title: [Dynamics and diffusion of Oncomelania snails in Danyang City, Jiangsu Province].
abstract: OBJECTIVE
  To understand the dynamics and the diffusion trend of Oncomelania snails in Danyang City, Jiangsu Province, so as to explore effective control measures.
  
  
  METHODS
  The data of historical records and routine surveillance of snails were collected and analyzed according to the river systems.
  
  
  RESULTS
  The snails were imported from external river systems and spread from the rivers to inland. The diffusion trend was from the upstream to downstream and from the rivers to irrigation canals.
  
  
  CONCLUSIONS
  The inland rivers connecting with the Yangtze River are the main routes where marshland snails can spread from outside to the inland. The irrigation system plays an important role in snail spreading to the irrigation areas. The regular surveillance in combination with the basic construction of farmland and irrigation system is needed to prevent the spread of the snails and the retransmission of schistosomiasis japonica in Danyang.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Zhu
authors.forename: Nong
authors.initials: N
authors.lastname: Chao
authors.forename: Xiao-Zhong
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Wang
mesh_terms: D000818:Animals; D011157:Population Dynamics; D045483:Rivers; D012908:Snails / Q000254:growth & development*