Susceptibility of North American big brown bats (Eptesicus fuscus) to infection with European bat lyssavirus type 1

• Published in: Journal of general virology 2008-08, Vol.89 (8), p.1998-2010
• Main Authors: Franka, R, Johnson, N, Muller, T, Vos, A, Neubert, L, Freuling, C, Rupprecht, C. E, Fooks, A. R
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Viral - blood; Biological and medical sciences; Chiroptera - virology; Disease Susceptibility; Eptesicus fuscus; Europe; Female; Fundamental and applied biological sciences. Psychology; Lyssavirus; Lyssavirus - classification; Lyssavirus - genetics; Lyssavirus - isolation & purification; Lyssavirus - pathogenicity; Male; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; North America; Reverse Transcriptase Polymerase Chain Reaction; Rhabdoviridae Infections - immunology; Rhabdoviridae Infections - transmission; Rhabdoviridae Infections - veterinary; Rhabdoviridae Infections - virology; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/vir.0.83688-0

1 Centers for Disease Control and Prevention, 1600 Clifton Road, Mail-Stop G33, Atlanta, GA 30333, USA 2 Department of Virology, Rabies and Wildlife Zoonoses Group, WHO Collaborating Centre for the Characterization of Rabies and Rabies-related Viruses, Weybridge, Addlestone, Surrey KT15 3NB, UK 3 Friedrich Loeffler Institute, Federal Research Institute of Animal Health, 16868 Wusterhausen, Germany 4 IDT Biologika, Am Pharmapark, 06861 Dessau-Roßlau, Germany Correspondence R. Franka rpf5{at}cdc.gov The aim of this study was to determine the susceptibility of insectivorous bats (using the big brown bat as a model) to infection with European bat lyssavirus type 1a (EBLV-1a), to assess the dynamics of host immune responses and to evaluate the opportunity for horizontal viral transmission within colonies. Two isolates of EBLV-1a, originating from Slovakia (EBLV-1aSK) and Germany (EBLV-1aGE), were tested. Four different routes of inoculation were used with isolate EBLV-1aSK [10 4.8 mouse intracerebral median lethal dose (MICLD 50 ) in 50 µl]: intramuscular (i.m.) in the deltoid area or masseter region, per os (p.o.) and intradermal (i.d.) scratches. Isolate EBLV-1aGE (10 3.2 and 10 2.2 MICLD 50 in 20 µl) was inoculated via the intranasal (i.n.), i.m. (low- and high-dose groups, into pectoral muscles); p.o. and intracerebral (i.c.) routes. None of the bats infected by the i.n., p.o. or i.d. route with either virus isolate developed disease during the experiments (91 or 120 days, respectively). Incubation periods were 9–12 days for i.c.-inoculated bats (66 % mortality), 12–33 days for bats inoculated i.m. with the higher dose (23–50 % mortality) and 21–58 days in bats inoculated i.m. with the lower dose of virus (57 % mortality). Virus or viral RNA in bat saliva was detected occasionally, as early as 37 days before death. All i.d.-inoculated and the majority of i.m.-inoculated bats seroconverted within 7–10 days of inoculation. These observations suggest that exposure of bats to varying doses of EBLV-1 from rabid conspecifics via natural (i.d.) routes could lead to an abortive infection and serve as a natural mode of immunization resulting in the presence of virus-neutralizing antibodies in free-ranging bats.