II. Epidemiology
- Incidence: 10,000 cases per year in United States
- Seroprevalence in United States: 13.9%
III. Pathophysiology
- Organism: Roundworms (Nematodes)
- Toxocara canis (dogs)
- Toxocara cati (cats)
- Transmission
- Dogs and cats ingest roundworm eggs in soil, feces
- Small mammals (rabbits) may act as intermediate hosts
- Female dogs or cats may transmit encysted larvae to puppies transplacentally or via Lactation
- Dog or cat feces contaminate soil
- Toxocara eggs incubate in feces for 2-4 weeks until larvae infectious
- Young children (age <3 years)
- Eat contaminated soil (Geophagia)
- Common in playgrounds and sandboxes (contamination rates are as high as 40%)
- Older children and adults
- Ingest undercooked meat or raw liver infected with Toxocara larvae
- Dogs and cats ingest roundworm eggs in soil, feces
- Infection
- Clinical manifestations are dependent on multiple factors
- Parasite load
- Host immune response
- Larvae migration path
IV. Findings: Toxocariasis Presentations
- Visceral Toxocariasis (children ages 2-4 years old)
- Inflammatory response in liver, heart, lungs, brain, Muscle
- Ocular Toxocariasis
- Covert Toxocariasis (most common)
- Asymptomatic or mild symptoms
V. Symptoms: Visceral Toxocariasis (children ages 2-4 years old)
- Constitutional
- Pulmonary
- Gastrointestinal
- Neurologic
- Meningoencephalitis
- Skin
VI. Complications
- Epilepsy may develop in toddlers
- Ocular Larva Migrans (Endophthalmitis)
VII. Differential Diagnosis
- Hepatitis
- Encephalitis
- Viral myalgia
- Epilepsy
- Pneumonia
- Trichinosis
- Eosinophilic Leukemia
- Periarteritis Nodosa
VIII. Labs
-
Complete Blood Count
- Anemia
- Leukocytosis with >20% Eosinophilia
-
Serology for Toxocara Antibody
- Does not distinguish acute versus prior infection
- Other findings/tests
IX. Course
- Typically a self limited course in most cases
- Generally benign
X. Management
- Indications
- Most cases are treated
- Severe cardiac or pulmonary disease
- Neurologic involvement
- Preparations
- Albendazole (Albenza)
- Dose: 7.5 mg/kg up to 400 mg orally twice daily for 5 days
- Preferred agent in United States
- Mebendazole (Vermox)
- Dose: 100-200 bid for 5 days
- Not available as of 2012 (use Albendazole instead)
- Diethylcarbamazine (Hetrazan)
- Dose: 6 mg/kg/day divided tid for 7-10 days
- Has been used outside U.S. to treat Visceral Larva Migrans
- Albendazole (Albenza)
- Adjunctive
- Corticosteroids are indicated if inflammation present (especially with Ocular Larva Migrans)
XI. Prevention
- Careful child supervision
- Prevent soil ingestion
- Encourage Hand Washing
- Regular worming of cats and dogs
- Clean up after pets
- Cover sandbox between use
- Cook liver and other organ meats well before eating
XII. Resources
- CDC Toxocariasis
XIII. References
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Related Studies
Definition (NCI) | A parasitic infection caused by worms found in domestic animals. In humans nematode larvae enter the portal system from the small intestine and disseminate in visceral organs causing inflammatory reactions. Signs and symptoms include eosinophilia, hepatomegaly, splenomegaly, and lung infections. |
Definition (MSH) | A condition produced in man by the prolonged migration of animal nematode larvae in extraintestinal tissues other than skin; characterized by persistent hypereosinophilia, hepatomegaly, and frequently pneumonitis, commonly caused by Toxocara canis and Toxocara cati. |
Concepts | Disease or Syndrome (T047) |
MSH | D007816 |
ICD10 | B83.0 |
SnomedCT | 87121004 |
English | Larva Migrans, Visceral, Migrans, Visceral Larva, Toxocara visceral larva migran, Visceral larva migrans, visceral larva migrans, visceral larva migrans (diagnosis), Visceral Larva Migran, Migran, Visceral Larva, Larva Migran, Visceral, Visceral Larva Migrans Syndrome, Larva Migrans, Visceral [Disease/Finding], larva visceral migrans, larva migrans visceral, Visceral larval migrans, Larva migrans, Visceral, Visceral larva migrans syndrome, Toxocaral visceral larva migrans, Visceral larva migrans syndrome (disorder), larva migrans; visceralis, visceral; larva migrans, Visceral Larva Migrans, Larva migrans visceralis |
Swedish | Larva migrans, visceral |
Japanese | ナイゾウヨウチュウイコウショウ, 幼虫移行症-内臓, 臓器幼虫移行症, 内臓幼虫移行症, 幼虫体内移行症, 幼虫内移行症, 幼虫内臓移行症, 内蔵幼虫爬行症, 幼虫内蔵爬行症, 臓器幼虫爬行症 |
Czech | larva migrans viscerální, Larva migrans visceralis, larvální toxokaróza |
Finnish | Viskeraalinen vaeltava toukka |
Russian | LARVA MIGRANS VISTSERAL'NAIA, LARVA MIGRANS ВИСЦЕРАЛЬНАЯ |
Korean | 내장 유충 이행증 |
Portuguese | Síndrome de Larva Migrans Visceral, Larva visceral migrante, Larva Migrans Visceral |
Spanish | Síndrome de Larva Migrans Visceral, síndrome de la larva migratoria visceral (trastorno), síndrome de la larva migratoria visceral, Larva migrans visceral, Larva Migrans Visceral |
Polish | Zespół larwy wędrującej trzewnej |
Hungarian | visceralis larva migrans |
Dutch | larva migrans; visceralis, visceralis; larva migrans, viscerale larva migrans, Larva migrans visceralis |
German | Larva migrans visceralis, Larva migrans, viszerale |
French | Larva migrans viscérale |
Italian | Larva migrans viscerale |
Ontology: Toxocariasis (C0040553)
Definition (MSHCZE) | Parazitární onemocnění způsobené červy (helmintóza) – larvami škrkavky Toxocara (psí, resp. kočičí). Člověk se nakazí vajíčky, z nichž v organismu vznikají larvy, které se krví či mízou dostávají do různých vnitřních orgánů (zažívacího ústrojí, plic, očí, mozku, srdce aj.). Příznaky závisejí na postiženém orgánu a množství parazitů. Důležitá je prevence (ochrana před znečištěním výkaly zvířat, např. dětských hřišť). Přítomnost larev v tkáních a jejich pohyb se označuje jako larva migrans. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ ) |
Definition (NCI) | A parasitic infection caused by Toxocara. Humans are infected by the larvae of Toxocara canis and Toxocara cati from dogs and cats respectively. Most cases remain asymptomatic. The parasites may affect the eye, causing diminished vision, or other major organs, causing hepatomegaly, eosinophilia, wheezing, and coughing. |
Definition (MSH) | Infection by round worms of the genus TOXOCARA, usually found in wild and domesticated cats and dogs and foxes, except for the larvae, which may produce visceral and ocular larva migrans in man. |
Concepts | Disease or Syndrome (T047) |
MSH | D014120 |
ICD9 | 128.0 |
ICD10 | B83.0 |
SnomedCT | 406619001, 38995001, 76695000 |
English | Toxocariases, Toxocariasis, toxocariasis (diagnosis), toxocariasis, Infection due to Toxocara, Infection due to toxocara (disorder), Infection due to Toxocara (disorder), Infection due to toxocara, Toxocariasis [Disease/Finding], toxocarosis, Toxocariasis (disorder), Toxocarosis, Toxocara infection |
Dutch | Toxocara-infectie, toxocariasis, Infectie, spoelworm-, Spoelworminfectie |
French | Infection à Toxocara, Toxocariase, Toxocarose |
German | Toxocarai-Infektion, Toxocarainfektion, Toxocariasis |
Italian | Infezione da Toxocara, Toxocariasi |
Portuguese | Infecção por toxocara, Toxocaríase |
Spanish | Infección por toxocara, toxocariasis (trastorno), toxocariasis, infección por Toxocara (trastorno), infección por Toxocara, Toxocariasis |
Japanese | トキソカラ症, トキソカラ感染, トキソカラカンセン, トキソカラショウ |
Swedish | Toxocariasis |
Finnish | Toksokariaasi |
Russian | TOKSOKAROZ, ТОКСОКАРОЗ |
Czech | Toxokaróza, toxokariáza, toxokaróza larvální, toxokaróza |
Polish | Zespół wędrującej larwy trzewnej, Toksokaroza |
Hungarian | Toxocara fertőzés, toxocariasis |