Diagnostic significance of intradermal test compared with radiologic findings for clonorchiasis

Shin, Bo Moon; Choi, Kyung Im

Abstract

BACKGROUND: Clonorchiasis is a trematodiasis caused by chronic infestation of liver flukes, Clonorchis sinensis(CS). We usually diagnosed clonorchiasis with stool examination. Intradermal(ID) test and radiologic findings have been also used for diagnosis. However, studies associated with ID test were very rare. So, we evaluated the stool examination and ID tests for CS detection associated with radiologic findings.
METHODS
We analyzed 69 cases of patients requested stool parasite examination and ID test concurrently. For stool parasite examination, formalin ether precipitation method was used. Abdominal US and/or CT were also reviewed. Eosinophil counts and liver function test(LFT) were evaluated. Clinical diagnosis were reviewed retrospectively.
RESULTS
Sensitivity and specificity of ID CS test were 63% and 71.4% respectively. Positive and negative predictive values were 58.6% and 75.0% respectively. US/CT findings showed 10% sensitivity and 52.9% specificity. Positive and negative predictive values of US/CT were 11.1% and 50% respectively. Paragonimiasis westermani ID test showed 17.2% positivity in CS ID test positive cases. No statistical differences were observed among groups in eosinophil and LFT results. Hepatobiliary diseases were the main clinical impression in CS ID test positive groups.
CONCLUSION
For the diagnosis of clonorchiasis, stool examination was the most effective method. ID test and radiologic examination still have some limitations in diagnosis because of cured past infestation, small number of parasitic infestation or irreversible anatomical changes etc. However, ID test could have a better supplementary role for diagnosis of clonorchiasis rather than US/CT.