Gallstones and Clonorchis sinensis infection: a hospital-based case-control study in Korea.

Background and Aim: A high prevalence of intrahepatic stones in some areas of East Asia has been believed to be related with Clonorchis sinensis infection. The authors conducted a hospital-based case-control study to evaluate the role of Clonorchis sinensis infection as a risk factor for the development of gallstones in Korea.
Methods: The cases of 138 patients with gallstones (intrahepatic 44, gallbladder 67, and extrahepatic 27) and matched controls underwent microscopy for C. sinensis, serological tests for C. sinensis using enzyme-linked immunosorbent assay, radiological examinations, and interviews concerning the history of eating raw freshwater fish. We assessed a relationship of three types of gallstones and variables regarding C. sinensis by using univariate and multivariate statistical analyses.
Results: Univariate statistical analyses showed that radiological evidence of C. sinensis and recent history of eating raw freshwater fish were related to an increased risk of intrahepatic stones (P = 0.0002 and 0.0039, respectively). According to multivariate statistical analyses, radiological evidence of C. sinensis was the only risk factor for intrahepatic stones (odds ratio = 7.835; 95% confidence interval = 1.671-36.724). Any evidence regarding C. sinensis was not related to an increased risk of either gallbladder or extrahepatic stones.
Conclusion: Radiological evidence of C. sinensis was significantly associated with intrahepatic stones.