Molecular tools for studies on the transmission biology ofEchinococcus multilocularis

Abstract

Two novel approaches for diagnosis of intestinalEchinococcus multilocularisinfection, the detection ofE. multilocularis-specific coproantigens in ELISA and of copro-DNA by PCR, have been successfully implemented. These methods have proven their value for thepost mortemand theintra vitamdiagnosis ofE. multilocularisin definitive hosts. They have also made novel approaches possible to study the transmission biology of the parasite as they allow detection of the infection in faecal samples collected in the environment. Coproantigen detection is the diagnostic method of choice as it is sensitive, fast and cheap. Studies on faecal samples collected in the field revealed that coproantigen detection did reflect the different prevalences in fox populations as assessed from foxes at necropsy and also the effect of deworming efforts in foxes as achieved by long-term distribution of praziquantel-containing baits. The use of PCR for routine diagnostic or large-scale purposes is hampered by the fact that DNA extraction from faecal material is a very laborious task. Therefore, PCR is rationally used for confirmatory purposes of copro-antigen-positive samples. As taeniid eggs cannot further be differentiated morphologically, PCR is the method of choice to identifyE. multilocularisinfections in faecal or environmental samples containing taeniid eggs. In intermediate rodent hosts, PCR is routinely used in epidemiological studies for identifyingE. multilocularisfrom liver lesions which are often very small, atypical or calcified.