Bat rabies surveillance in France: first report of unusual mortality among serotine bats

Abstract

BackgroundRabies is a fatal viral encephalitic disease that is caused by lyssaviruses which can affect all mammals, including human and bats. In Europe, bat rabies cases are attributed to five different lyssavirus species, the majority of rabid bats being attributed to European bat 1 lyssavirus (EBLV-1), circulating mainly in serotine bats (Eptesicus serotinus). In France, rabies in bats is under surveillance since 1989, with 77 positive cases reported between 1989 and 2016.Case presentationIn the frame of the bat rabies surveillance, an unusual mortality of serotine bats was reported in 2009 in a village in North-East France. Six juvenile bats from an E. serotinus maternity colony counting ~200 individuals were found to be infected with EBLV-1. The active surveillance of the colony by capture sessions of bats from July to September 2009 showed a high detection rate of neutralising EBLV-1 antibodies (≈ 50%) in the colony. Moreover, one out of 111 animals tested was found to shed viable virus in saliva, while lyssavirus RNA was detected by RT-PCR for five individuals.ConclusionThis study demonstrated that the lyssavirus infection in the serotine maternity colony was followed by a high rate of bat rabies immunity after circulation of the virus in the colony. The ratio of seropositive bats is probably indicative of an efficient virus transmission coupled to a rapid circulation of EBLV-1 in the colony.Electronic supplementary materialThe online version of this article (10.1186/s12917-017-1303-1) contains supplementary material, which is available to authorized users.

First Case of Lethal Encephalitis in Western Europe Due to European Bat Lyssavirus Type 1

“…Our results suggest that the risk of EBLV-1 transmission to human, even if low, persists and could be higher than previously perceived. Most EBLV-1 cases in bats are probably not detected (69 cases only detected in Western Europe in 2019-2020, eurl-rabies.anses.fr), but surveys indicate that the virus circulates in bat colonies [32][33][34] and sometimes lead to high mortality [35]. The public should be reminded to avoid direct interactions with bats.…”

Incursion of European Bat Lyssavirus 1 (EBLV-1) in Serotine Bats in the United Kingdom

“…Infection with EBLV-1 causes the disease rabies and can be fatal in bats [12,45,48]. Rabies usually presents itself with neurological impairment which can result in overly aggressive behaviour, motor impairment and poor sensory function [49].…”

Applying the Darwin Core data standard to wildlife disease – advancements toward a new data model

“…Taking the example of reporting rabies outbreaks in bat colonies 7 (Table 11a), the percentage of diseased individuals is reported together with an upper and lower confidence interval at 95%, which statistically reflect the 2.5% and 97.5% quantiles. These confidence intervals are dependent on the parent measurement (Table 11b), incurring a nested data structure.…”