2017-2018 Influenza Season, Update for Week 16*
(Week ending Saturday, 04/21/2018)
Key Points
National influenza activity has continued to steadily decline from its February peak ten weeks ago. The U.S.
Centers for Disease Control and Prevention (CDC) recently reported an additional weekly decrease (from
2.1 to 1.8%) in the percentage of people seeing their health care provider with influenza-like-illness (ILI),
which continues to decrease from the high percentage (7.7 %) observed during the peak weeks of the current
2017-2018 flu season. Although this national percentage of people seeking health providers with ILI has
now decreased below baseline levels, individual state % ILI rates remains elevated above background levels
within several regions of the continental United States, including the Northeast.
Influenza activity in Connecticut, which had decreased from its peak in early February, remains elevated
and had actually increased during the previous several weeks, in part, due to increased circulation of
influenza B viruses. This small second wave of influenza activity, which can be observed in most
surveillance system graphs, is now decreasing. This second wave of activity is especially apparent in the
increased percentage of patients with influenza-like illness presenting to hospital emergency departments
and outpatient providers, along with the increased number of laboratory confirmed flu cases and fluassociated
hospitalizations. We have received reports of five new flu-associated deaths during the past week
in Connecticut.
Classification of Connecticut geographic activity continues at widespread**.
Although influenza A (H3N2) viruses have been predominate within the US and Connecticut for most of the
2017-2018 season, numbers of influenza B viruses are now circulating in greater numbers than influenza A
viruses.
As elevated flu activity will likely continue well into May in Connecticut, there is still time to obtain your
flu vaccine and take other important steps to prevent influenza-related illness and hospitalization:
http://www.portal.ct.gov/DPH/Infectious-Diseases/Immunization/Seasonal-Influenza
...
A total of 3,245 hospitalized patients with laboratory-confirmed influenza admitted between August 27 and
April 21, 2018 have been reported to date. Of these 3,245 reports, 1,723 were Type A (subtype unspecified),
557 were Type A (H3N2), 38 were Type A (2009 H1N1), 921 were influenza B virus, and 6 of unknown
type. A total of 146 influenza-associated deaths (99 associated with flu A, 46 with flu B, 1 of unknown type)
have been reported to date. Five new flu-associated deaths have been reported during this week.
Of the 146
deaths reported to date, 122 were among patients greater than 65 years of age, 13 were 50-64 years of age, 7
were 25-49 years of age, 1 was between 19-24 years of age, and 3 were <18 years of age. The current season
total of 146 deaths is above the range of influenza-associated deaths (1-65) reported during the previous five
seasons (Figures 4 & 5).
...
http://portal.ct.gov/-/media/Depart...ous_diseases/flu/stats/thisweeksfluupdate.pdf
