Two Ocular Angiostrongyliasis Cases in Thailand with Molecular Identification of Causative Parasite Species

Human angiostrongyliasis is an important foodborne helminthic zoonosis caused by the nematodes of the genus Angiostrongylus. We describe two parasitologically confirmed cases of ocular angiostrongyliasis, presenting at a tertiary care hospital in Thailand between 2012 and 2018. Parasites were surgically recovered from patients' eyes and morphologically identified as Angiostrongylus species. DNA analysis allowed identification of Angiostrongylus cantonensis. Polymerase chain reaction was used to amplify all or part of the small nuclear ribosomal subunit, the second internal transcribed spacer region, and cytochrome c oxidase subunit 1. The sequences subsequently obtained were highly similar to those of A. cantonensis (97-100%). This is the first molecular confirmation that A. cantonensis is a causative agent of human angiostrongyliasis in Thailand.