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Chapter 21

Clonorchiasis and Other Liver Fluke Diseases;

Oriental Cholangiohepatitis

With Dr. Joan Kendall


Clonorchis sinensis is the most important of the liver flukes that infect man. It is found throughout East Asia and is chiefly responsible for the many patients with cholangiohepatitis seen in the Orient, where man's enjoyment of raw fish as a delicacy must be tempered by the sometimes terrible changes wrought in his biliary system and liver by these small flukes. C. sinensis was first described by McConnell in 1875 in the bile ducts of a Chinese carpenter in Calcutta., but the earliest historical record of clonorchiasis dates back to an ancient corpse buried in 278 B.C. in the West Han Dynasty in China.


Clonorchiasis. Chinese or Oriental liver fluke disease. Sp: Clonorquiasis. Fr: Clonorchiose. Ger: Clonorchisbefall. Leberegelkrankheit. Chinesischer leberegel.


Clonorchiasis is an infection of the biliary passages by the Oriental liver fluke, Clonorchis sinensis. It is often an asymptomatic infection, but patients with a severe infestation may develop cholangiohepatitis and liver failure.

Geographic Distribution

Fig. 21.1 Geographic distribution of clonorchiasis.

The trematode responsible for clonorchiasis is found throughout much of East Asia from Indochina to Japan as a common parasite of man and fish-eating mammals. An estimated 19 million people are infected in the heavily populated regions of China (especially the southern provinces), Taiwan, Hong Kong, the Red River delta in Indochina, Korea and Japan (Fig. 21.1). The incidence in China and Japan has been decreasing in recent decades; in the early 1960s, in some prefectures, especially the Okayama district in Central Japan, analysis of stool specimens indicated an infection rate of 13.5-27%. Hong Kong has a very high incidence; a 1964 study in a government hospital there revealed clonorchiasis in 27% of patients over 2 years of age and in 40% of patients over 30 years of age. These figures reflect the high incidence also in the adjacent Kwangtung Province of South China where fish raising is a major industry. There, as in many other regions, "night soil" (fertilizer contaminated with human feces) is used to "fertilize" fish ponds to increase fish production; unfortunately, this practice also stimulates snail growth with an increased number of secondary hosts.

In another study, eggs were found in the stools of 50% of the people living along the east coast of Vietnam. One area in south central Taiwan reported 34% positive stool specimens for Clonorchis ova, while one province of Korea reported that 36% of intradermal tests for Clonorchis were positive.

Some Chinese immigrants brought the disease with them to California in the early 1900's. Although it may persist in such immigrants for decades, the disease did not become endemic there because suitable intermediate hosts are lacking in America. Several Hawaiians have acquired clonorchiasis by eating infected raw, frozen, or salted fish shipped from China or Japan. More commonly, however, it is modern day immigrants from China and East Asia who are occasionally seen in Hawaiian and mainland U.S. hospitals with cholangiohepatitis caused by Clonorchis.

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Copyright: Palmer and Reeder