Ocular Sparganosis: The First Report of Spirometra ranarum in Thailand

Abstract

A 22-year-old Thai man from the Northeast region presented with acute eye swelling, itching, and discharge on his left eye. He was suspected of having gnathostomiasis and treated with albendazole and prednisolone for 3 weeks. Nine months later, he was treated with high-dose oral prednisolone for the preliminary and differential diagnoses with thyroid-associated orbitopathy and lymphoma. He had been administered prednisolone intermittently over a few years. Then he developed a painless movable mass at the left upper eyelid and recurrent pseudotumor oculi was suspected. The surgical removal of the mass was performed. A white pseudosegmented worm revealed a definite diagnosis of ocular sparganosis by a plerocercoid larva. Molecular diagnosis of the causative species was made based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Proper technique of extraction and amplification of short fragments DNA from formalin-fixed paraffin-embedded tissue successfully identified parasite species. The result from the sequencing of the PCR-amplified cox1 fragments in this study showed 99.0% sequence homology to Spirometra ranarum. This is the first report of S. ranarum in Thailand.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

“…Taenia asiatica Eom & Rim, 1993 Taenia saginata asiatica Eom & Rim, 1993 Taenia asiaticus Eom et al, 2020 Geographic distribution. East Asia (Ale et al 2014).…”

“…Definitive hosts are wild and domestic felids and canids. Zoonotic in humans as dead-end hosts that harbor plerocercoid larvae ( Jeon et al 2018a ; Saksirisampant et al 2020 ).…”

“…Route of infection. Ingestion of infected intermediate or paratenic host ( Saksirisampant et al 2020 ).…”

“…Site in human host. Skin and soft tissues, pleural and peritoneal cavities, abdominal viscera, eye, CNS ( Saksirisampant et al 2020 ).…”

Paediatric sparganosis

“…In Thailand, a tropical country in Indochina, the disease is also documented. The disease has been sporadically reported since 1943 and the most recent case report was in 2020 2 . Past studies show that the disease could affect patients of both sexes in a wide range of ages 3 .…”