British Columbia

B.C. turns the corner on influenza epidemic

Provincial officials say the worst is over in B.C. when it comes to the influenza season, while cases in the U.S. continue to climb. Why were we spared?

Infections waning here despite this year's ineffective vaccine while cases still climbing in the U.S.

People with influenza shed the virus through their airways which can then infect other people. (BCCDC)

Officials in B.C. say influenza infections across the province are starting to ebb after months of coughing, wheezing and aches for many people.

In its mid-season influenza surveillance report, the B.C. Centre for Disease Control says the number of people coming down with the virus has fallen to more normal rates after being above the 10-year average for the past three weeks.

"All signs seem to point to us having turned the corner on the current epidemic peak," said Dr. Danuta Skowronski with the BCCDC.

The black dotted line shows positive tests for influenza and other viruses from samples submitted to the B.C. Centre for Disease Control. The peak hit at the end of 2017 and the beginning of 2018. (BCCDC)

The good news comes in contrast to the U.S. where numbers from government reports on Friday show that one of every 14 visits to doctors and clinics were for fever, cough and other symptoms of the flu.

In the U.S. that's the highest level since the swine flu pandemic in 2009. Last week, 42 states reported high patient traffic for the flu, up from 39.

Deaths related to the virus are being counted in the thousands while there have been 120 deaths associated with influenza in Canada according to the latest numbers from the Public Health Agency of Canada.

Officials in the U.S. say they expect infections to climb for weeks to come.

Flu shot a miss

So how did B.C. dodge a bullet — so far?

It would be nice to say that people in B.C. do a better job at washing their hands, coughing into their elbows and getting the flu shot than our neighbours in the U.S. 

But that's simply not the case, according to Skowronski.

First of all, this season's flu shot was a bit of miss. The BCCDC says it's less than 20-per-cent effective against this year's strains.

Compared to the U.S. she says B.C. has had fewer cases of H3N2 — a strain of influenza A — which is particularly hard on elderly patients or those with weakened immune systems.

Influenza B, a different strain of flu which can be less severe, has been dominant in B.C., Skowronski  said, although H3N2 is also circulating in the province.

Overall in the U.S., Skowronski says 80 per cent of samples tested have come back positive as H3N2.

"So they're having a different experience," she said about the U.S.

Immunity from last season?

Another factor may be that more people in B.C have immunity to H3N2, since it was widespread in the region during the 2016-2017 flu season.

"That likely altered our population immunity and may have mitigated, reduced the impact of that H3N2 virus this season in Canada," said Skrowronski.

Meanwhile Skowronski says people here should continue with good hand washing hygiene, while those in vulnerable groups should seek medical attention if they contract the flu.

With files from the Associated Press.