Eur J Wildl Res (2008) 54:439–447 DOI 10.1007/s10344-007-0168-1
ORIGINAL PAPER
Integrated-baiting concept against Echinococcus multilocularis in foxes is successful in southern Bavaria, Germany Andreas König & Thomas Romig & Christof Janko & Ralph Hildenbrand & Ernst Holzhofer & York Kotulski & Christian Ludt & Michael Merli & Stefanie Eggenhofer & Dorothea Thoma & Johanna Vilsmeier & Dorothea Zannantonio
Received: 13 June 2007 / Revised: 18 December 2007 / Accepted: 19 December 2007 / Published online: 29 January 2008 # Springer-Verlag 2007
Abstract This paper describes the design and the preliminary evaluation of an integrated approach to the control of Echinococcus multilocularis in foxes using praziquantel bait. Air distribution of bait in agricultural and recreational areas was combined with distribution of bait by hand in towns and villages to cover the entire fox population in the 213-km2 baiting area. Bait distribution density was 50/km2, and bait was distributed once every 4 weeks. Pre-baiting prevalence was 35% (22–50% CI 95%). During a 1-year period following the first 4 months of bait distribution, only one positive fox was found (prevalence 1%; 0–4% CI 95%). No significant change had occurred in the unbaited control area. This prevalence decline is far more proCommunicated by F.-J. Kaup A. König (*) : C. Janko : R. Hildenbrand : Y. Kotulski : C. Ludt : S. Eggenhofer : J. Vilsmeier : D. Zannantonio Wildlife Biology and Management Unit, Technische Universität München, Am Hochanger 13, 85354 Freising, Germany e-mail:
[email protected] T. Romig : M. Merli : D. Thoma Parasitology Department, University of Hohenheim, Emil-Wolff-Str. 34, 70599 Stuttgart, Germany T. Romig e-mail:
[email protected] E. Holzhofer Holzhofer Flight Service, Unterschüpfer Str. 9, 97944 Boxberg, Germany e-mail:
[email protected]
nounced than in previous fox-baiting studies, which is likely to be due to the increased bait distribution density and baiting frequency, and the inclusion of the ‘urban’ fox population. Keywords Zoonosis . Red fox . Disease control . Vulpes vulpes . Wildlife management
Introduction High fox populations have been recorded since the beginning of the 1990s across broad swathes of central Europe and Germany (Ansorge 1990; Bellebaum 2003; Breitenmoser-Würsten et al. 2001; Chautan et al. 2000; Gloor et al. 2001; König et al. 2005; Vos 1990). This high fox population density is a consequence of the immunization of foxes against rabies (Bellebaum 2003; Vos 1990, 1993), and it is now double to treble what it was in Bavaria in the 1980s (König et al. 2005). At the same time, foxes here have annexed towns and communities, making them part of their habitat (Gloor et al. 2001; Harris 1977, 1981; Harris and Rayner 1986; Hofer et al. 2000; König 2005; Macdonald 1993). Living with these animals is not without its problems, as foxes in both rural and urban areas are infested in high numbers with the small fox tapeworm (Echinococcus multilocularis; Hofer et al. 2000; König 2005; König et al. 2005). In humans, this tapeworm can cause the severe zoonotic infection, alveolar echinococcosis. Although known cases of this disease are still relatively rare in Europe and Germany (Gerards 2005), the number of new clinical cases recorded is on the rise. In Switzerland, a mean
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annual incidence per 100,000 more than doubled from 0.10 during 1993–2000 to 0.26 during 2001–2005 (Schweiger et al. 2007). A similar trend is apparent in Bavaria, where, before 2002, approximately three new cases were recorded per year; in both 2005 and again in 2006, there were nine cases reported (Kern, unpublished). The average annual incidence per 100,000 inhabitants has thus risen in Bavaria from 0.03 in the period from 1985 to 1989 (Notdurft et al. 1996), and from 0.02 during 1992–2002 to 0.06 between 2003 and 2006 (T=−3.322, df=6.974, p
