Anthelmintic baiting of foxes against urban contamination with Echinococcus multilocularis.

Daniel Hegglin,Peter Deplazes,Paul I Ward

doi:10.3201/eid0910.030138

Abstract

In recent years, increases in the urban fox population have been observed in many countries of the Northern Hemisphere. As a result, Echinococcus multilocularis has entered the urban environment. Because of a possible increased risk for alveolar echinococcosis, intervention strategies need to be evaluated. In Zürich, Switzerland, 50 praziquantel-containing baits per km2 were distributed monthly in six 1-km2 bait areas and one 6-km2 bait area from April 2000 through October 2001. The proportion of E. multilocularis coproantigen–positive fox fecal samples collected remained unchanged in six control areas but decreased significantly in the 1-km2 bait areas (from 38.6% to 5.5%) and in the 6-km2 bait area (from 66.7% to 1.8%). E. multilocularis prevalence in the intermediate host Arvicola terrestris also decreased significantly in baited areas. This controlled baiting study shows that a pronounced reduction of E. multilocularis egg contamination is feasible in urban areas where the organism is highly endemic.

Highlights

The zoonotic tapeworm Echinococcus multilocularis is typically perpetuated in a wild life cycle, which includes foxes as definitive hosts and various rodent species as intermediate hosts [1]
Baiting and Environmental Contamination To evaluate the effect of the experimental baiting, we analyzed 682 fox fecal samples collected in the six 1-km2 bait areas and 523 fecal samples from the six control areas
The proportion of coproantigen-positive fecal samples in bait areas decreased from 38.6% during winter 1999 to 5.5% in summer/autumn 2001

Summary

Introduction

The zoonotic tapeworm Echinococcus multilocularis is typically perpetuated in a wild life cycle, which includes foxes (genera Vulpes and Alopex) as definitive hosts and various rodent species as intermediate hosts [1]. The high number of infected foxes in cities and villages, in close contact with domestic pets and humans, could increase the risk of alveolar echinococcosis [16]. The high prevalence of E. multilocularis in densely populated areas and the increase of foxes living in close vicinity to humans strongly suggest that evaluating possible intervention strategies is prudent. In extended rural areas of Germany and Japan, praziquantel baits lowered the prevalence of E. multilocularis in foxes [19,20,21] These results cannot be transferred to the condition of agglomerations and urban areas, where until now no attempt has been made to evaluate an intervention strategy for foxes

Methods

Results

Discussion

Conclusion