Human Exposure to Equine <i>Halicephalobus gingivalis</i> in an Occupational Context

Abstract

Halicephalobus gingivalis (H. gingivalis) is a very rare opportunistic cause of fatal meningoencephalomyelitis in equids but may also cause parasitic infections in exposed humans via zoonotic transmission (from animals to humans). We herein report a 39-year-old veterinarian who was exposed to aspirated gastric contents while inserting a nasogastric tube into a horse with signs of uveitis. This procedure requires application of oral suction to the end of the tube to ensure correct placement. Histopathology of the horse’s enucleated eye later revealed H. gingivalis infection, and the horse developed acute kidney injury, ataxia, and other signs of neurological disease. The horse later progressed to death despite supportive care and administration of the broad-spectrum antiparasitic, ivermectin. Two months later, the veterinarian received prophylactic ivermectin consisting of two 200-mcg/kg doses. The patient reported feeling well and was without any systemic or focal signs or symptoms prior to this prophylactic treatment and continued feeling well when followed up at 4 months post exposure. Blood work was unremarkable, with no eosinophilia (eosinophils 0.1 × 109/L, normal 9/L). Meticulous hand hygiene and alternatives to unprotected oral suction should be considered in veterinary medicine as the potentially increasing risk of occupational exposure to zoonotic helminthiases makes this a public health concern.

Keywords

• equine parasites
• <i>Halicephalobus gingivalis</i>
• occupational exposure
• helminthiases
• veterinary medicine