# The Spiky Side of Urban Wildlife, First Detection of a Zoonotic Assemblage of Giardia duodenalis in European Hedgehogs (Erinaceus europaeus) from Italy

## TL;DR

Giardia duodenalis, a zoonotic parasite, was found in Italian hedgehogs, raising concerns about its spread between wild and domestic animals.

## Contribution

First detection of a zoonotic assemblage of Giardia duodenalis in European hedgehogs from Italy.

## Key findings

- Giardia duodenalis cysts were identified in a hedgehog via fecal flotation and PCR-RFLP analysis.
- The parasite was classified as the zoonotic assemblage AI-like, indicating potential for cross-species transmission.
- Trophozoites were observed in the hedgehog's small intestine through histological examination.

## Abstract

Giardia duodenalis is a flagellate protozoan parasite of several mammals, that is transmitted via the fecal-oral route and causes gastrointestinal diarrheal illness. Molecular analyses of several genetic markers have classified G. duodenalis into eight assemblages (A to H) exhibiting different host specificities. Assemblages A and B have zoonotic potential and infect a broad range of hosts. The European hedgehog (Erinaceus europaeus) is one of the wild species well-adapted to live in close proximity to humans. Therefore, surveying potential zoonotic parasites harbored by hedgehogs can also be of public health concern, particularly in urban settings with high animal densities.

Coproparasitological examinations are routinely conducted on hedgehogs admitted to WildUmbria Wildlife Rescue Center. Giardia duodenalis cysts were found in the fecal flotation of a hedgehog and were further tested using a direct immunofluorescent assay and PCR-RFLP molecular analysis of the β-giardin gene for assemblage and sub-assemblage characterization. The RFLP protocol attributed the samples to the AI-like zoonotic assemblage. Additionally, trophozoites attached to the intestinal mucosa of the small intestine were detected via histological techniques.

Although G. duodenalis has been detected in hedgehogs from several countries, it was never before reported in Italian hedgehogs. The identification of a zoonotic assemblage in hedgehogs suggests the potential for the parasite to be shared between wild and domestic environments, with pets possibly serving as bringing hosts.