Avian Influenza in the Netherlands, 2018

Nancy Beerens, NRL meeting, Italy, June 2019

Wageningen BioVeterinaryResearch

Detections of HPAI H5N6 in 2017-2018

2

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

No virus transmission between farms

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

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

Detection of H5N6 in wild birds

4

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

Genetic analysis of poultry and wild bird viruses

5

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

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

7

Location Eemmeer

Central Lake area

Near Biddinghuizen

First outbreak, dec 2017

H5N6 is a reassortant of H5N8 2016

H5N6 is a reassortant of H5N8 Group B

Contains novel NA and PB2 segments,

derived from Eurasian LPAI viruses

Molecular clock analysis: reassortment

events likely occurred in 2015–2016

This was before the virus was introduced

into the Netherlands (dec 2017)

Late H5N6 virus has similar genetic

constitution

8

H5N8 Eurasia 2016, PA II

H5N6 Netherlands

PB2PB1PA

HANPNA

NSMP

MP

PB2PB1PA

HANPNA

NS

Median-Joining-Network Analysis

9

Most likely the virus still circulated in local wild birdpopulations

First time this is observed: higher risk for HPAI introduction all year round?

Eemmeer: common ancestorwith Biddinghuizen cluster

53 nt differences in 9 months

Eemmeer

Dead wild bird surveillance

10

VirusClade

2.3.4.4wild bird mortality

positive

# tested # species

H5N8 2014 Group A None 0 0

H5N8 2016 Group B Massive 84 17

H5N6 2017 Group B Limited 15 7

Eurasian wigeon

>3000 deaths

Tufted duck

>6000 deaths

Mute Swan Bird of Prey

Pathogenicity of HPAI H5N6

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

VirusClade

2.3.4.4wild bird mortality

IVPI chicken

IVPI 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

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

13

Jaar Maand Plaats Subtype

2018 2 Vaassen HxNx

2018 3 Neerkant H5Nx

2018 3 Hiaure H2N5

2018 3 Den Bommel H5Nx

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

2018 12 Witteveen H6N8

No detections of H3N1

in 2018/2019

Thanks to:

14

René Heutink

Sylvia Pritz-Verschuren

Frank Harders

Alex Bossers

Guus Koch

Saskia Bergervoet

Evelien Germeraad

* Beerens et al. TransboundEmerg Dis 2019