Over a period of 40 months, 4374 foxes were randomly
sampled from an area located in
northwestern Brandenburg, Germany, and examined parasitologically
for infections with
Echinococcus multilocularis. Spatial analysis of the
origin of infected animals identified two (one
central and one southeastern) high-endemic foci with an estimated
prevalence of 23·8%. By
contrast, a prevalence of 4·9% was found in the remaining
(low-endemic) area. The prevalences
among juvenile and adult foxes were compared in the high-endemic
and the low-endemic areas.
To analyse the central high-endemic focus further, the random
sample was stratified by zones
representing concentric circles with a radius of 13 km (zone 1)
or xn−1+7 km for the remaining
three zones from the apparent centre of this focus (anchor point).
Prevalences calculated for
each zone showed a decrease from zone 1 (18·8%) to zone
4 (2·4%) with significant differences
for all zones but zones 3 and 4. The relative risk of an
infection decreased rapidly in a distance
range of 26 km around the high-endemic focus, whereas the
relative risk remained unchanged
within a distance of 5 km around the anchor point. The importance
of heterogeneous spatial
distribution patterns for the diagnosis and epidemiology of
the infection is discussed.