SWINE FLU

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SWINE FLU

• Marcus Zervos, MD
• Division Head, Infectious Diseases, Medical
  Director, Infection Control
• Henry Ford Health System
• Clinical Professor of Medicine
• Wayne State University, Detroit, MI
• May 5, 2009

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Swine Influenza

• Mexico reported increased number of cases of
  severe respiratory disease, pneumonia and deaths,
  beginning in March 2009.
• Other countries Canada, Europe 13 countries
• USA reported cases 21 states
• CDC has been working closely with public health
  officials in Mexico, World Health Organization
  (WHO). 
• The etiologic agent has been identified as Swine
  Origin Influenza A H1N1 (S-OIV) Swine
  influenza
• It is known to have spread from pigs to humans
  and then widespread person to person transmission

05/1/2009
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US Human Cases of H1N1 US Declares Public
Emergency

•  

Arizona 4  California
24  Colorado 2 Connecticut
1  Delaware 4  Florida
2  Illinois 3  Indiana
3 Kansas 2 
Kentucky 1

• Massachusetts 8 
• Michigan 2
• Minnesota 1 
• Missouri 1 
• Nevada 1
• New Jersey 7
• New York 50 
• Ohio 1 
• South Carolina 13
• Texas 28 (1 death)
• Virginia 2 

TOTAL (21) 160 cases 1 death
As of 5/1/09
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Swine Influenza

• CDC public health officials cases of febrile
  respiratory illness caused by swine influenza
  (H1N1) viruses
• Illness onsets occurred from March 28, 2009. 
• Age range was 7-54 yo. Cases are 63 male.
• Mexico 2000 patients affected and 149 deaths.
• Other Countries 1 associated death- Austria,
  Canada, China, Hong Kong Special Administrative
  Region, Denmark, Germany, Israel, Netherlands,
  New Zealand, Spain, Switzerland, the United
  Kingdom

NOTE 4-27-09 WHO raises pandemic threat level
from 3 to 4 and 4-29-09 to level to 5 meaning
pandemic imminent
05/2/09
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Knowing your foe. Seasonal flu

• 5-20 infected by the flu each year
• Mortality due to influenza and pneumonia is the
  6th leading cause of death in the United States
  after cancer, heart disease, Cardiovascular
  diseases, and COPD .
• Estimated 36,000 deaths per year.
• 200,000 hospital admissions per year.

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Month of Peak Influenza Activity United States,
1976-2006
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20
13
13
3
3
MMWR 200655(RR-10)22
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Impact of Influenza

• 90 of deaths among persons 65 years of age
• Higher mortality during seasons when influenza
  type A viruses predominate
• Highest rates of complications and
  hospitalization among young children and people
  65 years

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Influenza Virus Knowing Your Foe

• Influenza Highly infectious viral illness
• Virus was first isolated in 1933
• Single-stranded RNA virus
• Orthomyxoviridae family
• 3 types A, B, C
• Subtypes of type A determined by hemagglutinin
  (H) and neuraminidase (N)

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Swine Influenza Type A Subtype H1N1

• Type A - moderate to severe illness - all age
  groups, potential for epidemic - humans and
  other animal
• Type B - milder disease - primarily affects
  children - humans only
• Type C - rarely reported in humans - no
  epidemics
• S-OIV contain a unique combination of gene
  segments that have not been reported previously
  among swine or human influenza viruses in the
  U.S. or elsewhere.
• Mutations-mistakes made by the RNA Polymerase is
  just only surpassed by HIVHIGH RATE OF
  MUTATIONS, INABILITY TO PROOF READ AND SEGMENTED
  GENOME THAT ALLOWS GENETIC REASORTMENT

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Influenza Virus Surface Proteins
haemagglutinin
neuraminidase
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• Influenza Virus

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Antigenic Drift

• Gradual change in the virus with mutations and
  substitutions in the amino acid chain of the
  surface proteins
• (neuraminidase and haemagglutinin).
• A new strain can trigger a new epidemic
• usually prevail for 2-5 years before next
  antigenic drift.

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Antigenic Shift

• A type A influenza virus with a completely novel
  haemagglutinin or neuraminidase formation moves
  into the human species from other host species
• The primary source is birds, with recombination
  in swine or humans.

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Pandemic influenza

• The fact is, that flu is one of the most
  formidable infections confronting humankind. The
  virus mutates constantly as it circulates among
  birds, pigs and humans. So each new flu season
  brings new challenges
• First pandemic known in 15th century
• In pandemic response and planning, prediction of
  the future is not possible. Thought is to hope
  for best, but plan for worst

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Recent Pandemics

• 1889-1890 first recorded pandemic
• 1918 Spanish flu- 20-40 million deaths
• 1957 Asian flu- 1 million deaths
• 1968 Hong Kong flu- 1 million deaths
• 1976 Swine flu unreported deaths

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Influenza Pathogenesis

• Respiratory transmission of virus
• Replication in respiratory epithelium with
  subsequent destruction of cells
• Viremia rarely documented
• Viral shedding in respiratory secretions for 5-10
  days

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Influenza Clinical Features

• Incubation period 2-3 days (range 1-7 days)
• Severity of illness depends on prior experience
  with related variants
• Often abrupt onset symptoms

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Knowing your foe..

• Symptoms of influenza include
• Fever
• Cough
• Headache
• Myalgia
• Fatigue and weakness
• Chest discomfort
• Nausea, diarrhea with swine flu

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Knowing your foe..

• Risk factors for complications
• Age 65 years
• Residence of nursing homes and other chronic care
  facilities
• Chronic cardiac or pulmonary disorders
• Chronic conditions such as diabetes
• Long term ASA therapy
• Immunosuppression

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Complications knowing your foe

• Pneumonia
• secondary bacterial
• primary influenza viral
• Reye syndrome
• Myocarditis
• Otitis media incidence up to 30
• Febrile convulsion in children
• Sinusitis and Bronchitis in all patient groups
• Exacerbation of asthma and croup
• Encephalopathy
• ARDS
• Death 0.5-1 per 1,000 cases
• Treatment may decrease the length of the disease
  and the complications

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Diagnosis

• Symptoms of cough and fever has a
• 30 40 predictive power.
• Symptoms with surveillance (flu in community) has
  a 70 - 80 predictive power.

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Influenza Diagnosis by Specialty
of Diagnoses
Physician Specialty
Data from IMS America, National Disease and
Therapeutic Index, Diagnosis, volume 2, 4Q 1997.
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Influenza vs Cold Symptoms

• Signs Symptoms Influenza Cold
• Onset Sudden Gradual
• Fever Characteristic, high (over Rare 101?F)
  lasting 3 to 4 days
• Cough Nonproductive can Hacking become severe
• Headache Prominent Rare
• Myalgia (aches and pains) Usual often
  severe Slight
• Fatigue weakness Can last up to 2 to 3
  weeks Very mild
• Extreme exhaustion Early and prominent Never
• Chest discomfort Common Mild to moderate
• Stuffy nose Sometimes Common
• Sneezing Sometimes Usual
• Sore throat Sometimes Common

Adapted from the National Institute of Allergy
and Infectious Diseases.
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S-OIV Diagnosis

• Clinicians should consider swine influenza
  infection in the DIFF DX of patients with febrile
  respiratory illness and who
• 1) who traveled recently to Mexico or were in
  contact with persons who had febrile respiratory
  illness and were in one of the three U.S.
  counties or Mexico during the 7 days preceding
  their illness onset.
• 2) 85 of current cases have not been linked to
  travel or to another confirmed case MMWR 4/2009
• This information is dynamically changing.

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S-OIV Testing

• Patients with flu like symptoms should be tested
  for influenza.
• The currently available Influenza A tests can be
  used for screening INFLUENZA A () should be
  sent to public health laboratories for further
  characterization. (Microbiology Lab)
• Clinicians who suspect it should
• obtain a nasopharyngeal swab (NPS) (NP wash or
  aspirate could also be done)
• place it in a viral transport medium,
• refrigerate it (2 hs) and
• then contact their state or local health
  department

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S-OIVTesting

• CDC requests that state public health
  laboratories promptly send all influenza A
  specimens that cannot be subtyped to the CDC,
  Influenza Division, Virus Surveillance and
  Diagnostics Branch Laboratory.
• Michigan
• The current recommendation for laboratory testing
  for detection of swine influenza as per the
  Michigan Department of Community Health (MDCH) is
  to perform the influenza rapid antigen test.
• HFH Patients with positive rapid antigen test
  for Influenza A will have their samples forwarded
  to MDCH for confirmatory testing for swine
  influenza.

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S-OIV Testing

• Current data indicates that the rapid antigen
  will test positive for Influenza A in patients
  with swine influenza although the test is not
  100 sensitive.
• Not Culture
• The recommendations are to NOT perform virus
  culture on samples from patients with suspected
  swine influenza.
• The only test to be performed is the influenza
  rapid antigen test.
• The recommended sample for collection is the
  nasopharyngeal swab in viral transport media
  (white capped tube (Starswab).

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Influenza Antigen
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Influenza Rapid Test
White CappedStarswabFlockedNP Swab
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If White Capped Flocked Swab is Not Available

• You can use Blue Capped Starswab media, but dont
  use the hard swab that comes with it.
• Use an orange capped nasopharyngeal swab instead
• Put the orange cap swab into the media from the
  blue capped kit

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Nasopharyngeal Swab
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Influenza Testing

• Point of care testing is not suggested poor
  sensitivity (57-81 for seasonal flu)
• Sensitivity for S-OIV not known
• Biohazard potential, needs BSL2, culture by
  clinical microbiology laboratories should not be
  done

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Management of Influenza
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SWINE FLU TREATMENT

• Sensitive to Oseltamivir (tamiflu) and Zanamivir
  (relenza) can be used for treatment if treatment
  is started early in illness (less than 3 days).
• Resistant to The H1N1 viruses are resistant to
  amantadine and rimantadine but not to oseltamivir
  or zanamivir.
• Flu Vaccine It is not anticipated that the
  current seasonal influenza vaccine will provide
  protection against the swine flu H1N1 viruses.

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SWINE FLU TREATMENT

• Antiviral Treatment for confirmed, suspected, or
  probable cases
• Antiviral treatment may include either Tamiflu
  or Relenza, with no preference given at this
  time.
• Recommendations for use of antivirals may change
  as more data on antiviral susceptibilities become
  available.
• Initiate treatment as soon as possible after the
  onset of symptoms (within 72 hours).
• Tamiflu dose for treatment 75 mg po bid for 5
  days

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SWINE FLU TREATMENT

• Antiviral chemoprophylaxis (pre-exposure or
  post-exposure) can be considered for close
  contacts of a highly confirmed or highly
  suspected case.
• Tamiflu dose for prophylaxis 75 mg po daily for
  10 days after last known exposure
• Oseltamavir and zanamavir are non-formulary
  agents for HFH inpatients. A limited quantity of
  Oseltamavir is available and may be obtained with
  approval by ID staff and completion of a
  non-formulary request form.

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Therapy for Influenza

• The therapy for influenza is generally
  supportive.
• Antivirals have been shown to reduce viral
  shedding by 3 days, and has a 1.3 day reduction
  in the median time to improvement. can be
  considered in individuals with an established
  diagnosis of influenza that are at high risk for
  complications, or with severe disease.
• Antibiotics are not indicated for influenza.

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Antiviral use and misuse

• Public health authorities strongly discourage
  healthcare providers from prescribing and the
  public from requesting antivirals for private
  stockpiling purposes.
• The indiscriminate use of Tamiflu may promote
  
• the development and spread of resistance
• may impact the ability for public health to
  adequately respond to a pandemic
• There are limited supplies of oseltamivir in the
  U.S. and hoarding of this drug becomes a concern
  because it will be unavailable for those who need
  it most.

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Influenza Management

• Most patients with influenza can be managed out
  of the hospital
• Major cause of morbidity and mortality post
  influenza is pneumonia WATCH OUT FOR CA-MRSA

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SWINE FLU

• Henry Ford Hospital Pandemic Flu Plan can be
  found in the HFH Emergency Operations Plan
  policies Appendix H Pandemic Flu Plan
• http//henry.hfhs.org/body.cfm?id41actionlistpo
  licycacheck5baca1412D2ca42D45712Da75b2De1d74
  7b29fcf5FOF5F0nPPP50
• For more information about swine flu
  http//www.cdc.gov/swineflu
•  
• Additional information is also available by
  calling 1-800-CDC-INFO (1-800-232-4636)

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Institutional pandemic flu planning

• Availability of testing, patient care
• Infection control
• Surge planning, facility needs
• Occupational health, staffing levels, prophylaxis
• Availability of supplies, distribution plans
• What to do with visitors, elective procedures
• Antivirals, vaccines
• Communication and education plan, hotlines
• Command structure

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Infection Control

• Febrile Respiratory Illness
• Do you have a new/worse cough, muscle aches or
  shortness of breath? andAre you feeling feverish?

Yes to both questions Initiate Droplet
Precautions and Prompts further questions
No to both questions Initiate Standard
Precautions
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Infection Control for Ambulatory Settings

• For acute respiratory illness, maintain
  respiratory isolation procedures.
• The ill person should wear a surgical mask when
  outside of the patient room, wash hands follow
  respiratory hygiene practices.
• Cohort or place in private room.
• Hand hygiene wash or sanitizer.
• Utensils Water and soap.
• Routine cleaning and disinfection strategies used
  during influenza seasons can be applied to the
  environmental management of swine influenza.

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Infection Control for Hospitalized Patients

• Standard, Airborne and Contact precautions for 7d
  after illness onset or until symptoms have
  resolved.
• Personnel should wear N95s when entering the
  patient room
• Use an airborne infection isolation room with
  negative pressure air handling, if available
  otherwise use a single patient room with the door
  kept closed. If a non-negative pressure room is
  used, one hour for proper air exchange is needed
  before the room can be opened.
• For suctioning, bronchoscopy, or intubation, use
  a procedure room with negative pressure air
  handling.

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S-OIV Decrease the Transmission

• Voluntary Isolation (Non-hospitalized patients)
  7d
• Hand hygiene
• Avoid unnecessary travel to affected areas
• ContagiousnessPersons with swine influenza A
  (H1N1) virus infection should be considered
  potentially contagious for up to 7 days following
  illness onset.
• Persons who continue to be ill longer than 7 days
  after illness onset should be considered
  potentially contagious until symptoms have
  resolved ( in children)

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Infection Control

• Survival of virus outside the human body
• 24-48 hrs on hard nonporous surface
• 8-12 minutes on cloth, paper, tissue.
• 5 minutes on hands
• Virus survives longer with low humidity and
  cooler weather.
• Routine cleaning agents sufficient
• Hand hygiene most important measure for control

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Vaccine Management

• Goal is to provide a safe and effective vaccine
  as soon as possible.
• To allocate, distribute, and administer vaccine
  to identified priority groups.
• Vaccine not likely to be available until closer
  to the second wave

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Questions and Thank You