Emergence of Echinococcus multilocularis among Red Foxes in northern Germany, 1991--2005

Abstract

The parasite Echinococcus multilocularis is currently of great concern in Europe because of its spreading behavior, which has public health implications. This study investigates the spatiotemporal distribution of Echinococcus multilocularis in Red Foxes. The infection status of 8459 foxes was sampled from 43 regions in the north German province of Lower Saxony over three investigation periods 1991--1994, 1994--1997 and 2003--2005. Linear empirical Bayesian smoothing within the binomial model was used to produce smoothed choropleth maps. Geostatistical kriging was applied to generate prevalence risk maps. Further geostatistical modeling of the prevalence difference between study periods facilitated spatiotemporal trend investigations. The spatial scan statistic was used for cluster detection analysis. The average prevalence risk for Lower Saxony increased from about 12 to 20% during 1991--2005. Specifically the increases from first to second and to third study periods were estimated by 3.3% (CI 95%: 0.6%-5.9%) and 8.5% (CI 95%: 5.2%-11.8%), respectively. Infections in foxes were clustering and a location stable disease cluster was detected in the south of the province. This study is the first showing evidence for steady emergence of Echinococcus multilocularis in Red Foxes. First cases of human Alveolar Echinococcosis were recorded recently.