Case Report: Periorbital Filariasis Caused by Brugia malayi

Abstract

Brugia malayi is a lymphatic nematode that accounts for approximately 10% of lymphatic filariasis cases worldwide. It is endemic in several countries in South and Southeast Asia. In Thailand, B. malayi is endemic in the southern region. The extralymphatic presentation of B. malayi is rare. Here, we report the case of a woman residing in the central region of Thailand who presented with an erythematous periorbital nodule at the left medial canthal area caused by lymphatic filaria. A viable sexually mature filarial adult was removed from the lesion. The nematode species was identified as B. malayi by histology staining and DNA sequencing of the partial mitochondrial 12S ribosomal RNA (rRNA) gene. As far as we know, this is the first case report of B. malayi presenting with a periorbital nodule that has occurred in a disease non-endemic area of Thailand with possibly a zoonotic origin.

Figure 1.

(A) Contrast computed tomography (CT) (A: axial view, B: coronal view) of the patient’s orbit revealing an enhancing nodule with central hypodensity at the superomedial aspect of the left orbit (shown by the arrow). (B) Contrast CT (A: axial view, B: coronal view) of the patient’s orbit revealing an enhancing nodule with central hypodensity at the superomedial aspect of the left orbit (shown by the arrow). This figure appears in color at www.ajtmh.org.

Figure 2.

The threadlike, whitish, slender-shaped coiled nematode as shown was removed from the patient’s lesion. The size of the nematode was approximately 9.5 cm long and 1 mm wide. This figure appears in color at www.ajtmh.org.

Figure 3.

Section of the nematode revealing a nematode with a thin cuticle, two uterine tubes (U) containing developing eggs, and one intestine (I). It has a few, well-developed broad muscle cells per quadrant and prominent lateral cords (Lcs) with a few Lc nuclei (shown by the arrows). This figure appears in color at www.ajtmh.org.