Effectiveness of oral immunization of free-living foxes in the reduction of rabies in Poland in 2011-2015

Abstract

SummaryThe paper presents the epidemiological situation of rabies in Poland in the period of 2011-2015, as well as discusses the effectiveness and costs of a national campaign of oral immunization of free-living foxes that has been carried out since 2002. It also evaluates the impact of the preventive measures on the dynamics of the number of foxes. During the study period, a decrease in the number of confirmed rabies cases in wild and domestic animals was recorded, but the primary reservoir of the virus continued to be free-living foxes. The high effectiveness of vaccination, evaluated by detailed laboratory tests, contributed significantly to the level of foxes immunization, which was also confirmed by ecological assessment. However, in some voivodeships and in some years of the study, the level of immunization was mediocre, as demonstrated by the results from 2015, when only every second fox examined had acquired resistance as a result of preventive vaccination. Despite the relatively high cost of these preventive measures, which include the cost of the vaccine and its distribution in the field, it seems necessary to continue the oral immunization of foxes, initiated in 1993 and expanded throughout the country in 2002. The dramatic decrease in the incidence of rabies in animals directly reduces epidemiological risks. Undoubtedly, a negative aspect of the aforementioned campaign is a persistently large and growing population of foxes and its adverse impact on the functioning of the main small animal species, as well as the possibility of an increased epizootic risk of other diseases affecting foxes. In this situation, it seems necessary to intensify the culling of foxes.

Histopathological Changes and Bacteriological Survey of Internal Organs in the Aspect of the Individual Condition of a Hare (Lepus Europaeus Pall.)

“…Another, not less important, element that directly affects the dynamics of the number of hares is predation. The use of oral treatments for immunization of free-living foxes eliminated one of the basic factors limiting the population, which in turn increased the impact of this species on small animals (Demirbas, 2015;Gołdyn, et al, 2003;Goszczyński and Wasilewski, 1992;Panek et al, 2006;Wasilewski, 2007;Flis et al, 2017Flis et al, , 2018. Hušek et al (2015) a high rate of fox predation targeting hares depending on the habitat and reported that hare males tend to fall as a prey.…”