Clonorchiasis and paragonimiasis in the Republic of Korea. Report on a prevalence survey using intradermal tests.

Until recently, information on the distribution of and prevalence of infection with the liver fluke, Clonorchis sinensis, and the lung fluke, Paragonimus westermani, was based almost entirely on surveys by stool or sputum examination, involving techniques insufficiently sensitive and too costly and time-consuming to allow of really adequate coverage. However, a simple and reliable intradermal test for these infections has now been developed, based on the use of purified antigens, and this has been used in a survey of nearly 10 000 persons in the Republic of Korea. The results show that the spread of these infections is much wider than had previously been thought. It is estimated that in South Korea alone some 4.5 million people are infected with clonorchiasis and up to 1.5 million with paragonimiasis-a public health problem of considerable magnitude.