Wild bird surveillance around outbreaks of highly pathogenic avian influenza A(H5N8) virus in the Netherlands, 2014, within the context of global flyways

Highly pathogenic avian influenza (HPAI) A(H5N8) viruses that emerged in poultry in east Asia since 2010 spread to Europe and North America by late 2014. Despite detections in migrating birds, the role of free-living wild birds in the global dispersal of H5N8 virus is unclear. Here, wild bird sampling activities in response to the H5N8 virus outbreaks in poultry in the Netherlands are summarised along with a review on ring recoveries. HPAI H5N8 virus was detected exclusively in two samples from ducks of the Eurasian wigeon species, among 4,018 birds sampled within a three months period from mid-November 2014. The H5N8 viruses isolated from wild birds in the Netherlands were genetically closely related to and had the same gene constellation as H5N8 viruses detected elsewhere in Europe, in Asia and in North America, suggesting a common origin. Ring recoveries of migratory duck species from which H5N8 viruses have been isolated overall provide evidence for indirect migratory connections between East Asia and Western Europe and between East Asia and North America. This study is useful for better understanding the role of wild birds in the global epidemiology of H5N8 viruses. The need for sampling large numbers of wild birds for the detection of H5N8 virus and H5N8-virus-specific antibodies in a variety of species globally is highlighted, with specific emphasis in north-eastern Europe, Russia and northern China

Discordant detection of avian influenza virus subtypes in time and space between poultry and wild birds; towards improvement of surveillance programs

Avian influenza viruses from wild birds can cause outbreaks in poultry, and occasionally infect humans upon exposure to infected poultry. Identification and characterization of viral reservoirs and transmission routes is important to develop strategies that prevent infection of poultry, and subsequently virus transmission between poultry holdings and to humans. Based on spatial, temporal and phylogenetic analyses of data generated as part of intense and large-scale influenza surveillance programs in wild birds and poultry in the Netherlands from 2006 to 2011, we demonstrate that LPAIV subtype distribution differed between wild birds and poultry, suggestive of host-range restrictions. LPAIV isolated from Dutch poultry were genetically most closely related to LPAIV isolated from wild birds in the Netherlands or occasionally elsewhere in Western Europe. However, a relatively long time interval was observed between the isolations of related viruses from wild birds and poultry. Spatial analyses provided evidence for mallards (Anas platyrhynchos) being more abundant near primary infected poultry farms. Detailed year-round investigation of virus prevalence and wild bird species distribution and behavior near poultry farms should be used to improve risk assessment in relation to avian influenza virus introduction and retarget avian influenza surveillance programs

Avian influenza a virus in wild birds in highly urbanized areas

Avian influenza virus (AIV) surveillance studies in wild birds are usually conducted in rural areas and nature reserves. Less is known of avian influenza virus prevalence in wild birds located in densely populated urban areas, while these birds are more likely to be in close contact with humans. Influenza virus prevalence was investigated in 6059 wild birds sampled in cities in the Netherlands between 2006 and 2009, and compared with parallel AIV surveillance data from low urbanized areas in the Netherlands. Viral prevalence varied with the level of urbanization, with highest prevalence in low urbanized areas. Within cities virus was detected in 0.5% of birds, while seroprevalence exceeded 50%. Ring recoveries of urban wild birds sampled for virus detection demonstrated that most birds were sighted within the same city, while few were sighted in other cities or migrated up to 2659 km away from the sample location in the Netherlands. Here we show that urban birds were infected with AIVs and that urban birds were not separated completely from populations of long-distance migrants. The latter suggests that wild birds in cities may play a role in the introduction of AIVs into cities. Thus, urban bird populations should not be excluded as a human-animal interface for influenza viruses

Deaths among wild birds during highly pathogenic avian influenza A(H5N8) virus outbreak, the Netherlands

During autumn–winter 2016–2017, highly pathogenic avian influenza A(H5N8) viruses caused mass die-offs among wild birds in the Netherlands. Among the ≈13,600 birds reported dead, most were tufted ducks (Aythya fuligula) and Eurasian wigeons (Anas penelope). Recurrence of avian influenza outbreaks might alter wild bird population dynamics

Effect of 2020-21 and 2021-22 Highly Pathogenic Avian Influenza H5 Epidemics on Wild Birds, the Netherlands

The number of highly pathogenic avian influenza (HPAI) H5-related infections and deaths of wild birds in Europe was high during October 1, 2020-September 30, 2022. To quantify deaths among wild species groups with known susceptibility for HPAI H5 during those epidemics, we collected and recorded mortality data of wild birds in the Netherlands. HPAI virus infection was reported in 51 bird species. The species with the highest numbers of reported dead and infected birds varied per epidemic year; in 2020-21, they were within the Anatidae family, in particular barnacle geese (Branta leucopsis) and in 2021-22, they were within the sea bird group, particularly Sandwich terns (Thalasseus sandvicensis) and northern gannet (Morus bassanus). Because of the difficulty of anticipating and modeling the future trends of HPAI among wild birds, we recommend monitoring live and dead wild birds as a tool for surveillance of the changing dynamics of HPAI

“Rapid Risk Assessment” voor introductie van hoog pathogene aviaire influenza in de Nederlandse commerciële pluimveehouderij

Deze “rapid risk assessment” voor introductie van hoog pathogene aviaire influenza (HPAI) op Nederlandse commerciële pluimveehouderijen is uitgevoerd in november 2021. Het doel van dit rapport is het bundelen van de beschikbare informatie over de aanwezigheid van HPAI in commerciële pluimveebedrijven en wilde vogels. Op basis van de beschikbare informatie wordt een kwalitatieve risicoanalyse voor de introductie van HPAI op commerciële pluimveebedrijven uitgevoerd. Dit rapport geeft een overzicht van de HPAI infecties die zijn gerapporteerd in de periode van 9 september 2021 t/m 2 november 2021. Rusland meldde in september 2021 de vondst van HPAI H5N1 virus in wilde vogels en daarna ook in pluimvee. Vervolgens werd HPAI H5N1 virus aangetoond in dode en/of levende wilde vogels in Finland, Denemarken en Duitsland. Vanaf half oktober 2021 is er ook HPAI H5N1 virus aangetoond in dode wilde vogels in Nederland: een Grauwe Gans die is gevonden in Bilthoven, een Knobbelzwaan in Olst en een Zilvermeeuw in Hallum. Daarnaast zijn er HPAI H5Nx virussen, H5 virussen waarvan het N-type niet getypeerd kon worden bij diagnostiek, aangetoond in wilde vogels in Nederland: een Grauwe Gans gevonden in Spaarndam, een Knobbelzwaan in Zoeterwoude, een Tureluur in Hallum en een Brandgans op Ameland. Op 26 oktober 2021 werd er HPAI H5N1 virus gedetecteerd op een uitloop-leghennenbedrijf in Zeewolde (Flevoland). Vier dagen later volgde een detectie op een vleeskuikenbedrijf in Grootschermer (Noord-Holland). Ook is er HPAI H5N1 virus gedetecteerd bij pluimvee van een hobbyhouder met >50 vogels in Assendelft (Noord-Holland). Genetische analyse heeft aangetoond dat het nieuwe HPAI H5N1 virus een andere genetische samenstelling heeft dan het HPAI H5N1 virus dat eerder in 2021 werd gevonden. Het betreft dus een nieuwe virus introductie, waarschijnlijk werd het virus in oktober door trekvogels in Nederland geïntroduceerd. De recente vondsten van besmette wilde vogels bevestigen dat er opnieuw sprake is van een vogelgriepuitbraak onder wilde vogels in Nederland, die al wijdverspreid is over het land. Door de najaarstrek zijn er veel wilde vogels in Nederland, dit zal verder toenemen aankomende periode en de vogels zullen zich verder verspreiden over (waterrijke gebieden) in Nederland. Ook zal naar verwachting de omgevingstemperatuur verder afnemen. Beide factoren verhogen de transmissie van HPAI tussen vogels. Concluderend, het risico voor de Nederlandse commerciële pluimveehouderij om besmet te raken met HPAI wordt ingeschaald als zeer hoog voor Nederland. Het ingeschatte risico is op dit moment hoger dan het ingeschatte risico van de vorige analyse (sept 2021), waarin het risico werd ingeschat als medium voor Nederland