Characteristics of the Spread of a Wildlife Rabies Epidemic in Europe

Abstract

The control of rabies in wildlife by reducing the fox population has led in Europe to inconsistent results, since little was known of the dynamics of the fox population and the interaction between rabies epidemics, host populations, and control measures. As part of the WHO/FAO Coordinated Research Programme on Wildlife Rabies in Europe, data on epidemics and persisting reservoirs of the disease were processed by computer. The results led to a better understanding of the mechanism of spread of the epidemic and to proposals for the improvement of rabies control in animals and the protection of man.Within the WHO/FAO Coordinated Research Programme on Wildlife Rabies in Europe, intensive epidemiological and ecological studies have been carried out on the interaction between fox populations, rabies, and control measures under different topographical conditions. Moreover, the role of other wild carnivores and the effect of rabies and fox control on these species, as well as on small game and rodents, have been investigated (5,6,7,8). In some European countries, these research projects were supplemented by ecological studies on the composition and annual turnover of stable fox populations and on the recovery rate of fox populations after reduction by rabies and control measures (1,3,9).Not all projects provided a basis for a numerical analysis of different phases of the wavelike spread of the disease. Country-or state-wide rabies records that could be evaluated for this purpose were not accurate enough and special surveys with the most intensive investigations were in areas too small for this analysis.The location of statistically reasonable numbers of rabies cases was therefore determined with ade-

The velocity of spatial population expansion

“…This corresponds to observations in the field (e.g. Bogel and Moegle 1980). Another remarkable thing is that for somewhat larger densities the velocity of rabies expansion slightly decreases with increasing fox population density.…”

Animal Rabies in Massachusetts, 1985–2006

“…This reflects population dynamics in the face of an epizootic of fatal disease and the exhaustion of susceptible animals to sustain the force of infectivity. This is consistent with the 48-mo period of the first epizootic phase in the predictive modeling and other temporal and spatial analysis of wildlife rabies (Bö gel et al, 1976;Hanlon et al, 1999;Guerra et al, 2003). Since that time, a less dramatic, approximate 5-yr cycle may be in evidence, with geotemporal hot spots of intensified activity occurring.…”

The Epidemiology of Fox Rabies in Europe

“…The shift of the front has varied between a temporary standstill and a progression of 60-80 km per year. In a computer analysis by Bogel et al (21), the mean monthly distance in which new cases were found beyond the frontline was 4.8 km, regardless of the relative fox population density above a critical threshold. Maximum monthly spread was 20 km.…”

“…In most surveys a lower percentage of rabies infected foxes is found. This is mainly due to underreporting in foxes and The analysis of the frontwave shows that foxes bring the infection into new areas (13,16,21,25). Of all rabies cases appearing before a given monthly frontline, 97.2 per cent are foxes, whereas Annual kill by hunting, accident and disease Rabies infected foxes FIGURE 5.…”