Experimental infection of foxes with European bat lyssaviruses type-1 and -2

Experimental studies have been undertaken to assess the susceptibility of silver foxes to bat variants of rabies virus, namely European Bat Lyssaviruses (EBLVs). Both EBLV-1 and EBLV-2 have been isolated in European bats since 1954, in Eptesicus serotinus and Myotis species, respectively. Since 2000, the number of reported cases has increased largely due to the improvement of the surveillance of bat rabies virus throughout Europe. Although over >800 EBLVs cases have been reported in bats in Europe, EBLV-1 and -2 viruses are rarely reported to infect humans and terrestrial animals. The study presented here shows that the sensitivity of silver foxes is low when infected with EBLVs via the intramuscular route; in contrast all animals infected via intracranial inoculation succumbed to the experimental challenge. The mortality rate was 100% for both EBLV-1 (approximately 4.5 log) and EBLV-2 (approximately 3.0 log). This data suggests that the susceptibility of foxes to EBLV-1 and EBLV-2 is low and that the transmission (spillover) and adaptation of EBLVs from a bat to a fox may be theoretically possible but unlikely.