Avian Influenza in the Netherlands, 2018
Nancy Beerens, NRL meeting, Italy, June 2019
Wageningen BioVeterinary Research Detections of HPAI H5N6 in 2017-2018
Location farm species date
Biddinghuizen Duck 7-12-2017 Oldekerk Chicken 25-2-2018 Kamperveen Duck 13-3-2018 Biddinghuizen various 15-12-2017 Rhoon various 20-1-2018
2 No virus transmission between farms
location host date day km nt code Biddinghuizen duck 7-12-2017 - - - BH
Oldekerk chicken 25-2-2018 80 97 47 OK
Kamperveen duck 13-3-2018 96 12 49 KV
. Full genome sequences of viruses isolated from the 3 commercial poultry farms were compared . Large number of genetic differences . Relatively long time between infections . No epidemiological links identified Separate introductions from wild birds
3 Detection of H5N6 in wild birds
location date family species #1 code2
Elburg 9-12-2017 Anatidae mute swan - Cygnus olor 1 wb1
Hulshorst 9-12-2017 Anatidae tufted duck -Aythya fuligula 1 wb2
Hulshorst 9-12-2017 Anatidae mute swan - Cygnus olor 5 wb3
Harderwijk 14-12-2017 Anatidae mute swan - Cygnus olor 1 wb4
Elburg 19-12-2017 Anatidae mute swan - Cygnus olor 1 wb5
Enkhuizen 21-02-2018 Anatidae greater scaup - Aythya marila 1 wb6
Westernieland 1-03-2018 Falconidae peregrine falcon - Falco peregrinus 1 wb7
Stavernisse 14-03-2018 Accipitridae buzzard - Buteo buteo 1 wb8
Zandfoort 15-03-2018 Accipitridae buzzard - Buteo buteo 1 wb9
Eemmeer 24-08-2018 Anatidae mallard - Anas platyrhynchos 1 wb10
Eemmeer 31-08-2018 Accipitridae Eurasian marsh harrier - Circus aeruginosus 1 wb11
4 Genetic analysis of poultry and wild bird viruses
Commercial farms Hobby farms Wild birds NL Wild birds EU
Biddinghuizen cluster
. Median-Joining-Network Analysis was performed for all viruses . Biddinghuizen in cluster of viruses derived from a common ancestor . Kamperveen and Oldekerk are more distantly related
5 Detections of H5N6 in August 2018
. H5N6 viruses detected between 12/2017 and 3/2018 . In previous epidemics, virus was not observed after winter . Wild birds migrate to breeding grounds in March-April . But on 24 August 2018: positive mallard, Eemmeer . Several days later, bird of prey from same area
Question: . A novel introduction by wild bird migration? . Or virus persisting during summer?
6 H5N6 detections in late August 2018
. Location Eemmeer . Central Lake area . Near Biddinghuizen . First outbreak, dec 2017
7 H5N6 is a reassortant of H5N8 2016
. H5N6 is a reassortant of H5N8 Group B PB2 PB1 PA HA . Contains novel NA and PB2 segments, NP NA MP derived from Eurasian LPAI viruses NS
H5N8 Eurasia 2016, PA II . Molecular clock analysis: reassortment events likely occurred in 2015–2016
PB2 PB1 . This was before the virus was introduced PA HA into the Netherlands (dec 2017) NP NA MP NS Late H5N6 virus has similar genetic
H5N6 Netherlands constitution
8 Median-Joining-Network Analysis
. Eemmeer: common ancestor with Biddinghuizen cluster . 53 nt differences in 9 months
. Most likely the virus still circulated in local wild bird populations Eemmeer . First time this is observed: higher risk for HPAI introduction all year round?
9 Dead wild bird surveillance
positive Clade wild bird Virus 2.3.4.4 mortality # tested # species H5N8 2014 Group A None 0 0 H5N8 2016 Group B Massive 84 17 Tufted duck H5N6 2017 Group B Limited 15 7 >6000 deaths
Eurasian wigeon >3000 deaths
Mute Swan Bird of Prey
10 Pathogenicity of HPAI H5N6
Clade wild bird IVPI IVPI Virus 2.3.4.4 mortality chicken duck H5N8 2014 Group A None 3.00 1.87 H5N8 2016 Group B Massive 3.00 2.99 H5N6 2017 Group B Limited 2.99 3.00
. Wild bird mortality related to H5N6 lower than for H5N8 2017 . Pathogenicity of the two viruses for ducks is similar: ● IVPI is not natural way of infection ● Pekin ducks not a model for all wild bird species . Lower prevalence of the virus in wild bird population . Protective immunity in wild bird population (H5N8 2016)
11 Detection of LPAI viruses in 2018
. No detections in commercial poultry . captive birds – Swan: H5N3 LP . wild birds – Mallard: H8N4 Eurasian Teal: H3N8
12 Results of passive surveillance program
Jaar Maand Plaats Subtype 2018 2 Vaassen HxNx No detections of H3N1 2018 3 Neerkant H5Nx 2018 3 Hiaure H2N5 2018 3 Den Bommel H5Nx in 2018/2019 2018 3 Maarsbergen H5N3 2018 4 Sterksel H9N7 2018 5 Steenwijkerwold H9N3 2018 6 Den Bommel H6N8 2018 6 Odoornerveen H7N3 2018 6 Winterswijk HxNx 2018 7 Boxmeer HxNx 2018 7 Tzummarum H2N5 2018 7 Idsegahuizum H10N7 2018 8 Aalten HxN3 2018 8 Donkerbroek HxN7 2018 8 Hierden HxN2 2018 9 Zuidwolde HxNx 2018 9 Overberg HxNx 2018 9 Tubbergen HxNx 2018 10 Nieuweroord HxNx 2018 10 Oosterwolde Fr H4Nx 2018 11 Radewijk HxNx 2018 12 Groesbeek H10Nx 2018 12 Elsloo Fr H6N2 2018 12 Lemelerveld H5N3 LP 2018 12 Milheeze H9N2 2018 12 Stadskanaal H6Nx 2018 12 Sint Philipsland H3N8 2018 12 Veeningen H5Nx LP 2018 12 Veeningen H5N3 LP 13 2018 12 Witteveen H6N8 Thanks to:
René Heutink Sylvia Pritz-Verschuren Frank Harders Alex Bossers Guus Koch Saskia Bergervoet Evelien Germeraad
* Beerens et al. Transbound Emerg Dis 2019
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