Chinese Science Bulletin

, Volume 58, Issue 26, pp 3183–3187 | Cite as

Epidemiological and risk analysis of the H7N9 subtype influenza outbreak in China at its early stage

  • QingYe Zhuang
  • SuChun Wang
  • MeiLi Wu
  • Shuo Liu
  • WenMing Jiang
  • GuangYu Hou
  • JinPing Li
  • KaiCheng Wang
  • JianMin Yu
  • JiMing Chen
  • JiWang Chen
Open Access
Progress Virology

Abstract

Dozens of human cases infected with H7N9 subtype avian influenza virus (AIV) have been confirmed in China since March, 2013. Distribution data of sexes, ages, professions and regions of the cases were analyzed in this report. The results showed that the elderly cases, especially the male elderly, were significantly more than expected, which is different from human cases of H5N1 avian influenza and human cases of the pandemic H1N1 influenza. The outbreak was rated as a Grade III (severe) outbreak, and it would evolve into a Grade IV (very severe) outbreak soon, using a method reported previously. The H7N9 AIV will probably circulate in humans, birds and pigs for years. Moreover, with the driving force of natural selection, the virus will probably evolve into highly pathogenic AIV in birds, and into a deadly pandemic influenza virus in humans. Therefore, the H7N9 outbreak has been assumed severe, and it is likely to become very or extremely severe in the future, highlighting the emergent need of forceful scientific measures to eliminate any infected animal flocks. We also described two possible mild scenarios of the future evolution of the outbreak.

Keywords

H7N9 avian influenza virus outbreak epidemiology risk 

References

  1. 1.
    Gao R B, Cao B, Hu Y W, et al. Human infection with a novel avian-origin influenza A (H7N9) Virus. New Engl J Med, 2013, Doi: 10.1056/NEJMoa1304459Google Scholar
  2. 2.
    Uyeki T M, Cox N J. Global concerns regarding novel influenza A (H7N9) virus infections. New Engl J Med, 2013, Doi: 10.1056/ NEJMp1304661Google Scholar
  3. 3.
    Kageyama T, Fujisaki S, Takashita E, et al. Genetic analysis of novel avian A (H7N9) influenza viruses isolated from patients in China, February to April 2013. Euro Surveill, 2013, 18: 7–21Google Scholar
  4. 4.
    Jia N, Feng D, Fang L Q, et al. Case fatality of SARS in mainland China and associated risk factors. Trop Med Int Health, 2009, 14(S1): 21–27CrossRefGoogle Scholar
  5. 5.
    National Bureau of Statistics of China. China Statistical Yearbook of 2012. Beijing: China Statistics Press, 2012Google Scholar
  6. 6.
    World Health Organization. Epidemiology of WHO-confirmed human cases of avian influenza A (H5N1) infection. Wkly Epidemiol Rec, 2006, 81: 249–257Google Scholar
  7. 7.
    Reichert T, Chowell G, Nishiura H, et al. Does glycosylation as a modifier of original antigenic sin explain the case age distribution and unusual toxicity in pandemic novel H1N1 influenza? BMC Infect Dis, 2010, 10: 5CrossRefGoogle Scholar
  8. 8.
    Chen Y Y, Sun Y X, Chen J W, et al. Quantification of the severity of an outbreak in human infection control. Int J Infect Dis, 2010, 14: e3–5CrossRefGoogle Scholar
  9. 9.
    Chen J M, Huang B X. Guidelines of Epidemiological Surveys of Important Animal Diseases. Beijing: Chinese Agricultural Sci-Tech Press, 2009Google Scholar
  10. 10.
    Ma W, Lager K M, Vincent A L, et al. The role of swine in the generation of novel influenza viruses. Zoonoses Public Health, 2009, 56: 326–327CrossRefGoogle Scholar
  11. 11.
    Baigent S J, McCauley J W. Influenza type A in humans, mammals and birds: Determinants of virus virulence, host-range and interspecies transmission. Bioessays, 2003, 25: 657–671CrossRefGoogle Scholar
  12. 12.
    China Livestock Yearbook Editorial Committee. Statistical Yearbook of China Animal Husbandry. Beijing: China Agriculture Press, 2011Google Scholar
  13. 13.
    Neumann G, Chen H, Gao G F, et al. H5N1 influenza viruses: Outbreaks and biological properties. Cell Res, 2010, 20: 51–61CrossRefGoogle Scholar
  14. 14.
    Smith R D. Responding to global infectious disease outbreaks: Lessons from SARS on the role of risk perception communication and management. Soc Sci Med, 2006, 63: 3113–3123CrossRefGoogle Scholar
  15. 15.
    Chen J M. A method to replace live bird market. PRC patent, 201110071333, 2012-09-19Google Scholar
  16. 16.
    Chen J M, Sun Y X. Variation in the analysis of positively selected sites using nonsynonymous/synonymous rate ratios: An example using influenza virus. PLoS One, 2011, 6: e19996CrossRefGoogle Scholar
  17. 17.
    Chua K B. Nipah virus outbreak in Malaysia. J Clin Virol, 2003, 26: 265–275CrossRefGoogle Scholar

Copyright information

© The Author(s) 2013

Authors and Affiliations

  • QingYe Zhuang
    • 1
  • SuChun Wang
    • 1
    • 2
  • MeiLi Wu
    • 1
    • 2
  • Shuo Liu
    • 1
  • WenMing Jiang
    • 1
  • GuangYu Hou
    • 1
  • JinPing Li
    • 1
  • KaiCheng Wang
    • 1
  • JianMin Yu
    • 1
  • JiMing Chen
    • 1
  • JiWang Chen
    • 3
  1. 1.China National Avian Influenza Professional LaboratoryChina Animal Health and Epidemiology CenterQingdaoChina
  2. 2.College of Animal Science and Veterirary MedcineQingdao Agricultural UniversityQingdaoChina
  3. 3.The Institute for Personalized Respiratory MedicineUniversity of Illinois at ChicagoChicagoUSA

Personalised recommendations