Qualitative veterinary risk assessment of the ...

Qualitative veterinary risk assessment of the introduction of rabies into the United Kingdom A report prepared for Defra (Department for Environment, Food and Rural Affairs) by

Tony Wilsmore Chris Hamblin Nick Taylor William Taylor Bill Watson Secretariat: Mrs Jane Putt July 2006

Veterinary Epidemiology and Economics Research Unit School of Agriculture, Policy and Development The University of Reading

Acknowledgements The authors acknowledge the help and enthusiastic support received from the Rabies and Wildlife Zoonoses Group, Veterinary Laboratories Agency (VLA), Weybridge, particularly Drs Tony Fooks and Sharon Brooks, also the Centre for Epidemiology and Risk Analysis, VLA, particularly Rowena Kosmider and the staff of the VLA library. We are also grateful for the help supplied by Tim Chapman, The University of Reading Library.

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Index Abbreviations .......................................................................................................................................6 Qualitative veterinary risk assessment of the introduction of rabies into the UK................................7 Introduction ......................................................................................................................................7 Qualitative veterinary risk assessment .............................................................................................9 Step 1 of risk pathway: What is the risk that an imported animal is exposed to infectious contact in the country of origin/travel/transit? ...........................................................................14 Steps 2 and 3 of the risk pathway: Risk management and possible adjustments to UK import regulations ..................................................................................................................................16 A cautionary note on compliance...................................................................................................19 Conclusions ....................................................................................................................................19 Annex 1. Types of Lyssa viruses .......................................................................................................21 Annex 2. History of rabies and its control in UK...............................................................................22 Annex 3. Rabies in man .....................................................................................................................25 Annex 4. Epidemiology, pathogenesis, treatment, prevention and control of rabies.........................28 Epidemiology .................................................................................................................................28 Rabies in bats .............................................................................................................................29 Pathogenesis ...................................................................................................................................30 Incubation period: ......................................................................................................................30 Clinical disease (morbidity): ......................................................................................................30 Survival after infection:..............................................................................................................30 Virus excretion before onset of clinical signs ............................................................................30 Treatment .......................................................................................................................................31 Post exposure treatment in man .................................................................................................31 Post exposure treatment of dogs by vaccination ........................................................................31 Prevention and control ...................................................................................................................31 Quarantine ..................................................................................................................................31 Vaccination.................................................................................................................................31 Stray dog control ........................................................................................................................32 Oral vaccination of dogs ............................................................................................................32 Eradication of rabies in wildlife .................................................................................................32 General .......................................................................................................................................33 Annex 5 Legislation ...........................................................................................................................35 Current Domestic Legislation ........................................................................................................35 Changes in Policy...........................................................................................................................35 The Rabies Importation of Dogs, Cats and Other mammals Order 1974. ...............................................................35 The Rabies (Importation of Dogs, Cats and Other Mammals) Order 1977 .............................................................36 The Rabies (Importation of Dogs, Cats and Other Mammals) (Amendment) Order 1984. .....................................36 The Rabies (Importation of Dogs, Cats (Other Mammals) (Amendment) Order 1986. ..........................................37 The Channel Tunnel (International Arrangements) Order 1993 No. 1813 as amended ..........................................37 The Rabies (Importation of Dogs, Cats and Other Mammals) (England) (Amendment) Order 2004. ....................37 The Non Commercial Movement of Pet Animals (England) Regulations 2004......................................................38 The Animals and Animal Products (Import and Export) Regulations 2004 ............................................................39 The Animals and Animal Products (Import and Export) No. 2 Regulations 2004. .................................................39

European Community Legislation. ................................................................................................40 Council Directive 89/662/EEC of 11 December 1989 concerning veterinary checks in intra-community trade with a view to the completion of the internal market..................................................................................................................40 Council Directive 90/425/EEC of 26 June 1990 concerning veterinary and zootechnical checks applicable in intraCommunity trade in certain live animals and products with a view to the completion of the internal market. .......41 90/424/EEC: Council Decision of 26 June 1990 in expenditure in the veterinary field. .........................................42 90/638/EEC: Council Decision of 27 November 1990 laying down Community criteria for the eradication and monitoring of certain animal diseases........................................................................................................................................42 Council Directive 90/675/EEC of 10 December 1990 laying down the principles governing the organisation of veterinary checks on products entering the Community from third countries. .........................................................................42 Council Directive 91/496/EEC of 15 July 1991 laying down the principles governing the organisation of veterinary checks on animals entering the Community and amending Directives 89/662/EEC, 90/425/EEC and 90/675. .................42

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Council Directive 92/65/EEC (Balai Directive). .................................................................................................... 43 Regulation EC No 998/2003 of the European Parliament and of the Council of 26 May 2003 on the health requirements applicable to the non-commercial movement of pet animals and amending Council Directive 92/65/EEC........... 44

Domestic Legislation in other selected Member States................................................................. 45 Malta .......................................................................................................................................... 45 Sweden....................................................................................................................................... 45 Germany .................................................................................................................................... 46 Denmark .................................................................................................................................... 46 Finland ....................................................................................................................................... 47 France ........................................................................................................................................ 47 Greece ........................................................................................................................................ 47 Domestic Legislation in selected Countries and Territories Listed in Annex II Section 2 of Commission Regulation (EC) No 425/2005.................................................................................. 48 New Zealand.............................................................................................................................. 48 Australia..................................................................................................................................... 48 Japan .......................................................................................................................................... 49 Vaccination requirements in other countries. ................................................................................ 49 Annex 6. Rabies Diagnosis................................................................................................................ 50 1. Collection and Submission of Samples ..................................................................................... 50 a. Biosafety considerations ........................................................................................................ 50 b. Transport of specimens.......................................................................................................... 50 2. Review of Diagnostic Tests for Rabies ..................................................................................... 50 a. Identification of the agent. ..................................................................................................... 51 Histological methods .............................................................................................................................................. 51 Immunological methods ......................................................................................................................................... 52 Virus isolation ........................................................................................................................................................ 54 Molecular techniques.............................................................................................................................................. 54 Monoclonal antibody (MAB) reactivity ................................................................................................................. 56

3. Intra Vitam Diagnosis of Rabies................................................................................................ 57 4. Antibody Detection.................................................................................................................... 57 5. Differential Diagnosis................................................................................................................ 61 6. OIE Manual Of Diagnostic Tests And Vaccines For Terrestrial Animals ................................ 61 7. Veterinary Laboratory Agency (VLA) and Rabies Diagnosis .................................................. 63 Annex 7. Rabies vaccines .................................................................................................................. 65 1. The nature of the immune response to rabies vaccines ............................................................. 65 2. Factors affecting the immune responses of dogs and cats to rabies vaccination....................... 65 3. The response of dogs to rabies vaccines.................................................................................... 65 Inactivated vaccine: ........................................................................................................................... 66 4. The response of cats to rabies vaccines ..................................................................................... 68 5. Vaccination of other species...................................................................................................... 69 6. Vaccine failures in cats and dogs............................................................................................... 69 7. Types of rabies vaccines............................................................................................................ 70 a. Inactivated rabies vaccines for humans ................................................................................. 71 b. First generation inactivated rabies vaccines for animals ....................................................... 71 c. Attenuated rabies vaccines for animals.................................................................................. 71 d. Second generation inactivated rabies for animals ................................................................. 72 e. Vaccines for ferrets ................................................................................................................ 73 f. Vaccines for wildlife hybrids ................................................................................................. 73 g. Recombinant rabies vaccines................................................................................................. 73 h. DNA vaccines........................................................................................................................ 73 8. Post Exposure Treatment in dogs .............................................................................................. 74 9. WHO World Survey of Rabies vaccines, 1998 ......................................................................... 74 10. Vaccination in the United States.............................................................................................. 74

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11. Vaccination in the United Kingdom.........................................................................................74 12. Rabies vaccines licensed for use in the vaccination of cats and dogs United Kingdom (and Europe) ...........................................................................................................................................75 a. NOBIVAC manufactured by Intervet UK Ltd, Science Park, Milton Road, Cambridge CB0 4FP .............................................................................................................................................75 b. QUANTUM RABIES manufactured by Schering-Plough Animal Health, Breakspear Road South, Harefield, Uxbridge, Middlesex UB9 6LS. ....................................................................75 c. RABISIN by Merial Animal Health Ltd. PO Box 327, Sandringham House, Harlow Business Park, Essex CM19 5TG ..............................................................................................75 d. CANIGEN by Vibrac Ltd, Woolpit Business Park, Windmill Avenue, Woolpit, Bury St Edmonds, IP30 9UP. ..................................................................................................................75 13. Experience with the PETS scheme...........................................................................................76 Appendix 1. The International Unit of serum potency...............................................................76 Appendix 2. The NIH and European Pharmacopoeia tests for rabies vaccine potency.............76 Appendix 3. Rabies vaccine standards set by the European Pharmacopeia 1997......................77 Rabies vaccine (inactivated) for veterinary use.......................................................................................................77 Tests ........................................................................................................................................................................77

Annex 8. Geographical distribution of rabies ....................................................................................79 1. South America............................................................................................................................79 2. North America............................................................................................................................80 a. Bats and rabies in North America ..........................................................................................80 3. Europe ........................................................................................................................................81 a. Northern Europe .....................................................................................................................81 b. Eastern Europe .......................................................................................................................83 c. Western Europe ......................................................................................................................83 d. Southern Europe and the Balkans ..........................................................................................84 e. Bats and rabies in Europe .......................................................................................................85 4. Asia.............................................................................................................................................87 5. Africa..........................................................................................................................................88 6. Australia .....................................................................................................................................88 Annex 9. Qualitative risk assessment for rabies by country of origin ...............................................89 What is the risk that a visiting pet or animal to be imported is exposed to infectious contact in the country of origin/travel/transit?............................................................................................89 a) What is the probability that rabies is present in the country? ...........................................89 OIE data available through ‘Handistatus’ ..................................................................................89 b) What is the risk that a visiting pet or animal to be imported is exposed to rabies infection (with the potential to be infected)? (Table 2).............................................................................91 Factors to be considered..........................................................................................................................................91 Sources of data ........................................................................................................................................................92 Assessment of risk of exposure leading to potential infection ................................................................................93

Conclusion..................................................................................................................................94 Annex 10. Terms of Reference ........................................................................................................110 Annex 11 Bibliography ...................................................................................................................115

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Abbreviations ARAV BHK CMI EBLV EU ELISA FAT FAVN FITC IHC IRKV KHUV LEP MAB MIT N antibody OIE PCR PETS RIO RNA RFFIT RREID RTCIT RT-PCR SIRVERA UK VLA VMD VRG WCBV WHO

Aravan lyssavirus Baby hamster kidney Cell mediated immunity European bat lyssavirus European Union Enzyme linked immunosorbent assay Fluorescent antibody test Fluorescent antibody virus neutralisation Fluorescein isothiocyanate Immuno-histochemistry Irkut lyssavirus Khujand lyssavirus Low egg passage Monoclonal antibody Mouse inoculation test Rabies-specific virus-neutralising antibody Organisation International des Epizooties (World Organisation for Animal Health) Polymerase chain reaction UK Pet Travel Scheme Rabies (Importation of Dogs, Cats and Other Mammals) Order 1974 Ribonucleic acid Rapid fluorescent focus inhibition test Rapid rabies enzyme immunodiagnosis Rabies tissue culture inoculation test Real time polymerase chain reaction Regional Rabies Surveillance System in the Americas United Kingdom Veterinary Laboratories Agency Veterinary Medicines Directorate Vaccinia recombinant glycoprotein West Caucasian bat virus World Health Organisation

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Qualitative veterinary risk assessment of the introduction of rabies into the UK Introduction Rabies is one of the most feared diseases affecting man. In the developing world tens of thousands of people die from rabies annually. African and Asian countries are particularly affected by rabies because the virus is maintained there in animal reservoirs and there is often inadequate healthcare and lack of control measures. In developed countries, widespread vaccination and animal control programmes have reduced the incidence of the disease in man to low levels. Human cases are now rare in Europe with the exception of the Russian Federation (page 35). The domestic dog is of paramount importance in the transmission of rabies to man, particularly in countries where there are reservoirs of rabies virus in kept, feral and stray dogs. The greatest risk of transmission of virus to UK is either human travellers (who are extremely unlikely to pass the disease on to other animals or man) or imported animals, the most important being domestic pets, particularly dogs and cats (page 38). While historically the dog and the wolf were important maintenance hosts for rabies, during the twentieth century, rabies emerged predominantly as a disease of the red fox causing significant epizootics in Europe and North America. Other species of wildlife are also involved, for example, in northern Europe the raccoon dog has emerged as a reservoir host and in North America raccoons and skunks are involved (page 38). Currently, rabies is increasingly diagnosed in bats. Traditionally, rabies has been associated with the vampire bat in South and Central America but now insectivorous and fruit bats are emerging as hosts for rabies virus throughout the world. Bat rabies variants are now responsible for more than half of the cases of rabies diagnosed in man in USA (page 90). Modern diagnostic methods, using monoclonal antibodies and molecular techniques, are able to characterise rabies viruses to identify their geographical origin and host species (Annex 6). While rabies diagnosis by antibody detection is not feasible because animals develop clinical signs and die before mounting an antibody response, antibody detection is used as a demonstration of rabies vaccine efficacy (Annex 6). Rabies has been associated with long incubation periods; hence the use of a six month quarantine for imported pets, but the literature on rabies shows that incubation periods are normally between two and 12 weeks (pages 27 and 40). Once clinical rabies has developed, with rare exceptions, death is inevitable within a few days. There is no immune response in the incubating animal or man and the virus cannot be reliably identified in tissues before the onset of clinical signs, thus there is currently no possibility of diagnosis of rabies in the incubating animal (Annex 6). As well as affecting the central nervous system, rabies virus can also colonise the salivary glands which allows the transmission of infection by infected saliva through bite wounds – the usual route. Animals may excrete virus by this route before the development of clinical signs, for up to 13 days in dogs (page 40). While treatment of clinically infected animals and man is of no avail, post exposure treatment of man with vaccine and hyperimmune serum is used successfully. This remedial treatment is only partially successful in dogs and other animals and is therefore not recommended (page 41). Vaccines are used successfully against rabies and can give up to three years immunity, although vaccination does not preclude the possibility of rabies infection, as confirmed cases of rabies have occurred in previously vaccinated dogs and cats. Nevertheless, overall, they provide a high level of protection. As well as by challenge experiments, the protection they can offer is measured by the antibody level they stimulate. The

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WHO standard is that a neutralizing antibody level of 0.5 IU/ml and above (measured against an international standard serum) is protective, although antibody responses have not been fully equated with protection as previously vaccinated animals with either lower titres or undetectable levels of antibody may still be protected (Annex 7.1 and Annex 7 Appendix 1). Vaccination is the favoured method of control of rabies in reservoir populations of dogs and wildlife. The development of oral vaccines has enabled the eradication of rabies from the red fox population throughout most of Europe. In addition, programmes for oral vaccination of wildlife are being undertaken in North America (page 43).

Rabies in the United Kingdom Quarantine has been the primary control method used to maintain freedom from rabies in the UK, since 1793. The result of this policy is that there have been no indigenous human cases of rabies in UK until 2002 when a bat conservationist died in Scotland from rabies caused by a bat-adapted rabies virus (page 32). However, two cases of rabies have occurred in dogs after leaving quarantine and as a result additional measures, which included vaccination against rabies on arrival, were introduced in 1972, to help avoid cross infection in quarantine kennels (page 32). Since then, quarantine measures have been completely successful. Import of pets through quarantine is controlled by the Rabies (Importation of Dogs, Cats and Other Mammals) Order 1974, and its amendments (page 45). In 1998 the Kennedy Report recommended vaccination, with demonstration of seroconversion and microchip identification, followed by a six month waiting period in the country of origin, for pet dogs, cats and ferrets from selected countries to replace quarantine. As a result, in 2000 the UK Pet Travel Scheme (PETS) started. Originally intended for countries within the European Union, amongst others, the list includes USA, Canada, Australia, New Zealand and the Russian Federation. The PETS scheme is enabled by the Non Commercial Movement of Pet Animals (England) Regulations 2004 and comparable legislation in Wales, Northern Ireland, the Channel Islands and the Isle of Man (page 48). The regulations are consequential to the application of EC Regulation No 998/2003, amending Council Directive 92/65/EEC (page 54). There are now two scenarios with regard to import of pets into UK: a) Pets coming to UK from countries where rabies is considered to be a significant problem are treated on the assumption that animals could be infected and vaccination and quarantine on arrival is imposed; b) Pets from countries on the list of “qualifying countries” (Annex 2, Table 1.), where the disease is seen to be controllable are prepared under the PETS scheme by identifying with a microchip, vaccinating and passing a serological test six months before entry to UK and are then allowed to enter without quarantine on the assumption that these animals are not infected.

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Qualitative veterinary risk assessment The qualitative veterinary risk assessment of the introduction of rabies into UK addressed the key concern that a risk to public health may occur as a result of a rabid animal entering UK from overseas through normal animal import channels and looked at changes in risk that might result from changes to import regulations with regard to the rabies disease situation around the world and advances in vaccine, diagnostic and surveillance technology. When interpreting the risk assessment and using it to inform any future decisions, consideration must be given to the consequences of introduction of rabies into UK which although variable, are severe with regard to disease in man, and expensive with regard to mitigation of the effects of rabies and its control and eradication. This assessment is to: • find out whether UK rabies controls relating to the import of rabies-susceptible mammals are proportionate and sustainable, and that their primary purpose is to protect public health. • inform the UK’s response to the EU review of some requirements of the EU pet movement regulation. • assess, using the best available current scientific evidence, the risk of introduction of rabies into the UK under current rabies polices and under alternative policies. The key concern of Defra is that a risk to public health may occur as a result of a rabid animal entering UK from overseas, through the normal animal import channels. Therefore, the risk to be assessed is: “Risk that a clinical case of rabies (or an infectious case – since infectivity can precede clinical signs) occurs outside quarantine1 in an animal2 in UK as a result of infection acquired overseas.” 1: in this risk assessment, other variations to quarantine, including the different control components of the PETS scheme, will be considered. 2: species to be considered are those to which the Rabies (Importation of dogs, cats and other mammals) Order 1974 applies and particularly pet dogs, cats and ferrets to which Regulation (EC) No. 998/2003 and the Non-Commercial Movement of Pet Animals (England) Regulations 2004 applies.

NOTE: An overall assessment of risk is considered less important than detailed assessment of the changes in risk that might result from: •

changes to import regulations;

•

changes with regard to the disease situation around the world;

•

advances in vaccine, diagnostic and surveillance technology.

In carrying out the risk assessment, attention is particularly paid to the sensitivity of the final risk to changes affecting steps along the risk pathway. When undertaking the risk assessment, it should be taken into consideration that the consequences of introduction of rabies into UK, though variable, are all severe. The following consequences need to be considered. a) Clinical disease in man: a clinical case of rabies results inevitably in death preceded by the most extreme clinical signs which are devastating for the sufferer and horrific for those who observe and nurse the victim. b) Tracing and control: if a case enters the country outside quarantine, a major exercise must be undertaken to identify and treat those who have been in contact and may be incubating the disease. c) Psychological effect: those who have witnessed the disease and/or believe that they might be infected may suffer from severe anxiety.

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d) Danger that rabies becomes endemic: if a rabies case introduced to this country is able to infect wildlife capable of supporting the disease, for example, the red fox population, while it is now possible to eliminate the disease from that population, the control measures that would need to be employed are expensive in resources and time. Therefore, even a small risk of importation of rabies is of serious concern. While it is not part of this risk assessment to consider control of an outbreak, it is important to note that the consequences of a case of rabies in a pet may be reduced by measures in place which will mitigate its effect. These could be: •

Home quarantine1.

•

Owner education to gain awareness of signs of rabies and risk of spread of rabies to other animals and man in order to allow early recognition of a case and limit an infected animal’s contacts with other people and animals.

•

Contingency plans and emergency preparedness to enable rapid containment of an outbreak of rabies outside quarantine if it occurs.

In this risk assessment, the risk pathway shown in Figure 1 is considered:

Figure 1. Risk pathway for rabies to enter UK via an imported animal, together with factors affecting the risk

RISK PATHWAY 1. Imported animal exposed to infectious contact in the country of origin/travel/transit.

Regional patterns of rabies incidence; information on contact between animals travelling (e.g. pets) and local reservoirs of infection.

2. Animal travelling is infected before travel to UK.

3. Infection is not detected before release into UK after quarantine or importation without quarantine.

Protection provided by vaccination and period of waiting before travel.

Inspection of animals before, and during import.

FACTORS AFFECTING RISK

The control points which have been identified along the risk pathway are shown in Figure 2. UK regulations make use of control points 1 to 6 for pets coming to UK from qualifying countries under the PETS scheme, and control point 7 for pets from other countries.

1

Home quarantine may apply to animals such as search and rescue, police and military dogs which are returning from work in another country. Home quarantine measures may include exercise only on a leash and exclusion from public places.

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Figure 2. Control points along the risk pathway

1.

2.

ID microchip

Rabies vaccination

3. Serological test

4.

5.

6.

6m wait

tapeworm & ticks treatment with veterinary certificate of treatment 24-48h prior to entry

Border control - at official port with docs.

7. Entry & release in UK OR

Vaccination & 6m Quarantine before release

1. The PETS scheme requires that an imported pet is implanted with a microchip that provides a unique and positive identification which validates the documents accompanying the animal and identifies it with the procedures (e.g. vaccinations) that it has undergone. 2. The rabies vaccination, given within the prescribed time limits, protects the vaccinated animal against further rabies challenge. 3. A positive serological test provides evidence that the animal has been effectively vaccinated and protected from rabies challenge. 4. The six month wait from the time the serological test to time of entry into UK is to ensure that if an animal has been infected prior to protection by vaccination and is incubating rabies, it would develop clinical disease before entry to UK. 5. The tapeworm and ticks treatment with veterinary certification conducted 24-48h prior to entry to UK is an opportunity to ensure that the animal to be imported has been properly prepared and has the correct microchip and certificates that show that it has been correctly vaccinated and had a positive blood test. 6. The border control on entry to UK is a final opportunity to check that animals entering under the PETS scheme have been properly prepared and have the correct microchip identity and documents. Pet animals entering via the PETS scheme or to a registered quarantine via an approved carrier can be controlled. 7. The vaccination and six months quarantine ensures that animals which are already infected with rabies will develop the disease within the controlled environment of the quarantine and, coupled with separation from other animals in quarantine, vaccination at entry controls the risk that an infected animal will be able to infect others undergoing quarantine.

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When considering the control points used in the PETS scheme, it is useful to consider their relative importance in terms of risk reduction, and how well their performance, and compliance with them, can be validated: 1. Microchip identification: it is important that there is accurate, tamperproof, identification of an animal being prepared for importation as provided for under the PETS scheme, so that there is confidence that the animal imported is the one to which the vaccination and blood testing certification relates. While there is not such an obvious requirement for identifying those animals which come into quarantine for six months in UK, microchipping them when they are vaccinated at the commencement of quarantine would ensure that there could be no substitution and would assist traceability if an animal escapes from quarantine, or after quarantine in the event that there is a suspicion that they may have had contact with a rabid animal while in quarantine. 2. Rabies vaccination: vaccination should give a high level of protection against rabies. Following vaccination, 98.7% of 20,597 dogs and 98.9% of 2,825 cats demonstrated an acceptable positive antibody response (Fooks 2001). The presence of rabies-specific virus-neutralising (N) antibodies provides an indirect indicator that an animal will withstand challenge with virulent rabies virus. Although measuring N antibodies is a convenient way to evaluate vaccine efficacy, the absence of such antibodies does not exclude possible protection as the antibodies cannot be quantitatively correlated with protection. Responses to vaccination are not uniform: the same dose of vaccine in dogs can induce antibody responses of between zero and 20 IU/ml and a positive history of vaccination does not preclude the possibility of rabies infection: in Texas, vaccine failures have been documented in 1% of rabid animals (Fooks, Roberts et al. 2004). It is difficult to accurately quantify the level of vaccine failures. Whilst failures due to technical deficiencies of the vaccine may be extremely rare, as indicated by the figures quoted above, failures due to ‘operator error’ (poor injection technique) and poor storage conditions (cold chain failure) might increase the failure rate (perhaps up to 10%), particularly in countries where veterinary infrastructure and regulation are weak. Nevertheless, while protection achieved by vaccination is not complete, it significantly reduces the risk of a pet becoming infected with rabies: even if 10% of vaccinations were to fail (a pessimistic estimate), the risk of infection is reduced by 90%. When in nature, the probability of a dog or cat coming into contact with a rabid animal is, in absolute terms, very low, the probability of a vaccinated animal coming into contact and subsequently developing rabies is very low indeed (at least 10 times lower). Thus vaccination is an important control when given as a preparation for import through PETS. When vaccination is given at the start of a six month quarantine on admittance to UK, it is given to the imported animal to protect it from any other animal in the quarantine which may develop rabies (having been infected before import and vaccination). In 1969 and 1970 two cases of rabies occurred in dogs after they were released from quarantine. It is believed that they were infected while they were in quarantine. Measures were introduced to vaccinate animals on entry and to keep them separate from each other while in quarantine. Since then, there have been no more cases of rabies occurring in pets after they have been released from quarantine. This indicates that the procedure for rabies vaccination and separation of animals while they are in quarantine is a necessary and successful one. 3. Serological testing after vaccination: under the PETS scheme, blood taken at a time according to the vaccine manufacturer’s recommendation after vaccination must have neutralizing antibodies of a titre of ≥ 0.5 IU/ml. This is the WHO standard for protection2. This is an important control point because it ensures that the pet has been properly protected by vaccination and therefore effectively removes the risk associated with vaccine failure discussed above. Another reason for confirmation that the pet has been successfully vaccinated is that the efficacy guidelines given in the European Pharmacopeia (Annex 6, 2

The WHO standard for neutralizing antibody level of 0.5 IU/ml (measured against an international standard serum) is empirical: antibody responses have not been fully equated with protection and previously vaccinated animals with either lower titres or undetectable levels of antibody have been shown to be protected. The use of the 0.5 IU/ml standard is precautionary, in that virtually all animals passing this test can be assumed to be protected, even though some animals failing the test might also be protected.

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Appendix 3) translate to an acceptable efficacy of only 90% (with a 95% confidence interval of 61% 97%) with the sample sizes quoted. Serological testing should be be easy to validate, as laboratories that can undertake serology are approved and listed by EU and subject to quality control procedures. Antibody levels progressively decline after vaccination but seronegative dogs appear to remain protected and can survive challenge. It can be concluded that dogs with N antibodies at the time of challenge have a very high chance of surviving challenge, as do dogs with no demonstrable N antibody if they demonstrably seroconverted at the time of vaccination. Results of studies appear to be similar for cats (Annex 7). Thus, if a dog or cat has a positive antibody titre when blood tested after vaccination, and has a vaccination history which complies with the manufacturer’s recommendations approved by the Veterinary Medicines Directorate (VMD), it should be considered that the risk of it becoming infected with rabies, if exposed to infection, is extremely low. 4. Six month wait from the time the serological test is conducted to time of entry into UK: this is to ensure that an animal which has been infected prior to protection by vaccination and is incubating rabies, develops clinical disease before entry to UK. Vaccination in already infected animals does not significantly alter the clinical picture or development time of the disease (Blancou and others 1989) cited by (Fooks and McElhinney 2000). It is, therefore, possible that an animal infected before vaccination would continue to incubate the disease despite developing a high antibody titre (Fooks and McElhinney 2000). Thus, dogs and cats may not enter or re-enter UK until six months after they have been serologically tested. This regulation prevents the possible import of an animal that had been infected before it was vaccinated (Fooks and McElhinney 2000). According to EU regulations, pets must, when they come from a non-listed third country, be identified, vaccinated and blood tested at least 30 days after vaccination, and then wait three months after a successful blood test before being moved (i.e. effectively a four month wait after vaccination), while for movement from listed third countries to most Member States the requirement is to identify, vaccinate and wait 21 days only. The majority of incubation periods observed after experimental inoculation are between 3 and 6 weeks only (Wandeler 2004) while (Swanepoel 2004) describes incubation periods of one to three months in man and two to four weeks in dogs. While there are occasional reports of much longer incubation periods, they appear to be rare and may be due to later, unobserved infection. In consideration of this information, it appears that there is justification for a shorter than six months wait between serological test and import. The minimum four month waiting period from unlisted countries stipulated in EU regulations is greater than the reported range of incubation periods and should ensure that an animal infected before vaccination would develop clinical disease before the four month period elapses. There is some evidence that clinical rabies is in part due to an immuno-pathological effect, and stimulating an immune response will accelerate the course of disease (Swanepoel 2004). Whether the waiting period is four months or six months, this is a very important control point because, without it, vaccination is worthless: if an animal is imported directly after vaccination, it is as likely to be incubating disease as if it had not been vaccinated. 5. Tapeworm and ticks treatment with veterinary certification conducted 24-48h prior to entry to UK: while the treatments the animal undergoes have nothing to do with rabies control, the treatment and veterinary certification is a good opportunity to ensure that the animal to be imported has been properly prepared: has the correct microchip and certificates that show that it has been vaccinated, had a positive blood test and waited the required period. Thus, it is a very useful control point in terms of verifying compliance with the regulations. 6. Border control on entry to UK: this is a final opportunity to check that animals entering under the PETS scheme have been properly prepared and have the correct microchip identity and documents before release into UK. However, not all animals are inspected at approved ports of entry: many are allowed to pass through without inspection. Thus, this control point, as it is currently operated, is weaker than it was before the introduction of the PETS scheme. Before PETS, animals were not allowed to proceed through a port unless proceeding direct to quarantine. The regulations require that dogs, cats and ferrets are transported by an approved carrier on a specified route with the carrier required to check the microchip and accompanying certification. If checked abroad, and the carrier is not satisfied that the requirements are met, the animal shall not be brought into UK; if checked during transport or on landing and the requirements are not met, the animal shall be transferred to quarantine in accordance with the

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Rabies (Importation of Dogs, Cats and Other Mammals) Order 1974. If satisfied after the checks are made the carrier shall issue a certificate of compliance. Conditions for the training and approval of carriers are laid down in the Regulations. If only a proportion of pets are examined on entry, it is a major responsibility of the carrier (this includes ferry companies) to ensure that the conditions of entry under the PETS scheme have been met if this is to be an effective control point. Effective monitoring and enforcement of carriers’ responsibilities strengthen this control point.

Step 1 of risk pathway: What is the risk that an imported animal is exposed to infectious contact in the country of origin/travel/transit? Epidemiological situation - Risk of a country being a source for the introduction of rabies into UK according to distribution in host species A study of the literature on the epidemiology of rabies, its prevalence, and reservoir hosts in different species, enables the placing of countries into different categories with regard to the risk of introduction of rabies from them into UK. The different risk presented by different countries has already been recognised to some extent by UK Government by allowing pets to come from a list of countries (Annex 2, Table 1) without being subjected to six months quarantine. When assessing the risk different countries might pose with regard to introduction of rabies into UK via animals capable of being infected by rabies and transmitting the disease, countries can be divided into four risk categories based on the epidemiological situation. 1. Rabies in insectivorous and fructiferous bats As rabies in bats is increasingly under scrutiny it appears that lyssavirus infection may be found in populations of bats in most countries (Annex 4). As a result, there is an increasing awareness of bats as a source of infection to man and other animals and cases of rabies of bat origin are diagnosed in north and south America, Europe, and even Australia. However, with the exception of haematophagous bats, there is no evidence in the literature of domestic animals becoming infected with rabies by bats and the human cases of rabies derived from bats have been through direct contact with infected bats, rather than via a pet or other domestic animal. Therefore, countries where there is a reservoir of rabies in insectivorous or fructiverous bats (this appears to include UK) are considered to be of least risk with regard to this qualitative risk assessment of the introduction of rabies into UK. 2. Rabies in rural wildlife In countries where there is rabies in rural populations of wildlife, for example, red foxes in North America, haematophagous bats in South America, and red foxes and raccoon dogs in some countries in Europe, there is separation between these reservoir populations and pets and domestic animals. Therefore, it is considered that there is only medium risk with regard to this qualitative risk assessment of the introduction of rabies into UK. 3. Rabies in urban wildlife In countries where wildlife may exist in urban areas and be infected with rabies, for example foxes in some parts of Europe and raccoons in USA, domestic animals, particularly pets, are more likely to come into contact with rabid animals than when wildlife are restricted to rural locations. Hence, it is considered that there is a higher risk with regard to this qualitative risk assessment of the introduction of rabies into UK. 4. Dog-mediated rabies In countries where rabies is endemic in feral, stray and roaming dogs, there is the greatest possibility of pets and other domestic animals becoming infected with rabies. Therefore, imports of animals from countries in this situation are considered to be of highest risk with regard to this qualitative risk assessment of the introduction of rabies into UK. While there may be more than one epidemiological situation in a country, the overall level of risk depends overwhelmingly on the highest risk scenario present, because the increase in risk between each of the four epidemiological situations is large.

14

Within these four broad categories, risk will vary depending on amount of disease in the country. In Annex 9, Organisation International des Epizooties (OIE) data in Handistatus (http://www.oie.int/hs2/report.asp.) has been analysed. Using this data, an attempt has been made to classify individual countries with regard to risk of introduction of rabies in animals brought from them. Such a classification is highly dependent on the quality of the OIE data, which is questionable in many cases. Thus, the amount of disease in a country is difficult to assess because the level of veterinary surveillance and animal health control, and the reliability of surveillance data varies between different countries (see annex 9 for more detail). If the level of veterinary surveillance and animal health control is poor in a country of origin of an animal for importation into UK, it is more difficult to estimate the risk of rabies infection and to take control measures to avoid the risk of an animal to be exported to UK becoming infected. Importantly, the OIE data also does not reliably indicate the epidemiological scenario of rabies in terms of the four important situations detailed above, therefore the analysis presented in Annex 9 does not divide countries’ risk levels according to these four scenarios. Furthermore, the annual risk of importing an animal incubating rabies into UK increases as the total number of imported animals increases(‘volume of traffic’) (Jones, Kelly et al. 2005). While under current regulations the number of pets imported from a country may be small, if regulations are changed to make it easier for animals to be imported (in particular, the removal of the quarantine requirement), it follows that the number of imported pets will increase. With regard to pets from UK visiting a country with rabies, the risk of becoming infected with rabies increases with the length of time spent in that country. The length of time a visiting pet spends in a country will obviously influence the risk that that particular animal comes into contact with rabies infection. As the length of time increases, so the risk increases. However, for the purposes of assessing risk that an animal that is incubating rabies is imported into UK, only the risk of exposure during the preceding few months (the time equivalent to the incubation period) is important. Therefore, when considering the risk associated with importing an animal, risk will increase with increasing length of sojourn up to a maximum for a sojourn of between three and six months. Theoretically it could be possible to consider different import regulations depending on length of time abroad spent by an animal travelling from UK and back. But bearing in mind that the conclusions of the rest of this report suggest that vaccination (with other safeguards), rather than quarantine on return, would be suitable for most trips of any length to any country (for example for rescue dogs), it is hard to imagine that any less stringent requirements could be feasibly considered for trips of a short length. The UK imposes differing import regulations on animals travelling from different countries in order to mitigate the risk of rabies introduction that animal importation may present. The import streams from different countries contributing to overall risk of introduction of rabies are summarised in Figure 3.

15

Figure 3. Import streams contributing to overall risk DIFFERENT RABIES DISEASE SITUATIONS – DIFFERENT RISKS OF EXPOSURE TO RABIES INFECTION*

EU member states

Other qualifying states (e.g. USA)

The rest (e.g. Africa, India, Eastern Europe, Asia etc.)

DIFFERENT VOLUMES OF TRAFFIC (partly influenced by the different requirements)

DIFFERENT IMPORT REGULATIONS (PETS scheme OR QUARANTINE)

DIFFERENT RISKS OF RABIES INTRODUCTION VIA DIFFERENT ‘STREAMS’

OVERALL ANNUAL RISK OF RABIES INTRODUCTION

Steps 2 and 3 of the risk pathway: Risk management and possible adjustments to UK import regulations UK, which is considered to be rabies-free by OIE3, focuses on either control through the PETS scheme for countries from qualifying countries (Annex 2, Table 1.), or on vaccination and six months quarantine on entry, for other countries of origin, to ameliorate any risk of rabies introduction through imported animals. Which of the two risk reduction methods is used ostensibly depends on an assessment of the rabies disease situation in the country of travel / origin. Animals coming to UK from countries where rabies is considered to be a significant problem have to undergo quarantine for six months on entry to UK. This approach can be described as working on the assumption that the animals could be infected and quarantine is seen as the only method to ensure detection of infected animals and protection of the general public and livestock from them. Animals coming to UK from countries where rabies is considered to be a less significant problem (EU and non-EU ‘qualifying states’) are not subject to quarantine and are allowed to travel under the PETS scheme. This basically implies an assumption that these animals are not infected (therefore no need to attempt disease detection) – or in ‘risk parlance’, the risk that animals could be infected is assumed to be negligible or ‘acceptable’. This assumption is strengthened by requirements that ensure animals are vaccinated and have immunity demonstrated by blood testing before travel. Some of the countries in the list of qualifying countries have on-going problems with rabies, for example North America, which has rabies in bats and rural and urban wildlife, hence, according to the above classification it is an area of higher risk. Lithuania, which, as an EU State, is a qualifying country, still has some dog-mediated cases of rabies, putting it in the highest risk category. However, being an EU country 3

UK is regarded by OIE to be a rabies free country as this status is not affected by isolation of a European Bat Lyssavirus, but WHO does not consider UK to be rabies free because it does not regard a country to be rabies free where lyssavirus of bat origin is found.

16

which has adopted EU standards of animal health control may guarantee a good level of compliance. As discussed above, other significant risk factors are level of compliance with PETS regulations and number of pets being imported. In a risk assessment conducted by (Jones, Kelly et al. 2005), assuming 100% compliance with PETS and the then current level of importation of cats and dogs from North America, the annual probability of importing rabies is lower for animals travelling via PETS (7.22x10-6, 95th percentile) than quarantine (1.01x10-5, 95th percentile). USA is the source of one of the highest levels of imports of pets. Therefore, there appears to be acceptance that there is a high level of compliance with PETS regulations with regard to import of pets from USA to enable it to be a qualifying country. If the same level of compliance can be reached, it seems that pets from any country can be acceptable under the PETS scheme. Figure 4 (below) is a schematic representation to show visually that, no matter what the starting level of risk that an imported animal has been infected recently and is incubating rabies, vaccination reduces the risk of infection to very low levels (red, green and purple lines). The red line shows vaccination applied without the confirmation of serological testing. For illustrative purposes, the line shows the level of risk reduced to 10% of its starting level (i.e. assumes 10% of vaccinations fail to protect). The serological test reduces the risk further because it excludes the animals with unsuccessful vaccination and verifies good compliance (green and purple lines compared with red line). The pink line (quarantine only) indicates that an animal remains a high risk until after it has been quarantined, while the green and purple lines (indicating vaccinated and tested animals from both highest risk and least risk countries) have a low risk of introducing rabies, following an appropriate wait period between vaccination and importation (similar to animals after release from six months quarantine). The waiting period between vaccination and import is crucial, because vaccination does not prevent disease developing in already infected animals. The risk that an animal is incubating disease at the time of vaccination is the same as the risk that an unvaccinated animal is incubating disease when it is imported. Vaccination without a waiting period is therefore useless as a risk reduction measure (blue line). Any waiting period following vaccination will reduce risk by an amount related to the distribution of rabies incubation period. The lines on the figure assume a waiting period covering 99% of rabies incubation periods. If the waiting period were only as long as 40% of rabies incubation periods, risk of clinical rabies developing after importation is reduced by 40%. Thus, the overall risk is very sensitive to the waiting period. Any non-compliance with PETS regulations (e.g. shorter than required wait, incorrect vaccination, falsified test result) would push the red, green and purple lines up towards the blue line. The lower the level of compliance, the higher the line goes (e.g. less overall risk reduction is achieved because successful vaccination has only been achieved in some of the imported animals). Thus, the overall risk is also very sensitive to compliance with requirements.

17

Figure 4: schematic representation of risk reduction achieved by different control points

RISK PATHWAY

1: Imported animal exposed to infectious contact in the country of travel/ origin/ transit

2: Animal travelling is infected before travel to UK

3: Infection is not detected before release into UK

Rabies in urban wildlife

HIGHEST RISK COUNTRY / +vaccination; +serotest; +wait period; -quarantine HIGHEST RISK COUNTRY / +vaccination; -serotest; +wait period; -quarantine HIGHEST RISK COUNTRY / +vaccination; +serotest; -wait period; -quarantine

Rabies in rural wildlife

Rabies in insectivorous and fructiferous bats

HIGHEST RISK COUNTRY / -vaccination; -serotest; -wait period; +quarantine LEAST RISK COUNTRY / +vaccination; +serotest; +wait period; -quarantine

risk level

'starting' risk that animal is incubating rabies

Dogmediated rabies

risk level decreases in response to controls applied along pathway

CONTROL POINTS ALONG THE PATHWAY

t.worm & ticks treatment with veterinary certificate of treatment 24-48h prior to entry

Pre- travel scenario: +/- Rabies vaccination +/- Serological test +/- Waiting period

18

Border control at official port with docs.

Entry & release in UK OR… Vaccination & 6m Quarantine before release

A cautionary note on compliance Importation of domestic pets under the PETS scheme requires that prior to import, animals are identified by microchip, vaccinated against rabies, serologically tested for anti-rabies antibodies and kept for six months before entry to UK accompanied by certificates to show that these safeguards have been properly undertaken. If the regulations are not complied with and the pets are not properly prepared, then this increases the risk of an animal bringing rabies into UK (Jones, Kelly et al. 2005). From a scientific point of view, the conditions to be met under the PETS scheme, or a modification of it, might provide a similar level of control of the risk of rabies importation as the quarantine system. However, it has to be accepted that the more complex a ‘risk control scheme’ is, the higher the risk of intentional or unintentional non-compliance are. If less than 100% of entering animals have their i.d. and documentation checked at the border, some animals are being allowed entry ‘on trust’ that they are compliant. There are several ways that animals could be entered without being compliant with regulations: • They could be entering from a qualifying country, but without the correct documentation (or with intentionally forged documentation): - to demonstrate that either they have been vaccinated correctly and kept up to date, - or that they have had a successful blood test, - or both, - or their i.d. and documentation may not match. • They could have correct documentation but have travelled from a non-qualifying country (e.g. have travelled outside EU and avoided controls on re-entry to EU). • They could be travelling from a non-qualifying country without documentation (effectively, being smuggled to avoid quarantine). To make any assessment of the (increased) risk of rabies importation as a result of non-compliant animal movements it would be necessary to have an estimate of the level and types of non-compliant movement. The data to support such an estimate are likely to be hard to obtain and, if they exist, are likely to be of questionable reliability. It is important to note that quarantine following entry into UK is the only risk reduction method that is under direct control of the UK authorities. It follows that a key criterion in making any decision about whether to apply PETS regulations for import, or to require quarantine within UK, is the level of confidence that can be achieved in compliance with PETS regulations. If compliance is doubtful, perhaps because of poor veterinary regulation in the oversease country, then the lower risk option is to require quarantine within the UK.

Conclusions In the risk analysis, a risk pathway was considered which starts at the country of origin and ends at release of animals into UK. When assessing the risk different countries might pose with regard to introduction of rabies into UK via animals capable of being infected by rabies and transmitting the disease, countries can be divided into four risk categories based on the epidemiological situation: 1. Rabies in insectivorous and fructiferous bats – least risk 2. Rabies in rural wildlife – medium risk 3. Rabies in urban wildlife – higher risk 4. Dog-mediated rabies – highest risk. While there may be more than one epidemiological situation in a country, the overall risk depends overwhelmingly on the highest risk scenario present.

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Within these four broad categories, risk will vary depending on amount of disease in the country. However, the amount of disease in a country is difficult to assess because the level of veterinary surveillance and animal health control, and the reliability of surveillance data varies between different countries (see annex 9 for more detail). The annual risk of rabies introduction from any one country will also be influenced directly by the number of movements of animals from a country to the UK – the more movements per year, the higher the annual risk. Considering available control methods, control points along the risk pathway were identified. These are: 1. Animal identification (by microchip) 2. Rabies vaccination 3. Serological testing 4. Waiting period after vaccination and testing before entry 5. Tapeworm and ticks treatment with veterinary certification 24-48 hours prior to entry 6. Border control at port of entr 7. Vaccination and six months quarantine after entry. Their importance was considered as follows: 1. Microchip is considered to be important as it gives confidence that vaccinations and blood tests relate to the animal presented for import. 2. Rabies vaccination is considered the most important measure to protect an animal against rabies before entry to UK. 3. Serological testing provides confidence that an animal has been successfully vaccinated and there is good compliance in the country of origin. 4. Waiting period after vaccination and testing before entry is vital if quarantine after importation is not used – vaccination at point of entry provides no safeguard against importing an infected animal and it will not prevent clinical disease developing in animals infected before vaccination, but vaccination followed by a pre-import waiting period of longer than the incubation period of rabies is an effective safeguard against importing an infected animal. 5. Tapeworm and ticks treatment with veterinary certification 24-48 hours prior to entry is a useful control point as it gives an opportunity to confirm identification and certification of vaccination, blood test and waiting period before entry (especially in view of the fact that certification checks may not be carried out on all animals at the port of entry). 6. Border control at port of entry is also a useful control point if it is efficiently implemented, both by the carrier and immigration officials. 7. Vaccination and six months quarantine after entry is well proven as a successful barrier to the release of a rabid animal into the population after import into UK. When considering the suitability of the different control measures listed above, account must be taken of the level of compliance with rabies control measures that can confidently be expected in different overseas countries.

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Annex 1. Types of Lyssa viruses There are seven rabies virus genotypes, six of which have similar effects in man. The exception is genotype 2, which has never been isolated in human cases. The main genotypes of interest are 1, 5 and 6. Genotype 1 viruses have a worldwide distribution and are generally found in terrestrial animals. Genotypes 5 and 6, commonly known as European bat lyssaviruses (EBLVs), are restricted to Europe and are frequently isolated from European bats. Genotype 1 viruses have never been isolated from European bats but in North America, bat rabies is caused by genotype 1 (Finnegan, Brookes et al. 2002). New genotypes are emerging: in addition to a recently characterised Australian bat lyssavirus, four novel lyssaviruses from bats in Eurasia have been described: Aravan (ARAV), Khujand (KHUV), Irkut (IRKV), and West Caucasian bat virus (WCBV) (Hanlon, I. V. Kuzmin et al. 2005). Different biotypes of rabies virus have been observed. A particular biotype is a virus variant adapted to a particular host species, with especially high pathogenicity, high rate of excretion, and with low immunogenicity for this species (Wandeler 2004). Partial gene sequence of a rabies isolate can not only determine whether an isolate is of canine or chiropteran origin, but also its geographical origin (McColl, Tordo et al. 2000).

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Annex 2. History of rabies and its control in UK There have been claims of rabies from the times of Homer, ca. 8th Century BC (Neville 2004). First mention of rabies in UK appears to date back to 1026 “numerous dogs were suffering from “madness”. In 1793, a plan for eradicating rabies in the British Isles consisted of establishing a universal quarantine for dogs within UK and a total prohibition of importation of dogs during the existence of the quarantine. Forty years later, the duration of the quarantine was proposed to be eight months. The General Rabies Order, 1897, empowered the Board of Agriculture to enforce muzzling of dogs in specified districts. The first Importation of dogs Order required imported dogs to be isolated at their owner’s premises for three months. This was later extended to six and dogs had to be kept on a veterinary surgeon’s premises (Blancou 2004). UK has been rabies free since 1902 and Ireland since 1903. Since then, there have been no indigenous human cases of rabies in UK until 2002 when a bat conservationist died in Scotland from rabies caused by a bat-adapted rabies virus. Between 1977 and 2002, 11 human rabies cases were reported in UK in recent immigrants from India (four), Pakistan (two), Nigeria (two), and one each from Zambia, Bangladesh and the Phillipines. All were caused by dog bites (Fooks, Roberts et al. 2004). Rabies has never become established in wildlife in UK, although two outbreaks occurred in deer. The first in Barnsley in 1856 when 100 animals were involved, and the second in Richmond Park in 1886 when 257 fallow deer (which were seen to bite each other) died but did not pass on the disease to red deer in the same park (Fooks, Roberts et al. 2004). An outbreak of urban rabies occurred between 1918 and 1922, originating from dogs smuggled into the country by returning First World War servicemen. During this period, 312 dogs, eight cattle, two sheep, three swine and three horses were confirmed cases. The disease was controlled and eliminated by muzzle and leash restrictions placed on dogs and the destruction of stray dogs (Fooks, Roberts et al. 2004). Since 1901, protection from rabies in UK has been based on the quarantine of imported domestic pets, normally for six months, on the quarantining of other susceptible species and on import certification for farm livestock and horses. Quarantine for dogs was established in 1922 and that for cats in 1928. Between 1922 and 1969 there were 27 cases of rabies within quarantine: 25 dogs, one cat and one leopard. In 1966, rabies occurred in a rhesus monkey which had been imported 53 days earlier and been taken directly to a research establishment (Fooks, Roberts et al. 2004). Two cases of rabies have occurred in dogs after release from quarantine: •

In July 1969, a collie imported from India in April died of rabies in the quarantine kennel. In October 1969, another imported dog died of rabies 10 days after its release following six months in the same quarantine kennels. In November 1969, a third dog showed signs of rabies which was later confirmed by laboratory examination. Investigators concluded that there was a strong possibility that at least one of the dogs contracted rabies while in quarantine.

•

In 1970, a second case of rabies in an imported dog after release from quarantine kennels occurred. Signs of illness were noted three months after release from quarantine and death from rabies occurred seven days later.

Following these outbreaks, recommendations to prevent cross-infection within kennels were implemented. The recommendations included rabies vaccination on arrival at the quarantine premises. Since 1972, two further cases of rabies in dogs have occurred in quarantine (Fooks, Roberts et al. 2004). Quarantine has therefore been the primary control method used to maintain freedom from rabies in the UK, since 1793. The result of this policy is that there have been no indigenous human cases of rabies in UK until

22

2002 when a bat conservationist died in Scotland from rabies caused by a bat-adapted rabies virus (see Annex 3). Import of pets through quarantine is controlled by the Rabies (Importation of Dogs, Cats and Other Mammals) Order 1974, and its amendments. In 1998, the Kennedy Report recommended that quarantine be replaced by vaccination, with demonstration of seroconversion and microchip identification, followed by a six month waiting period in the country of origin, for pet dogs, cats and ferrets from selected countries (Kennedy 1998). Following recommendations by OIE (OIE, 1997) cited by (Fooks and McElhinney 2000), Kennedy’s group proposed a six month delay for dogs and cats to re-enter the UK after primary vaccination (Kennedy 1998). This was implemented to prevent the possible import of an animal that was infected before it was vaccinated (Fooks and McElhinney 2000). In 2000, amendments to the UK quarantine laws were made and the Pet Travel Scheme (PETS) was launched for companion animals travelling from European Union countries and rabies-free islands. Since its introduction, it was proposed that other countries should be included within the UK scheme. Following the example set by Australia and New Zealand, the scheme was extended to include North America, even though rabies is endemic there. Australia and New Zealand had imported 15,000 dogs and cats from USA without any cases of rabies (Briggs and Schweitzer, 2001) cited by (Fooks 2001). A quantitative risk assessment was developed to assist in the policy decision to amend the long-standing quarantine laws for dogs and cats from North America. It was determined that the risk of rabies entry is very low and is dependent on the level of compliance (legally conforming to all of the required regulations) with PETS and the number of pets imported. Assuming 100% compliance with PETS and the current level of importation of cats and dogs from North America, the annual probability of importing rabies is lower for animals travelling via PETS (7.22x10-6, 95th percentile) than quarantine (1.01x10-5, 95th percentile). These results, and other scientific evidence, directly informed the decision to expand the PETS scheme to North America as of December 2002 (Jones, Kelly et al. 2005). The list of countries currently included in UK PETS is given in Table 1, and now includes USA, Canada, Australia, New Zealand and the Russian Federation. The PETS scheme is enabled by the Non Commercial Movement of Pet Animals (England) Regulations 2004 and comparable legislation in Wales, Northern Ireland, the Channel Islands and the Isle of Man. The regulations are consequential to the application of EC Regulation No 998/2003, amending Council Directive 92/65/EEC. There are now two scenarios with regard to import of pets into UK: 1. Pets coming to UK from countries where rabies is considered to be a significant problem are treated on the assumption that animals could be infected and vaccination and quarantine on arrival is imposed; 2. Pets from countries on the list of “qualifying countries”, where the disease is seen to be controllable, are prepared under the PETS scheme by identifying with a microchip, vaccinating and passing a serological test six months before entry to UK and are then allowed to enter without quarantine on the assumption that these animals are not infected. Entry from one of these countries requires (Fooks 2001): • microchip identification; • anti-rabies vaccination with inactivated vaccine; • blood taken one month after vaccination must have neutralizing antibodies (titre ≥ 0.5 IU/ml) tested at least six months before import; • 24 – 48 hours prior to entry, treatment for ticks and tapeworms.

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Table 1. List of Pets Qualifying Countries

COUNTRY

DATE

Australia (guide and hearing dogs only) Austria Belgium Denmark Finland France Germany Gibraltar Greece

Italy Luxembourg Netherlands New Zealand (guide and hearing dogs only) Norway Portugal Spain Sweden Switzerland

Antigua & Barbuda Ascension Island Australia Barbados Bermuda Cayman Islands Cyprus Falkland Islands Fiji French Polynesia Guadaloupe Hawaii Jamaica Japan

Malta Martinique Mauritius Mayotte Montserrat New Caledonia New Zealand La Reunion St Helena St Kitts & Nevis St Vincent Singapore Vanuatu Wallis and Fortuna

28 February 2000

31 January 2001

Bahrain

1 May 2002

USA Canada

11 December 2002

Czech Republic Latvia Slovenia Estonia Lithuania Poland Hungary Slovakia

Croatia Greenland Faroe Islands Grenadines French Guiana St Pierre et Miquelon Netherlands Antilles Aruba

3 July 2004

Chile Hong Kong Russian Federation United Arab Emirates Spanish territories – Ceuta and Melilla

20 October 2004

Taiwan

20 January 2005

Argentina

26 July 2005

Guam Trinidad and Tobago Mexico Belarus Romania

2 December 2005

Bulgaria Bosnia-Herzegovina

10 March 2006

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Annex 3. Rabies in man Rabies can probably infect most, if not all mammals. The virus enters the central nervous system of the new host, causing an encephalomyelitis which is fatal once clinical signs have developed. The manifestations in human cases include extreme agitation, convulsions, spasms, hallucinations, paralysis and coma (Finnegan, Brookes et al. 2002). Gross under reporting of rabies is likely because many countries lack the necessary diagnostic facilities. Also the populations most affected tend to be rural (especially in developing countries) with erratic surveillance. Nevertheless, a WHO World Survey of Rabies for 1997 estimated that between 35,000 and 50,000 people die of rabies annually (Anon. 2000). African and Asian countries are particularly affected by rabies because of their animal reservoirs and lack of healthcare and control measures (Finnegan, Brookes et al. 2002). In developed countries, such as the USA, widespread animal vaccination and control programmes introduced in the 1950s have reduced numbers of human cases from around 40 cases per year to one or two cases per year now (Table 1) and a large proportion of these are transmitted by bat bites. Table 1. Decline of number of human cases of rabies in USA over five decades. Decade

No. of human rabies cases

1950s

99

1960s

15

1970s

23

1980s

10

1990 – 1996

32

Human cases are now rare in Europe and occur mostly in the Russian Federation (Table 2). In western Europe, when human cases occur, infection has most often been contracted in a country where the disease is endemic. Table 2. Human cases of rabies in Europe Year

No. of human rabies cases

Distribution of human cases

1997

17

Russian Federation 12, Romania 3, Lithuania 1, France 1 (imported)

1998

7

Russian Federation

1999

11

Russian Federation

2000

9

Russian Federation 7, Romania 1, Lithuania 1

The last human death from indigenous classical rabies in UK occurred in 1902 and until 2000 there had been only 23 human cases of imported rabies reported since 1946 (UK Department of Health 2000) cited by (Fooks, Johnson et al. 2003). But in 2001, UK had 2 confirmed human rabies cases, imported from Philippines and Nigeria respectively. Phylogenetic analysis demonstrated that virus from the former was closely related to that of canine variants currently circulating in the Philippines, and from the latter was a genotype 1of the Africa 2 subgroup (Fooks, Johnson et al. 2003). (Fooks, Johnson et al. 2003) comment that these cases illustrate an increasing risk associated with an increase in international travel. In 2003, UK recorded its first case of indigenous human rabies in 100 years. The patient was a volunteer bat handler who had been bitten by what he believed to be a Daubenton’s bat (Myotis daubentonii), about 19 weeks previously (Nathwani, McIntyre et al. 2003). Two cases of rabies have been confirmed in UK in Daubenton’s bats, the first in 1996 at Newhaven and the second in 2002 in Lancashire. The latter developed abnormal behaviour, including unprovoked aggression, while in captivity. Both cases in bats were caused by

25

EBLV type 2a. Genomic sequencing from brain samples from the human case also identified the causal virus as EBLV-2a (genotype 6). Phylogenetic comparisons showed that it was closely related to the 1996 bat isolate and isolates from bats in the Netherlands (Johnson, Selden et al. 2003). In Europe, three human deaths caused by EBLV have been reported. Daubenton’s bat is the second most common bat in UK (Nathwani, McIntyre et al. 2003). The most recent isolation of EBLV type 2 was made from a juvenile Daubenton’s bat that died in Surrey in September 2004 (Anon 2004a). Bat rabies has been implicated in transmission of rabies via organ transplants. In 2004, in USA, four recipients of kidneys, a liver, and an arterial segment from a common organ donor died of encephalitis. Rabies was diagnosed. The donor had told others of being bitten by a bat (Srinivasan, Burton et al. 2005). In a review of animal species known to transmit rabies to man (Table 3), the dog was shown to be responsible for 93% of cases in man (Thraenhart 2004).

Table 3. Animal species known to transmit rabies to man and their relative importance as vectors (Thraenhart 2004) Species

% cases

Dogs

93

Cows

1.4

Buffaloes

1.2

Jackals

1.02

Mongooses

0.6

Equines

0.56

Monkeys

0.4

Cats

0.4

Goats

0.09

Sheep

0.09

Pigs

0.09

Panthers

0.09

Camels

0.08

Foxes

0.05

Rats

0.02

Bears

0.02

Wolves

0.007

Lions

70 IU/ml). After the animal was released and monitored for 18 months by radiotracking, it was concluded that the oncilla had a nonfatal exposure to rabies virus (Deem, Davis et al. 2004).

2. North America In North America, in 1998, 92.4% of rabies diagnoses were made on wild animals. The diagnoses indicate the wildlife reservoirs: in the south east States raccoons (40.6% of diagnoses); north and south central States skunks (29.4%); Canada and New England red foxes (14%); Alaska red and arctic foxes (5.4%); bats 14%. Prevalence in red foxes is declining in Canada following oral rabies vaccination programmes, but persists in Alaska in red and arctic foxes) 5.4% (Finnegan, Brookes et al. 2002). A North American Rabies Control Plan between Canada, USA, and Mexico is being developed (Fearneyhough and Sanders 2004). Mexico has made major advances in control of urban rabies through massive dog vaccination campaigns (McColl, Tordo et al. 2000). Hawaii is recognised by OIE as being free from rabies.

a. Bats and rabies in North America Rabies virus has been isolated from all species of North American bats which have been adequately sampled (King, Haagsma et al. 2004). By 1984, USA had reported several thousand cases of bat rabies, and in that year a peak of 1,038, representing 20% of the 5,174 wildlife cases, or 18.4% of total cases. In 1998, the number of positive bats was 992, a lower proportion (12.5%) of the total 7,961 cases. Between 1951 and 1999 the number of human deaths attributed to bat rabies was 34, of which 20 were in the 1990s, although eight of these had no history of bat contact (King, Haagsma et al. 2004). In Mexico, to investigate if non-haematophagous bats play a role in outbreaks of rabies the seroprevalence in several species of non-haematophagous bats on the sub-tropical Pacific coast of the state of Colima, were studied. A total of 151 non-haematophagous bats (16 species) were captured. Fifty-six (37%) had anti-rabies antibodies (Salas-Rojas, Sanchez-Hernandez et al. 2004). In Colorado (USA), in relation to rabies virus transmission, 35 big brown bats (Eptesicus fuscus) were captured in late summer 2001 and held captive for five months. Two of the bats succumbed to rabies virus within the first month of capture. Despite group housing, all of the remaining bats were healthy over the course of the investigation; none developed rabies, although one of the rabid bats was observed to bite her cage mates. Sera obtained six times throughout the study were assayed for rabies virus neutralizing antibodies. Five bats were seropositive prior to their capture and maintained titres throughout captivity. Two adult bats sero-converted during captivity. Two juvenile bats had detectable antibody titres at the first serum collection but were negative thereafter. A serological survey of big brown bats in the roost from which one of the captive rabid bats had originated showed a significant rise in seroprevalence during 2002 (Shankar, Bowen et al. 2004). USA. From 1998 to 1999 rabies in feline, canine and equine species decreased by 1.4%, 1.8% and 14% respectively but increased in bovines, ovines and porcines by 16.4%, 12.5% and 200%. Highest numbers of cases were in Iowa (57) and Texas (54). For the first time a bat-associated rabies virus was isolated from a cat in Maryland. Raccoon-variant rabies was confirmed in seven pet rabbits and one pet guinea pig in New York State, requiring post-exposure treatment to be given to several adults and children (Eidson, Matthews et al. 2005).

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During 2003, 49 states and Puerto Rico reported 7,170 cases of rabies in animals and three cases in man. This represents a 10% decrease from the 7,967 cases in animals and three cases in man reported in 2002. More than 91% (6,556) were in wild animals, and 8.6% (614) were in domestic animals (compared with 92.5% in wild animals and 7.4% in domestic animals in 2002). The relative contributions of the major groups of animals were as follows: raccoons 36.7%, skunks 29.4%, bats 16.9%, foxes 6.4%, cats 4.5%, dogs 1.6%, and cattle 1.4%. Compared with cases reported in 2002, the number of cases reported in 2003 decreased among all reporting groups with the exception of cats, dogs, equids, and swine. Ten of the 19 states with enzootic rabies in raccoons, the District of Columbia, and New York City reported decreases in the numbers of rabid raccoons during 2003. Tennessee reported 4 cases of indigenous rabies in raccoons during 2003, becoming the twentieth state where rabies in raccoons is known to be enzootic. On a national level, the number of rabies cases in skunks during 2003 decreased by 13.2% from those reported in 2002. Texas again reported the greatest number (620) of rabid skunks during 2003, as well as the greatest overall state total of rabies cases (909). As in 2002, Texas did not report any cases of rabies associated with the dog/coyote variant of the rabies virus, but did report 61 cases associated with the grey fox variant of the virus (compared with 65 cases in 2002). The 1,212 cases of rabies reported in bats during 2003 represented a decline of nearly 12% from the previous year's record high of 1,373. Cases of rabies reported in foxes and raccoons declined 10.2% and 8.9%, respectively, during 2003. Rabies among sheep and goats decreased from 15 cases in 2002 to 12 cases in 2003, whereas cases reported in cats, dogs, and equids increased 7.4%, 18.2%, and 8.6%, respectively. In Puerto Rico, reported cases of rabies in mongooses and dogs decreased 26.9% and 35.7%, respectively, from those reported in 2002. Three cases of rabies in human beings were reported in California, Virginia, and Puerto Rico during 2003. The Virginia case was the first reported occurrence of rabies in a human being infected with the raccoon rabies virus variant; however, the exposure history was unknown. The California and Puerto Rico cases were the result of infections with bat and dog/mongoose rabies virus variants, respectively, and each patient had a history of a bite (Krebs, Mandel et al. 2004). The invasive spread of raccoon rabies through Connecticut has been studied. Its spread is associated with forest cover: rabies moves up to three-times slower through the most heavily forested townships compared with those with less forestation and rivers present natural barriers to its progress (Smith, Waller et al. 2005). The USDA-APHIS-Wildlife Services provide updates on the USA National Oral Rabies Vaccine (ORV) Programme which is a collaborative programme between the federal, state and local governments. ORV strategic components include enhanced rabies surveillance, natural barriers, contingency action planning and more effective baits (McColl, Tordo et al. 2000). Canada. In Canada, fox-variant rabies virus underwent an epidemic expansion in foxes into eastern and southern Ontario. The fox rabies virus variant descended as an irregular wave with two arms invading from northern Ontario into southern Ontario over the 1980s and 1990s (Real, Henderson et al. 2005). In Canada, insectivorous bat rabies variants have been isolated from cattle and foxes (McColl, Tordo et al. 2000).

3. Europe a. Northern Europe Rabies has never been diagnosed in Iceland (Fooks, Roberts et al. 2004), nor has it been diagnosed in mainland Norway, but an outbreak of arctic fox mediated rabies in the Svalbard islands, 600 miles north of mainland Norway occurred in 1980. Rabies was diagnosed in 12 artic foxes, three reindeer and one ringed seal, followed by two arctic foxes in 1981, two arctic foxes and one reindeer in 1987 and one arctic fox in 1990. By contrast, rabies was present in Sweden up to the nineteenth century with wolves and dogs being the main vectors (Westerling, Andersons et al. 2004). In Finland the last case of dog-mediated rabies in a human occurred in 1934, but in 1985 a biologist who had been working with bats in several countries died of bat rabies. Virological screening for the virus in

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Finnish bats gave negative results. In the 1980s, Finland faced incursions of sylvatic rabies from Russia with the raccoon dog (Nyctereutes procyonoides) being the primary vector and victim. Altogether, 48 raccoon dogs, 12 red foxes, two badgers, two cats, one dog and one young bull were diagnosed by FAT. Control was made by dog vaccination and in 1988 oral vaccination of raccoon dogs and foxes was started. The last case was in 1989 and in 1991 Finland was declared rabies free. To maintain freedom baits are distributed every autumn along the border with Russia and hunting dogs and show dogs are vaccinated (Westerling, Andersons et al. 2004). An archival brain sample from an infected dog taken during the 1988/89 rabies outbreak in Finland was investigated to confirm that it was infected with classical rabies virus (genotype 1). The Finnish dog isolate was identical to a virus isolated from a raccoon-dog also recorded during the 1988/89 outbreak and closely related to a third isolate from the Russian city of Pskov (Johnson and Fooks 2005). Rabies seems to persist throughout most arctic regions, and the northern parts of Norway, Sweden and Finland, is the only part of the Arctic where rabies has not been diagnosed in recent times. The arctic fox is the main host, and the same arctic virus variant seems to infect the arctic fox throughout the range of this species. The epidemiology of rabies seems to have certain common characteristics in arctic regions, but answers to questions concerning the maintenance and spread of the disease remain largely unknown. The virus has spread and initiated new epidemics also in other species such as the red fox and the raccoon dog. Large land areas and cold climate complicate the control of the disease, but experimental oral vaccination of arctic foxes has been successful (Mark and Prestrud 2004). In Estonia. After the second World War, 300-500 cases of rabies were diagnosed annually. Vaccination of dogs started in 1951 caused a decline in rabies until during 1962-67, no cases were diagnosed. However, sylvatic rabies emerged in 1968 when a red fox was diagnosed with rabies and in 1970 rabies was reported in 110 red foxes, 24 raccoon dogs, 10 other wild, and some domestic animals. The annual total of cases now appears to be between 100 – 200, mostly foxes and raccoon dogs, followed by dogs and cats. Currently there is no control of sylvatic rabies (Westerling, Andersons et al. 2004). A similar situation occurs in Latvia where the dog was the main vector up to 1955, after which, wildlife rabies was observed. It was first seen in the raccoon dog (introduced from Russia in 1948) in 1958. Cases peaked in 1990 at 306 (39% foxes, 26.8% raccoon dogs, 5.2% other wild animals, 11.4% dogs, 10.8% cats, 6.8% other domestic animals. Rabies in dogs and cats is now always associated with the epizootic in wildlife and shows a direct correlation with the size of the raccoon dog and fox populations. The disease is present throughout Latvia and wildlife oral vaccination campaigns were introduced in 1991 (Westerling, Andersons et al. 2004). In Lithuania, rabies occurs in domestic animals, including cattle, dogs, cats, pigs, horses, goats and sheep, but these cases appear to be a spill-over from rabies in wildlife where the disease is most common in foxes and raccoon dogs but is also found in martens, lynx, hares, squirrels, badgers and polecats. Infection in the fox population appears to be cyclical, with peaks every 3-4 years; in the raccoon dog the disease peaks every four years. Dog rabies cases have fallen to 9-11 cases/year. Most rabies cases occur in the Autumn and since 1995 the number of cases in wild animals has increased. In 1995, of 80 reported cases 41.2% were in wildlife (foxes 66.7%). In 1999, 75% of cases were in wild animals (foxes 47.1%, raccoon dogs 45.4%) (Westerling, Andersons et al. 2004). In 1995-2002, a total of 2,313 cases of rabies were registered among wild animals in Lithuania, with the majority of cases being registered in foxes (46%) and raccoon dogs (43%). Within the last 3 years, rabies among foxes and raccoon dogs increased significantly (3 and 6 times, respectively), compared with the period from 1997 to 2000. During the last 3-5 years, the fox population has been growing very fast, (from an estimated 12,650 in 1995 to 28,300 in 2001), while the increase in the raccoon dog population was 3 times higher than that in foxes (from an estimated 6,100 in 1995 to 22,900 in 2001). During 1995-2001, the numbers of hunted wildlife in Lithuania increased, with minimal influence on the rabies situation in the country. During 1995-2000, oral rabies vaccination was introduced to prevent rabies in wild animals. Vaccines were distributed over 8000 km2 in 27 of 44 districts of Lithuania twice per year (during April-May and October-November) (Zienius 2004). In Russia, Belarus and Ukraine historically, dog rabies predominated and wolves were also involved, but in the first half of the twentieth century, wolf, fox and raccoon dog populations increased. Consequently, fox rabies began to predominate. Mass vaccination of dogs began in the early 1950s but oral vaccination of wild carnivores has not yet been widely practised. Thus, as Eastern Europe remains a focus of wild canid

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biodiversity and rabies virus, and fox rabies predominates in Russia, conditions are there for further outbreaks of rabies in humans and domestic animals (Botvinkin and Kosenko 2004). In Ukraine, human rabies cases after bat bite have been repeatedly reported. In 2002, a 34 year old man was bitten on the finger by a bat approximately 45 days before death from rabies (Botvinkin, Selnikova et al. 2005).

b. Eastern Europe Compulsory vaccination of dogs was introduced in Poland in 1949 and the number of canine and other domestic animal cases decreased from 3,749 in 1949 to 264 in 1951 and 65 in 1956. As in northern Europe, the epidemic of sylvatic rabies in the 1980s spilled over into domestic animals and the number of dog and cat cases increased. Between 1986 and 1996 there was an annual average of 284 cases in dogs and cats despite compulsory vaccination programmes. From the mid-1980s the number of rabies cases overall dramatically increased and the next 10 years saw the highest incidence ever recorded in Poland until in 1992 a programme of oral vaccination of wildlife (foxes) was introduced. During 1989-1994 there were 11,278 cases, of which 81.9% were in wildlife (82.7% foxes and 8.7% raccoon dog) (Matouch 2004). During the period of 20012003, rabies incidences reduced dramatically from 2,964 cases in 2001, 1,191 in 2002 to 391 in 2003 (Bednarski and Rudy 2005). A problem remains along Poland’s borders with Belorussia and Ukraine, countries where no vaccination of wild foxes is conducted. Observations indicate that there is a necessity to continue a fox immunization campaign along these borders (Smeja 2005). In the Czech Republic, dog vaccination campaigns in the first half of the 1900s reduced the number of cases of rabies but after the Second World War, rabies cases increased together with an increase of the red fox population and sylvatic rabies in the fox population increased up to the 1980s (Matouch 2004). The incidence of rabies in the Czech Republic has now declined to zero since the launch of a fox oral vaccination campaign in 1989 (Matouch and Vitásek 2005). In the Slovak Republic, sylvatic rabies was first reported in 1947 and from 1962 an increase in cases of rabies was noticed in both wildlife (principally foxes) and domestic animals. While rabies in wolves was rare, its epidemiological consequences were dramatic. Oral vaccination of wildlife started in 1992-93 bringing positive results, but incidence of rabies again increased in 98-99 and compulsory vaccination of dogs was introduced. During 1969-79, rabies strains with different biological properties from street rabies virus were isolated from small wild rodents “murine variants of rabies virus”. These findings, and the fact that small rodents constitute a major source of fox diet, supported the theory that species other than the fox (wild rodents) might be rabies virus reservoirs in the Slovak Republic (Matouch 2004). Hungary was one of the first countries to gain good control of dog rabies when it introduced mass vaccination of dogs, together with compulsory dog registration and capture of stray dogs in the 1930s. During 1954-1965, fox rabies was reported only sporadically, and during this period dog and cat rabies cases outnumbered fox cases by 127 to 113. However, fox rabies increased from 17 in 1966 to 212 in 67 and 772 in 1968. By 1974, rabies was epizootic among foxes with an average of 1,151 laboratory-diagnosed cases reported annually. The country is now being cleared of fox rabies by an oral vaccination campaign (231 fox cases in 2001). In 1999, a bat was diagnosed with rabies in Budapest (Lontai 2004). In Romania, in 1965, wolves were important in the epidemiology of rabies. Then the fox epizootic emerged and in 2001, of 386 rabies diagnoses, 282 were in foxes. In Moldova, in 2001, out of 16 diagnoses of rabies, eight were in foxes. In Bulgaria, 62 cases of rabies were diagnosed in wildlife in 2001 (Lontai 2004).

c. Western Europe In the majority of European countries, throughout the 1900s, the dog was the main reservoir, vector and victim of rabies. Human cases were reported as a result of infection from dogs and other domestic animals. the application of strict sanitary measures allowed the elijminatio of canine rabies in these countries gby the middle of the 20th Century. Sylvatic fox rabies spread to Belgium and Luxembourg in 1966, Switzerland in 1967, France in 1968 and The Netherlands in 1974. In all these countries, the different measures aimed at fox population decimation failed to stop the progression of the rabies epidemic, whereas oral vaccination of foxes by means of vaccine bait was shown to be the only efficient tool to control the disease. As a result of successful oral vaccination programmes, these countries have been reported officially free of terrestrial

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rabies: The Netherlands in 1991, Switzerland in 21999, France in 2000, Belgium and Luxembourg in 2001. However, bat rabies have been, or are still, reported in most of these countries. In the years leading up to the First World War, dog control measures led to a marked reduction in cases of rabies in Western Europe. Chaos after World War 1 brought a new wave of rabies in Germany and Austria and after World War 2, an increase in the fox population in western Europe was accompanied by thousands of cases of rabies in a westward spread in the red fox population. This species of wildlife alone could maintain the reservoir of infection (Müller, Cox et al. 2004). In Germany, though murine variants of rabies virus were found, they were not considered to be a danger to foxes. For many years, vaccination of dogs was forbidden on the grounds that dogs they could become symptom-less excretors of virus. After much debate, permission to vaccinate domestic animals on a voluntary basis was first established in 1969. Control of foxes by gassing was introduced and this, together with rabies, reduced the badger population to 10%. A characteristic of the fox-mediated rabies epidemic, as opposed to urban rabies was a steady move of the frontline into previously non-infected areas. In 1974 gassing of foxes was stopped, but in 1978 there was an all time peak of 8,842 rabies cases. Germany started oral vaccination in 1984 with Tübingen fox bait but by 1999 there were still 55 cases of rabies in terrestrial animals (37 foxes, 7 other wild animals, 11 domestic animals). Also 15 bat rabies cases were recorded in north Germany. Although the rabies epidemic was in foxes, dogs were the main causes of infection of man: of 42 indigenous rabies cases in man between 1950-1999, sources of infection were: dog 29, cat 4, bovine 1 and fox 8 (Müller, Cox et al. 2004). In Denmark, control of the fox population by shooting and gassing stopped three incursions of rabies and from 1985 onwards, only bat rabies has been reported. Ten bat rabies cases were reported in 1999 and in 1998, three sheep were infected with bat rabies EBLV 1, indicating that transmission from bats to terrestrial animals is possible (Müller, Cox et al. 2004). Also, antibodies to EBLV-1 have been demonstrated in a domestic cat in Denmark (Tjrnehj, Rnsholt et al. 2004). Switzerland was the first country to introduce oral vaccination of foxes. In 1978 a field trial to immunize foxes by oral vaccination was conducted using chicken heads as baits. In Austria, in 1946 a focus of urban rabies existed on its borders with Hungary and Yugoslavia. This was eradicated by 1951 through a programme of vaccination of dogs. Austria started oral vaccination in 1986 and by 1999, only three foxes, one roe deer and one dog (imported from Turkey) were diagnosed with rabies (Müller, Cox et al. 2004). In the majority of European countries, throughout the 1900s, the dog was the main reservoir, vector and victim of rabies. Human cases were reported as a result of infection from dogs and other domestic animals. the application of strict sanitary measures allowed the elimination of canine rabies in these countries by the middle of the 20th Century. Sylvatic fox rabies spread to Belgium and Luxembourg in 1966, Switzerland in 1967, France in 1968 and The Netherlands in 1974. In all these countries, the different measures aimed at fox population decimation failed to stop the progression of the rabies epidemic, whereas oral vaccination of foxes by means of vaccine bait was shown to be the only efficient tool to control the disease. As a result of successful oral vaccination programmes, these countries have been reported officially free of terrestrial rabies: The Netherlands in 1991, Switzerland in 21999, France in 2000, Belgium and Luxembourg in 2001. However, bat rabies have been, or are still, reported in most of these countries (Aubert 2004). In France from 1989 to 2002, 14 cases of bat rabies caused by EBLV-1 have been diagnosed in serotine bats (Eptesicus serotinus) (Picard-Meyer, Barrat et al. 2004).

d. Southern Europe and the Balkans There is a rich historical record of rabies from Italy, Greece and countries of the former Republic of Yugoslavia. Italy and Greece have succeeded in eradicating the disease, whereas countries such as Albania, Bosnia, Croatia and Slovenia continue to deal with rabies in wildlife due in part to the movement of infected foxes from the north (Müller, Cox et al. 2004). In Italy, dog rabies vaccination was made compulsory in 1954. In Sicily, rabies was reported in red foxes in 1961-1963. The disease spread to cattle. Control measures were control of foxes by poisoning and

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vaccination of cattle and dogs. No cases have been reported in Sicily since 1971 (Mutinelli, Stankov et al. 2004). Sylvatic rabies emerged in northern Italy from 1977 to 1986, a second epizootic (from Slovenia) occurred in 1988-89, and a third epizootic (from Slovenia) occurred in 1991-95. In 1993-94 there was an epizootic in Bolzano from across the nearby border with Austria. Oral fox vaccination campaigns started in 1984. In December, 1995, the last cased of rabies was reported in a fox in Trieste. All bats tested in Italy have been negative. Italy was recognised as rabies free in 1997. Active rabies surveillance and some border fox vaccination are practiced (Mutinelli, Stankov et al. 2004). In Spain, where there is exhaustive surveillance, rabies has been reported (perhaps only on serological grounds) for each of the eight years 1996 to 2004 (OIE Handistatus, Annex 9). In 1987, two bat cases were reported in Valencia and Grenada, another in Grenada in 1994, and in 1999, four further cases in Eptesicus serotinus were reported. Serological studies and virus isolations show that bat rabies (EBLV-1) is limited to the Mediterranean coast of Spain. Compulsory dog vaccination continues throughout most of Spain, the biggest threat to Spain is considered to be the entry of dog-mediated rabies from North Africa (Abellan Garcia, Sánchez-Serrano et al. 2004). In Portugal, rabies in animals was present in the 1920s and 30s and again in the 1950s but, apart from four cases in 1960 (2 dogs and 2 cats) the last animal rabies case was in 1956 (Abellan Garcia, Sánchez-Serrano et al. 2004). After introduction of dog vaccination, from 1967-77 Croatia was free of rabies. Fox rabies then came in from the north with four cases in 1977, rising to 485 in 1985. Oral vaccination of foxes was started in the 1990s but so far has not eliminated rabies. There have been no human cases since 1964 (Mutinelli, Stankov et al. 2004). In 1971 in Bosnia Herzogovina, a new dog rabies outbreak emerged after rabies had been absent since 1964 and sylvatic rabies emerged from the north in 1982. In Slovenia, free of human rabies since 1950 its rabies free status changed in 1973 when fox-mediated rabies spread from Hungary with epizootic peaks in 1988 (805 cases) and 1995 (1,084 cases). Oral fox vaccination campaigns started in 1988 but, while controlling sylvatic rabies, it has not eliminated it. In Macedonia, rabies eradication was achieved in 1977 and since then the country has remained free. Albania has been rabies free since 1976 (Mutinelli, Stankov et al. 2004). However, there was an outbreak of rabies in south east Albania in 2004 affecting domestic animals and man, reportedly caused by a rabid wolf which came out of the forest (Tony Wilsmore, personal communication). In Greece, as rabies cases have reduced to zero for a number of years, compulsory vaccination of dogs has been gradually suspended. Dog vaccination may still be performed, particularly among shepherd and hunting dogs, in a 30 kilometre zone along borders with Albania, Macedonia, Bulgaria and Turkey. Surveillance shows no rabies in wildlife (Mutinelli, Stankov et al. 2004). In Slovenia, after the first experimental oral vaccination of foxes and study of vaccination models from 1988-1992, spring and autumn campaigns have been carried out since 1995. The baits have been distributed by plane. A rapid decline in rabies cases was observed from 1995 to 1999, when the oral vaccination programme covered the whole territory. In 1999, only 6 rabies cases were confirmed, whereas in 1995, 1089 rabies cases were documented. In 2000 and 2001, rabies incidence increased again, so it was decided to increase bait distribution in 2001. In 2002, after changing the vaccination strategy, positive cases rapidly dropped and there were only 15 cases in 2002, and in 2003 eight cases were found near the non-vaccinated border with Croatia (Hostnik, Barlic-Maganja et al. 2005).

e. Bats and rabies in Europe In Europe, two bat lyssaviruses referred to as EBLV types 1 and 2 (genotypes 5 and 6 respectively) which are closely related to classical rabies virus are responsible for an emerging zoonosis (Fooks, Brookes et al. 2003).

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In 1954 a boy in Hamburg was bitten by a sick bat. A mouse inoculation test on bat brain which revealed Negri bodies was positive. The boy received post exposure treatment and survived. This was the first bat rabies case diagnosed in Europe. From 1985 increasing numbers of bat rabies cases were diagnosed and by 2000, over 600 cases from 17 countries had been recorded, including Yugoslavia, Turkey, Greece, Russia (one girl died after being bitten by a bat in 1985), Ukraine (one girl died after a bat bite), Poland, Switzerland, Finland (the victim probably contracted rabies from a bat abroad), Czechoslovakia, Slovak Republic, Hungary, UK, Germany (regularly reported), Denmark (regularly reported), The Netherlands (reported thru’ regular surveillance, Spain and France (King, Haagsma et al. 2004). In Europe, bat rabies isolates are genetically different from those found in bats in North.America. Eptesicus serotinus is the principal reservoir for genotype 5, while Myotis dasyeneme and M.daubentonii are principal reservoirs for genotype 6 (Finnegan, Brookes et al. 2002). EBLVs are host restricted to bats, and have been known to infect not only their primary hosts but also in rare circumstances, induce spill-over infections in terrestrial mammals, including domestic livestock, wildlife and man. Although spill-over infections have occurred there has been no evidence that the virus adapted to a new host. Since 1977, four human deaths from EBLVs have been reported. None of the victims had a record of prophylactic rabies immunization. Only fragmentary data exist about the effectiveness of current vaccines in cross-protection against EBLVs (Fooks, Brookes et al. 2003). (Fooks, Brookes et al. 2003) comment “EBLV in bats cannot be eliminated using conventional strategies similar to the control programmes based on vaccine baits used for fox rabies in Europe. Due to the protected status of bats in Europe, knowledge of EBLV prevalence and epidemiology is limited. It is possible that EBLV is under-reported and that the recorded cases of EBLV represent only a small proportion of the actual number of infected bats. For this reason, any interaction between man and bats in Europe must be considered as a possible exposure. Human exposure through biting incidents, especially unprovoked attacks, should be treated immediately with rabies post-exposure treatment and the bat, where possible, retained for laboratory analysis. Preventative measures include educating all bat handlers of the risks posed by rabies-infected animals and advising them to be immunized”. European bat lyssavirus type 1 (EBLV-1, genotype 5) is known to endemically circulate in insectivorous bats in Germany. In August 2001, a rabies suspect stone marten was found in Burg, Saxony-Anhalt, Germany and was sent for rabies diagnosis. EBLV-1was isolated which was closely related to a previous isolate of EBLV-1 from a serotine bat in Saxony-Anhalt obtained in the same year in an adjacent area to the place where the EBLV-1 infected stone marten was found. This is the first report of an EBLV-1 spill-over from an insectivorous bat into wildlife in Europe (Müller, Cox et al. 2004). (Vos, Müller et al. 2004a) investigated the susceptibility of ferrets (Mustela putorius furo) and mice to experimental EBLV-1 and EBLV-2 infection. All ferrets receiving a large dose of EBLV-1 succumbed to infection. In contrast, only 3 of 7 ferrets inoculated with a low dose of EBLV-1 died. By comparison, all of the EBLV-2 infected ferrets survived infection at high and low doses and seroconverted. While the virus could be detected in different tissues, it could not be found in any saliva samples taken during the 84 day observation period. In UK, samples from 96 Daubenton’s bats were tested for EBLV-2 antibodies from two a priori locations where there was reason to believe that positive bats would be found. Additionally, 183 Daubenton’s bats were sampled from a further 25 locations. Prevalence of positive bats at the a priori locations was 8% (95% c.i. 3-16%). Prevalence at other sites was 2% (1-5%). Other bat species tested were negative. None of the Daubenton’s bats were RT-PCR positive (Fooks, Brookes et al. 2004). In Europe, more than 700 EBLV cases in bats have been reported between 1977 and 2003, mainly in Denmark, Holland, Germany, Poland, France and Spain, the majority (