A total of 13 allozymes of 7 populations of Oncomelania snails trom 7 provinces in the mainland China were examined by horizontal starch gel electrophoresis. Results demonstrated that out of 17 loci examined, 10 were monomorphic loci: Aldh,Ao,G6pd ,Gpdh,Hbdh,Ldh, Sdh,Est-2,Est-3,and Est-6,and 7 were polymorphic loci:Est-4,Est-5,Xdh,Mdh,Idh,Got and Ap. Banding pattern showed that six enzymes were polymorphic accounting for 46.15 % (6/13) of total enzyme systems examined. Results indicated that a certain of relative relation-ship was existed along with the significant variation presented based on their environment and location among the 7 populations of snails from the mainland of China. It was revealed that the 7 polymorphic loci were the important loci affecting the gentic variation in the differ-ent populations of Oncomelania spp.

Schistosomiasis is a neglected tropical disease that severely threatens human health and affects the socioeconomic development. The causative agent that parasitizes in humans mainly involves Schistosoma japonicum,S. mansoni,S. haematobi-um,S. intercalatum and S. mekongi. As the firstly identified schistosome,S. haematobium infection is found to strongly correlate with bladder cancer. This paper mainly reviews the discovery,morphology and life cycle of S. haematobium.

The surveillance of schistosomiasis in Sanzhou Village, Dantu District, Zhenjiang City, a national schistosomiasis surveillance site, showed that in 2008, the area with snails was 27 hm~2, among which the area with infected snails was 14 hm~2, the densities of living snails and infected snails were 0. 86 and 0.002 1 snails/0. 1 m~2, respectively. The infection rate of snails was 0.25% , the positive rate of IHA was 3. 10% and the infection rate of schistosome in human populations was 1%. There were no infected domestic animals found, and there were no acute schistosomiasis and newly advanced schistosomiasis cases found in the surveillance site in 2008. It is indicated that the endemic situation of schistosomiasis is stable. The comprehensive control, including molluciciding and environmental modification, should be implemented for snail control. The comprehensive measures with emphasis on infectious source control should be further strengthened.

Objective To evaluate the outcomes of implementation of integrated schistosomiasis control strategy with empha? sis on infectious source control using a bibliometric method. Methods The literature pertaining to integrated schistosomiasis control strategy with emphasis on infectious source control was retrieved from CNKI,Wanfangdata,VIP,PubMed,Web of Sci? ence,BIOSIS and Google Scholar,and a bibliometric analysis of literature captured was performed. Results During the period from January 1,2004 through September 30,2014,a total of 94 publications regarding integrated schistosomiasis control strate? gy with emphasis on infectious source control were captured,including 78 Chinese articles(82.98%)and 16 English papers (17.02%). The Chinese literature was published in 21 national journals,and Chinese Journal of Schistosomiasis Control had the largest number of publications,consisting of 37.23% of total publications;16 English papers were published in 12 interna? tional journals,and PLoS Neglected Tropical Diseases had the largest number of publications(3 publications). There were 37 affiliations publishing these 94 articles,and National Institute of Parasitic Diseases,Chinese Center for Disease Control and Pre? vention(16 publications),Anhui Institute of Schistosomiasis Control(12 publications)and Hunan Institute of Schistosomiasis Control(9 publications)ranked top three affiliations in number of publications. A total of 157 persons were co?authored in these 94 publications,and Wang,Zhou and Zhang ranked top 3 authors in number of publications. Conclusion The integrated schistosomiasis control strategy with emphasis on infectious source control has been widely implemented in China,and the achievements obtained from the implementation of this strategy should be summarized and transmitted internationally.

Oncomelania hupensis is the only intermediate host of Schistosoma japonicum. The elimination of Oncomelania snails is the key technique step for schistosomiasis control. This paper summarizes the progress of the techniques of snail control，including the methods of ecology engineering，biology，molluscicides and the study on novel molluscicides，and reviews their features. In addition，this paper explores the appropriate approach to control the snails.

Objective To understand the distribution,variance and dynamics of Oncomelania snails in the water system of the Bianmin River after the river bank being protected with concrete.Methods The snails in the water system of the Bianmin River were investigated with the systemic sampling method and environmental spot-checking method in spring from 2002 to 2005.The indexes including area with snails,area with infected snails,rate of frames with snails,density of living snails and infection rate of snails in different environments were collected,analyzed and compared year by year.Results From 2002 to 2005,in the main river of the water system of the Bianmin River,irrigation areas and the adjacent marshlands of the Yangtze River,the areas with snails were 20.94-31.88,39.30-48.08 hm2 and 275.13-292.31 hm2,respectively;the rates of frames with snails were 9.96%-21.88%,29.61%-58.54% and 62.14%-85.97%,respectively;the mean densities of snails were 0.97-1.86,0.92-3.96 snails/0.1 m2 and 7.72-11.15 snails/0.1 m2.In 2005,in the main river,irrigation areas and the adjacent marshlands,the rates of frames with snails were 21.88%,39.33% and 83.81%,respectively;the densities of living snails were 1.30,3.96 snails/0.1 m2 and 11.15 snails/0.1 m2.During the last four years,the rates of frames with snails increased quickly in the main river of the water system of the Bianmin River;the densities of snails increased by 4 times in the irrigation areas;the indexes mentioned above were stable in the adjacent marshlands of the Yangtze River.However,the rate of frames with snails in the marshlands was 2-3 times higher than that in the irrigation areas and the mean density of snails in the marshlands was 3-8 times higher than that in the irrigation areas.Conclusions The main factor causing the increase of snails is that the river beach has not been cleaned yet in the water system of the Bianmin River,and so the key of schistosomiasis control is that first,the river beach should be cleaned completely,and at the same time,strengthening the snail control in the irrigation areas and the snail surveillance and snail control with molluscicides in the outfalls of the rivers of the water system of the Bianmin River to the Yangtze River.

Objective To evaluate the mid-term effectiveness of the medium-and-long-term programme of the prevention and control of schistosomiasis in Jiangsu Province. Methods The programme was carried out in Jiangsu Province and the comprehensive measures relied mainly on snail control, detection and chemotherapy of schistosomiasis for residents and livestock. The mid-term effectiveness of the programme was observed and evaluated longitudinally. Results The coverage rate of snail control areas and the ratio of chemotherapy of schistosomiasis for residents and livestock rose year after year. The snail areas, the infected snail areas and the infection rate of schistosome for residents and livestock reduced year after year. There were negative correlations between the coverage rates of snail control and the infected snail areas, the number of settings with infected snails, the infection rate of schistosome for residents, the infection rate of schistosome for livestock and the morbidity of acute schistosomiasis, respectively (rInfected snail areas=-0.897,P=0.039;rNo. of settings with infected snail=-0.937,P=0.019;rInfection rate for residents=-0.913,P=0.031;rInfection rate for livestock=-0.991,P=0.001;rMorbidity of acute schistosomiasis=-0.894,P=0.041). There were negative correlations between the ratio of chemotherapy of schistosomiasis for residents and the infected snail areas, and between the ratio of chemotherapy of schistosomiasis for livestock and the infected snail areas (rRatio of chemotherapy for residents =-0.965,P=0.008;rRatio of chemotherapy for livestock=-0.921,P=0.027). There were negative correlations between the funds of schistosomiasis control and the infection rate of schistosome for residents livestock, respectively (rInfection rate for residents=-0.897,P=0.039;rInfection rate for livestock=-0.971,P=0.006). The multiple linear regression analysis showed that there were the linearity relationships between the infection rate of schistosome for residents and the coverage rates of snail control, and between the infection rate of schistosome for livestock and the coverage rates of snail control, and between the morbidity of acute schistosomiasis and the coverage rates of snail control. Conclusions The effect of the comprehensive strategy of schistosomiasis control which relies mainly on snail control, detection and chemotherapy of schistosomiasis for residents and livestock are remarkable. The snail control and chemotherapy are effective and immediate. The increased funds would be essential guarantee for control and elimination of schistosomiasis.

0.05). There were significant differences among 3- or 6- or 9- or 12-hour groups and 24- or 36-hour groups in 6, 13 ℃ and 28 ℃ respectively (P

Objective To understand the effect of Schistosoma japonicum infection on Oncomelania hupensis. Methods Uninfected Oncomelania snails were collected from the marshland of the Yangtze River in Anhui Province and exposed to and infected with miracidia of S.japonicum in the laboratory. After the exposure, those snails and unexposed snails as the control were raised in the natural environment of the same field and all the snails were observed and recorded every 10 days. The survival rate and death rate were calculated, and expected survival time was also calculated with the animal life table method. Results The peak of death of the infected snails was between 60 and 70 days after the exposure, and the expected survival time was 63.46 days and the longest survival time was 135 days. The peak of death of the unexposed snails was between 80 and 90 days, and the expected survival time was 83.54 days and the longest survival time was 155 days. The expected survival time of the infected snails was 24.04% shorter compared with that of the uninfected. Conclusion The death rate of snails infected with S.japonicum increases and the survival time decreases in the natural environment.

Objective To explore the rela ti onship between the environmental temperature and the oxygen demand of [WT5” BX]Oncomelania snails, and the relationship between the hiber nation or aestivation and the oxygen demand of snails.Me thods The oxygen demand of Oncomelaniasnails between 0 ℃ and 40 ℃ was determined by increasing the temperature gradually in lab, the relationship between the environmental tempera ture and the oxygen demand, and the correlative relationship between the oxygen demand and the percentage of snails in hibernation or aestivation were analysed. Results The oxygen demand increased as the tem perature rose between 1 ℃ and 36 ℃, and the regression equation between the oxygen demand and the variation of environmental temperature was [WT5”BX ]=6.6?10 -5-3?10 -6x+4.4?10 -6x2-8?10 -8x 3(R2=0.998,F=2775,P