Fox baiting against Echinococcus multilocularis: contrasted achievements among two medium size cities

Area of Science:

• Veterinary Parasitology
• Zoonotic Disease Control
• Urban Ecology

Background:

• Red foxes (Vulpes vulpes) are definitive hosts for the zoonotic cestode Echinococcus multilocularis in Europe.
• High fox and human population overlap increases the risk of Echinococcus multilocularis transmission.
• Praziquantel baits have shown success in reducing infection pressure in rural and small urban areas.

Purpose of the Study:

• To evaluate the efficacy of praziquantel baiting campaigns in controlling Echinococcus multilocularis in two medium-sized French cities.
• To assess bait consumption rates in urban versus suburban environments.
• To analyze the impact of treatment on parasite prevalence in fox populations.

Main Methods:

• Conducted 14 praziquantel baiting campaigns (August 2006-March 2009) in Annemasse and Pontarlier (33 km(2) each, 40 baits/km(2)).
• Monitored bait consumption in urban and suburban zones.
• Assessed Echinococcus multilocularis prevalence using EM-ELISA on fox feces collected from treated and control areas.

Main Results:

• Bait consumption was lower in urban areas (78.9%) than suburban (93.4%) and varied between cities (Annemasse 82.2% vs. Pontarlier 89.5%).
• Annemasse showed a significant decrease in fox fecal prevalence post-treatment (13.3% to 2.2%) compared to the control area.
• Pontarlier exhibited stable prevalence (9.1%), suggesting parasite life cycle resilience possibly due to recontamination, counteracting prophylaxis.

Conclusions:

• Praziquantel baiting can reduce Echinococcus multilocularis prevalence in urban fox populations, as seen in Annemasse.
• Treatment efficacy is influenced by local factors, including bait uptake and recontamination pressure, as demonstrated by contrasting results in Annemasse and Pontarlier.
• Anthelmintic treatment frequency for foxes should be tailored to specific local conditions for effective zoonotic cestode control.