#Person-to-Person #Transmission of #Avian #Influenza A (#H7N9) Among #Family Members in Eastern #China, 2016 (Disaster Med Public Health Prep., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Disaster Med Public Health Prep, 1-6 2020 Mar 27 [Online ahead of print]

Person-to-Person Transmission of Avian Influenza A (H7N9) Among Family Members in Eastern China, 2016

Chao Shi # 1, Ping Shi # 1, Xu Yang 1, Jing Bao 2, Yanhua Qian 1, Yuan Shen 1

Affiliations: 1 Departments of Disease Control, Wuxi, Jiangsu Province, China. 2 Laboratory, Wuxi Center for Disease Control and Prevention, Wuxi, Jiangsu Province, China.

Contributed equally.

PMID: 32216856 DOI: 10.1017/dmp.2020.6




Human infections with avian influenza A (H7N9) virus are associated with exposure to poultry and live poultry markets, but the evidence of person-to-person transmission remains limited. This study reports a suspected person-to-person transmission of H7N9 virus, and explores what factors influenced this transmission.


We interviewed 2 patients with H7N9 infection and their family members as well as health-care workers. Samples from the patients and environments were tested by real-time reverse transcription-polymerase chain reaction.


The index patient became ill 5 to 6 days after his last exposure to the poultry bought in the market of Weimiao town. The second patient, the sister of the index patient, who had sustained intensive and unprotected close contact with the index patient, had no exposure to poultry. This study documents that the H7N9 virus was transmitted directly from the index patient to his sister.


Our findings suggest that person-to-person transmission may be associated with sustained close contact with the patient during his onset of early stage, when the H7N9 viral shedding increases sharply.

Keywords: infection; influenza A (H7N9) virus; person-to-person transmission.

Keywords: Avian Influenza; H7N9; Human; China.


Evaluation of the #immune #response of a #H7N9 candidate #vaccine virus derived from the fifth wave A/Guangdong/17SF003/2016 (Antiviral Res., abstract)

[Source: Antiviral Research, full page: (LINK). Abstract, edited.]

Antiviral Research | Volume 177, May 2020, 104776

Evaluation of the immune response of a H7N9 candidate vaccine virus derived from the fifth wave A/Guangdong/17SF003/2016

Ji Dong a1, Peihai Chen bc1, Yang Wang a1, Yunhua Lv a, Ji Xiao a, Qinming Li a, Zhixia Li c, Beiwu Zhang c, Xuefeng Niu a, Chufang Li a, Weiqi Pan a, Ling Chen a

{a} State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; {b} Institute of Health Sciences and Technology, Anhui University, Hefei, China; {c} State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China

Received 28 October 2019, Revised 4 February 2020, Accepted 16 March 2020, Available online 19 March 2020.

DOI: https://doi.org/10.1016/j.antiviral.2020.104776



  • Systemically evaluated the immune response to H7N9 CVV A/Guangdong/17SF003/2016 (GD/16) in mice and rhesus macaques.
  • GD/16 elicited robust neutralizing and IgG antibodies, but poor hemagglutination inhibition antibody titers.
  • Receptor binding avidity should be considered in interpretation of HI data for evaluation of influenza antigenic variation.



Highly pathogenic influenza H7N9 viruses that emerged in the fifth wave of H7N9 outbreak pose a risk to human health. The World Health Organization has updated the candidate vaccine viruses for H7N9 viruses recently. In this study, we evaluated the immune response to an updated H7N9 candidate vaccine virus, which derived from the highly pathogenic A/Guangdong/17SF003/2016 (GD/16) in mice and rhesus macaques. GD/16 vaccination elicited robust neutralizing, virus-specific immunoglobulin G antibodies and effective protection, but poor hemagglutination inhibition antibody titers. Furthermore, mouse and rhesus macaque serum raised against the previous H7N9 CVV A/Anhui/1/2013 (AH/13) were tested for its cross-reactivity to GD/16 virus. We found that although AH/13-immune serum has poor hemagglutination inhibition reactivity against GD/16 virus, AH/13 elicit efficient cross-neutralizing antibodies and in vivo protection against GD/16. Further studies showed that the hemagglutinin of GD/16 has strong receptor binding avidity, which might be associated with the decreased hemagglutination inhibition assay sensitivity. This study underscores the point that receptor binding avidity should be taken into account when performing quantitative interpretation of hemagglutination inhibition data. A combination of multiple serological assays is required for accurate vaccine evaluation and antigenic analysis of influenza viruses.

Keywords: H7N9 influenza Virus – Vaccine – Immune response – Cross-reactivity – Haemagglutination inhibition – Receptor binding avidity

Keywords: Avian Influenza; H7N9; Vaccines.


#Avian #influenza #human #infections at the human-animal interface (J Infect Dis., abstract)

[Source: Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]

Avian influenza human infections at the human-animal interface

Damien A M Philippon, Peng Wu, Benjamin J Cowling, Eric H Y Lau

The Journal of Infectious Diseases, jiaa105, https://doi.org/10.1093/infdis/jiaa105

Published: 10 March 2020




Avian influenza A viruses (AIVs) are among the most concerning emerging and re-emerging pathogens because of the potential risk in causing an influenza pandemic with catastrophic impact. The recent increase in domestic animals and poultry worldwide was followed by an increase of human AIV outbreaks reported.


We reviewed the epidemiology of human infections with AIV from the literature including reports from the World Health Organization, extracting information on virus subtype, time, location, age, sex, outcome and exposure.


We described the characteristics of more than 2,500 laboratory-confirmed human infections with AIVs. Human infections with H5N1 and H7N9 were more frequently reported than other subtypes. The risk of death was highest among reported cases infected with H5N1, H5N6, H7N9 and H10N8 infections. Older people and males tended to have a lower risk of infection with most AIV subtypes, except for H7N9. Visiting live poultry markets were mostly reported by H7N9, H5N6 and H10N8 cases, while exposure to sick or dead bird mostly reported by H5N1, H7N2, H7N3, H7N4, H7N7 and H10N7 cases.


Understanding the profile of human cases of different AIV subtypes would guide control strategy. Continued monitoring of human infections with AIVs is essential for pandemic preparedness.

avian influenza, human infection, review

Issue Section:  Review

This content is only available as a PDF.

© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Avian Influenza; Human; H5N1; H5N6; H7N3; H7N7; H7N9; H9N2; H10N8.


Specificity, #Kinetics and Longevity of #Antibody #Responses to #Avian #Influenza A(#H7N9) Virus #Infection in #Humans (J Infect., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

J Infect. 2020 Jan 16. pii: S0163-4453(20)30025-6. doi: 10.1016/j.jinf.2019.11.024. [Epub ahead of print]

Specificity, Kinetics and Longevity of Antibody Responses to Avian Influenza A(H7N9) Virus Infection in Humans.

Chen J1, Zhu H2, Horby PW3, Wang Q1, Zhou J1, Jiang H4, Liu L5, Zhang T6, Zhang Y7, Chen X1, Deng X1, Nikolay B8, Wang W1, Cauchemez S8, Guan Y2, Uyeki TM9, Yu H10.

Author information: 1 School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, 200032, China. 2 Joint Institute of Virology (STU-HKU), Shantou University, Shantou, 515041, China; State Key Laboratory of Emerging Infectious Diseases, School of Public Health, The University of Hong Kong, Hong Kong SAR, China. 3 Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK. 4 Beijing Chest Hospital, Capital Medical University, Beijing, 101149, China; Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, China. 5 Joint Institute of Virology (STU-HKU), Shantou University, Shantou, 515041, China. 6 Jiangxi Provincial Center for Disease Control and Prevention, Nanchang, 330000, China. 7 Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 100049, China. 8 Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, UMR2000, CNRS, 75015 Paris, France. 9 Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. 10 School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, 200032, China. Electronic address: yhj@fudan.edu.cn.




The long-term dynamics of antibody responses in patients with influenza A(H7N9) virus infection are not well understood.


We conducted a longitudinal serological follow-up study in patients who were hospitalized with A(H7N9) virus infection, during 2013-2018. A(H7N9) virus-specific antibody responses were assessed by hemagglutination inhibition (HAI) and neutralization (NT) assays. A random intercept model was used to fit a curve to HAI antibody responses over time. HAI antibody responses were compared by clinical severity.


Of 67 patients with A(H7N9) virus infection, HAI antibody titers reached 40 on average 11 days after illness onset and peaked at a titer of 290 after three months, and average titers of ≥80 and ≥40 were present until 11 months and 22 months respectively. HAI antibody responses were significantly higher in patients who experienced severe disease, including respiratory failure and acute respiratory distress syndrome, compared with patients who experienced less severe illness.


Patients with A(H7N9) virus infection who survived severe disease mounted higher antibody responses that persisted for longer periods compared with those that experienced moderate disease. Studies of convalescent plasma treatment for A(H7N9) patients should consider collection of donor plasma from survivors of severe disease between 1-11 months after illness onset.

Copyright © 2020 Elsevier Ltd. All rights reserved.

KEYWORDS: Antibody response; Clinical severity; Follow-up; Influenza A(H7N9)

PMID: 31954742 DOI: 10.1016/j.jinf.2019.11.024

Keywords: Avian Influenza; H7N9; Serotherapy; Human.


#H7N9 #Influenza Virus Containing a #Polybasic HA Cleavage Site Requires Minimal Host #Adaptation to Obtain a Highly Pathogenic Disease Phenotype in Mice (Viruses, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Viruses. 2020 Jan 5;12(1). pii: E65. doi: 10.3390/v12010065.

H7N9 Influenza Virus Containing a Polybasic HA Cleavage Site Requires Minimal Host Adaptation to Obtain a Highly Pathogenic Disease Phenotype in Mice.

Chan M1, Leung A1, Hisanaga T2, Pickering B2,3, Griffin BD1,3, Vendramelli R1, Tailor N1, Wong G4,5, Bi Y6, Babiuk S2, Berhane Y2, Kobasa D1,3.

Author information: 1 Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB R3E 3R2, Canada. 2 National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB R3E 3M4, Canada. 3 Department of Medical Microbiology and Infectious Diseases, University of Manitoba, 745 Bannatyne Avenue, Winnipeg, MB R3E 0J9, Canada. 4 Institut Pasteur of Shanghai, Chinese Academy of Sciences, Life Science Research Building 320 Yueyang Road, Xuhui District, Shanghai 200031, China. 5 Département de microbiologie-infectiologie et d’immunologie, Université Laval, 1050 avenue de la Médecine, QC G1V 0A6, Canada. 6 CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China.



Low pathogenic avian influenza (LPAI) H7N9 viruses have recently evolved to gain a polybasic cleavage site in the hemagglutinin (HA) protein, resulting in variants with increased lethality in poultry that meet the criteria for highly pathogenic avian influenza (HPAI) viruses. Both LPAI and HPAI variants can cause severe disease in humans (case fatality rate of ~40%). Here, we investigated the virulence of HPAI H7N9 viruses containing a polybasic HA cleavage site (H7N9-PBC) in mice. Inoculation of mice with H7N9-PBC did not result in observable disease; however, mice inoculated with a mouse-adapted version of this virus, generated by a single passage in mice, caused uniformly lethal disease. In addition to the PBC site, we identified three other mutations that are important for host-adaptation and virulence in mice: HA (A452T), PA (D347G), and PB2 (M483K). Using reverse genetics, we confirmed that the HA mutation was the most critical for increased virulence in mice. Our study identifies additional disease determinants in a mammalian model for HPAI H7N9 virus. Furthermore, the ease displayed by the virus to adapt to a new host highlights the potential for H7N9-PBC viruses to rapidly acquire mutations that may enhance their risk to humans or other animal species.

KEYWORDS: H7N9; HPAI; influenza virus; mammalian adaptation; mice; polybasic HA

PMID: 31948040 DOI: 10.3390/v12010065

Keywords: Avian Influenza; H7N9; Viral pathogenesis; Animal models.


Association Between #Cardiac #Injury and #Mortality in Hospitalized Patients Infected With #Avian #Influenza A (#H7N9) Virus (Crit Care Med., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Crit Care Med. 2020 Jan 9. doi: 10.1097/CCM.0000000000004207. [Epub ahead of print]

Association Between Cardiac Injury and Mortality in Hospitalized Patients Infected With Avian Influenza A (H7N9) Virus.

Gao C1,2, Wang Y3, Gu X4,5, Shen X6, Zhou D7, Zhou S8, Huang JA9, Cao B3,5,10, Guo Q2; for the Community-Acquired Pneumonia–China Network.

Author information: 1 Department of Critical Care Medicine, Dushuhu Public Hospital Affiliated to Soochow University, Suzhou, Jiangsu, China. 2 Department of Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China. 3 Department of Pulmonary and Critical Care Medicine, National Clinical Research Center for Respiratory Diseases, China-Japan Friendship Hospital, Capital Medical University, Beijing, China. 4 Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing, China. 5 Institute of Respiratory Medicine, Chinese Academy of Medical Science, Beijing, China. 6 Department of Critical Care Medicine, The Fifth People’s Hospital of Suzhou, Suzhou, Jiangsu, China. 7 Department of infectious diseases, Taizhou People’s Hospital, Taizhou, Jiangsu, China. 8 Department of Critical Care Medicine, The Third Affiliated Hospital of Soochow University, The First People’s Hospital of Changzhou, Changzhou, Jiangsu, China. 9 Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China. 10 Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China.




To evaluate the prevalence of cardiac injury and its association with mortality in hospitalized patients infected with avian influenza A (H7N9) virus.


Retrospective cohort study.


A total of 133 hospitals in 17 provinces, autonomous regions, and municipalities of mainland China that admitted influenza A (H7N9) virus-infected patients between January 22, 2015, and June 16, 2017.


A total of 321 patients with influenza A (H7N9) virus infection were included in the final analysis.




Demographics and clinical characteristics were collected from medical records. Cardiac injury was defined according to cardiac biomarkers, electrocardiography, or echocardiography. Among the 321 patients, 203 (63.2%) showed evidence of cardiac injury. Compared with the uninjured group, the cardiac injury group had lower PaO2/FIO2 (median, 102.0 vs 148.4 mm Hg; p < 0.001), higher Acute Physiology and Chronic Health Evaluation II score (median, 17.0 vs 11.0; p < 0.001), longer stay in the ICU (10.0 vs 9.0 d; p = 0.029), and higher proportion of in-hospital death (64.0% vs 20.3%; p < 0.001). The proportion of virus clearance until discharge or death was lower in the cardiac injury group than in the uninjured group (58.6% vs 86.4%; p < 0.001). Multivariable-adjusted Cox proportional hazards regression analysis showed that cardiac injury was associated with higher mortality (hazards ratio, 2.06; 95% CI, 1.31-3.24) during hospitalization.


Cardiac injury is a frequent condition among hospitalized patients infected with influenza A (H7N9) virus, and it is associated with higher risk of mortality.

PMID: 31923027 DOI: 10.1097/CCM.0000000000004207

Keywords: Avian Influenza; H7N9; Human; Cardiology.


Comparative #Pathogenicity and #Transmissibility of #H1N1pdm09, #Avian #H5N1, and #Human #H7N9 #Influenza Viruses in Tree #Shrews (Front Microbiol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Front Microbiol. 2019 Dec 20;10:2955. doi: 10.3389/fmicb.2019.02955. eCollection 2019.

Comparative Pathogenicity and Transmissibility of Pandemic H1N1, Avian H5N1, and Human H7N9 Influenza Viruses in Tree Shrews.

Xu S1, Li X1, Yang J1, Wang Z1, Jia Y1, Han L1, Wang L1, Zhu Q1.

Author information: 1 State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.



Influenza A viruses (IAVs) continuously challenge the poultry industry and human health. Studies of IAVs are still hampered by the availability of suitable animal models. Chinese tree shrews (Tupaia belangeri chinensis) are closely related to primates physiologically and genetically, which make them a potential animal model for human diseases. In this study, we comprehensively evaluated infectivity and transmissibility in Chinese tree shrews by using pandemic H1N1 (A/Sichuan/1/2009, pdmH1N1), avian-origin H5N1 (A/Chicken/Gansu/2/2012, H5N1) and early human-origin H7N9 (A/Suzhou/SZ19/2014, H7N9) IAVs. We found that these viruses replicated efficiently in primary tree shrew cells and tree shrews without prior adaption. Pathological lesions in the lungs of the infected tree shrews were severe on day 3 post-inoculation, although clinic symptoms were self-limiting. The pdmH1N1 and H7N9 viruses, but not the H5N1 virus, transmitted among tree shrews by direct contact. Interestingly, we also observed that unadapted H7N9 virus could transmit from tree shrews to naïve guinea pigs. Virus-inoculated tree shrews generated a strong humoral immune response and were protected from challenge with homologous virus. Taken together, our findings suggest the Chinese tree shrew would be a useful mammalian model to study the pathogenesis and transmission of IAVs.

Copyright © 2019 Xu, Li, Yang, Wang, Jia, Han, Wang and Zhu.

KEYWORDS: H1N1; H5N1; H7N9; infectivity; transmissibility; tree shrew

PMID: 31921093 PMCID: PMC6933948 DOI: 10.3389/fmicb.2019.02955

Keywords: Influenza A; H7N9; H5N1; H1N1pdm09; Animal models.