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Controlling Rabies in Foxes Unprecedented Success in Europe

The European Union (EU) aims to eliminate fox-mediated rabies from its territory by 2020. At first sight, this seems a rather ambitious goal considering that this horrifying disease has tormented humans and animals in Europe since ancient times.

Highly efficacious and safe vaccines for humans are available in Europe and, consequently, human rabies cases are extremely rare, the majority being reported in Russia. However, the potential threat remains, as the disease has not been eliminated from the main reservoir host species, the red fox (Vulpes vulpes). This zoonotic disease has the highest fatality rate among humans of any infectious disease known, so its elimination from such a large geographical area as the EU would be a major accomplishment. This is especially so when considering the red fox is an evasive wildlife species making control difficult to implement.

The latest rabies epidemic among red foxes is believed to have started in the Kaliningrad region of Russia, which borders Poland and Lithuania, in the 1940s. It then spread to most countries of Eastern, Central and Western Europe by the mid-1970s. Initially, control efforts concentrated on reducing the density of the fox population, through intensified hunting, culling cubs, poisoning and gassing of dens, to below a threshold that could sustain transmission. These population reduction efforts were not only highly controversial, they had little impact and, retrospectively, were actually considered to be counterproductive.

With the development of oral vaccination of foxes against rabies – using vaccine-loaded baits distributed in the environment – a completely new approach to wildlife disease management became available. The first field trial took place in Switzerland in 1978, followed by efforts in other European countries, starting with Germany, Italy, France and Belgium.

Rabies Bulletin Europe

By coincidence, shortly before the first field trial, a European database and rabies reporting system was established by the World Health Organization (WHO), in 1977. Called the WHO Rabies Bulletin Europe (RBE), it aimed to meet the demand for adequate and reliable rabies surveillance data across borders. The use of this single reporting system has encouraged collaborative control efforts in neighbouring countries through the evaluation of shared epidemiological data – even across political boundaries! Cross-border cooperation is essential for sustained rabies control, especially for a disease with a wildlife reservoir species that does not respect borders or political boundaries.

Of course, during the initial years of RBE when the Cold War was nearing its height, the political climate in Europe sometimes hindered uncensored data-sharing. However, despite this situation, RBE not only collect and analyse data across political divides, but it also enabled certain countries to improve their rabies surveillance data collection system. Initially, RBE appeared in printed form every quarter but nowadays is available electronically (www.who-rabies- bulletin.org). This European rabies database is maintained

by the WHO Collaborative Centre for Rabies Surveillance and Research. Initially, it was compiled at the Federal Research Institute for Virus Disease of Animals in Tübingen, Germany, but now it is based at the Friedrich-Loeffler-Institute in Insel Riems – Greifswald, Germany.

This availability of detailed European rabies data – spanning four decades of oral rabies vaccination (ORV) campaigns – gives a unique opportunity to analyse progress in the elimination of fox-mediated rabies in Europe.

Rabies Incidence

During the past four decades, 31 European countries implemented ORV programmes within their territories. The total area ever covered, at least once, with vaccine baits between 1978 and 2018 encompassed 2.73 million km2 (Fig 1). This peaked in 2007 when baits were concurrently distributed over approximately 1 million km2. As a result of the implementation of ORV, the number of rabies cases reported annually in Europe to the RBE steadily declined from 15,355 in 1978 to 4027 in 2018, with intermediate peaks in 1984 and 1989. However, to appraise the true impact of ORV on rabies incidence, it is necessary to differentiate geographical and time-based use of this disease management tool.