Avian Influenza and other bird diseases
Abstracts from the BOU’s 2006 Autumn Scientific Meeting held at The Great Northern Hotel, Peterborough, UK
20-21 November 2006
Environment and Heritage Service (Northern Ireland) | Joint Nature Conservation Committee | Scottish Natural Heritage | Wildlfowl & Wetlands Trust | WildWings Bird Management
Richard Drummond | Head of Veterinary Exotic Diseases Research and Official Controls Division, Defra
It has been known for several decades that Avian Influenza viruses circulate in wild bird populations, and from time to time infection spills over in the domestic poultry compartment. The profile of AI has risen within the last three years because of widespread outbreaks of high pathogenic Asian type H5N1 in the Far East, which are thought to have led to countless cases of human infection and over 130 human fatalities. This has put pressure on the EU Member States to gather evidence about wild bird populations, and in particular the risk from migratory waterbirds. Defra has worked with members of a number of ornithological organisations, who have been of very great value in gathering the evidence base on which future control policies in the UK – and more widely in the EU – can be based. Recently, this arrangement has been enhanced by the creation of the Ornithological Epidemiology Panel. This will ensure that a more structured approach to risk assessment can be adopted, allowing better targeting of future surveillance.
Richard Drummond qualified as a vet at Edinburgh University in 1976. After 6 years in mixed general practice, he joined the Ministry of Agriculture, Fisheries and Food as a Veterinary Officer. He has held a number of posts in England and Wales, in both policy and delivery roles. He is currently Head of Veterinary Exotic Diseases, Research and Official Controls Division, with a team of 40 people, responsible for policy on notifiable exotic diseases, research and development to support animal health and welfare, official controls and fish health and aquaculture. He is based in central London.
Disease as a Conservation Issue for Birds
Ruth Cromie | Wildfowl & Wetlands Trust
Historically diseases of wildlife have been seen as having little ecological importance and being of interest only as a source of agricultural or human infections. Nowadays, disease in its broadest sense, represents an increasing and challenging threat to the conservation of global biodiversity.
Current anthropogenic activities are resulting in a diversity of animal health problems, for example:
┬À climate change which affects the physiology of both hosts and their parasites (particularly northern-breeding species), alters habitats, and changes distribution of parasites and their invertebrate vectors.
┬À habitat change and degradation which can lead to nutritional disease and subsequent pre-disposition to infectious disease.
┬À pollution leading to toxic disease and pre-disposition to infectious diseases.
┬À introduction of novel parasites around the globe by movements of domestic livestock, animals in the pet trade, and introduced species can put na├»ve native wild hosts at risk.
┬À contact with domestic animals from which infections can be passed to the wild.
┬À intensive management of wildlife which may create high population densities increasing likelihood and prevalence of infectious disease.
From disease-related extinctions of Hawaiian avifauna to more recent high profile toxic diseases of Gyps vultures, problems associated with bird tables or avian influenza H5N1, birds find themselves as victims of a range of diseases as well as being considered as vectors of agricultural and human disease which brings with it conservation problems.
In general terms our understanding of wildlife disease is poor. However, with an ornithological heritage, world class bird population monitoring programmes, and internationally important numbers of e.g. wintering waterbirds, the UK is well placed to conduct wild bird health research and surveillance, which should inform how we better manage healthy populations of wild birds.
Ruth Cromie is Head of Waterbird Biology at the Wildfowl & Wetlands Trust, and teaches wildlife health on a number of postgraduate courses. Previously, she has worked at the Durrell Institute of Conservation and Ecology on a raptor conservation and welfare project; and at the Smithsonian Institution on diseases of marsupials.
Causes of avian mortality in the UK
Vic Simpson | Wildlife Veterinary Investigation Centre
‘It is difficult to understand how we can ever conserve wildlife populations without a wide knowledge of the diseases to which they are subjectÔÇª.! (McDiarmid 1965)
Millions of birds die each year in the UK but most corpses go unnoticed by humans. Of the small number of birds that are found, very few are subjected to detailed pathological examination. This happens because no government department or conservation body in the UK accepts responsibility for wildlife health and, with a few notable exceptions, there are no clear cut arrangements for post mortem examinations to be carried out. As a result, we have a poor understanding of the principal causes of mortality in the majority of bird species. This paper will describe some of the more important infectious agents, toxic chemicals, nutritional disorders and traumatic conditions that affect birds and their relevance to human and animal health. It will also consider emerging diseases that could enter the UK and affect our wild bird populations.
McDiarmid A (1965) Modern trends in animal health and husbandry – some infectious diseases of free living wildlife. British Veterinary Journal, 121, 245
Vic Simpson runs the Wildlife Veterinary Investigation Centre in Cornwall. For over 20 years he was a pathologist in the Veterinary Investigation Service and prior to that spent ten years in Africa. During his career he studied a number of problems affecting British wildlife, including lead poisoning in swans and mortality in otters.
The Garden Bird Health Initiative: the scheme and its findings to date
Becki Lawson | Institute of Zoology
The Garden Bird Health initiative (GBHi) research project, launched in spring 2005, is being coordinated by the Institute of Zoology, and involves the collaboration of the British Trust for Ornithology, Royal Society for the Protection of Birds, Scottish Agricultural College, University of Liverpool, Universities Federation for Animal Welfare and the Wildlife Veterinary Investigation Centre. A surveillance system has been created to record and investigate causes of garden bird mortality and disease across Great Britain. Through opportunistic and systematic monitoring of garden bird mortality, achieved with assistance from the general public and by volunteers from the BTO/CJ Garden BirdWatch scheme, we aim to learn more about ecological and anthropogenic factors associated with increased risk of infectious disease at garden feeding stations. Results will be used to evaluate supplementary feeding practices, recommend methods to mitigate identified risk factors and to inform the development of best practice guidelines for feeding garden birds based on sound science.
British garden birds suffer from a range of diseases, including those caused by a variety of bacterial (e.g. Salmonella Typhimurium, E.coli serotype 086) and viral pathogens (e.g. avian pox, fringilla papilloma virus) and parasites (e.g. Cnemidocoptes sp., Trichomonas sp.).
During its first year, the GBHi performed post mortem examinations on circa 500 birds, covering 34 species, of which the greenfinch (Carduelis chloris), chaffinch (Fringilla coelebs) and house sparrow (Passer domesticus) were the most frequent submissions. Infectious disease was implicated in the cause of death in over half of these cases.
Further information is available at www.ufaw.org.uk.
Becki Lawson graduated from Cambridge Veterinary School in 1997 and the MSc in Wild Animal Health in 2001. Her research work has focused on UK wildlife population health studies based at the Wildlife Veterinary Investigation Centre and Institute of Zoology. She is currently co-ordinator of the Garden Bird Health initiative.
Wildlife disease surveillance in the UK: current situation and potentiaL developments
Matthew Hartley | Defra & Paul Duff | Veterinary Laboratories Agency
Surveillance for wildlife disease has been provided with support from Defra by the Veterinary Laboratories Agency since 1998. This involves diagnostic examinations of wild bird and mammal species submitted to VLA Regional Laboratories. In addition to scanning surveillance, more targeted surveillance, for example for Avian Influenza and West Nile Virus is also undertaken. The VLA Disease of Wildlife Scheme (VLADoWs) is a component of the national disease surveillance program.
Wildlife disease surveillance may be important to Defra for several reasons: –
Notifiable Disease – of 38 notifiable diseases in the UK, 23 have wildlife hosts.
New and Emerging Diseases
Exotic Diseases Introduced by Migrant Species
The major objectives are:
┬À The provision of an updated list of endemic diseases in wildlife in the UK to allow completion of the OIE report.
┬À The recognition of any change in the pattern of wildlife disease, or wildlife movements in the UK, which could have significant policy implications.
┬À The investigation of cases of unusual mortality or morbidity in wildlife to ascertain aetiology and assess risk to human or animal health.
┬À The investigation of mass mortality incidents in wildlife species.
┬À Surveillance for West Nile Virus
┬À Enteric bacterial pathogen surveillance. Salmonella culture on intestinal content of all wildlife cadavers (avian and mammalian) examined.
482 general diagnostic submissions were made in 2005. With many more carcasses being examined through targeted surveillance projects.
Wildlife disease surveillance will be reviewed and developed as part of the Wildlife Health Strategy.
Matt Hartley has a background in zoo and wildlife medicine including wildlife disease research in Australia and conservation veterinary work as Head of Veterinary Services for Johannesburg Zoo, South Africa. In 2005 Matt was appointed as Wildlife and Zoological Veterinary Adviser for Defra, where he is responsible for development of the UK Wildlife Health Strategy, manages zoo and wildlife disease surveillance and provides technical veterinary support across Defra.
The evolution and ecology of avian malaria
Matt Wood | Edward Gray Institute, University of Oxford
Avian malaria is a common disease of birds worldwide, including resident birds in the U.K. Recent progress in the use of molecular diagnosis techniques is revealing avian malaria as a useful model for the study of the ecology and evolution of host-parasite interactions. One aspect of our work focuses on avian malaria in a woodland population of blue tits. Avian malaria at this site is comprised of several different genetic lineages, that together show marked seasonal variation. The spatial ecology of avian malaria is important in revealing the environmental influences on the distribution of disease. Infection varies markedly at a local scale within the study population, and we are investigating the influences of fine-scale environmental variation and vector abundance. Although avian malaria is unlikely to pose a zoonotic threat to humans, due to its apparently slow rate of evolution and phylogenetic separation from human species of malaria, this diverse parasite taxon looks likely to continue to be a rich study system for evolutionary ecologists.
Matt Wood’s work concerns host-parasite interactions in birds. He has studied the parasites of blackbirds, tits and flycatchers in the U.K., France and Sweden. Current research focuses on the spatial ecology of avian malaria in tits, and a curious disease, puffinosis in Manx shearwaters, the cause of which remain unknown.
Pathogen resistance and host genetics: the Seychelles Warbler and other birds
David Richardson | University of East Anglia
Given the impact that pathogens (parasites and diseases) can have it is not surprising that genetic resistance to pathogens often evolves. However, the rapid rate at which pathogens can change to avoid host defences means that resistance is often undermined and results in an evolutionary arms race between pathogens and hosts. Major histocompatibility complex (MHC) genes play a vital role in determining the vertebrate immune response. Extraordinary levels of genetic variation occur at the MHC and individual differences influence pathogen resistance. MHC alleles that confer resistance to pathogens such as malaria, nematodes and even avian flu have been reported. Parasite mediated selection appears to play a major role in driving MHC variability but, intriguingly, mechanism such as mate choice may also be involved. Birds provide excellent model systems in which to study the role of the MHC in pathogen resistance and mate choice. In the Seychelles warbler, selection has maintained variability at the MHC despite a severe population bottleneck. Interestingly, the MHC influences extra-pair, but not social mate choice. Females were more likely to obtain extra-pair fertilisations when their social mate had low MHC diversity, and from males of higher MHC diversity. Thus females may be seeking extra-pair fertilisations to improve the MHC diversity – and, therefore, the scope of pathogen resistance – in offspring. The type and prevalence of avian malaria and gastro-intestinal parasites in individuals is now being determined to investigate how such pathogens may interact with the MHC to influence survival and fitness.
David S Richardson’s research combines modern molecular techniques with detailed behavioural studies on model avian systems (e.g. the Seychelles warbler), to investigate questions in evolutionary/behavioural ecology (i.e. the evolution of cooperative breeding, the benefits of mate choice). The conservation of endangered bird species is also an important part of his work.
Epidemiology of zoonoses in wild birds. West Nile Virus and avian influenza viruses in the camargue, France
Michel Gauthier-Clerc, Elsa Jourdain & Camille Lebarbenchon | Tour du Valat, France
Wild birds share with humans the capacity of moving fast over large distances. During migration, they may carry various pathogens and be responsible for the emergence of diseases in na├»ve areas. European wintering wetlands, such as the Camargue (Rh├┤ne delta, France), are identified as potential hot spots of introduction and transmission risks of bird-borne diseases. West Nile virus recently re-emerged in the Mediterranean basin, including France in 2000, 2003 and 2004. In the Camargue, West Nile virus neutralizing antibodies were detected and in migrants coming from Sub-Saharan Africa and in resident birds. Two isolates from a house sparrow and a common magpie were completely sequenced. Wild birds, in particular waterbirds, are also the central element of the viral ecology of avian influenza. In 2006 several outbreaks of HP H5N1 occurred in France. During winter 2005-2006, we crossed molecular analysis and population surveillance by sampling living and freshly killed birds and performed aerial census and death surveillance. Avian influenza prevalence was 1.8% in wild ducks, but none of the infected birds contracted HP H5N1 virus. Population census did not revealed population decrease or abnormal mortalities. During spring 2006, we collected samples of migrating or breeding species. Only two individuals were positive (Larus melanocephalus) supporting the low prevalence rates of avian influenza in terrestrial species, in particular passerines.
Michel Gauthier-Clerc is a Doctor in Veterinary Medicine and obtained his PhD at CNRS of Strasbourg on behavioural ecology of the King penguin. He moved to Station Biologique de la Tour du Valat in the Camargue in 2002. His main researches are actually on population dynamic of wintering ducks in relation with wetlands management and on ecology of infectious diseases carried by wild birds such as West Nile and avian influenza.
Examining the flip-side of disease: avian immune defencesand what we can learn from measuring them
Kevin Matson | University of Groningen, The Netherlands
Immune systems comprise all defences (physical, chemical, physiological, etc.) of an organism aimed at minimizing impacts of foreign or infectious agents. Though governed by complex and dynamic interactions among interrelated components, immune systems are traditionally subdivided into innate and acquired arms. These arms (especially acquired immunity) are further divided by mechanism into humoral and cellular immunity. Quantification of immune function in birds presents a unique set of problems that are not associated with immunological studies of traditional mammalian models. Inclusion of different species/populations and, in particular, free-living birds magnifies these problems. Despite such limitations, a number of methods have been developed or adapted for use in comparative and ecological studies of immune function in wild birds, and these methods effectively span the different immune system branches. A number of indices of immune function are reviewed here including PHA-induced inflammations, vaccination responses, hemolysis-hemagglutination titres, bacteria-killing and phagocytic abilities, and acute phase response markers. Over the last five years, this expanding array of immunological methods has translated into a growing body of research at the intersection of immunology and ornithology, which includes studies of behavioural ecology, life history evolution, invasion biology, and conservation biology, and epidemiology. A brief review of some of these studies illustrates that while some of the foundation is in place, overall the work is still in its infancy and countless hypotheses remain to be tested.
Kevin Matson studied at UNC-Chapel Hill (BSPH), UC-Davis (MS) and UM-St Louis (PhD), and currently works as a researcher at the University of Groningen. With a special interest in island-continent comparisons, he studies immune function in wild birds. Currently, he is extending his comparative work to larks and shorebirds. He is also interested in quantifying bird associated microorganisms.
Recent changes in the epidemiology of AI viruses
Dennis Alexander | Independent Consultant Virologist
Only viruses of the Influenzavirus A genus have been isolated from birds and termed avian influenza [AI] viruses, but viruses with all 16 haemagglutinin [H1-H16] and all 9 neuraminidase [N1-N9] influenza A subtypes in the majority of possible combinations have been isolated from avian species.
Influenza A viruses infecting poultry can be divided into two groups. The very virulent viruses causing highly pathogenic avian influenza [HPAI], with flock mortality as high as 100%. These viruses have been restricted to subtypes H5 and H7, although not all H5 and H7 viruses cause HPAI. All other viruses cause a milder, primarily respiratory, disease [LPAI], unless exacerbated.
Until recently HPAI viruses were rarely isolated from wild birds, but for LPAI viruses extremely high isolation rates have been recorded in surveillance studies, with overall figures of about 11% for ducks and geese and around 2% for all other species. Influenza viruses may infect all types of domestic or captive birds in all areas of the world, the frequency with which primary infections occur in any type of bird usually depending on the degree of contact there is with feral birds. Secondary spread is usually associated with human involvement, either by bird or bird product movement or by transferring infective faeces from infected to susceptible birds, but potentially wild birds could be involved.
In recent years there have been costly outbreaks of HPAI in poultry in Italy, The Netherlands and Canada and in each millions of birds were slaughtered to bring the outbreaks under control.
Since the 1990s AI infections due to two subtypes have been widespread in poultry across a large area of the World. LPAI H9N2 appears to have spread across the whole of Asia in that time and has become endemic in poultry in many of the affected countries. However, these outbreaks have tended to have been overshadowed by the H5N1 HPAI virus, initially isolated in China, that has now spread in poultry and/or wild birds throughout Asia and into Europe and Africa, resulting in the death or culling of hundreds of millions of poultry and posing a significant zoonosis threat.
Dennis Alexander OBE retired from the Virology Department of the Veterinary Laboratories Agency at Weybridge in 2005 (having been head of the department from Sept 2001 to Oct 2004). He was a awarded the Robert Fraser Gordon Memorial Medal for distinguished contributions to poultry science, 2000, and elected Honorary Life Member of the British Veterinary Poultry Association in March 2006. He received the World Organisation for Animal Health (OIE) meritorious award – Médaille du Mérite in 2006 and served on the European Community Scientific Veterinary Committee 1994-1997 and EU Scientific Committee on Animal Health and Animal Welfare 1997-2003. He was a member of OIE Ad Hoc Working/Expert Groups on Newcastle disease 2000, Avian Influenza 2002 (2) & 2004-2005 and a member of the EFSA working group on avian influenza 2004-2005. Dennis has been sole or joint authors of 412 publications (including 228 in international peer-review journals).
Current knowledge on the evolution, transmission and host range of Asian H5N1 HPAI
Ian Brown | Veterinary Laboratories Agency
Highly pathogenic avian influenza H5N1 viruses of the Asian-lineage continue to evolve in animal reservoir. They have spread widely in poultry becoming established in many parts of Eurasia. The detection of virus in populations of aquatic wild birds in areas where infection is absent in poultry raises questions over the possible role of wild birds in the epidemiology and spread of the virus. The virus has evolved during ten years both through genetic drift and reassortment. Three genetic clades of the haemagglutinin gene have been identified, of which clade 2 viruses have been shown to infect a wide variety of aquatic birds principally from the Anatidae family. The prevailing viruses appear to have a higher fitness with one genotypic form dominant and associated with transmission to mammalian hosts including humans and Felidae species. Key genetic mutations have occurred in multiple gene segments (PB2, HA and NS) although to date these viruses have not acquired the capacity to transmit within mammalian hosts. In contrast to other HPAI viruses, studies of infection with Asian-lineage H5N1 viruses in domestic and wild ducks have revealed a spectrum of mortality that can approach 100% dependent on the infecting strain. Wild birds that die often have neurological symptoms and extensive systemic infection. In addition, these viruses have a preferential tropism for the respiratory tract in contrast to low pathogenic avian influenza viruses. In Europe and Africa virus has most probably been introduced and spread both via movements within the poultry sector (including illegal) and via migratory birds.
Ian Brown is Head of Avian Virology and Mammalian Influenza, VLA-Weybridge, UK, He is a nominated OIE expert on Avian influenza and Newcastle Disease and member of the OFFLU scientific committee. He provides consultancy at both national and international level on these diseases, specialising in laboratory applications and their relevance to disease control. He has acquired a wide experience in Virology in over 30 years, and his team carry out diagnosis, surveillance and active programmes of research for avian virus diseases with strong emphasis on AI. He and his team undertakes research into the epidemiology, pathogenicity, transmission and control of influenza in animal hosts. He formally represents VLA on working groups concerned with international interaction between FAO, OIE and WHO. He has provided support to global initiatives and workshops through FAO/OIE/EU including membership of international missions on AI at the invitation of national governments. He is a member of working groups of the Scientific Committee on Animal Health and Welfare of the EU and is director of the EU community reference laboratory. He currently serves on a working group of the European Food Safety Authority concerned with the role of migratory wild birds in the spread of HPAI.
The processes and problems of data collection in far off places
Ruth Manvell | Veterinary Laboratories Agency
The increased awareness of avian influenza (AI) viruses in the last few years in particular has led to higher numbers of haemagglutinating viruses being submitted to the EU/OIE/FAO reference laboratory at VLA Weybridge. Because of the high profile of these viruses in particular avian influenza it has been important to get a swift diagnosis of viruses submitted from all corners of the globe in order to allow governments to implement control strategies for dealing with AI.
Laboratories throughout the world need to have good diagnostic procedures and expertise and use recognised methods in order to have the ability to compare results with other laboratories experiencing the disease problems in avian species.
The dispatch and transportation of these viruses needs careful planning even before an outbreak by both the dispatching and receiving laboratories ensuring that all necessary licences and paperwork are complete. It is essential for a rapid diagnosis and characterisation that samples are received in good condition and that steps are taken to ensure the samples are delivered in a timely way. Communication is essential in order to deal with any complications arising from dispatch, an in depth history and origin of the samples submitted and also timely reporting of characterisation results.
Ruth Manvell is Manager of the OIE/FAO/EU International Reference Laboratory for Avian Influenza and Newcastle Disease and Avian Virology Diagnostic Unit, VLA-Weybridge, United Kingdom. She is a member of the OFFLU scientific collaborators and has provided consultancy nationally and internationally on avian influenza and Newcastle disease. She specialises in laboratory diagnostics and has 28 years experience in working primarily with these two viruses but also on other avian viral diseases. She has provided support to global missions and workshops to China, Romania, Poland, Canada, South Africa. Her small diagnostic team carry out the initial diagnostic testing and characterisation on submitted samples and viruses for most avian diseases and are actively involved in EU avian influenza surveillance programs for both domestic poultry and wild birds. She has authored/co-authored over 90 publications primarily on avian diseases but also on reptilian viruses. She has given numerous presentations around the world on avian influenza and Newcastle disease.
Outbreaks of highly pathogenic avian influenza in wild birds
Chris Feare | WildWings Bird Management
The highly pathogenic avian influenza (HPAI) H5N1 virus that appeared in south-east Asia in 1996-7 has been above all a disease of poultry, although a variety of other animals, including wild birds, humans and other mammals, have been affected. Wild birds are the natural hosts of low pathogenic avian influenza (LPAI) viruses and are largely unaffected by infection with them, but HPAI H5N1 appears to be lethal to wild birds. The vast majority of wild birds that have been found to be infected have been dead or sick, and evidence of asymptomatic infection in a few wild waterbirds is not convincing.
Outbreaks of HPAI H5N1 in wild birds have involved resident species, including commensals of human environments and scavengers that have been found close to outbreaks in poultry, and also some migrant species, especially waterbirds. An outbreak that killed >6000 birds, mainly geese, ducks and gulls, at lake Qinghai in western China in May-June 2005 was followed by outbreaks in poultry and wild birds across southern Siberia, and eventually into Europe and Africa. This led to concerns that wild bird migration was responsible for much of the spread of the virus. The origin of the ‘Qinghai-like! virus strains remains uncertain, however, and its subsequent spread seems most likely to have involved human activities. The spread within Europe in late winter 2006 illustrated that wild birds can carry the virus but the movements were probably short-distance dispersal, and certainly not long-distance seasonal migration.
Chris Feare. Following a career in the former UK Ministry of Agriculture, Fisheries and Food, where he studied bird problems in agriculture, urban areas and aviation, Chris Feare now offers a consultancy, WildWings Bird Management, on issues relating to interactions between birds and man. In addition to topics including bird pest management and the sustainable use of birds, he has recently been investigating the role of wild birds in the circulation of highly pathogenic avian influenza H5N1. He is currently Vice-Chairman of the British Ornithologists’ Union and chairs the International Steering Committee of the European Vertebrate Pest Management Conference.
The outbreak at Ruegen (Germany): ficts and facts
Franz Bairlein | Institute of Avian Research, Germany
On 14 February 2006, the first four positive cases of HPAI H5N1 were reported in ‘swans! from the Baltic Island of Ruegen, NE Germany. Until 3 August, when the most recent case was reported of a Black Swan in the zoo of Dresden, 344 cases of HPAI H5N1 in wild birds were reported in Germany. 54.4% of all HPAI H5N1 cases were of swans, of which 91% of the identified swans were Mute Swans. Geese accounted for 16.9%, raptors for 10.2% and ducks for 8.7%, respectively.
Much has been speculated about the origin of the virus, namely the role of migrating birds, but there is not a single strand of evidence for that. Recent molecular data reveal two different clusters of HPAI H5N1 with the north-eastern different from the south-eastern ones. This may hint at possibly two different routes of transport of HPAI H5N1 to Germany. The southern HPAI H5N1 genotype is similar to the one reported from the Black Sea, while the northern one is distinct. Therefore, it is unlikely that the first Ruegen outbreak is linked to the Black Sea area, the closest known outbreak area in January 2006. Neither numbers nor mortality of Mute Swans around Ruegen were exceptional in 2006. As HPAI H5N1 in wild water birds did not cause added mortality, HPAI H5N1 wasn’t detected prior to the normal late winter mortality, and the increased attention of the public due to the link of HPAI H5N1 in birds and human pandemic influenza.
Franz Bairlein was born 1952, 1980 PhD in zoology at University of Constance, 1980-1982 Postdoctoral fellow at the Max-Planck-Institute for Behavioural Physiology, 1982-1986 research assistant at Dept. of Zoology, University of Cologne, 1986-1990 Heisenberg Fellow of the German Research Council and assistant professor in zoology at the University of Cologne, 1988 sabbatical at the University of Southern Mississippi, Hattiesburg, USA, since 1990, Director of Institute of Avian Research, Wilhelmshaven, Germany, and professor for zoology and ecology at University of Oldenburg. Among several other duties President of the German Ornithologists’ Society (DO-G), and Editor-in-Chief of Journal of Ornithology.
H5N1: Conservation impacts and research needs
Andy Evans | RSPB
The global spread of HP H5N1 and its incursion into wild bird populations from poultry has many potential impacts for conservation. These can broadly be divided into five main categories:
a) direct effects: the conservation status of some wild bird species could be adversely affected as a result of increased mortality, either from the disease itself or from misguided attempts at culls of wild birds as a disease control measure. Species with small, range-restricted populations will be most at risk. This risk extends to captive breeding populations for conservation programmes of both birds and mammals.
b) indirect effects resulting from the cultivation of ornithophobia by inaccurate, sensationalist media reporting: this has led to widespread persecution of wild birds, particularly species which nest in close proximity to human habitation. Deliberate and cynical exploitation of ornithophobia has been used to support arguments for the destruction of wetland habitats.
c) Financial implications for conservation organisations: many NGOs have had to divert considerable resources into Public Affairs issues, and surveillance. Conservation charities have, in some cases, also suffered a reduction in income as a result of (b).
d) Curtailment or cancellation of conservation research programmes
e) Conservation benefits: In many affected countries, hunting bans have been brought into place. For over a year now, the EU has imposed a temporary global ban on the wild bird trade, potentially benefiting several globally endangered species.
Unfortunately, the scale of many of these impacts will never be quantified, although there is evidence that at least some are occurring.
Andy Evans joined the RSPB in 1988 and has spent most of his career working on the effects of agricultural intensification on farmland birds in the UK. From March 2005 until August 2006 he led the RSPB’s response to the spread of HP H5N1, assessing scientific knowledge to inform our Public Affairs teams and organising surveillance on our reserves.
European surveillance for avian influenza viruses. Beyond 2005 . . .
David Stroud | Joint Nature Conservation Council | & Ruth Cromie | Wildfowl & Wetlands Trust
The spread of highly pathogenic avian influenza H5N1 of Asian lineage across the Palearctic in 2005 focussed considerable attention on the need to establish a European framework for AI surveillance in wild birds. We summarise the development of the EU legislative background for AI surveillance which establishes the legal and financial framework for such activity, and outline progress to date.
We explore some of the practical constraints on the establishment of an ideal programme of surveillance of migratory wild bird populations at European level. The novelty of many aspects of the epidemiology of H5N1, not least the fact that the viral dynamics of HPAI H5N1 in different wild waterbird populations was almost completely unknown in 2005, severely constrained to the development of surveillance programmes, as also did limited capacity and expertise in many countries. Further, the migratory nature of waterbirds populations which are moving between EU Member States and other countries highlighted the need for continuing international coordination and cooperation. International organisations have had a particularly valuable role in co-ordinating the range of different national responses.
Major progress was made in many countries however, including the UK, to establish national AI surveillance programmes in wild birds from ‘a standing start’ in late 2005. Unsurprisingly perhaps, a wide range of issues have emerged from attempts to analyse the initial data collected. However, these problems have informed the development of improved standards for the collection of future data, with clear guidance published by the European Commission in May 2006.
Further work is needed to improve responsiveness of reporting at European levels and to implement a desire expressed at several international meetings in the last year to establish web-based systems of reporting. A more strategic approach is needed at a European scale, linked to movements of higher risk species. In developing ‘early-warning systems’ for the European Union, attention needs also to be given to developing capacity for AI surveillance in non-EU countries lying on migratory flyways linked to Europe.
David Stroud is Senior Ornithologist with the UK’s Joint Nature Conservation Committee and represents the Ramsar Convention’s Scientific and Technical Review Panel on the Scientific Task Force on Avian Influenza. He is an advisor on bird conservation to the UK government and has had long involvement in bird, and especially waterbird, conservation at national and international scales. This has especially been in the context of the work of Wetlands International, the EU Birds Directive’s Ornis Committee (and its Scientific Working Group), AEWA’s Technical Committee as well as the International Wader Study Group. In early 2006 he was a member of the Working Group established by the European Food Safety Authority which undertook a risk assessment of the risk of HPAI H5N1 arriving in Europe (www.efsa.europa.eu/en/science/ahaw/ahaw_opinions/1484.html).
Tools to assess the risk of AI incursion into the UK from wild birds
Philip W. Atkinson, Stuart E. Newson, Dan Chamberlain, Jacquie A. Clark, Nigel A. Clark,
Humphrey Q.P. Crick, Andy Musgrove, Robert A. Robinson & Lucy Snow | British Trust for Ornithology & Veterinary Laboratories Agency
Recent outbreaks of highly pathogenic H5N1 Avian Influenza (AI) in Europe and elsewhere in the world have highlighted the need for enhanced surveillance and early detection of the disease in Great Britain (GB). One possible route by which AI could be introduced into GB is through migratory wild birds carrying infection in from Europe or Asia. Using knowledge of the GB poultry industry and wild bird populations, we present a series of tools to identify priority areas and species for surveillance. We focus here on 24 migratory wild bird species, which are thought most likely to introduce and spread the disease to poultry.
The first tool rapidly assesses the migration of each species. By identifying the major directional movements, and the timing of these movements, it is possible to assess the likelihood of any individual species to carry AI from an outbreak in Europe to GB.
The second tool uses information in Defra’s GB poultry register to rank domestic poultry holdings according to the estimated likelihood of an incursion of H5N1 directly from a wild bird source based on a number of premise-level variables including the number and species of poultry present and whether birds were housed indoor or outdoor. By overlaying national bird monitoring data, maps can be produced showing areas where AI incursion is thought more likely to occur.
This work provides a means to direct resources and enable the early detection of H5N1 in GB in higher risk areas. The tool can be updated to incorporate new wild bird or poultry data or additional species as the international situation changes. This work has important practical applications for contingency planning and for directing targeted surveillance.
Stuart Newson is a Population Biologist in the BTO’s Demography Unit, where he is principally involved in survey design and analysis of data from large national surveys of wild bird and mammal populations, particularly relating to population trend and population size estimation.
Potential effects on countryside access and use
Andy Douse | Scottish Natural Heritage
During the 2001 outbreak of Foot & Mouth Disease in the United Kingdom, widespread denial of access to the countryside had major, adverse consequences for the rural economy. With the potential arrival of highly pathogenic avian influenza (HPAI) into the UK, concerns were raised that similar denial of access would occur, repeating some of the impacts seen during the 2001 FMD outbreak. These concerns focussed on three issues: the potential for people to act as vectors of the virus; disturbance of wild birds, leading to its spread; and, the potential for people to become infected by direct contact with infected sick or dead wild birds. For these reasons access restrictions might be seen as a wise, precautionary measure to limit the spread of the virus, but the FMD experience demands a more measured approach, and existing contingency plans for HPAI explicitly rule out wide-scale countryside closure. Additionally, new access legislation in both England & Wales (Countryside Rights of Way Act) and the Land Reform Act in Scotland, have led to a much more permissive approach to countryside access, with much tighter control on implementing access restrictions. The April 2006 occurrence of HPAI in a whooper swan at Cellardyke, Fife, provided an opportunity to validate contingency plans, in government and the statutory agencies. No access restrictions to the countryside were imposed. However, the incident raised a number of issues relevant to access that will be discussed in this talk, including a number of continuing uncertainties.
Andy Douse is a Senior Ornithologist with Scottish Natural Heritage, a non-departmental public body which advises the Scottish Executive on a range of environmental issues. SNH has a statutory duty to advise on access issues. His principal interests are seabirds and waterfowl and he currently leads on SNH’s involvement in avian influenza issues.
Avian Influenza and other bird diseases was a scientific meeting organised by Chris Feare (WidWings Bird Management), Ruth Cromie (Wildfowl & Wetlands Trust), David Stroud (Joint Nature Conservation Committee) and Steve Dudley (BOU) on behalf of the British Ornithologists’ Union.
The BOU is grateful to the individual speakers and their respective organisations for presenting their work at the conference.
The BOU is grateful for the funding provided by Environment and Heritage Service (Northern Ireland) and Scottish Natural Heritage for supporting the conference.
The British Ornithologists’ Union (BOU), founded in 1858 by Professor Alfred Newton FRS, is one of the world’s oldest ornithological bodies. The BOU’s aim is to promote ornithology and a better understanding of ornithology, birds and related issues, within the scientific and birdwatching communities. To help achieve this aim, the BOU organises regular meetings, seminars and conferences at which ornithologists and others can discuss and learn more about work being undertaken around the world and topical ornithological issues. The BOU has been organising conferences and meetings for over 100 years, and they provide an opportunity for people, from widely differing professional backgrounds, to explore and relate to a discrete scientific theme of common interest. Recent topics have included Lowland Farmland Birds (in 1999 with follow up conference being held in March 2004), Long-term Studies of Birds and Birds & Public Health. Such meetings help to promote understanding of environmental issues and the sharing of knowledge. The presentation of contentious academic theories to critical public debate and the defence of such ideas lie at the heart of healthy science. The BOU further achieves its aim by the quarterly publication of our international journal – Ibis. Established in 1859, Ibis – the world’s leading ornithological journal – publishes work at the cutting edge of our understanding of the world’s birdlife, be it behaviour, population dynamics, systematics, breeding biology, taxonomy, habitat use or conservation. Ibis is available in print and online – visit www.ibis.ac.uk.
© 2006 The Authors
Compilation © 2006 British Ornithologists’ Union