Toxocariasis

Abstract

Toxocariasis is one of the most commonly reported zoonotic helminth infections in the world with a higher prevalence in tropical settings and in rural populations. It is caused by the larval stages of the ascarids Toxocara canis, the common roundworm of dogs, and probably also by the larval stages of Toxocara cati, the roundworm of cats. The clinical spectrum of toxocariasis in humans varies from asymptomatic infection to severe organ injury caused by larval migration to the major organs ("visceral larva migrans"). Clinical involvement of the nervous system in visceral larva migrans due to Toxocara is thought to be rare, although in experimental animals the larvae frequently migrate to the brain. The CNS migration leads to a variety of neurological disorders such as meningo-encephalitis, space-occupying lesion, cerebral vasculitis, epilepsy, and myelitis. Several studies have evidenced high seropositivity rates for T. canis among people with epilepsy suggesting that toxocariasis could play a role in the incidence of epilepsy in endemic areas. Diagnosis of neurotoxocariasis is based on the history; blood tests, including differential blood cell count; CSF investigations, including determination of antibodies anti-Toxocara canis; and neuroimaging. Like the visceral manifestations, neurological manifestations of toxocariasis are treated with benzimidazole components.

Keywords: Neurotoxocariasis; epilepsy; neuroimaging; serodiagnosis; treatment.