Sensitivity comparison between Mini-FLOTAC and conventional techniques for the detection of Echinococcus multilocularis eggs.

Abstract

Canines serve as the definitive host of Echinococcus multilocularis. This study evaluated the sensitivity of the Mini-FLOTAC technique (MF) for the detection of E. multilocularis eggs in definitive hosts. First, we investigated the effects of heat inactivation and preservative conditions on the detection rate of eggs obtained from experimentally infected dogs. The sensitivity of MF was compared with that of eight other techniques: the centrifugal flotation with sucrose or zinc sulfate, MGL, AMS III, and a combination of MF and flotation/sedimentation techniques. Finally, we compared the sensitivity of MF and the centrifugal flotation with sucrose for the feces of E. multilocularis-infected foxes. The detection rate reached a plateau level with a specific gravity (s.g.) 1.22 for fresh eggs, but the highest rates were obtained with s.g. greater than 1.32 for heat-inactivated eggs. There was no significant difference in the detection rate among the preservative conditions. MF showed significantly higher EPG than the other techniques. Moreover, it showed higher diagnostic sensitivity for the fox feces than the centrifugal flotation technique. These results suggest that heat inactivation may alter s.g. of E. multilocularis eggs and that MF with zinc sulfate (s.g. = 1.32) would be effective for detecting heat-inactivated E. multilocularis eggs.