Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 22, Number 1—January 2016
Dispatch

Avian Influenza A(H7N9) Virus Infection in 2 Travelers Returning from China to Canada, January 20151

Danuta SkowronskiComments to Author , Catharine Chambers, Reka Gustafson, Dale B. Purych, Patrick Tang, Nathalie Bastien, Mel Krajden, and Yan Li
Author affiliations: British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada (D.M. Skowronski, C. Chambers, P. Tang, M. Krajden); University of British Columbia, Vancouver (D.M. Skowronski, R. Gustafson, D.B. Purych, P. Tang, M. Krajden); Vancouver Coastal Health Authority, Vancouver (R. Gustafson); LifeLabs Medical Laboratories, Surrey, British Columbia, Canada (D.B. Purych); Public Health Agency of Canada, Winnipeg, Manitoba, Canada (N. Bastien, Y. Li); University of Manitoba, Winnipeg (Y. Li)

Main Article

Table 1

Antibody titers to avian influenza A(H7N9) virus and recent human influenza A(H3N2) and A(H1N1)pdm09 virus strains for 2 persons with virologically confirmed H7N9 virus infection and for an HCW contact, British Columbia, Canada, January 2015*

Person, date of specimen collection Duplicate inverse HI titers and GMT for influenza antibody
A/British Columbia/1/2015(H7N9)†
 A/Switzerland/9715293/2013(H3N2)‡§
 A/California/07/2009(H1N1)‡¶
Titer 1 Titer 2 GMT Titer 1 Titer 2 GMT Titer 1 Titer 2 GMT
Index patient#
January 26 20 20 20 10 10 10 10 10 10
March 5
 80
 160
 113
10
 10
 10
10
 10
 10
Second patient#
January 26 20 40 28 10 10 10 10 10 10
March 5
 160
 160
 160
20
 20
 20
20
 20
 20
HCW contact**
January 27 <10 <10 <10 40 40 40 20 20 20
May 1 <10 <10 <10 40 40 40 20 20 20

*The 2 H7N9 virus–infected persons were a married couple; the woman was the index patient, and the man was the second patient. GMT, geometric mean titer; HCW, healthcare worker; HI, hemagglutination inhibition.
†Assay was conducted by using homologous H7N9 virus isolated from the index patient (Global Initiative on Sharing Avian Influenza Data accession no. EPI_ISL_171342); the virus was antigenically equivalent to influenza A/Anhui/1/2013(H7N9), which was used in the population serosurvey reported in Table 2. The HI assay was conducted by using horse erythrocytes, as previously described (6).
‡Assay was conducted by using viruses of each human influenza A H1 and H3 subtype to which strains identified globally during the 2014–15 influenza season were considered antigenically related (see http://www.who.int/influenza/vaccines/virus/recommendations/2015_16_north/en/). Titers were measured according to standard assay protocols of the National Microbiology Laboratory, Canada’s influenza reference laboratory.
§Assay was conducted by using guinea pig erythrocytes and in the presence of oseltamivir carboxylate to address potential neuraminidase-mediated binding of influenza A(H3N2) viruses to erythrocytes.
¶Assay was conducted by using turkey erythrocytes.
#Received neither the 2013–14 nor 2014–15 influenza vaccine nor prior pneumococcal vaccine.
**Received the 2013–14 and the 2014–15 influenza vaccines.

Main Article

References
  1. Lam  TT, Zhou  B, Wang  J, Chai  Y, Shen  Y, Chen  X, Dissemination, divergence and establishment of H7N9 influenza viruses in China. Nature. 2015;522:102–5 . DOIPubMedGoogle Scholar
  2. European Centre for Disease Prevention and Control. Human infection with avian influenza A(H7N9) virus. Fourth update, February 2, 2015 [cited 2015 Jul 23]. http://ecdc.europa.eu/en/publications/Publications/RRA-Influenza-A-H7N9-update-four.pdf
  3. To  KKW, Chan  JFW, Chen  H, Li  L, Yuen  K-Y. The emergence of influenza A H7N9 in human beings 16 years after influenza A H5N1: a tale of two cities. Lancet Infect Dis. 2013;13:809–21. DOIPubMedGoogle Scholar
  4. Skowronski  DM, Li  Y, Tweed  SA, Tam  TWS, Petric  M, David  ST, Protective measures and human antibody response during an avian influenza H7N3 outbreak in poultry in British Columbia, Canada. CMAJ. 2007;176:47–53. DOIPubMedGoogle Scholar
  5. European Centre for Disease Prevention and Control. Risk assessment guidelines for infectious diseases transmitted on aircraft (RAGIDA)—influenza. 2014 [cited 2015 Sep 6]. http://ecdc.europa.eu/en/publications/Publications/influenza-RAGIDA-2014.pdf
  6. Centers for Disease Control and Prevention. Modified hemagglutination-inhibition (HI) assay using horse RBCS for serologic detection of antibodies to H7 subtype avian influenza virus in human sera. Version 1 [cited 2015 July 23]. https://consise.tghn.org/site_media/media/articles/160713_Modified_Hemagglutination_Inhibition_Assay_Using_Horse_RBCs.pdf.
  7. Skowronski  DM, Janjua  NZ, De Serres  G, Purych  D, Gilca  V, Scheifele  DW, Cross-reactive and vaccine-induced antibody to an emerging swine-origin variant of influenza A virus subtype H3N2 (H3N2)v. J Infect Dis. 2012;206:1852–61. DOIPubMedGoogle Scholar
  8. Skowronski  DM, Chambers  C, Sabaiduc  S, Janjua  NZ, Li  G, Petric  M, Pre- and postpandemic estimates of 2009 pandemic influenza A(H1N1) seroprotection to inform surveillance-based incidence by age, during the 2013–2014 epidemic in Canada. J Infect Dis. 2015;211:109–14. DOIPubMedGoogle Scholar
  9. Gao  H-N, Lu  H-Z, Cao  B, Du  B, Shang  H, Gan  J-H, Clinical findings in 111 cases of influenza A (H7N9) virus infection. N Engl J Med. 2013;368:2277–85. DOIPubMedGoogle Scholar
  10. Zhang  A, Huang  Y, Tian  D, Lau  EH, Wan  Y, Liu  X, Kinetics of serological responses in influenza A(H7N9)-infected patients correlate with clinical outcome in China, 2013. Euro Surveill. 2013;18:20657 .PubMedGoogle Scholar
  11. Yang  S, Chen  Y, Cui  D, Yao  H, Lou  J, Huo  Z, Avian-origin influenza A(H7N9) infection in influenza A(H7N9)–affected areas of China: a serological study. J Infect Dis. 2014;209:265–9. DOIPubMedGoogle Scholar
  12. Guo  L, Zhang  X, Yu  X, Chen  L, Zhou  H, Gao  X, Human antibody responses to avian influenza A(H7N9) virus, 2013. Emerg Infect Dis. 2014;20:192–200. DOIPubMedGoogle Scholar
  13. Chen  Z, Liu  H, Lu  J, Luo  L, Li  K, Liu  Y, Asymptomatic, mild, and severe influenza A(H7N9) virus infection in humans, Guangzhou, China. Emerg Infect Dis. 2014;20:1535–40. DOIPubMedGoogle Scholar
  14. Ip  DK, Liao  Q, Wu  P, Gao  Z, Cao  B, Feng  L, Detection of mild to moderate influenza A/H7N9 infection by China's national sentinel surveillance system for influenza-like illness: case series. BMJ. 2013;346:f3693. DOIPubMedGoogle Scholar
  15. Pabbaraju  K, Tellier  R, Wong  S, Li  Y, Bastien  N, Tang  JW. Full-genome analysis of avian influenza A(H5N1) virus from a human, North America, 2013. Emerg Infect Dis. 2014;20:887–91 . DOIPubMedGoogle Scholar

Main Article

1Preliminary results from the population serosurvey were presented at the CACMID-AMMI Canada 2014 Annual Conference, April 3–5, 2014, Victoria, British Columbia, Canada.

Page created: December 18, 2015
Page updated: December 18, 2015
Page reviewed: December 18, 2015
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external