Visceral larva migrans is a condition in humans caused by the migratory larvae of certain nematodes, humans being a terminal host, and was first reported in 1952. Nematodes causing such zoonotic infections are Baylisascaris procyonis

Baylisascaris procyonis

Baylisascaris procyonis is a roundworm nematode, found ubiquitously in raccoons, its larvae migrating in the intermediate hosts causing visceral larva migrans . Baylisascariasis as the zoonotic infection of humans is rare, though extremely dangerous due to the ability of the parasite's larvae to...

, Toxocara canis

Toxocara canis

Toxocara canis is worldwide distributed helminth parasite of dogs and other canids. T. canis are gonochorists, adult worms measure from 9 to 18 cm, are yellow-white in color, and occur in the intestine of the definitive host. In adult dogs, the infection is usually asymptomatic. By the...

, Toxocara cati

Toxocara cati

Toxocara cati is worldwide distributed parasite of cats and other felids and it is one of the most common nematode of cats. Adult worms are localised in gut of the host. In adult cats, the infection is usually asymptomatic. However, massive infection in juvenile cats can be fatal.-External links:*...

, and Ascaris suum. These nematodes can infect but not mature in humans and after migrating through the intestinal wall, travel with the blood stream to various organs where they cause inflammation and damage. Affected organs can include the liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

, heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 (causing myocarditis

Myocarditis

Myocarditis is inflammation of heart muscle . It resembles a heart attack but coronary arteries are not blocked.Myocarditis is most often due to infection by common viruses, such as parvovirus B19, less commonly non-viral pathogens such as Borrelia burgdorferi or Trypanosoma cruzi, or as a...

) and the CNS

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 (causing dysfunction, seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

s, and coma). A special variant is ocular larva migrans

Ocular larva migrans

Ocular larva migrans is the ocular form of the larva migrans syndrome that occurs when toxocara canis larvae invade the eye. They may be associated with visceral larva migrans...

 where usually T. canis larvae travel to the eye.

Cutaneous larva migrans

Cutaneous larva migrans

Cutaneous larva migrans is a skin disease in humans, caused by the larvae of various nematode parasites of the hookworm family...

 is a condition where nematodes such as Ancylostoma braziliense

Ancylostoma braziliense

Ancylostoma braziliense is a species of Ancylostoma.It can cause creeping eruption....

migrate to the skin.

A list of causative agents of larva migrans syndromes is not agreed upon and varies with the author.