Experimental infection of foxes with European Bat Lyssaviruses type-1 and 2.
BACKGROUND
Since 1954, there have been in excess of 800 cases of rabies as a result of European Bat Lyssaviruses types 1 and 2 (EBLV-1, EBLV-2) infection, mainly in Serotine and Myotis bats respectively. These viruses have rarely been reported to infect humans and terrestrial mammals, as the only exceptions are sheep in Denmark, a stone marten in Germany and a cat in France. The purpose of this study was to investigate the susceptibility of foxes to EBLVs using silver foxes (Vulpes vulpes) as a model.


RESULTS
Our experimental studies have shown that the susceptibility of foxes to EBLVs is low by the intramuscular (IM) route, however, animals were sensitive to intracranial (IC) inoculation. Mortality was 100% for both EBLV-1 approximately 4.5 logs) and EBLV-2 (approximately 3.0 logs) delivered by the IC route. Virus dissemination and inflammatory infiltrate in the brain were demonstrated but virus specific neutralising antibody (VNA) was limited (log(ED50) = 0.24-2.23 and 0.95-2.39 respectively for specific EBLV-1 and EBLV-2). Foxes were also susceptible, at a low level, to peripheral (IM) infection approximately 3.0 logs) with EBLV-1 but not EBLV-2. Three out of 21 (14.3%) foxes developed clinical signs between 14 and 24 days post-EBLV-1 infection. None of the animals given EBLV-2 developed clinical disease.


CONCLUSIONS
These data suggest that the chance of a EBLV spill-over from bat to fox is low, but with a greater probability for EBLV-1 than for EBLV-2 and that foxes seem to be able to clear the virus before it reaches the brain and cause a lethal infection.
Cliquet
Florence
F
WHO Collaborating Centre for Research and Management in Zoonoses Control, OIE Reference Laboratory for Rabies, Community Reference Laboratory for Rabies, Community Reference Laboratory for Rabies Serology, AFSSA Malzeville, France. f.cliquet@afssa.fr
Picard-Meyer
Evelyne
E
Barrat
Jacques
J
Brookes
Sharon M
SM
Healy
Derek M
DM
Wasniewski
Marine
M
Litaize
Estelle
E
Biarnais
Mélanie
M
Johnson
Linda
L
Fooks
Anthony R
AR
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D005589:Foxes; D018114:Lyssavirus / Q000145:classification* / Q000472:pathogenicity; D012367:RNA, Viral / Q000302:isolation & purification; D018353:Rhabdoviridae Infections / Q000662:veterinary* / Q000821:virology; D013995:Time
D000914:Antibodies, Viral; D012367:RNA, Viral