Abstract

Presently, in Chile, ascariosis is an infrequently reported parasitism due to the gradual improvement of health infrastructure and education. Moreover, expelling juvenile Ascaris lumbricoides is an exceptional fact and, due to their morphological characteristics, it can lead to an error in its taxonomic diagnosis. For this reason, a review of differential taxonomic diagnosis keys for nematode larvae is presented, arising from a case of elimination of a juvenile stage of the parasite whose identification was difficult. In addition, aspects of A. lumbricoides lifecycle and the recommended procedures for taking and sending samples to the laboratory are reviewed.