Echinococcus multilocularis management by fox culling: An inappropriate paradigm

With the ongoing spread of Echinococcus multilocularis in Europe, sanitary authorities are looking for the most efficient ways of reducing the risk for human populations. Fox culling is one particular tool that has recently shifted from predation control to population health management. Our study aims to assess the effectiveness of this tool in limiting E. multilocularis prevalence in fox populations in France. Duting four years, a culling protocol by night shooting from cars was implemented around the city of Nancy (eastern France) representing 1700 h of night work and 15,000 km driven. The 776 foxes killed represented an overall increase of 35% of the pressure on the fox population over 693 km(2). Despite this consequent effort of culling, not only did night shooting of foxes fail to decrease the fox popu. lation, but it resulted in an increase in E. multilocularis prevalence from 40% to 55% while remaining stable in an adjacent control area (585 km(2)). Though no significant change in age structure could be described, an increase in immigration and local recruitment is the best hypothesis for population resilience. The increase in prevalence is therefore considered to be linked to a higher rate of juvenile movement within the culled area shedding highly contaminated faeces. We therefore advocate managers to consider alternative methods such as anthelmintic baiting, which has been proven to be efficient elsewhere, to fight against alveolar echinococcosis.