Coproantigen detection in rats experimentally infected with Strongyloides ratti.

The possibility of coproantigen detection in the diagnosis of strongyloidiasis was investigated in rats experimentally infected with Strongyloides ratti. A capture ELISA was developed using affinity-purified polyclonal antibodies raised in rabbits against adult and filariform larval somatic antigens. The first detection of coproantigen coincided with patency and the coproantigen level remained elevated even when the parasite count was low. Following challenge infection, when examination of stool for larvae or ova was negative, coproantigen was detected by anti-adult somatic capture ELISA. Despite the use of antisera raised against crude worm extracts, the test was specific showing only low cross-reactivity with Necator americanus and Syphacia muris.