2010

Authors

  • Don McManus Don McManus
  • Darren Gray Darren Gray
  • Yuesheng Li Yuesheng Li
  • Zheng Feng Zheng Feng
  • Gail M. Williams Gail M. Williams
  • Donald Stewart Donald Stewart
  • Jose Rey-Ladino Jose Rey-Ladino
  • Allen Ross Allen Ross

Summary: The potential impact of the Three Gorges Dam (TGD) on schistosomiasis transmission in Chi has invoked considerable global concern. The TGD will result in changes in the water level and silt deposition downstream, favoring the reproduction of Oncomelania sils. Combined with blockages of the Yangtze River's tributaries, these changes will increase the schistosomiasis transmission season within the marshlands along the middle and lower reaches of the Yangtze River. The changing schistosome transmission dymics necessitate a comprehensive strategy to control schistosomiasis. This review discusses aspects of the epidemiology and transmission of Schistosoma japonicum in Chi and considers the pathology, clinical outcomes, diagnosis, treatment, immunobiology, and genetics of schistosomiasis japonica together with an overview of current progress in vaccine development, all of which will have an impact on future control efforts. The use of synchronous praziquantel (PZQ) chemotherapy for humans and domestic animals is only temporarily effective, as schistosome reinfection occurs rapidly. Drug delivery requires a substantial infrastructure to regularly cover all parts of an area of endemicity. This makes chemotherapy expensive and, as compliance is often low, a less than satisfactory control option. There is increasing disquiet about the possibility that PZQ-resistant schistosomes will develop. Consequently, as mathematical modeling predicts, vaccine strategies represent an essential component in the future control of schistosomiasis in Chi. With the inclusion of focal mollusciciding, improvements in sanitation, and health education into the control scerio, Chi's target of reducing the level of schistosome infection to less than 1% by 2015 may be achievable.