Visceral larva migrans is caused by which of the following organism?
**Core Concept**
Visceral larva migrans is a condition caused by the migration of larval nematodes through the body's internal organs. This condition is typically associated with **Toxocara** species, which are parasitic nematodes found in dogs and cats. The lifecycle of these parasites involves a complex process of migration through various tissues.
**Why the Correct Answer is Right**
The correct answer is **Toxocara**, as it is the primary cause of visceral larva migrans in humans. The larvae of **Toxocara canis** or **Toxocara cati** can infect humans through the ingestion of contaminated soil or feces, leading to the migration of larvae through various organs, including the liver, lungs, and brain. This migration triggers an immune response, resulting in tissue damage and inflammation.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not specified, but typically other options would include other parasites that do not cause visceral larva migrans.
**Option B:** Incorrect for the same reason as Option A.
**Option C:** Incorrect as it is not the primary cause of visceral larva migrans.
**Option D:** Incorrect because, like the other options, it is not the primary cause of the condition.
**Clinical Pearl / High-Yield Fact**
Visceral larva migrans is often associated with eosinophilia, as the immune system responds to the presence of the larvae. It is essential to consider this condition in patients with a history of exposure to contaminated soil or feces, especially in those with eosinophilia and organ inflammation.
**Correct Answer:** D. Toxocara.