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 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.

Objective To explore the spatial distribution of schistosomiasis cases and Oncomelania snails in the provinces of Jiangsu, Anhui and Jiangxi with the assistance of geographic information systems (GIS). Methods Epidemiological data of schistosomiasis in recent 20 years were collected, and the relevant GIS databases were established. The spatial autocorrelation analysis was carried out with ArcView 3\^x, S\|Plus, and Spatial Statistics software. Results Except for schistosomiasis cases in Jiangsu, the spatial distribution of schistosomiasis cases and Oncomelania snails in the three provinces were fitted to the spatial autocorrelation at a certain degree. Generally the autocorrelation coefficients (Moran′s I) in Oncomelania snails were higher than that in schistosomiasis cases. Conclusion Spatial autocorrelation analysis can be used to estimate the value of one variable in different spatial position, and it is a good way to find out the spatial cluster distribution in different stages.

Objective To observe hibernation phenomena of Oncomelanai hupensis and explore the way of inducing the hibernation in laboratory. \ Methods\ Snails, O\^hupensis hupensis, were collected from marshland of Jiangsu. The snail hibernation was induced by the way of cultivation at a mimic natural environment in the laboratory with gradually changing temperature. The amount of oxygen consumed by snails was tested by iodine titration, and their hibernation was tested by pin puncture followed by warm water. \ Results \ There was no significant difference on the rate of snail \{hibernation\} when the temperature was reduced by 1 ℃ per 24 hrs and by 1 ℃ per 48 hrs. The hibernation rate \{increased\} with the decreasing temperature. There was a significant regression relationship between hibernation rate and temperature with R\+2=0\^967 (F=207\^72, P

Objective To study the expression of nitric oxide synthase (NOS)mRNA in the gonad of Oncamelania hu-pensis in different temperature. Methods The snails were cultured at temperature of 0℃ , 15 ℃and 25℃for 1 month. The total RNA of each group was extracted with the RNA extraction kit. A pair of degenerate primers was designed from conserved regions of mammalian NOSs, and the expression of NOS mRNA in the gonad was measured by means of reverse transcription polymerase chain reaction (RT-PCR). Results The target genes of NOS were detected in the gonad of snails. The level of expression of snail NOS mRNA in 25℃ group and 0℃group was significantly higher than that in the control group( P 0.05). Conclusion The designation of primers of the snails was validated. The impact of temperature on the expression of snail NOS mRNA was determined, which suggested that NO plays an important role in the physiological and pathological modulation.

Objective To study the impact of environmental temperature on the development of Schistosoma japonicum larvae within the Oncomelania hupensis. Methods Oncomelania snails, collected from the field and free of S. japonicum infection, were exposed to miracidiae of S. japonicum in a ratio of 1∶20 and raised at 30 ℃, 27 ℃, 24 ℃, 21 ℃ and 18 ℃, respectively. The prepatent period of larvae within the Oncomelania hupensis and the developmental velocity were determined, of which the relationship with the temperature was analysed. Results The average prepatent period of cercariae in snail was (128.89?16.05) d,(95.00?21.03) d,(71.93?12.74) d and (62.74?14.19) d at 21 ℃, 24 ℃, 27 ℃, 30 ℃, respectively. The regression formulation between prepatent period and temperature was y =730.68x -0.8918 (r=0.9976, P