AI-NDV SUBCOMMITTEE REPORT - USAHA
Transcript of 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 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
FAO H7N9 Situational Update Updated August 7, 2018
October 2016 and 25 July 2018
Poultry Sample Origin
FAO H7N9 Situational Update Updated August 7, 2018
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
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/Chicken/Netherlands/EMC-14/2018
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/Black-headed_Gull/Netherlands/29/2017
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/Black-headed_Gull/Netherlands/29/2017
A/Black-headed_Gull/Netherlands/29/2017
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/Chicken/Netherlands/EMC-14/2018
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/Mandarin_duck/Korea/K17-1896/2017
A/Mandarin_duck/Korea/K17-1879/2017
A/Mallard/Korea/K17-1825/2017
A/duck/Korea/H35/2017
A/duck/Korea/H80/2017
A/duck/Korea/H107/2017
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