European Bat Lyssavirus Transmission among Cats, Europe

We identifi ed 2 cases of European bat lyssavirus subtype 1 transmission to domestic carnivores (cats) in France.Bat-to-cat transmission is suspected.Low amounts of virus antigen in cat brain made diagnosis diffi cult.M ost countries in western Europe are currently free of rabies in terrestrial mammals, as was the case in France during 2001-2008 (1).However, rabies still remains a public health problem in these countries because of natural circulation of bat-specifi c viruses (order Mononegavirales, family Rhabdoviridae, genus Lyssavirus) such as European bat lyssaviruses (EBLVs).These viruses are divided into genotypes 5 (EBLV-1) and 6 (EBLV-2); the fi rst genotype is subdivided into subtypes a and b (2).Knowledge of the prevalence and epidemiology of EBLV is limited (2-5).To date, natural transmission of EBLV-1 has been reported in a limited number of terrestrial mammals, including 5 sheep in Denmark (6) and 1 stone marten in Germany (7) (Table 1).Since 1985, only 3 human deaths from EBLVs have been confi rmed (3) (Table 1).We describe 2 documented cases of spillover transmission of EBLV in domestic carnivores (cats, Felis domesticus) in Europe. The StudyIn November 2003, a 6-month-old female stray cat (cat no. 1) was found ill in a public garden in Vannes (Morbihan District) in western France and taken to a veterinary clinic.This animal had convulsions and moderate dehydration and was emaciated.It was infected by feline immunodefi ciency virus, which was compatible with the clinical symptoms.The veterinarian was bitten while providing veterinary care to the cat.After a few days, the cat recovered and was impounded for veterinary surveillance.It died suddenly the following night.No information about potential contact with bats was available.On November 8, 2007, an 18-month-old female cat (cat no. 2) was taken by its owner to a veterinarian in Fontenayle-Comte (Vendée District) in western France because of abnormal behavior.The owner reported having been bitten by the cat.The next day, the cat showed severe central neurologic disorders and aggressive behavior.It died during the next night.Its outdoor access appeared to have been restricted.Two months later, the carcass of a bat (Eptesicus serotinus) was recovered in the same area of Fontenay-le-Comte and submitted for rabies testing.Recommended techniques for rabies diagnosis were used for all animals (8).For cat no. 1, results of a repeated direct immunofl uorescence antibody test (FAT) with a polyclonal antirabies conjugate (Bio-Rad, Marnes-la-Coquette, France) performed on different cortex and spinal bulb smears were negative.Viral isolation by using a rabies tissue culture infection test (RTCIT) was also unsuccessful, as was attempted isolation of virus by using a mouse inoculation test (MIT) (Table 1).The only test routinely used that gave a positive result was an antigen-capture ELISA (WELYSSA) for lyssavirus antigen (9).The presence of EBLV RNA (03011FRA) was determined by reverse transcription-PCR (RT-PCR) targeting short viral gene regions (5).Lyssavirus antigens were repeatedly detected by FAT in different areas of the brain of cat no. 2. Viral isolation by using RTCIT was positive only after the second cell culture passage.Results for isolation of EBLV (07240FRA) by MIT were positive.Lyssavirus antigen detection by WEL-YSSA was variable, depending on the part of the brain tested.Viral RNA was detected by RT-PCR (Table 1).The bat was positive for EBLV by FAT, RTCIT (08120FRA), MIT, and RT-PCR.Nucleotide sequencing and phylogenetic analysis identifi ed isolate 03011FRA as EBLV-1b and isolates 08120FRA and 07240FRA as EBLV-1a (Figure 1).Sequencing of the complete genome (10) of the 2 EBLV-1a isolates showed a high percentage of homology (Table 2).After identifi cation of these 2 cases of spillover transmission of EBLV-1 to domestic cats, postexposure prophylaxis measures were implemented.The veterinarian who