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Note: With
this Influenza Summary, the Washington State Department of
Health bids a fond farewell to Phyllis Shoemaker who has
been the DOH Influenza Surveillance coordinator for years.
At the end of June 2008, Phyllis retires after 34 years in service
to Washington State. Thanks and best wishes, Phyllis. Enjoy
your new life -- you will be missed here at DOH.
_____________________________________
Influenza Season Summary,
2007-2008
May 22, 2008 (CDC Week 20)
The Washington State Department of
Health (DOH), in collaboration with local health
jurisdictions and the U.S. Center for Disease Control and
Prevention (CDC), conducts routine influenza surveillance
each year from October to May. Influenza surveillance
activities in the state include sentinel laboratory
reporting, monitoring of school absenteeism, sentinel
long-term care facility surveillance, reporting of
influenza-like illnesses by health care providers enrolled
in the CDC’s Sentinel Provider Surveillance Network, and
other surveillance activities.
Because influenza is not a notifiable
condition in Washington State, information on incidence
rates statewide are not gathered. However, routine
influenza surveillance provides useful information on
influenza activity levels and trends in influenza virulence
and pathogenicity. Subtyping of influenza isolates by
sentinel laboratories also yields information on what
subtypes are in circulation and helps with the selection of
influenza strains to include in seasonal flu vaccines.
The Washington State Influenza
Coordinator reports on influenza activity each week on the
DOH website at http://www.doh.wa.gov/EHSPHL/Epidemiology/CD/fluupdate.htm
Each year, at the end of the regular
influenza season, a report summarizing the seasonal activity
is posted on this site. The following is a summary of the
2007-2008 influenza season.
Synopsis
Sporadic cases of influenza A began to
appear in October, 2007. Reports of laboratory confirmed
cases peaked in the first week of February. Reported
influenza activity began to decrease in the middle of March,
with sporadically cases being reported through the end of
May. Sixty-three percent of cases were influenza A. School
absenteeism related to influenza was very low over-all this
season. Nursing home influenza outbreaks that were reported
were higher than last season.
Sentinel Laboratories
Sentinel influenza surveillance
laboratories reported 975 isolates from 19 counties. Six
hundred eleven (63%) of the cases were influenza type A.
Three hundred sixty four 37%) of cases were influenza B. Of
the 611 influenza A, 16 % were influenza A, H1N1; 7 percent
were influenza A, H3N2; and 76% were influenza A, not
subtyped. Seven percent of surveillance isolates were
obtained from patients under one year of age, 10% from
persons 1-4 years of age, 12% from persons 5-9 years of age,
12% from persons 10-19 years of age, 16% from persons 20-29
years of age; 12% from persons 30-39 years of age; 11% from
persons 40-49 years of age; 6% from persons 50-59 years of
age; and 11% from persons 60 years or older. Age was not
reported for 14 cases.
School Absenteeism
Influenza absenteeism in school was
extremely low for the 2007-2008 influenza season. Ten
schools reported influenza absenteeism from October 2007
through January, 2008. During February, a total of 20
schools reported greater than 10% absenteeism with
influenza-like illnesses (ILI). During March 17 schools
reported absenteeism. No influenza related absenteeism was
reported during the month of May.
Sentinel Long-Term Care Facilities
Nineteen long-term care (LTC) or
assisted living (AL) facilities participated in sentinel
influenza surveillance in Washington during the 2007-2008
season. Twenty-one outbreaks were reported with 6 reported
as influenza A, not subtyped, 3 as influenza A, H3N2-like, 8
influenza B, Not subtyped, 4 influenza B, Yamagata and 1
influenza B , Shanghai.
Sentinel Physicians
While Washington State has been able to
meet the Centers for Disease Control and Preventions goal of
one physician per 250,000 state' population, not all of our
physicians who sign up participate fully. Fifty percent of
Washington sentinel physicians did reported at least once to
CDC on the level of influenza activity among their patients.
A few physicians reported 50% or more of the time.
Four physicians reported 80% to 100% of the time.
Influenza Trivalent Vaccine
2008-2009
As many of you know, two of the
components of this years' vaccine did not match the
circulating strains of influenza circulating this season.
Because of this all three components of the 2008-2009
trivalent vaccine are being changed. The following
recommendations are based on antigenic analyses of recently
isolated influenza viruses, epidemiologic data, and
post-vaccination serologic studies in humans. The vaccine
for the 2008-2009 influenza season will contain the
following strains:
A, Brisbane/59/2007-like (H1N1)
A, Brisbane/10/2007-like (H3N2)
B, Florida/4/2006-like
These viruses are currently included in
the 2008 Southern Hemisphere vaccines. This recommendation
was based on surveillance data related to epidemiology and
antigenic characteristics, serological responses to
2007-2008 vaccines, and the availability of candidate
strains and reagents.
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