RESUMO
Angiostrongylus costaricensisis is an intra-arterial nematode of rodents. Man may become accidentally infected through ingestion of contaminated food or water. Our objective was to describe the parasite structures recognized by human antibodies in serum samples from acute and convalescent phases of abdominal angiostrongyliasis. An indirect immunofluorescent method was employed to study reactivity on whole eggs and sections of female worms and first stage larvae (L1). L1 were also studied before and after sonication. Fluorescence, always higher with acute phase sera, was detected on the surface of whole eggs and in L1 fragments and was neither present on whole L1 nor on their sections. An inespecific reactivity was seen on the cuticular border of the general cavity and reproductive organs. The data indicate the latter as a main source of antigenicity.