Preparing for the Upcoming Respiratory Virus Season

1
Preparing for the Upcoming Respiratory Virus
Season

• Thomas Haupt, M.S.
• Respiratory Disease Surveillance Coordinator
• Bureau of Communicable Diseases and Preparedness
• 608-266-5326
• hauptte_at_dhfs.state.wi.us
• Carol Kirk
• Laboratory Network Coordinator
• Wisconsin State Laboratory of Hygiene
• 608-262-1021
• cjk_at_mail.slh.wisc.edu

2
Overview of Presentation

• Influenza The Basics
• Laboratory Diagnosis of Influenza
• Surveillance for Influenza
• Current Situation
• Pandemic Influenza
• Pandemic Preparedness Activities
• Summary

3
Influenza The Disease

• A respiratory disease caused by influenza virus.
• Abrupt onset of fever, cough, sore throat,
  chills, body aches.
• Not typically associated with vomiting or
  diarrhea.
• Typical incubation period 14 days.

4
Influenza The Disease, continued

• Spread person to person primarily by discharges
  from the nose and mouth (coughing and sneezing).
  
• Infectious period
• Adults - the day before symptoms through 5 days
  after onset.
• Children - can be infectious for 10 days
• Young children can shed virus for several days
  before their illness onset.
• Severely immunocompromised can shed virus for
  weeks or months.

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Influenza The Virus

• Family Orthomyxoviridae
• Genera 3 Influenzavirus Types
• - A B C
• - Type B influenza viruses only infect humans.
• - Type A influenza viruses infect humans birds
  other mammals.
• Influenza A Subtypes
• Human - H1N1, H3N2, H1N2, H2N2
• Birds - H1 to H16, N1 to N9
• Bird ?Human - H5N1, H9N2 ,H7N7, H7N2, H7N3

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Influenza Nomenclature
Location of Original Isolation
Year of Initial Isolation

• A/Fujian/411/2002 (H3N2)-like
• Strains A/California/7/2004 (H3N2)-like
• (2005-6) A/New Caledonia/20/99 (H1N1)-like
• B/Shanghai/361/2002-like

Subtype (Influenza A Viruses Only)
Original Lab ID
Type
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Influenza - Impact

• Influenza causes annual epidemics, usually
  beginning in Nov/Dec and peaking in late
  January.
• Epidemic Outbreak that is in a specific
  geographic area Northern Hemisphere in Winter
  and Southern Hemisphere in Summer.
• Influenza causes periodic pandemics.
• Pandemic Outbreak that is worldwide

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Influenza Annual Impact
U.S. population 290 million
Lab Tested
10-20 Infected (29-59 million)
Hospitalized200,000
Seek Care
Death 36,000
50 Symptomatic (15-30 million)
Treat at Home
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Influenza Seasonality Demonstrated by Testing
Data
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Laboratory Diagnosis of Influenza
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Laboratory Diagnosis of Influenza
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Laboratory Diagnosis of Influenza Rapid EIA-Like
Tests
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Laboratory Diagnosis of Influenza Rapid EIA-Like
Tests, continued
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Impact of Prevalence on Predictive Values
Test with 95.0 Sensitivity, 96.0 Specificity

• Prevalence 20.0
• Disease
• Test
• PVP TP/TPFP380/444
• 85.6
• PVN TN/TNFN1536/1556
• 98.7

• Prevalence 1.0 Disease
• Test
• PVP TP/TPFP19/99
• 19.2
• PVN TN/TNFN1900/1901
• 99.9

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Laboratory Test Data as a Prevalence Indicator
High Prevalence
Low Prevalence
Low Prevalence
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Recommendations for Use of Rapid Influenza Tests

• Educate clinicians on predictive values
  limitations of test results
• Culture confirm early-season late-season
  positives
• Culture confirm peak-season negatives, if
  applicable
• Recognize the value of negative results.
• Use prevalence indicators to decide
• When to test
• When to qualify result
• When to confirm results

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Recommendations for Use of Rapid Influenza Tests

• Perform a risk assessment.
• Review laboratory safety practices.
• Consider use of a biosafety cabinet, if
  available.
• Consider additional personal protective equipment
  (N95 masks, face shields, eye protection).
• Consider performing tests in areas that minimize
  potential exposure of other staff.
• Request travel history on samples.
• Be prepared to prioritize testing or provide
  alternate testing options.

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Influenza Surveillance
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Objectives of Influenza Surveillance

• Determine when influenza viruses are circulating
• Determine where influenza viruses are circulating
• Determine how much influenza activity is
  occurring (intensity and impact)
• Identify the types strains of circulating
  influenza viruses
• Detect unusual events
• Infection by unusual viruses
• Unusual syndromes caused by influenza viruses
• Unusually large/severe outbreaks of influenza
• Increased mortality

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U.S. Influenza Surveillance Weekly Updates at
http//www.cdc.gov/flu/weekly.htm
State and Territorial Epidemiologists
Pediatric Hospitalization
Pediatric Mortality
Health Departments
Vital Statistics Registrars
Sentinel Providers
CDC
Laboratories
Other
Public Health Officials
Public
Physicians
Media
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Influenza Surveillance in Wisconsin
Sentinel Providers
Institutional/Outbreak Reports
Pediatric Mortality
WDPH
Laboratories
Other
Public Health Officials
Public
Clinicians
Media
22
Statewide Laboratory-Based Influenza Surveillance
in Wisconsin
Virology Laboratories
Sentinel Submitters
Rapid Test Sites
WSLH
Public Health Epidemiologists
Laboratories
Clinicians
23
Current Influenza Situation

• In Wisconsin, NO confirmed cases of influenza
  this season.
• 2 positive rapid tests reported, both negative by
  culture PCR.
• ILI Activity below baseline in all regions for
  week ending October 8, 2005.

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Current Influenza Situation

• In U.S.
• ILI Reports ILI Activity below baseline levels
  for week ending October 8, 2005.
• Lab Reports 2 specimens reported positive for
  influenza 1 influenza A (H3N2), 1 influenza A
  (not subtyped).
• State Territorial Epidemiologist Reports 44
  states reported no influenza activity.
  California, Hawaii, Michigan, Pennsylvania, New
  York City Puerto Rico reported sporadic
  activity.

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AVIAN INFLUENZA
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Not all outbreaks of avian influenza are caused
by influenza A (H5N1).
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Confirmed Outbreaks of Avian Influenza Worldwide,
2002-present
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Confirmed Human Cases of Avian Influenza,
Worldwide, 2002-present
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Confirmed Outbreaks of Avian Influenza United
States, 2002-present
H7N3
H3N2
H5N2
H7N2
H5N1
H7N2
H5N2
H2N2, H5N8 H5N2, H7N2
H3N2
H3N2
H5N2 H7N3
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Confirmed Human Cases of Avian Influenza United
States, 2002-present
H7N3
H3N2
H7N2
H7N2
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Confirmed Human Cases of Avian Influenza Worldwi
de, 2002-present
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Avian Influenza (H5N1) in Asia, 2003-2005
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Spread of H5N1 virus
Poultry
Wild Waterfowl
Mammals
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Pandemic Influenza
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Pandemic Influenza
An influenza pandemic is unlike any other public
health emergency or disaster
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Generation of Pandemic Influenza Strain
Avian virus
Avian reassortant virus
Reassortment in humans
Human virus
Avian virus
Avian-human pandemic reassortant virus
Reassortment in swine
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What is Pandemic Influenza?

• An influenza Type A virus never/rarely identified
  among humans (a novel virus) that spreads
  quickly from person-to-person and results in a
  worldwide influenza epidemic.
• Pandemic influenza can occur at any time with
  little warning and may last for 2 or more years.

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Influenza Pandemics and Novel Influenza
Viruses in U.S. History

• Novel viruses
• 1977 - Swine Flu (New Jersey)
• 1988 - Swine flu case in Wisconsin
• 2003-05 - H5N1 avian Influenza, SE Asia

• Past Pandemics
• 1918 Spanish Flu
• 1957 Asian Flu
• 1968 Hong Kong Flu

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Emergence of Influenza Viruses in Humans
41
Influenza Like Illness Rates, 1997/1998
2000/2001
1999
2000
2001
1998
1997
42
Influenza Like Illness Rates Expected During a
Pandemic
1999
1997
2000
2001
1998
43
Impact of an Influenza Pandemic
In Wisconsin, approximately 8-10 times normal
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Pandemic Phases
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Pandemic Phases
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Pandemic Phases
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Whats Being Done?

• Wisconsin instituted Enhanced Surveillance for
  Avian Influenza in February, 2003 to identify
  potential human cases.
• Remains in effect today.
• Criteria Patient with illness within 10 days of
  return from affected country.
• Contact DPH to receive approval for testing.

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Whats Being Done?

• WSLH developed real-time PCR capability for
  influenza A B, A subtypes H1 H3.
• Submit nasopharyngeal swabs (1 dry, 1 in virus
  transport medium) to the WSLH.
• Arrange transport so specimens are received at
  WSLH within 24 hours of collection. Call WSLH if
  you need assistance arranging transport.
• WSLH will perform RT-PCR for influenza A and B
  if positive for influenza A, will perform RT-PCR
  for influenza A (H1) and (H3) to rule out H5 or
  other unusual subtypes.

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Whats Being Done?

• Many Wisconsin communities conducting exercises
  to review and practice their pandemic influenza
  plans.

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Whats Being Done?

• In November, 2003, Wisconsin developed a
• pandemic influenza response document.
• http//dhfs.wisconsin.gov/preparedness/pdf_files/W
  IPandemicInfluenzaPlan.pdf
• Soon to be released
• State of Wisconsin
• Response to Animal Influenza

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Objectives of the Wisconsin Response to Pandemic
Influenza

• Structured response by designating who is in
  charge of what.
• Surveillance for index cases of the novel
  influenza virus.
• Maintenance of essential services including
  health care.
• Develop and implement an effective communication
  system.
• Identify, deliver, and administer vaccine and
  antivirals.

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Objectives of the Wisconsin Response to Animal
Influenza

• Prepare and implement a coordinated, multi-agency
  approach to an animal influenza event in the
  state.
• Rapid identification of a potential animal
  influenza event.
• Define communication procedures.
• Rapid collection, shipping and testing of
  laboratory specimens.
• Implementation of quarantine, de-population and
  disinfection policies.
• Identification of persons exposed to animal
  influenza.

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Summary of Facts

• An influenza pandemic is inevitable although not
  imminent at this time.
• An influenza pandemic will affect everyone in
  one way or another.

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Summary of Facts (continued)

• Prevention (identification) of the novel virus is
  priority.
• Control of the virus, maintaining essential
  services, including health care is essential.
• Wisconsin is ahead of most, but far from winning
  the game.

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Resources

• Wisconsin DPH Influenza http//dhfs.wisconsin.gov/
  communicable/influenza/
• WSLH website
• http//www.slh.wisc.edu/comdis/index.php
• Wisconsin Laboratory graphics
• http//www.slh.wisc.edu/labupdates/index.php
• CDC Influenza home page
• http//www.cdc.gov/flu/index.htm
• CDC National Influenza SummaryWeekly Update
• http//www.cdc.gov/ncidod/diseases/flu/weekly.htm
• WHO Influenza home page
• http//www.who.int/topics/influenza/en/