Visceral larva migrans (VLM) is a condition in humans caused by the migratory larvae of certain

nematodes The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...

, humans being a dead-end host, and was first reported in 1952. Nematodes causing such

zoonotic A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

infections are ''

Baylisascaris procyonis ''Baylisascaris procyonis'', also known by the common name of raccoon roundworm, is a roundworm nematode, found ubiquitously in raccoons, the definitive hosts. It is named after H. A. Baylis, who studied them in the 1920s–30s, and Greek '' as ...

'', ''

Toxocara canis ''Toxocara canis'' (also known as dog roundworm) is a worldwide-distributed helminth parasite of dogs and other canids. The name is derived from the Greek word "," meaning bow or quiver, and the Latin word "caro," meaning flesh.Bassert , J., & T ...

'', ''

Toxocara cati ''Toxocara cati'', also known as the feline roundworm, is a parasite of cats and other felids. It is one of the most common nematodes of cats, infecting both wild and domestic felids worldwide. Adult worms are localised in the gut of the host. I ...

'', and ''

Ascaris suum ''Ascaris suum'', also known as the large roundworm of pig, is a parasitic nematode that causes ascariasis in pigs. While roundworms in pigs and humans are today considered as two species (''A. suum'' and '' A. lumbricoides'') with different hos ...

''. 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 The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

(causing

myocarditis Myocarditis, also known as inflammatory cardiomyopathy, is an acquired cardiomyopathy due to inflammation of the heart muscle. Symptoms can include shortness of breath, chest pain, decreased ability to exercise, and an irregular heartbeat. The ...

) and the CNS (causing dysfunction,

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

s, and coma). A special variant is

ocular larva migrans Ocular larva migrans (OLM), also known as ocular toxocariasis, is the ocular form of the larva migrans syndrome that occurs when '' Toxocara canis'' (dog roundworm) larvae invade the eye. They may be associated with visceral larva migrans. Unilate ...

where usually ''T. canis'' larvae travel to the eye. Only a few roundworm eggs are necessary to cause larva migrans in the human child or adult. However, visceral larva migrans seems to affect children aged 1–4 more often while ocular larva migrans more frequently affects children aged 7–8. Between 4.6% and 23% of U.S. children have been infected with the dog roundworm egg. This number is much higher in other parts of the world, such as Colombia, where up to 81% of children have been infected.

Cutaneous larva migrans Cutaneous larva migrans (abbreviated CLM) is a skin disease in humans, caused by the larvae of various nematode parasites of the hookworm family ( Ancylostomatidae). These parasites live in the intestines of dogs, cats, and wild animals and should ...

is a condition where nematodes such as ''

Ancylostoma braziliense ''Ancylostoma braziliense'' is a species of hookworm belonging to the genus ''Ancylostoma''. It is an intestinal parasite of domestic cats and dogs. Severe infection is often fatal to these pets, especially in puppies and kittens. The infection ...

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

Signs and Symptoms

Fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

hepatomegaly Hepatomegaly is the condition of having an enlarged liver. It is a non-specific medical sign having many causes, which can broadly be broken down into infection, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdomi ...

leucocytosis Leukocytosis is a condition in which the white cell ( leukocyte count) is above the normal range in the blood. It is frequently a sign of an inflammatory response, most commonly the result of infection, but may also occur following certain paras ...

coughing A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phas ...

etc.

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Helminthiases Tropical diseases {{infectious-disease-stub

Signs and Symptoms

See also

References

External links