BET405/3 Medical and Veterinary Helminthology - Nematode Vocabulary

Vocabulary flashcards for Veterinary and Medical Helminthology, focusing on Nematodes.

Nematode

A roundworm; the subject of Lectures 1, 2, 3, and 4 in BET405/3 Medical and Veterinary Helminthology SEM 2 2024/2025.

Rhabditiform Larva (L1)

First-stage larva of Strongyloides; diagnostic form found in human feces. Measures 250 μm long × 16 μm width, with a short buccal cavity and double bulb esophagus.

Filariform Larva (L3)

Third-stage larva of Strongyloides; infective stage to humans, measuring 630 μm long × 16 μm width with a long cylindrical esophagus and notched tail.

Autoinfection (Strongyloides)

Process where Rhabditiform larvae in large intestine become filariform, penetrate intestinal mucosa (or perianal skin) and migrate to other organs.

Parthenogenesis (in Strongyloides)

Reproductive mode in parasitic female worms, where eggs are produced without fertilization, yielding rhabditiform larvae.

Strongyloides stercoralis Epidemiology

Mainly found in hot, humid tropical areas with poor sanitation. Transmission occurs through skin penetration of L3 larva.

Hyperinfection Syndrome

Complication of strongyloidiasis; involves repeated autoinfection cycles leading to large numbers of filariform larvae, often due to impaired host immunity.

Disseminated Strongyloidiasis

Severe complication of strongyloidiasis; larvae invade GIT and migrate to organs, potentially leading to Gram-negative sepsis, pneumonia, or meningitis.

Loeffler's Syndrome

Eosinophilic pneumonia that can result from Ascaris larval migration in the lungs

Ascaris lumbricoides

The largest nematode parasitizing the human intestine, commonly called roundworm.

Ocular Larva Migrans (OLM)

Occurs when larvae localize in the eye and cause a granulomatous response around the larva, common symptoms include unilateral visual impairment, causing failing vision and subsequent strabismus, leukocoria.

Visceral Larva Migrans (VLM)

VLM occurs most commonly in young children and is thought to be associated with a larger infectious dose and multi-systemic disorder, resulting in hepatitis and pneumonitis as the larvae migrate through the liver and lungs, respectively.

Toxocara canis

Dog roundworm, an ascarid species that can cause toxocariasis in humans.

Toxocara cati

Cat roundworm, an ascarid species that can cause toxocariasis in humans.

Anisakidae Genera

Anisakis, Contracaecum, Hysterothylacium, Pseudoterranova