females of lab A.albopictus without DV were added to each treatment) were designed to process of virus detection by one-step and two-step TaqMan MGB Real-time PCR. Fluorescent signal was observed to show the results. Results For all pools,the minimal concentration which could be detected was 2 mosquitoes/ 500 μl and 3 mosquitoes/ 1 000 μl for two-step TaqMan MGB Real-time PCR,but 5 mosquitoes/ 500 μl for one-step TaqMan MGB Real-time PCR. There was no evident effect on the detection of DV RNA by the RNA of A.albopictus. Conclusion TaqMan MGB is sensitive and specific to detect DV,and is a perfect surveillance method for DV index of A.albopictus. It is better for 20-30 mosquitoes/pool and 500 μl dilution/pool by two-step TaqMan MGB Real-time PCR.

Objective To study the morbidity rate,epidemical distribution,clinical symptoms and treatment of the cases bitten by red imported fire ants(RIFA),and to provide the scientific evidence for disease control and prevention.Methods(All the) peasant bitten by RIFA in Z village were screened and investigated to collect their epidemiological characters,clinical symptoms and treatments.Results Each family in the village had one or more members bitten by RIFA.The accumulative morbidity rate was(93.8%)((289/)308).The first suspect case bitten by RIFA occurred in 1999,and cases had been increasing year by year since then.Among the persons who were bitten by RIFA,there was no significant difference between male and female and among the persons from different ages.(78.5%) peasants were bitten in the field while cultivating,in which(81.7%) were bitten on four limbs.The clinic symptoms were mainly including itch-pain(100%),ruddy((99.2%)),blain((98.8%)),pimple((59.0%)),and severe symptoms such as systemic hypersusceptibility((0.8%)) and shock((0.8%)) rarely occurred.(85.3%) patients treated themselves,and no one died of the bite of RIFA.Anti-inflammation and anti-hypersusceptibility drugs had a good effectiveness.Conclusion Peasants are bitten by RIFA quite widely,but the clinic symptoms are mainly represented in localized part and patients have good prognoses.

Objective To learn the morphological characteristics of red fire ant in Wuchuan,Guangdong and compare the characteristics with those in other countries. Methods Both field survey and lab investigation were used to study the stages of the red fire ant and nest figure. Results The morphological characteristics of egg,larva,pupa and adult of the ant were given. Diagnostic characterisitics of adult were described. A mature nest is alveolate,and form big mound with (26.00±7.42) cm high,and (82.00±41.04) cm diameter on average of thirty random samples. which size far excess of other ants'. Conclusion There are many same morphological characteristics between red fire ant in Wuchuan,Guangdong and introduced Solenopsis invicta.

Objective To establish the system of surveillance and forecast for dengue fever,a sensitive,effective,and feasible appliance was developed for the monitoring of dengue fever vector, Aedes albopictusin field.Methods According to the ecological characters of, Aedes albopictus,and the structure of CDC(USA) ovitrap and housefly trap,we invented a Mosqovitrap in which the mosquito would be attracted to oviposit,and would be caught. The attractive effect was tested in laboratory and in field.Results In laboratory both the positive mosquito and oviposition indexes of new Mosqovitrap were 100 and the average adults and eggs were 12.25 and 1 369.2 in one trap,while in the dweller environment,the indexes were 26.2 and 27.1 respectively,and they were higher than the container index and similar to the Bretaeu index. The positive oviposition index was 18.6 in field. Conclusion As an appliance for monitoring vector of dengue fever,the new Mosq ovitrap had a high attractive effect for Aedes albopictus.

Objective To explore the dosage of beta cypermethrin against Aedes albopictus by ultra low volume(ULV) spraying in Guangzhou City.Methods Adult mortality of Aedes albopictus,sensitive and field population collected from Guangzhou,was observed after ground ULV exposured to beta cypermethrin in laboratory and in field.Results The beta cypermethrin was applied at 0.5 ai·mg/m ² in the field resulted in 100% control of the field population 5 m from the point of application,control decreased to 96.0% at 10 m,and to 75% at 15 m.Conclusion The study showed that Aedes albopictus collected in Guangzhou was controlled by ground ULV exposured to beta cypermethrin at the dosage of 0.5 ai·mg/m ².

Objective:To evaluate the high activity poison bait against resistant German Cockroach.Method:Spraying.Baiting.Result:The density of German Cockroach decreased 96.1% after a day on the field treated with the poison bait at the dosage of 1-2 g/m ²,and decreased 97.4% after 8 weeks.But the density of German cockroach decreased 30.3% after one day treated with the deltamethrin suspension at the dosage of 40 mg a.i./m ²,and became no efficacy after 6 weeks,after 8 weeks on the same place treated with the poison bait the density decreased 95.1% for one day.Conclusion:The experiment result show that the poison bait have high and quick and persistent activity against the high resistan strains of Germant cockroach.It is harmless to mankind,and easy to use.