Ocular linguatuliasis in Ecuador: Case report and morphometric study of the larva of Linguatula serrata

Linguatula serrata is a pentastomid, a cosmopolitan parasite belonging to t he Phylum Pentastomida. Humans may act as an intermediate or accidental def initive host of this parasite, manifesting the nasopharyngeal or visceral f orm, with the latter having been described more frequently. The occurrence of ocular linguatuliasis is extremely rare, but it has been reported in the United States and Israel. The objective of the present paper was to report the first case of ocular linguatuliasis in Ecuador and to extend the morph ologic study of L. serrata by morphometric analysis. The patient studied wa s a 34-year old woman from Guayaquil, Ecuador who complained of ocular pain with conjunctivitis and visual difficulties of two-months duration. Biomic roscopic examination revealed a mobile body in the anterior chamber of the eye. The mobile body was surgically removed. The specimen was fixed in alco hol, cleared using the technique of Loos, stained with acetic carmine, and mounted on balsam between a slide and a coverslip. It was observed with ste reoscopic and common light microscopes in combination with an automatic sys tem for image analysis and processing. The morphologic and morphometric cha racteristics corresponded to the third-instar larval form of L. serrata. To our knowledge, ocular linguatuliasis has not been previously described in South America, with this being the first report for Ecuador and South Ameri ca. The present study shows that computer morphometry can adequately contri bute both to the morphologic study and to the systematic classification of Pentastomids, and L. serrata in particular.