# Dirofilaria repens Parasite: Review with Emphasis on Ultrasound Findings with Looking for Worm Mobility

**Authors:** Jacques Malghem, Bruno Vande Berg, Benoît Lengelé, Frédéric Lecouvet

PMC · DOI: 10.5334/jbsr.4072 · 2026-03-26

## TL;DR

This paper reviews the Dirofilaria repens parasite in humans, focusing on how ultrasound can detect worm movement to confirm the diagnosis.

## Contribution

The paper emphasizes the unique use of ultrasound to detect worm mobility for diagnosing Dirofilaria repens infection.

## Key findings

- Dirofilaria repens infection in humans is expanding due to global warming.
- Ultrasound can show double echogenic 'rail' images suggesting the diagnosis.
- Observing spontaneous worm motility via ultrasound confirms the diagnosis.

## Abstract

Human dirofilariasis is caused by infection with a parasite relatively common in dogs. Occasional transmission of larvae to humans occurs via an insect bite and development of an immature worm at the bite site. The disease, once confined to southern Europe, is becoming increasingly widespread, particularly due to global warming. Clinical signs are nonspecific and laboratory findings usually normal. Imaging shows pseudotumor features also nonspecific on computed tomography (CT) and magnetic resonance imaging (MRI) scans. Ultrasound may suggest the diagnosis by the presence of double echogenic ‘rail’ images. However, only spontaneous motility of the parasite observation can confirm the diagnosis.

## Linked entities

- **Diseases:** dirofilariasis (MONDO:0015636)
- **Species:** Dirofilaria repens (taxon 31241)

## Full-text entities

- **Diseases:** infection (MESH:D007239), dirofilariasis (MESH:D004184)
- **Species:** Canis lupus familiaris (dog, subspecies) [taxon 9615], Dirofilaria repens (species) [taxon 31241], Homo sapiens (human, species) [taxon 9606]

## Figures

16 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13025202/full.md

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Source: https://tomesphere.com/paper/PMC13025202