Diagnosis of human opisthorchiasis with cocktail and eluted Bithynia goniomphalos snail antigens by indirect elisa

Abstract

This study aimed to develop a sensitive and specific immunodiagnosis method for Opisthorchis viverrini infection using purified Bithynia goniomphalos snails as a cocktail antigen by gel filtration chromatography and an eluted antigen by SDS-polyacrylamide gel electrophoresis and electroelution method. Effectiveness and specificity in the serological diagnosis of opisthorchiasis using these wwo prepared antigens were tested by indirect ELISA against sera of 61 cases with opisthorchiasis, 125 cases with other parasitic infections and 30 normal healthy sera. The sensitivity, specificity,, positive and negative predictive values of cocktail antigen were 95.1%, 79.4%, 64.4% and 97.6%, respectively, at the cut off OD of 0.786. Cross reactions were observed with trichuriasis (1/7), trichinellosis (5/10), hookworm infection (5/9), angiostrongvliasis (2/9), toxocariasis (1/5), ascariasis (1/8), filariasis (1/6), taeniasis (1/9), hymenolepiasis (1/4), hydatidosis (2/3 and gnathostomiasis (7/9). No cross-reaction was found with normal healthy sera. The sensitivity, specificity, positive and negative predictive values of eluted antigen (53 kDa) were 96.7% , 92.9%, 84.3, and 98.6%, respectively, at the cut off OD of 0.814. Cross reactions were observed with strongyloidiasis (4/10), angiostrongbliasis (1/9), gnathostomiasis (3/9), hymenolepiasis (1/4) and paragonimiasis (2/4). No cross-reaction was found with normal healthy sera. Further studies on improvement of cocktail and eluted antigen preparation may provide a better specific diagnosis of opisthorchiasis.