Aidan: Created page with "{{DISPLAYTITLE:''Toxocara''}} == Background == * Genus of nematode * Includes two species of medical importance: Toxocara canis, the dog roundworm Toxocara cati, the cat roundworm * Dogs/cats are the definitive hosts, while humans are incidental hosts ** In humans, the larva are unable to mature into adult worms or to release eggs * Distributed worldwide, particularly in low-resource settings with high numbers of feral dog or cat populations..."

2025-07-20T23:33:32Z

Created page with "{{DISPLAYTITLE:''Toxocara''}} == Background == * Genus of nematode * Includes two species of medical importance: ** Toxocara canis, the dog roundworm ** Toxocara cati, the cat roundworm * Dogs/cats are the definitive hosts, while humans are incidental hosts ** In humans, the larva are unable to mature into adult worms or to release eggs * Distributed worldwide, particularly in low-resource settings with high numbers of feral dog or cat populations..."

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{{DISPLAYTITLE:''Toxocara''}}

== Background ==

* Genus of [[Nematodes|nematode]]
* Includes two species of medical importance:
** [[Toxocara canis]], the dog roundworm
** [[Toxocara cati]], the cat roundworm
* Dogs/cats are the definitive hosts, while humans are incidental hosts
** In humans, the larva are unable to mature into adult worms or to release eggs
* Distributed worldwide, particularly in low-resource settings with high numbers of feral dog or cat populations
* About 20% of the global population is seropositive, though there is variation
** Africa 40%, Southeast Asia 34%, Western Pacific 24%, Americas 23%, Europe 11%, Eastern Mediterranean 8%
* Risk factors include contact with outdoor dogs and cat, and children

== Clinical Manifestations ==

* Asymptomatic

=== Visceral Larva Migrans ===

* Most common in children less than 5 years of age
* Fevers, malaise, weight loss, respiratory symptoms, hepatomegaly, rash, lymphadenopathy
* Most commonly affects lung and liver, but can also affect cardiac and urinary systems
* Often see peripheral eosinophilia
* Pulmonary disease
** Coughing, wheezing, dyspnea
** May present as eosinophilic pneumonia or as asthma
* Liver disease
** Fevers, abdominal pain, peripheral eosinophila
** Liver lesions can mimic [[Fasciola hepatica]], bacterial infection, and malignancy
** Can be complicated by bacterial abscess
* Cardiac disease
** Rare
** Primarily [[myocarditis]], but also [[pericarditis]] and [[Loeffler endocarditis]]

=== Neurotoxocariasis ===

* Invasion of larvae into the CNS
* Syndromes can include meningoencephalitis, myelitis, spinal abscess, optic neuritis, and cerebral vasculitis
* May present with epilepsy, cognitive impairment, and behaviour changes

=== Ocular Toxocariasis ===

* Painless (though painful in 30%) unilateral vision loss
* Photophobia and floaters
* On ophthalmoscopy, may see vitreitis, posterior of intermediate uveitis, traction retinal detachment, granuloma formation, endophthalmitis, optic neuropathy, and crystoid macular edema
* Vision loss is usually permanent

=== Common Toxocariasis ===

* Non-specific symptoms in seropositive patients
* Abdominal pain, anorexia, nausea, vomiting, lethargy, hedaches, myalgias, behaviour change
* May have eosinophilia

== Management ==

* [[Albendazole]] 400 mg p.o. twice daily for 5 days
* Alternatively [[mebendazole]], [[DEC]]
* Neoadjuvant corticosteroids should be given be antihelminthic therapy and continued throughout treatment for patients with: cardiac disease, VLM with severe peripheral eosinophilia, ocular infection, neurotoxocariasis
** Followed by taper

[[Category:Nematodes]]

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