European Bat Lyssavirus Infection in Spanish Bat Populations

Abstract

From 1992 to 2000, 976 sera, 27 blood pellets, and 91 brains were obtained from 14 bat species in 37 localities in Spain. Specific anti-European bat lyssavirus 1 (EBL1)-neutralizing antibodies have been detected in Myotis myotis, Miniopterus schreibersii, Tadarida teniotis, and Rhinolophus ferrumequinum in the region of Aragon and the Balearic Islands. Positive results were also obtained by nested reverse transcription-polymerase chain reaction on brain, blood pellet, lung, heart, tongue, and esophagus-larynx-pharynx of M. myotis, Myotis nattereri, R. ferrumequinum, and M. schreibersii. Determination of nucleotide sequence confirmed the presence of EBL1 RNA in the different tissues. In one colony, the prevalence of seropositive bats over time corresponded to an asymmetrical curve, with a sudden initial increase peaking at 60% of the bats, followed by a gradual decline. Banded seropositive bats were recovered during several years, indicating that EBL1 infection in these bats was nonlethal. At least one of this species (M. schreibersii) is migratory and thus could be partially responsible for the dissemination of EBL1 on both shores of the Mediterranean Sea.

Antibodies against Lagos Bat Virus in Megachiroptera from West Africa

“…Nine seropositive bats (8 E. helvum, 1 E. buettikoferi) were apparently healthy pregnant females. These results support theories that lyssaviruses are endemic within specifi c bat populations, that they may not cause high mortality rates, that exposure rates of LBV between megachiroptera in Old World African bats are high, and that bats may breed successfully after LBV exposure (7,8). The number of high reciprocal titers against LBV (Figure 1) and the history of LBV isolation in E. helvum suggest that LBV circulates in megachiroptera in Ghana.…”

“…No previous estimate of R 0 for genotype 2 Lyssavirus has been calculated, and although anamnesis may lead to no detectable antibodies in bats with immunity and a consequent underestimate of R 0 , this value indicates the potential R 0 and is comparable to values previously estimated for lyssavirus infections in bats (7,11). More detailed analysis relating to age-specifi c infection and survival rates or mode of transmission was precluded by the diffi culty in determining the age of adult bats, the lack of juveniles in the sample, and the cross-sectional sample used.…”

“…The modifi ed FAVN test requires a cut-off threshold, which in prior bat lyssavirus studies has been a titer of 27, to avoid false-positive results (6,7). The fi rst 121 samples collected were tested against the challenge virus standard; no tested bat was seropositive at 1:3 dilutions.…”

Twenty years of active bat rabies surveillance in Germany: a detailed analysis and future perspectives

“…Passive surveillance as the method of choice focuses on investigations of bats which were found with suspicious clinical symptoms or dead, whereas active surveillance for bat lyssavirus infections consisting of collecting and investigating micro-samples of blood and saliva from free-living indigenous bat populations as pioneered in North America [14][15][16] is considered valuable for obtaining additional information. As a consequence, active bat rabies surveillance in free-ranging bat populations was implemented in the UK [17,18], France [19], Spain [20][21][22][23][24], Switzerland [25], Sweden [26], Slovenia [27,28], Serbia [29] and Belgium [30]. While in some countries results from passive surveillance were confirmed by active surveillance, the detection of virus neutralizing antibodies (VNA) in sera of insectivorous bats indicated the presence of lyssaviruses in countries where bat rabies cases had not yet been reported [6] resulting in speculation as to whether bat lyssavirus infections are in fact more frequent and more widely distributed than assumed from passive surveillance data.…”

Public health risk analysis of European bat lyssavirus infection in The Netherlands

“…Active surveillance in Serotine bats [20] or experimental EBLV infection in Serotine bats could fill the information gap. EBLV is generally believed to be excreted in the saliva in a low concentration, but only limited data on this subject are available [21,22].…”