[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Nematodes](https://durgical.com/en/microbiology/groups/nematodes/) › Trichostrongylus spp.

# Trichostrongylus spp.

- Parasite
- For completeness

A small roundworm of sheep, goats and cattle. People swallow its larvae on raw vegetables; its eggs look like hookworm eggs.

Updated Nov 13, 2026

Also called: Trichostrongylus colubriformis, Trichostrongylus orientalis, Trichostrongylus axei, trichostrongylosis

## Quick facts

**Type**
Parasite · [Nematodes](https://durgical.com/en/microbiology/groups/nematodes/)

**Gram / shape**
Thin

**Spread**
Vegetable gardens fertilised · Unlike hookworm

**Causes**
Trichostrongylosis

**Treatment**
Benzimidazoles

On this page

- The basics Key points
- At a glance
- Morphology
- Transmission
- Life cycle
- Memory aid
- What the colours mean

- Clinical Virulence factors
- Diseases it causes
- Clinical picture
- Diagnosis

- Treatment Treatment
- Prevention

- Study Test yourself

- Connections Connections

## Key points

- Herbivore worm; humans infected by swallowing larvae, not through the skin.
- Egg looks like a larger, more pointed hookworm egg: a classic lab pitfall.
- Eosinophilia may be the main clue.
- Source: raw vegetables fertilised with sheep or goat manure.

## At a glance

**Shape**
Thin, thin-shelled colourless egg, tapering at one end, often already segmented

**Family**
Trichostrongylidae

**Type**
Strongylid nematode of herbivores; humans are incidental hosts

**Size**
Eggs 75–95 × 40–50 µm, longer and narrower than hookworm eggs (60–75 × 35–40 µm)

## Morphology

- Egg larger than a hookworm egg, with one or both ends more pointed.
- The inner membrane may look wrinkled.
- Adults are small, slender worms of the small intestine.

## Transmission

- Swallowing infective larvae on raw vegetables or water contaminated with herbivore manure.
- Vegetable gardens fertilised with sheep or goat manure are a classic source.
- Unlike hookworm, larvae do not need to penetrate the skin to infect.

**Reservoir:** Sheep, goats, cattle and other herbivores; Soil and vegetation contaminated with their faeces

### Isolation precautions

What the care team adds to standard precautions.

- Standard

## Life cycle

- Eggs leave in the faeces of a herbivore, usually a sheep, goat or cow.
- In warm, moist, shaded soil the larvae hatch within days.
- After two moults (5–10 days) they become infective third-stage larvae on soil and plants.
- A person swallows larvae on raw vegetables or in water.
- The worms mature in the small intestine, attach to the mucosa and lay eggs.

## Virulence factors

- Adults embed their front end in the small-intestine mucosa, causing local inflammation.
- Heavy burdens cause blood loss and anaemia.
- The tissue phase drives eosinophilia, sometimes very high.

## Diseases it causes

- Trichostrongylosis: usually silent; heavy infection causes abdominal pain, diarrhoea and anaemia

## Clinical picture

- Most infections are light and asymptomatic.
- Epigastric pain, diarrhoea, loss of appetite, fatigue, headache.
- Unexplained eosinophilia in several members of a household who share a vegetable garden.
- Has been misdiagnosed as acute fascioliasis when eosinophilia and diet suggest it.

## Diagnosis

- Eggs in stool; concentration or flotation methods help in light infections.
- Measure eggs carefully to separate them from hookworm; mixed infections occur.
- Stool larval culture can tell larvae apart from hookworm larvae.
- Adult worms may be recovered in stool after treatment.

## Treatment

Benzimidazoles (albendazole or mebendazole); pyrantel pamoate is an alternative. Anthelmintic resistance is common in livestock strains.

Drug class only; doses and regimens are set by the clinician from the current guideline.

In Pharmacology:

- [Albendazole](https://durgical.com/en/pharmacology/albendazole/)
- [Mebendazole](https://durgical.com/en/pharmacology/mebendazole/)
- [Pyrantel pamoate](https://durgical.com/en/pharmacology/pyrantel-pamoate/)

## Prevention

- Do not fertilise vegetable gardens with fresh animal manure.
- Wash and disinfect raw vegetables; safe drinking water.
- Hand hygiene after contact with soil and livestock.

## Memory aid

Tricho-STRONG-ylus came from the sheep's garden: same look as the hookworm, but it entered through the salad, not the foot.

## Test yourself

Think of the answer, then tap the question to see it.

## How do humans acquire Trichostrongylus?

By swallowing infective larvae on raw vegetables or in water contaminated with herbivore manure.

## Which helminth egg is most easily confused with a Trichostrongylus egg?

The hookworm egg; Trichostrongylus eggs are longer, narrower and more pointed at one end.

## Which laboratory clue often leads to the diagnosis in a family cluster?

Eosinophilia, sometimes marked, in several people who eat vegetables from the same garden.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/microbiology/trichostrongylus-spp/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

## Connections

## Related 3

- [Necator americanus / Ancylostoma duodenale](https://durgical.com/en/microbiology/necator-americanus-ancylostoma-duodenale/)
- [Strongyloides stercoralis](https://durgical.com/en/microbiology/strongyloides-stercoralis/)
- [Fasciola hepatica](https://durgical.com/en/microbiology/fasciola-hepatica/)

[← Back to the group: Nematodes](https://durgical.com/en/microbiology/groups/nematodes/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [CDC - DPDx - Trichostrongylosis](https://www.cdc.gov/dpdx/trichostrongylosis/index.html) (CDC, 2017); [Familial Trichostrongylus Infection Misdiagnosed as Acute Fascioliasis](https://wwwnc.cdc.gov/eid/article/21/10/14-1392) (Emerging Infectious Diseases (CDC), 2015).

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Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/trichostrongylus-spp/