Published Date: 2012-09-28 11:22:27
Subject: PRO/AH/EDR> Influenza (93): Canada (ON) H1N1v, sequence data
Archive Number: 20120928.1312982
INFLUENZA (93): CANADA (ONTARIO), H1N1V, SEQUENCE DATA
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Date: Thu 27 Sep 2012
From: Anne Winter <anne-luise.winter@oahpp.ca> [edited]
[Previously it was reported in ProMED-mail post: Influenza (91): Canada (ON) H1N1v, human case 20120926.1311060 that it had not been confirmed that the M gene of the pandemic H1N1 virus, which is also present in the swine flu viruses that have been causing human infections in the USA this summer 2012, was present in the Canadian isolate. In fact, the complete sequence had been obtained, and the relevant data are presented below. - Mod.CP]
* PCR and sequencing results of HA and NA showed that this virus is an H1N1 subtype, which is closely related to H1N1 swine triple reassortant viruses identified in the United States in 2011 and 2012
* Sequencing revealed that this H1N1 carries the M gene of influenza A(H1N1)pdm09, as was found in the last 2 documented cases of H1N1v infection, in Wisconsin (December 2011) and Missouri (reported September 2012).
Based on the testing results from PHOL and NML, we conclude that this patient was infected with an influenza A H1N1 variant (H1N1v) virus.
* The HA gene was found to have nucleotide sequence homologies of:
* 98.8 percent to the HA of the H1N1v reported in Missouri earlier this month [September 2012].
* 96.2 percent to the HA of the H1N1v reported in Wisconsin in December 2011
* 92 percent to the HA of A/California/7/2009 (H1N1)-like virus, the A(H1N1)pdm09 strain in the current seasonal influenza vaccine.
Based on data from the US Centers for Disease Control and Prevention, 2 H1N1v viruses (A/Wisconsin and A/Missouri) isolated from humans in the US in 2011 and 2012, separately, are closely related antigenically to A/California/7/2009 virus, which is a vaccine component of the currently available influenza vaccine. It is expected that the 2012-2013 seasonal influenza vaccine is likely to protect against the H1N1v influenza virus, although the seasonal influenza vaccine may not protect people against some other variant influenza viruses that are very different from currently circulating human influenza viruses.
J.B.Gubbay1,2, Y.Li3, D.J. Farrell1,2, A.L. Winter1, E. Kristjanson1, A. Li1, A. Eshaghi1, P. Rosenfeld1, R.Wheeler1 F. Plummer3, F. Jamieson1,2.
1. Public Health Ontario, Canada.
2. University of Toronto, Toronto, Ontario, Canada.
3. National Microbiology Laboratory, Public Health Agency of Canada.
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Anne Winter RN, BScN, MHSc, CIC: Manager (A) Surveillance Services
Communicable Disease Prevention and Control
Public Health Ontario
480 University Avenue, Suite 300
Toronto, ON, Canada M5G 1V2
[ProMED-mail thanks the authors for this clarification. - Mod.CP
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