Human intraocular filariasis caused by Dirofilaria sp. nematode, Brazil

Abstract

A case of human intraocular dirofilariasis is reported from northern Brazil. The nematode was morphologically and phylogenetically related to Dirofilaria immitis but distinct from reference sequences, including those of D. immitis infesting dogs in the same area. A zoonotic Dirofilaria species infesting wild mammals in Brazil and its implications are discussed.

Video

Surgical removal of a Dirofilaria sp. nematode from the left eye of a 16-year-old boy, Brazil. VA, visual acuity; CF, count fingers; IOP, intraocular pressure. A portion of the material in this video was previously published in the journal Parasites and Vectors (http://www.parasitesandvectors.com/content/pdf/1756-3305-4-41.pdf).

Figure 1

Corneal edema and episcleral hyperemia in the left eye of a 16-year-old boy from Brazil and a free-swimming filarid in the anterior chamber. A) Macroscopic view. B) Five pairs of ovoid pre-cloacal papillae (arrows) and 1 postcloacal caudal papillae (arrowhead). Scale bar = 50 µm. C) Small (arrowhead) and large (arrow) spicules. Scale bar = 40 µm. D) Longitudinal ridges of the area rugosa. Scale bar = 50 µm.

Figure 2

Phylogeny of filarial nematodes based on cytochrome c oxidase subunit 1 (cox1) gene sequences. Thelazia spp. species were used as outgroup. Bootstrap confidence values (100 replicates) are shown at the nodes only for values >50%. Solid diamond indicates nematode isolated in this study. Numbers in parentheses are GenBank accession numbers. Scale bar indicates nucleotide substitutions per site.