Geographical genetic structure of Schistosoma japonicum revealed by analysis of mitochondrial DNA and microsatellite markers

Background: Schistosoma japonicum is a significant public health risk in parts of China and elsewhere in Southeast Asia. To gain an insight into the epidemiology of schistosomiasis japonica, a detailed investigation of S. japonicum genetic population structure is needed. Methods: Using three mitochondrial DNA fragments and ten microsatellite loci, we investigated the genetic diversity within and structure among twelve populations of S. japonicum sampled on a geographical scale covering most major endemic areas. Results: Schistosoma japonicum lineages from Indonesia, the Philippines and Chinese Taiwan were clearly distinct from each other and from those in mainland China. Within mainland China, there was some evidence for genetic divergence between populations from the mountain and lake regions. However, the analysis inferred no clear sub-population structure in the lake region of mainland China. High genetic diversity was found among S. japonicum populations of mainland China and this was significantly higher than those from island regions. Conclusions: High genetic diversity within and substantial differentiation among populations were demonstrated in S. japonicum.