Echinococcus granulosus in the wolf in Italy.

Area of Science:

• Veterinary Parasitology
• Wildlife Epidemiology
• Echinococcosis Research

Background:

• Echinococcus granulosus is a parasite with significant public health and economic impacts.
• Wolves are definitive hosts for Echinococcus granulosus, potentially playing a role in its transmission cycle.
• Understanding parasite dynamics in wildlife populations is crucial for disease control and prevention.

Purpose of the Study:

• To investigate the prevalence and intensity of Echinococcus granulosus infection in Italian wolves.
• To determine factors influencing parasite infection in wolves, including age and local disease prevalence.
• To model the potential role of wolves in a sylvatic cycle of Echinococcus granulosus.

Main Methods:

• Examination of 119 wolf cadavers from 1987-1999 across the Apennines range in Italy.
• Analysis of Echinococcus granulosus prevalence and mean intensity in positive wolf samples.
• Statistical analysis to identify correlations between wolf infection and local cystic echinococcosis (CE) prevalence in sheep.
• Development of a deterministic model to simulate a theoretical sylvatic parasite cycle.

Main Results:

• Eighteen out of 119 wolves (15%) tested positive for Echinococcus granulosus.
• Mean infection intensity was 697.5 parasite units, with a force of infection of 8.2 year(-1).
• Wolf infection prevalence was significantly correlated with local CE prevalence in sheep.
• Wolf age and local CE prevalence in sheep significantly influenced mean infection intensity.

Conclusions:

• Wolves in Italy are infected with Echinococcus granulosus, with prevalence linked to sheep cystic echinococcosis.
• A theoretical sylvatic cycle suggests potential CE prevalence of 10-25% in wild intermediate hosts.
• Despite increasing wolf and wild ungulate populations, wolves remain integral to the primary dog-sheep parasite cycle.