Flu is taking a tougher toll than usual this year
Main strain hits seniors hard, vaccine mismatch potential reasons for more illnesses this season
The start of the year saw the flu spreading to more Canadian provinces and most U.S. states, officials say.
A report from the Public Health Agency of Canada for the week ending Jan. 3 showed widespread activity in more regions of British Columbia, Alberta, Manitoba, Ontario, Quebec and Newfoundland and Labrador than the previous week.
Lab detections are perhaps "nearing the peak" for the season, the agency said.
The majority of tests done at the agency’s National Microbiology Laboratory in Winnipeg showed the most common type of flu this season is H3N2, which doesn't match with the strain this year's flu vaccine works best against. But the vaccine can still offer some protection against two other flu strains that have been found, federal health officials said.
Since mid-November, outbreaks at long-term care facilities have been higher than those of previous seasons and similar to 2012 when the H3N2 strain was also the main circulating flu strain, the FluWatch report said.
When H3N2 dominates, hospitalization rates tend to be higher and seniors and very young children can be hit harder compared with seasons when the H1N1 virus or influenza B viruses are the main ones circulating.
The majority of lab-confirmed hospitalizations and all 16 deaths with influenza in hospital have been among people aged 65 and older. A total of 69 deaths have been reported since the start of the season.
This is shaping up to a "bad year for flu," Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention (CDC) told reporters in a teleconference Friday.
The CDC’s map of flu activity for the week ending Jan. 3 showed Alaska, California, Hawaii and Arizona as the only states without widespread flu.
With files from Reuters