Occurrence of rabies in Poland in 2011-2015 in relation to the free-living fox population

Abstract

The aim of study was to evaluate the epizootic situation of rabies in Poland in 2011-2015 in relation to the free-living population of foxes, which are the main vectors of the rabies virus. The number of rabies cases increased in the first two years of this period, but subsequently diminished. The primary reservoir of the virus are still free-living foxes and, among domestic animals, dogs and cats. In terms of the frequency of virus occurrence in Poland, a shift has been noted in recent years from Podkarpackie Voivodeship to Lesser Poland Voivodeship. In 2015, over 80% of all rabies cases were diagnosed in Lesser Poland, and in domestic animals the virus was diagnosed solely in this voivodeship. During the study period, the population of free-living foxes was stable, but there was a slight increase in the number of foxes hunted. Nevertheless, the hunting index for the fox population, which does not exceed 72%, suggests that hunting is currently not the only mortality factor among foxes. The analysis of the size and density of the fox population in particular voivodeships revealed that density is not the main determinant of the occurrence and spread of the virus. The results of the study confirm that the immunization of free-living foxes, although costly, is still necessary to improve the situation, especially in regions with a high prevalence of the virus.