Objective To evaluate the toxic effect of Bacillus thuringiensis var. israelensis(Bti)wettable powder against Ae-des,Culex and Anopheles larvae. Methods The biological assay was applied to test the lethal concentration of 50%(LC50)of Bti wettable powder against Aedes,Culex and Anopheles larvae. Results The LC50(s) of Bti wettable powder against Aedes albopictus, Culex pipiens pallens and Anopheles sinensis larvae were 0.104,0.160μg/ml and 0.324μg/ml,respectively;its biological poten-cies against them were 0.125,0.192 IU/ml and 0.389 IU/ml,respectively. The LC50(s) of continuous contact of Bti wettable powder with An. sinensis stageⅢlarvae for 1,2 d and 3 d were 0.324,0.092μg/ml and 0.032μg/ml,respectively,and its biological po-tencies were 0.389,0.110 IU/ml and 0.038 IU/ml,respectively. The LC50(s) of the bacteria against An. sinensis stageⅠ,Ⅱ,Ⅲ,Ⅳwere 0.024,0.137,0.324 μg/ml and 0.450 μg/ml,respectively,and the biological potencies were 0.029,0.164,0.389 IU/ml and 0.540 IU/ml,respectively. Conclusion Bti wettable powder has a good toxicity to Aedes,Culex and Anopheles larvae,espe-cially for the latter two. It is better to apply the bacteria at the early stage of mosquito larvae.

Objective To explore the effect of different temperatures on the different development stages of Aedes albopic?tus. Methods The changes at different development stages of mosquitoes(egg,larva,pupae)and gonotrophic cycle were ob?served at different temperature conditions of 10,15,20,25,30,35℃and 40℃. The full developmental cycles were com?pared during different temperatures. Results All the stages of the mosquitoes could not develop at 10℃. Under the different temperatures of 15,20,25,30,35℃and 40℃,the hatchabilities of the mosquitoes were 0,32%,82%,83%,82%and 59%respectively;the pupation rates of the mosquitoes were 38%,53%,84%,88%,72%and 42%respectively;and the emer?gence rates of the mosquitoes were 92% 95% 97% 97% 83%and 17%respectively. The mosquitoes could well develop at 20 25 30℃and 35℃ the development time was 37.73 18.50 16.92 and 13.66 days respectively. Conclusion The devel?opment time of Aedes albopictus is shorter at the higher temperature. The optimum temperature for the mosquitoes to develop is between 25-30℃ and higher or lower the temperatures will suppress the development of the mosquitoes.

ObjectiveTo observe the effectiveness of Responsar against Anopheles sinensis and Anopheles anthropophagus. MethodsThe cotton and nylon gauze absorbing Responsar solutions of 10,15 and 20 mg/m~2 (effective dosage) were used in the test. An. sinensis and An. anthropophagus raised in the lab were used as probational worms, having the knockdown power, lethiferous power and effective keeping observation. ResultsWith Responsar of 10,15 and 20 (mg/m~2) impregnating two different kinds of bednets, the KT_(50(s)) of An. sinensis and An. anthropophagus were between 3.98 and 7.30 min after touching the bednets. The knocked down mosquitoes were resumed breeding for 24 h, and the mortality was 100%. Touching nets 3 min, resuming breeding for 24 h, the mortality of mosquitoes was more than 90%. The nets hung for 180 d after impregnated with the insecticide and the knockdown power was still between 8.57 and 16.31 min for Anopheles vector, and resuming breeding for 24 h, the mortality was still 100%. ConclusionThere is strong deadly effect of Responsar to Anopheles sinensis and Anopheles anthropophagus, and the effect can keep more than 180 d.

Objective To analyse the epidemic characteristics and control measures of malaria in Jiangsu Province during the past fifty years, evaluate the control effect and explore the current appropriate control strategy and measures. Methods The historical data about malaria cases and control measures from 1951 to 2008 in Jiangsu Province were collected, and the effects of malaria control in different stages were assessed. Results The integrated control measures with emphasis on the control of infectious source were adopted during the stage of two outbreaks of malaria. In the stage of basical elimination of malaria, the comprehensive measures with emphasis on the vector control in the areas of Anopheles anthropophagus were adopted, and the measures with emphasis on the surveillance of infectious source surveillance and early treatment of malaria in other areas were adopted. In the stage of consolidation, the measures including the surveillance of infectious source and management, surveillance of vector and epidemic situation, management of floating population, etc, were adopted. The malaria incidence dropped from 2 495/10 000 in 1960 to 0.09/10 000 in 2008, and was under 1/10 000 in all the counties of Jiangsu Province during the past 2 years, which demonstrated the various measures were feasible and effective in different stages of malaria. Conclusions Malaria has been controlled effectively in Jiangsu Province, however, the improvement of early diagnosis and norm treatment of malaria cases, the enhancement of health education and promotion, as well as the malaria surveillance and management among floating population, are still necessary for achieving the goal of malaria elimination.

Objective To observe the residual effect of Demand CS - impregnated bednets to Anopheles sinensis.Methods The numbers of adult mosquitoes which were knocked down at every minute after treatment were observed by using the enforced contact method recommended by WHO,and the mortality of mosquitoes tested after 24 h was calculated.Results The Kt_(50) of Demand CS - impregnated bednets with impregnations concentrations of 10,15,20 mg/m~2 to Anopheles sineasis were 21.40,16.20,15.70 min,respectively,and the 24 h mortality was 100%.The Kt_(50) of Responsar SC (12.5 % Beta - cyfluthrin) impregnated bednets with a impregnation concentration of 15 mg/m~2 to Anopheles sinensis was 16.06 min,and the 24 h mortality was 100%,too.Conclusions Both the Demand CS - impregnated bednets and the Responsar SC impregnated bednets can kill Anopheles sinensis.

Objective To analyze the genetic characteristics of deltamethrin resistant strain of Anopheles anthropophagus. Methods The study was performed with LC-P curve method for the genetic mode of deltamethrin resistant of An. anthropophagus. Results The resistant coefficient of F_1 generation from cross and reciprocal cross were 15.19 and 16. 66 respectively. The LC-P curve of F_1 generation got near to that of resistant parents (D=0.651). There were no obvious platforms in 50% mortality of BC generation and 25% - 75% mortality of F_2 generation.There were significant differences between the determining curve and theoretical cure in both BC and F_2 generations, P

Objective To analyze the channels of going abroad of imported malaria patients in Jiangsu Province,so as to provide the evidence for the control of imported malaria and health intervention for high?risk population. Methods The data of imported malaria cases in Jiangsu Province in 2015 were collected and the channels of going abroad were analyzed. The Quan?tum GIS 1.7.4 software was applied to map. Results Totally 405 imported cases were reported in Jiangsu Province in 2015, and the cases increased by 14.1%compared with those in 2014. All the patients were migrant workers. The migrant workers were mostly sent abroad by construction companies[43.21%(175/405)]. The dispatching companies were mainly concentrated in Taizhou,Lianyungang,Zhenjiang and Yangzhou cities,accounting for 6.17%(25/405),3.21%(13/405),2.72%(11/405) and 2.22%(9/405),respectively. Totally 176(43.46%)patients returned to China having accompanied workers,and 1.21%(9/745)of accompanied workers were found having symptoms of malaria later. Conclusions It is difficult to monitor malaria in overseas migrant works in Jiangsu Province. The channels of going abroad of migrant workers are various and complicated ,for?mulating the main difficulty and challenge of imported malaria control.

Objective To understand the resistance of Anopheles vectors to pyrethroid after several years mosquito control with the impregnated bed net method. Methods The resistant level was measured by the tentative diagnostic dose and degree method of China combined with the standard methods of WHO. Results In the area after more than 5 years mosquito control with the impregnated bed net method, An.sinensis had initial resistance to deltamethrin and permethrin. However, An.anthropophagus did not be captured. In the area after less than 5 years mosquito control with the impregnated bed net method, both An. sinensis and An.anthropophagus were susceptive to deltamethrin and permethrin. Conclusion In this research, no resistance of An.anthropophagus to deltamethrin and permethrin has been found. An.sinensis has initial resistance to them. So we must pay more attention to monitor the resistance in future malaria control programs.

Objective To discuss the malaria control strategy and its effects in different stages during past 30 years, and search anti-malaria measures fit for the current situation. Methods The historical anti-malaria and epidemical data in Jiangsu Province during the past 30 years were collected and analyzed. Results 6216128 malaria cases were reported in the province in 1973, and the incidence was 1136.34/10000. Through the five anti-malaria stages in past 30 years, the epidemic has been effectively controlled gradually. Six hundred and thirty-eight malaria cases were reported in the province in 2003, and no individual locally infected with P.falciparum was found for 16 successive years. Conclusion The anti-malaria strategy of the five stages is basically suitable for the actual situation of malaria control in Jiangsu Province.

Objective To investigate the real incidence of malaria in Sihong County located in the north of Jiangsu Province and estimate the epidemic actuality in this area. Methods By using the capture-recapture method (CRM), the patients and incidence of malaria were estimated in Sihong. Results In 9 villages of 3 townships, 4896 residents among 1248 families were investigated and 56 cases of malaria found (65 cases reported before) in 2002.There were 121 cases calculated by using CRM and the theoretic cases were 1.86 times of those which had been reported. Conclusion The data of blood-examination collected from the county and towns are obviously different. It indicates that there are potential troubles in the routine blood examination to the fevered patients in this county. The incidence of a certain town is still above 0.2%. The epidemic actuality of malaria is still serious in this county.[