Occurrence of Giardia in Swedish Red Foxes ( Vulpes vulpes )

Area of Science:

• Veterinary Parasitology
• Wildlife Epidemiology
• Zoonotic Diseases

Background:

• Giardia duodenalis is an intestinal protozoan causing gastrointestinal illness in various animals.
• Understanding its epidemiology in wildlife is crucial for both animal and public health.
• Wild red foxes (Vulpes vulpes) are abundant predators in Sweden, potentially influencing parasite transmission.

Purpose of the Study:

• To investigate the occurrence and prevalence of Giardia duodenalis in wild Swedish red foxes.
• To provide preliminary data on the role of red foxes in Giardia duodenalis transmission dynamics.
• To identify specific assemblages of Giardia duodenalis circulating in this wildlife population.

Main Methods:

• Fecal samples from 104 wild red foxes were analyzed for Giardia duodenalis cysts using a direct immunofluorescent antibody test.
• Samples with high cyst counts (>2,000 cysts/gram) were subjected to molecular analysis via PCR and gene sequencing.
• The triosephosphate isomerase (tpi) gene was targeted for amplification and sequencing.

Main Results:

• Giardia duodenalis cysts were detected in 44% (46/104) of the fecal samples.
• Excreted cyst counts ranged from 100 to 140,500 cysts per gram of feces.
• Molecular analysis of four positive samples revealed the presence of assemblage B.

Conclusions:

• Wild red foxes in Sweden are a significant host for Giardia duodenalis.
• The detection of assemblage B suggests potential transmission pathways between foxes and other hosts.
• This study establishes baseline data on the epidemiology of Giardia duodenalis in Swedish red foxes.