The Successful Elimination of Sylvatic Rabies Using Oral Vaccination of Foxes in Slovenia.

Danijela Černe,Peter Hostnik,Ivan Toplak

doi:10.3390/v13030405

Abstract

Sylvatic rabies was present in Slovenia between 1973 and 2013, with the red fox as the main reservoir of the rabies virus. The first oral rabies vaccination (ORV) control program in foxes started in 1988, using the manual distribution of baits. Significant improvement of fox vaccination was achieved with the aerial distribution of baits, starting in 1995 and successfully finished with the final, fifty-ninth vaccination campaign in 2019. Between 1979 and 2019, a total of 86,471 samples were tested, and 10,975 (12.69%) rabies-positive animals were identified. Within the ORV, two different vaccines were used, containing modified live virus strain Street Alabama Dufferin (SAD) B19 and SAD Bern, while the last ORV campaigns were completed in 2019, with a vaccine containing a genetically modified strain of SPBN GASGAS. Molecular epidemiological studies of 95 rabies-positive samples, originating from red foxes, badgers, cattle, dogs, martens, cats, and horses, revealed a low genetic diversity of circulating strains and high similarity to strains from neighboring countries. During the elimination program, few vaccine-induced rabies cases were detected: three in red foxes and one case in a marten, with no epidemiological relevance. Slovenia has been officially declared a country free of rabies since 2016.

Highlights

Rabies is a fatal viral disease that affects all warm-blooded mammals, including humans
The first successful implementation of a rabies elimination program by using oral rabies vaccination (ORV) of foxes started in Switzerland in 1978 [7]; starting in 1984, the same approach was adopted in several European countries, resulting in rapid decreases of the number of reported rabies cases
Sylvatic rabies was firstly detected in a red fox on 3 September 1973 in the eastern part of Slovenia and locally spread, mainly among red foxes in the Prekmurje region

Summary

Introduction

Rabies is a fatal viral disease that affects all warm-blooded mammals, including humans. The disease can be maintained in wild and domestic animals and transmitted to a susceptible host almost exclusively through biting [1] It is caused by an enveloped RNA virus, of the family Rhabdoviridae, genus Lyssavirus, and order Mononegavirales [2]. At the beginning of the 1940s, sylvatic rabies in Europe began to appear among foxes, and spread progressively from Poland to central and western Europe [5]. These epidemiological changes from urban to sylvatic rabies required a new disease control strategy [6]. Recurrences of rabies in Italy [9], Greece [10], and Slovakia showed the need for continuous surveillance of the epidemiological situation within the European Union (EU) in wildlife and domestic animals [11]

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