Objective: To predict the intensity and scale of impact on transmission of schistosomiasis japonica in China caused by the climate warming.
Methods: By using climate data from 193 weather stations in China from 1951 to 2000, the GIS database was created to analyze the tendency of average daily temperature. By using the results from the effective accumulated temperature models on Oncomelania snails and Schistosoma japonicum, the climate-transmission model for schistosomiasis was established at country level, by which the spatio-temporal analysis was performed to create the distribution maps of Oncomelania snails and Schistosoma japonicum, respectively, by means of GIS approaches based on the ratio of effective accumulated temperature to the snail or the parasite development temperature (ET/SDT) in all 193 stations. The potential distribution maps with the dispersal risk areas of schistosomiasis japonica in 2030 and 2050 were created based on forecast data that the average temperature of the country will increase by 1.7 degrees C in 2030 and by 2.2 degrees C in 2050.
Results: The GIS database of climate-schistosomiasis of the country was established. It was found that the average temperature in the last 5 decades inclined, especially after 1990 it increased significantly with its increasing regression formula T = 0.0198X - 28.476. The climate-transmission model for schistosomiasis was established, and it was found that the geographical distribution of Schistosoma japonicum was much larger than that of Oncomelania snails based on the ratio of ET/SDT. The prediction maps for distribution of schistosomiasis in 2030 and 2050 were created, respectively, which showed that the sensitive areas were extended with the time, the risk of expansion northward for schistosomiasis will be increasing due to directly the climate warming.
Conclusion: It is predicted that a northward expansion of transmission area of schistosomiasis may occur due to the climate warming, the expanded potential area for schistosomiasis transmission will be important for future surveillance.