EBLV-2 prevalence in the United Kingdom as determined by surveillance testing

Five cases of EBLV-2 have been detected in the UK since 1996, with all wildlife cases in the Daubenton's bat: one on the south coast in Sussex in 1996, one in Lancashire in 2002, another in 2003, one in Surrey in 2004 and a human fatality in Angus, Scotland, in 2002. As a result of the human case, a seroprevalence study, aimed primarily at the Daubenton's bat was conducted in 2003 in Scotland and at some sites in England. In Scotland, 198 Daubenton's, 20 Natterer's and 6 pipistrelles were caught at 19 sites and analysed, while in England 67 Daubenton, 2 Brandts/ Whiskered and 4 pipistrelle bats were analysed from four sites in Lancashire. Analysis of blood was performed by a modified fluorescent antibody virus neutralisation test (mFAVN) to determine antibody titre to EBLV-2. Ignoring those sites where we had a priori reason to expect infected bats, the overall seroprevalence was between 0.7-5.1 % (95 % confidence interval), with a maximum likelihood estimate of 2.2 %. Mouth swabs were taken and tested for virus genome by RT-PCR and live virus by tissue culture isolation. All of the PCR and isolation results were negative suggesting that none of the bats sampled were actively excreting virus. This suggests a low level of active infection in Britain and raises the possibility that bats may recover following exposure to EBLV-2.