Aminu Shittu. Department of Public Health and Animal Production, Faculty of Veterinary Medicine,

1. European Bat Lyssaviruses in the United Kingdom: Focus on Changing Epidemiology and Detection Methods Aminu Shittu. Department of Public Health and Animal Production, Faculty of Veterinary Medicine, Usmanu Danfodiyo University, Sokoto.

2. Overview • Introduction • Distribution • The Rhabdoviridae family • Importance of EBLVs • Diagnostic tests • Diagnosis • Past and current situations in the UK • Surveillance and control in the UK • Future strategies • Control scenarios • Conclusions/recommendations

3. Introduction • BATS • Kingdom: Animalia • Phylum: Chordata • Class: Mammalia (20%) • Infraclass: Eutheria • Superorder: Laurasiatheria • Order: Chiroptera • Distribution: worldwide • Habitat: caves, old buildings, trees

4. Distribution

5. The geographical distribution of Eptesicus serotinus in Europe

6. First description in the Hebrew Talmud • Various Arabic writings

7. The Rhabdovirus family • Rabies • Lagos – bat • Makola • Duvenhage • European Bat Lyssavirus type 1 (EBLV – 1) • European Bat Lyssavirus type 2 (EBLV – 2) • Australian Bat Lyssavirus (ABL)

8. European Bat Lyssaviruses • EBLVs in Europe – 1954 • Genetics – N &/or G genes • EBLV – 1 • 2 lineages 1a & 1b • Majority in E. serotinus • EBLV – 2 • First isolated in 1984 from human biologist • Isolated in 1986 in M. daubentonii and M. dasycneme

9. Lyssavirus classification, with geographical origin, original and secondary host species

10. The importance of EBLV rabies • Bat rabies is an emerging zoonosis • Public health threat • High risk groups: • Bat handlers • Cavers • Researchers • Wildlife officers • Veterinarians

11. The importance of EBLV rabies (2) • Rabies is a zoonotic disease which is invariably fatal in all humans that are not vaccinated and do not get post-exposure treatment • 5 cases of human exposure in Europe so far including a fatal case in Scotland (2002) • Spillover of EBLV-1/EBLV-2 into humans, sheep, stone marten and domestic cats has been reported (see Harris et al. 2006). • EBLV is endemic in some European countries’ bat population and the possibility of infected bats coming to the UK cannot be ruled out. • Likelihood of impact

12. Diagnostic tests • Direct fluorescent antibody test (dFA) (Standard test for rabies) • RT-PCR • Other tests Electron Microscopy (EM) Histopathology Immunoperoxidase staining Virus Isolation

13. Rabies Diagnosis (1) Direct Fluorescent Antibody Test (DFAT) • Detection of virus nucleocapsid protein infected tissues Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) • Can be used to detect presence of pan-lyssavirus in saliva or oropharyngeal samples (specific primers can be used detect specific EBLV) Rabies Tissue Culture Inoculation Test (RTCIT) • Homogenised suspension of suspect tissue (brain or saliva) is inoculated into tissue culture for isolation of virus

14. Rabies diagnosis (2) Mouse Inoculation Test • Inoculation of homogenised suspect tissue into cerebellum of 48h old mice for later virus isolation Modified Fluorescent Antibody Virus NeutralisationTest (mFAVN) • Can be used on pooled saliva or blood samples for detection of antibodies to EBLV Histopathology • Detection of negri bodies in brain tissue

15. Vaccination

16. Past and current situation of EBLV-1 in the UK EBLV-1 seroprevalence in bats: • 1 serotine bat in the South of England (2005) • 1 serotine bat in Scotland (2007)

17. Past and current situation of EBLV-2 in the UK EBLV-2 seroprevalence in bats: • The seroprevalence in Daubenton’s bats in England and Scotland is estimated at 2% (95% confidence interval 1 to 5%) • 8 infections with EBLV-2 confirmed in Daubenton’s bats

18. Surveillance of bat Lyssaviruses • Sample submission: members of public and bat conservation groups • Sick, injured or suspect cases, captive bats • Testing animals and humans bitten by suspect bat

19. Strengths and weaknesses of surveillance • Bias due to location and bat conservationist activity • Not a representative sample • Sensitivity – only method by which EBLVs detected in the UK

20. Current strategies: The public Bat handlers The control of EBLVs in the UK

21. Current control strategies • Health education • Raising awareness Public: No bat handling If pet is bitten: advice on potential risk and report any suspicious signs to the local vet. Bat handlers: • If bitten seek medical advice • Prevent direct contact - gloves • Pre-exposure vaccination and Post-exposure treatment

22. Stokesay Castle example • Follow up possible human contacts • Advise to receive post exposure treatment • Public access to second floor was not allowed • Signs informing visitors about the bats • Staff checking for bats before opening

23. But does the classical rabies vaccine protect humans against EBLV? Genotype 1: classical rabies Genotype 5: EBLV1 Genotype 6: EBLV2

24. Future Strategies • Legislation changes • Compulsory vaccination of bat handlers • Wild bats: cannot control their movement, vaccinate using RAORAL V-RG • Quarantine bats coming in ships from other countries • Prevent colony establishment in certain buildings (e.g. schools, hospitals) • Preventive immunization of populations living in highly endemic areas

25. Control Scenarios

26. Translocation of Wild bat colony • Geographic translocation of bats could potentially spread EBLV • Natural, accidental or deliberate means • Protracted incubation period allows survival of the virus • Bats undergo hibernation to extend survival

27. What could be done; -Consult bat conservationists -If suspect EBLV should be tested -If positive should be killed -If negative would have to be housed

28. Identified in Novel Bat Species • Currently in only two species found in the UK • Testing finds antibodies/antigen in naive species; -Surveillance will expand -Communicate to bat conservationists and public

29. Infected bats in public places • Infected bat found which roosts in public area; -Random sampling of roost -Slaughter not an option -Possibly move population?? -Warn public and protect staff

30. 4.EBLV found in bats away from public • As negligible risk to humans – continued surveillance: • Collection of excreta for virus detection and serology • Marking of sampled bats • Collection and testing of dead/sick bats

31. 4.EBLV found in bats away from public • If clinical disease detected: • Epidemiological data: destruction of bat colony ineffective • disturbs metacolony • may cause dispersion of infected animals. • Enhanced surveillance.

32. 5.EBLV found in carnivores • Transmission of lyssaviruses from bats to terrestrial mammals and humans rare, none so far in UK BUT • EBLV1 demonstrated in sheep in Denmark • Lyssaviruses isolated in cattle/foxes in Canada.

33. 5.EBLV found in carnivores • Very difficult! • Oral baits: BUT classical rabies oral vaccine not protective against EBLV1 • Culling near urban areas? • POSITIVE -> PTS BUT difficult to detect until showing CS or seen attack • PREVENTION : cats indoors during high risk periods • i.e. summer & evenings where bats resident. • EDUCATION • If infected bat preyed upon by foxes or cats • FOXES • CATS

34. 6. EBLV clinical disease in humans • In highly unlikely event of outbreak in humans: • Pre & post exposure vaccination • EDUCATION • Signs/barriers near colonies: prevent access & direct bat movements • Bat-proofing buildings • Vaccinating/culling bats?

35. Conclusions/recommendations • EBLVs can cause fatal infections in humans • Bats can excrete EBLV in saliva but amounts are unknown • Public health risk of EBLV in bats cannot be ignored but is hard to assess • Active and passive surveillance • Improved detection methods • Translocation factors