News

SNH releases latest bat lyssavirus monitoring results
03/07/2009
The latest results of the SNH bat lyssavirus monitoring programme have been released today. The monitoring has, for the first time, detected the EBLV-2 virus in a single Daubentonís bat captured at a feeding area in Perthshire in 2008.

EBLV has been found in bat populations across Europe in the form of two closely related strains of virus, EBLV-1 and EBLV-2, over recent years. The viruses are both members of the family of rabies viruses found around the world. Results of the Scottish study in 2008 showed that 3% of Daubentonís bats tested were positive for antibodies to EBLV-2.

SNH now has four years of comparable data on the level of EBLV antibodies in Scottish bats from 2005 to 2008. Over the period of the study, there have been over 900 captures of Daubentonís bats and blood samples from each of these have been tested for antibodies. To detect the virus itself (as viral RNA) saliva samples from all bats captured in 2005 were tested. In the years 2006 - 2008, saliva samples were tested from all bats captured at those colonies where evidence of antibody was detected.

In addition, blood samples from two Nattererís bats have tested positive for antibodies to the EBLV-1 strain, (one in 2007 and one in 2008). Evidence of exposure to EBLV in this species has not been found in Britain before. No virus has been found in Nattererís bats.

Professor Colin Galbraith, director of policy and advice at SNH, confirmed: "This work continues to show that a relatively small percentage of the bats sampled have antibodies to EBLV. The detection of virus in a single Daubentonís bat is noteworthy, but not surprising, given the number of bats that have tested positive for antibodies over the past four years. Indeed, it is remarkable that it has taken this much sampling to find an infectious bat.Ē

Dominic Mellor, Veterinary Adviser to Health Protection Scotland said: "The results from this work show how scarce infectious bats actually are. However, it does reinforce the need for the public not to touch bats. Existing rabies vaccines protect against infection and current guidelines and protocols for the protection of exposed groups and for the management of people bitten or scratched by any species of bat offer fully adequate protection."

If a person finds a sick or injured bat, they should not handle it but seek advice from a local bat conservation group or the Bat Conservation Trust Helpline on 0845 1300 228. In Scotland, they may also phone the SNH Bat Helpline on 01738 458663 for pre-recorded advice. If the bat appears injured, they can contact the Scottish SPCA on 03000 999999, who may be able to help. Householders with enquiries concerning bat roosts in their property should contact their local SNH office for advice (see local telephone directory for details).

SNH has commissioned further work to continue the monitoring of the virus in Scottish bat populations during the summer of 2009.

ENDS

For further information:

Fergus Macneill, SNH Public Relations: 01463 725021

NOTES TO EDITORS

Bats, like other mammals can carry rabies, although in Europe the actual virus that may be carried by them is not classical rabies, but the closely-related European Bat Lyssavirus (EBLV) and it is present in some British bats.

European bat lyssaviruses (EBLVs) -1 and -2, commonly referred to as bat rabies, are two strains of rabies-related lyssaviruses found in bats across Europe. They have been known to infect not only the primary hosts (insectivorous bats) but, on very rare occasions, other animal hosts and human beings.

The Veterinary Laboratories Agency (VLA) undertakes passive surveillance for EBLVs in bats found dead in the UK. The VLA has tested over 9000 bats for lyssaviruses between 1987 and 2009. Since passive surveillance started in 1986, there have been eight bat-associated EBLV cases identified in England in Daubentonís bats. Apart from these cases, all the bats tested under passive surveillance have been negative for EBLV.

The results from the SNH active EBLV surveillance indicate that in 2005, 2006, 2007 and 2008, around 15%, 8%, 5% and 3% (respectively) of Daubentonís bats tested showed antibodies to EBLV. These differences show a statistically significant downward trend.

In November 2002, a Scottish bat handler died from an EBLV- 2 infection following contact with a bat. Since 1977, there have been four human deaths from rabies in Europe attributed to EBLV infections, all in cases where the human had been bitten or scratched by bats and had not received rabies vaccination either before or after being bitten by bats.

Human infection can only occur after being bitten or scratched by an infected bat, but as few people, including roost owners, have ever seen a bat at close quarters, there is minimal risk provided people do not touch or handle a bat or have contact with its saliva. If a person is bitten or scratched by a bat, they should wash the wound thoroughly with soap and running water for at least five minutes and seek immediate medical advice. An effective post exposure rabies prophylaxis is available.

All bats are protected by the Conservation (Natural Habitats, &c.) Regulations 1994 (as amended).

Bats are usually seasonal visitors to houses and are typically present for only four to five months of the year. They tend to form maternity colonies during May and June and then leave during August and early September once the young are independent. The colonies are often most obvious during July, when the young are starting to fly. The vast majority of bat roosts in houses in Scotland are occupied by pipistrelles and these account for 80-90% of all the bats present. The EBLV virus has never been detected in these bats in Britain, despite more than twenty years of surveillance. Daubentonís bats are uncommon in houses, preferring bank-side trees and built structures associated with watercourses, e.g. bridges and tunnels.

Scottish Natural Heritage is the Governmentís advisor on all aspects of nature and landscape across Scotland. Our role is to help everyone understand, value and enjoy Scotlandís nature now and in the future. For further information visit our website at www.snh.org.uk