An outbreak of schistosomiasis japonica in Taiwan

The present study was undertaken to determine the current status of Schistosoma japonicum infection in the newly found endemic focus at Hanpao Farm, Fangyuan District, Changhua County, West-Central Taiwan. Two field surveys and one laboratory investigation were conducted from July to October 1987. Of 705 snails examined by shedding and crushing methods, 17.0% were found to harbor cercariae of S. japonicum. By sodium sulfate-acid-ether-triton centrifugal sedimentation technique, 25% of 16 cattle, 40% of 5 goats, and 50% of 4 dogs were found to be positive for S. japonicum eggs. In the laboratory, 21 mice were exposed to cercariae from single naturally infected snails. Following inoculation, 7 mice died early, 7 were found infected with male worms, 2 with female worms, and 1 with bisexual infection. The results of the present study indicated that the infection rates of snails and domestic animals are higher than those previously reported from elsewhere in Changhua County.