Institute of Molecular Virology and Cell Biology (IMVZ)

Rabies, one of the oldest known viral zoonotic diseases, i.e. diseases that are transmissible from animals to humans, occurs worldwide and is an internationally notifiable disease. According to estimations of the WHO still several tens of thousands of humans die from this disease every year, especially in the poorer countries of Africa and Asia. Therefore, it is also considered a neglected zoonosis. 

Rabies is an acute, progressive and incurable viral encephalitis caused by negative strand RNA viruses of the Lyssavirus genus, family Rhabdoviridae of the Mononegavirales order that is transmitted following bites of infected mammals. The recognized etiological agents are classified into 16 recognized and 2 putative Lyssavirus species. Rabies virus (RABV), the causative agent of „classical or terrestrial rabies“, has a worldwide distribution with a variety of mesocarnivores (dog, fox, coyote, raccoon, raccoon dog, mongoose) as main reservoirs. 

From an epidemiological point of view, classical rabies can be differentiated into a „sylvatic “ and „urban“ cycle. While sylvatic rabies designates rabies transmitted by wildlife carnivores, dogs (Canis canis) are the main reservoir of urban rabies. The reservoir hosts independently maintain the infectious cycle thereby transmitting rabies virus to other animals and humans. In Europe, the red fox (Vulpes vulpes) is responsible for the persistence and spread of the disease. 

In the past 40 years, rabies control in Europe has been as successful as never before. The implementation of oral rabies vaccination (ORV) of foxes using modified live rabies vaccines virtually resulted in the elimination of the disease in Europe and Germany. Like other Western and Central European countries, in 2008 Germany was officially declared rabies-free (freedom from classical rabies). Rabies control is a top priority for the EU, which has called for the elimination of wildlife rabies in EU countries by 2020.

Intriguingly, bats are the sole reservoir of 15 known lyssaviruses worldwide, and hence are the true reservoirs. In contasrt to the classical rabies virus (RABV) bat –associated lyssaviruses have a narrower geographic and host range distribution. Even for RABV bats are a main reservoir, however only in in the Americas). For two further lyssaviruses it is presumed that bats are the reservoirs too. European bats can also develop rabies disease and die. Most strongly affected are Serotine bats, which have been shown to harbor European bat lyssavirus 1 (EBLV-1). Pond bats and Daubenton’s bats are the reservoirs for EBLV-2, while the Natterer’s bat is the reservoir for Bokeloh bat lyssavirus (BBLV). The West Caucasian bat lyssavirus (WCBV) and the Lleida bat lyssavirus (LLEBV) have been detected in sub species of the Schreiber’s bat (Miniopterus schreibersii) in West Caucasia, Spain and France, respectively. Bats of this species are seen only rarely as migratory animals in Germany.