AI-NDV SUBCOMMITTEE REPORT - USAHA

AI-NDV

SUBCOMMITTEE

REPORTDavid L. Suarez

Report is based on OIE, FAO, WHO, ProMed,

published manuscripts and personal research

H7N9 Human Cases

Vaccination

Started

First HPAI

reported

H7N2

HPAI

H7N9 Phylogenetic Tree

• Two divergent lineages emerged from initial

outbreak in 2014 (Yangtze and Pearl River)

• All H7N9 viruses were low pathogenic until

late 2016 with emergence of Highly

Pathogenic Avian Influenza (HPAI)

• The HPAI emergence was in Yangtze River

lineage by 4 aa insert at cleavage site• LPAI cleavage site PKG----R/G

• HPAI cleavage site PKRKRTAR/G

• Some reassortant viruses have been

detected (H7N6, H7N2, internal genes)

Phylogenetic Tree-Guan, C. et al. 2018. New Threats from H7N9 influenza

virus: Spread and evolution of high-and low-pathogenicity variants with high

genomic diversity in wave 5. Journal of Virology 92:e00301-18.

Positive Poultry Samples by Chinese Province

FAO H7N9 Situational Update Updated August 7, 2018

Data through July 25, 2018

Location of Positive Samples


October 2016 and 25 July 2018

Poultry Sample Origin


October 2016 and 25 July 2018

Chinese Broiler Farmers Control Measures

Out of 331 surveys Percentage

Adoption of HPAI vaccination 286 86.4%

Adoption of antiviral medication 296 89.4%

Adoption of farm cleaning 280 84.6%

Adoption of farm disinfection 289 87.3%

Adoption of all 4 practices 193 58.3%

Huang et al. Factors affecting Chinese broiler farmers’ main preventive practices in response to

highly pathogenic avian influenza. 2016. Preventive Veterinary Medicine 134:153-159

• Farmers surveyed in 3 Northern and 3 Southern provinces

• Conducted June-August 2015

• Farm experience positively correlated with preventive measures

• 28.4% of respondents refused to use government designated vaccines

Biosecurity Practices of Poultry Farmers

of Jiangsu Province

Biosecurity Preventive Behaviors Percentage of

297 respondents

Check for dead or sick chickens daily 99%

Prevented contact neighbor’s poultry 94.9%

Conducted all in and all out method 93.6%

Pay attention to the nutrition balance of poultry 87.5%

Quarantined new purchase of poultry 85.9%

Closed doors and windows all the time in winter 77.1%

Prevented poultry contact wild poultry 66.3%

Disinfected staff, vehicles, and goods entering the poultry house 39.1%

Continuously disinfected with chickens in cage 2-3 times weekly 7.1%

Frequently cleaning floors and chicken cages 1.7%

Cui, B. and Z.P. Liu. 2016 Determinants of Knowledge and Biosecurity preventive

behaviors for highly pathogenic avian influenza risk among Chinese poultry farmers Avian

Diseases 60:480-486.

Control Measures for H7N9

• Closure of LPMs was credited for reduction in human

cases

• LPM system is slowly being replaced with centralized

slaughter facilities (infrastructure more developed in

Northern China)

• Some large cities permanently banned LPMs

• Principals of Biosecurity are well known, but often poorly

applied

• Because of the spike in human cases and the mutation

from LPAI to HPAI, vaccination became the government

mandated option

Vaccine for H7N9• Vaccine was made by reverse genetics with the H7 gene from

2013 virus and the PR8 internal gene cassette

• Killed vaccine with adjuvant-A/pigeon/Shanghai/1069/2013

• Laboratory and clinical trials reported as having good results

• 2 doses of vaccine needed to stimulate immunity in ducks and geese

• Vaccine was made as bi-valent vaccine to include the re-8 H5 vaccine

• Government provides the vaccine for free

• Mass vaccination program started in September 2017

• Targeted to layers and slow growing chickens with high use of vaccine (73%)

• Vaccine credited with reducing both human and poultry cases

Hualan Chen, Animal Influenza Laboratory of the Ministry of Agriculture and National Key Laboratory of

Veterinary Biotechnology, Harbin Veterinary Research Institute

Conclusion

• Virus continues to circulate with two unique antigenic

lineages, with the Yangtze lineage having both LP and HP

variants

• No evidence of wild bird involvement in spread of the

virus

• China remains an epicenter for emerging avian influenza

viruses

• Vaccination has provided a marked reduction in reported

human and animal cases

• Because of large LPM system and questionable

biosecurity practices, eradication of H7N9 is unlikely

Countries with poultry adapted H9N2 (2012-2018)

H5N6-Europe

• Multiple wild bird introductions in late 2017-2018 in

Netherlands, England, Denmark, Sweden, Finland, Ireland,

Switzerland

• Clade 2.3.4.4b

• Commercial outbreaks in Netherlands in ducks and chickens

and backyard poultry Germany

Amino Acid Substitution per 100 residues

0

0.6

A/common_pochard/Germany-BY/AR09-18-L024

A/Great_black-backed_gull/Netherlands/1/

A/canada_goose/England/AV58_18OPpoolEP1/

A/pochard_duck/England/AVP_18_003254/201

A/mute_swan/England/AVP_18_001986/2017

A/Tufted_Duck/Netherlands/17017367-007/2

A/Mute_Swan/Netherlands/17017377-001/201

A/Mute_Swan/Netherlands/17017367-012/201

A/Chicken/Netherlands/EMC-1/2018


A/Domes tic_Duck/Netherlands/EMC-2/2018

A/Domes tic_Duck/Netherlands/EMC-6/2018

A/Black-headed_Gull/Netherlands/29/2017

A/Eurasian_wigeon/Netherlands/1/2018

A/Duck/Netherlands/17017237-001-005/2017

A/Duck/Netherlands/17017236-001-005/2017


A/Great_Black-backed_Gull/Netherlands /1/

_A/Great_Black-backed_Gull/Netherlands/1

H5N6-Asia

• Multiple wild bird

introductions in

2017-2018

• South Korea,

Vietnam, Japan,

China

Nucleotide Substitution per 100 residues

0

5.8

24



A/Mute_Swan/Netherlands/17017377-001/20�

A/Duck/Netherlands/17017237-001-005/201�

A/Eurasian_wigeon/Netherlands/1/2018

A/pochard_duck/England/AVP_18_003254/20�

A/canada_goose/England/AV58_18OPpoolEP1�

A/mute_swan/England/AVP_18_001986/2017

A/Great_black-backed_gull/Netherlands/1�

A/Tufted_Duck/Netherlands/17017367-007/�

A/common_pochard/Germany-BY/AR09-18-L02�


A/Armenian_Gull/Republic_of_Georgia/4/2�

A/Domestic_Duck/Netherlands/EMC-2/2018

A/Anas_platyrhynchos/Korea/W614/2017

A/Anas_platyrhynchos/Korea/W615/2017

A/Mandarin_duck/Korea/K17-1815/2017



A/Mallard/Korea/K17-1825/2017

A/duck/Korea/H35/2017



A/Mallard/Republic_of_Georgia/1/2018

A/Great_Black-backed_Gull/Netherlands/1�

A/mallard/Korea/Jeju-H24/2017

A/mute_swan/Shimane/3211A001/2017

A/duck/Korea/HD1/2017

A/jungle_crow/Hyogo/2803A002/2018

A/jungle_crow/Hyogo/2803E022/2018

A/tufted_duck/Shimane/3211TY001/2017

A/spoonbill/Taiwan/DB645/2017

A/Fujian-Sanyuan/21099/2017

A/duck/Vietnam/QuangBinh/DH330718/2017

A/duck/Vietnam/QuangBinh/QN530206/2018

A/Quail/Guangxi/GX-2/2017__(H5N6)

A/chicken/Vietnam/QuangBinh/BD1113/2017

A/duck/Vietnam/QuangBinh/DH130723/2017

A/chicken/Guangdong/G1012/2018

A/duck/Guangdong/G1378/2018

A/muscovy_duck/Vietnam/HU7-17/2017

FAO Sub-Saharan Africa HPAI situation update (Oct 10, 2018)

H5N1 reports from 2018

TogoH5N8 reports from 2018

Nigeria, Democratic Republic of

Congo, and South Africa

Documents

AI-NDV SUBCOMMITTEE REPORT - USAHA