# 4094
The Public Health Agency of Canada produces a weekly influenza summary called FluWatch, which is very similar to the US FluView report from the CDC. In it you will find maps, charts, and summaries of the previous week’s influenza surveillance.
As in the United States, while numbers this week are declining, Canada is in the midst of a serious outbreak of influenza. More befitting of what might be expected in January or February than mid November.
A few excerpts from this week’s report (ending Nov 21st), but follow the FluWatch link to read it in its entirety.
November 15, 2009 to November 21, 2009 (Week 46)
Summary of FluWatch Findings for the
Week ending November 21, 2009
- Nationally, the activity level reported this week decreased compared to the previous week. All influenza indicators declined during week 46.
- A possible epidemic peak has been reached by all provinces and territories.
- The Pandemic (H1N1) 2009 strain accounted for nearly 100% of the positive influenza A subtyped specimens this week.
- The intensity of Pandemic (H1N1) 2009 in the population was still high with 1,554 hospitalizations, 243 ICU admissions and 61 deaths reported this week. Hospitalized cases occurred in all provinces and territories (P/T) that reported this week while the deaths were from all P/T except PE, NL and NU. From August 30 to November 21, 2009, a total of 5,507 hospitalized cases including 819 (14.9%) cases admitted to an intensive care unit (ICU) as well as 203 deaths had been reported.
- While the number of hospitalized cases, ICU admissions and deaths reported this week decreased, the number of hospitalizations was higher than the overall number of hospitalizations for the first wave.
- The proportion of severe cases (ICU admissions and deaths) among all hospitalized cases was lower in the second wave than in the first wave.
Canadian situation
Antigenic Characterization
Since September 1, 2009, NML has antigenically characterized 310 Pandemic (H1N1) 2009 viruses and four seasonal influenza viruses (two influenza A/H1N1, one influenza A/H3N2 and one B virus) that were received from Canadian laboratories. Of the 310 Pandemic influenza A (H1N1) viruses characterized, 309 (99.7%) were antigenically related to A/California/7/2009, which is the pandemic reference virus selected by WHO as Pandemic (H1N1) 2009 vaccine. One virus (0.3%) tested showed reduced titer with antisera produced against A/California/7/09. Sequence analysis of the HA showed that the virus with reduced titer did not have the mutation at amino acid position 222 as reported by Norway. CDC also reported that of the 348 pandemic H1N1 viruses tested, one virus showed reduced titer with antisera produced against A/California/7/09.
Antiviral Resistance
NML: Pandemic (H1N1) 2009 viruses tested so far have been sensitive to zanamivir (220 samples) but resistant to amantadine (231 samples). Of the 258 Pandemic (H1N1) 2009 viruses tested, 255 were sensitive to oseltamivir and three viruses were resistant to oseltamivir with the H275Y mutation. The three resistant cases, 2 from Ontario and 1 from Quebec, were associated with oseltamivir treatment.
Provinces: Three cases of oseltamivir resistant Pandemic (H1N1) 2009 were reported to date in Canada from the province of Quebec on July 21, 2009, from Alberta on September 15, 2009 and from Ontario on October 13, 2009.
