Influenza Update Week Ending 12-23-2017
Earlier in this flu season, the CDC posted an expectation that this flu season (2017-18) would likely start early and be more severe (as it was last year) than previous few flu seasons. This prediction was made based on the severe flu season that Australia was experiencing and since Influenza A H3N2 was the predominant strain. Flu seasons in the Southern Hemisphere are often good predictors of North American flu seasons since there winter occurs during our summer.
This prediction was correct and the CDC has posted a Health Advisory outlining the current flu season as early, severe and expecting a more serious impact on those over 65 and younger children than other age groups. https://emergency.cdc.gov/han/han00409.asp
The Advisory goes on to say that Health Care Providers (HCPs) should being suspicious of influenza (flu) in those patients with any signs and symptoms consistent with flu. For those in high risk groups (including over age 65 or younger children), those hospitalized, or who have severe, complicated or worsening illness, should include the rapid start of appropriate antiviral medications, ideally within 48 hours of the onset of flu symptoms, but may be appropriate even beyond this time frame at the provider’s discretion. Antivirals may also be given to those not in high risk groups who present within 1-2 days of the onset of symptoms, when the HCP thinks it’s appropriate. There is no need to wait for flu test confirmation of flu before starting antivirals.
Week #51 (ending 12-23-17) is the 5th week in a row of increasing cases and all regions are reporting widespread flu and influenza-like-illness (ILI)This week showed a much sharper rise in the number of cases than previously seen this season. This pattern suggests a season similar to the 2014-15 one, which also had A H3N2 dominating and was considered severe.
There is a continuing uptick in the number of FirstWatch RIN (Reginal Influenza Network) Alerts that correlates with this rise in ILI and diagnosed flu.
Anyone who has not been vaccinated with this year’s flu vaccine, should still be vaccinated until the flu season has ended. Those experiencing signs and symptoms of flu should be closely monitored for complications of flu https://www.cdc.gov/flu/weekly/