Novel Influenza H1N1 Virus Swine Flu

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Novel Influenza (H1N1) Virus (Swine Flu)
COA Meeting June 2, 2009 Jennifer L. Cleveland,
DDS, MPH Division of Oral Health Centers for
Disease Control and Prevention JLCleveland_at_cdc.gov
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Pandemic Influenza

• Caused by Influenza A viruses
• Results from change in viral structure
• Acquires a new H or HN
• Characterized by virus that spreads easily and
  has high morbidity

Haemophilus influenzae using gram-stain
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Flu Pandemics in the 20th Century

• 1918-19 Spanish Flu A(H1N1)
• gt500,000 deaths in U.S.
• 50 million deaths worldwide
• 1957-58 Asian Flu A(H2N2)
• 70,000 deaths in U.S.
• 1968-69 Hong Kong flu A(H3N2)
• 34,000 deaths in U.S.

Negative stain of influenza A
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Why Is H1N1 Infection Of Concern?

• Lack of pre-existing immunity
• No vaccine available at this time
• As a result, illness may be more severe and
  widespread
• Patients who require hospitalization are much
  younger than most patients with seasonal flu
• (avg age 27 years as of 5/20/09)
• Could mutate again before next flu season
• 25 with diarrhea and vomiting could introduce a
  new route for transmission

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H1N1 Influenza Virus
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What Is Influenza H1N1 (Swine Flu)?
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Transmission

• Transmission occurs with close contact
• Direct Contact - exposure of mucous membranes to
  large droplets (50 100 µm) - requires close
  contact (lt6 ft)
• Indirect Contact exposure of mucous membranes
  to hands that have touched contaminated surfaces
• Short range exposures to aerosols exposure to
  small-particle aerosols (lt5 µm) in immediate area
  of infected persons

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Direct Contact Transmission from Pigs to
Humans (or vice versa)
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H1N1 Flu

• Incubation period is unknown and could range from
  1-7 days, more likely 1-4 days.
• Persons should be considered potentially
  contagious for seven (7) days from symptom onset
  or until the resolution of symptoms, whichever is
  longer.

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Fever, chills, headache
Cough
Sore throat
Runny nose
Fatigue
Vomiting, diarrhea
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Suspected Case of H1N1 Flu

• Patient resides in a community where H1N1
  transmission is occurring AND has febrile
  respiratory illness and stuffy nose, sore throat
  or cough
• Patient resides in a community where H1N1
  transmission is NOT occurring, has febrile
  respiratory illness AND
• close contact with a person who is a confirmed,
  probable, or suspected case of H1N1 flu within
  the past 7 days OR
• travel to a community either within the US or
  internationally where there are one or more
  confirmed novel H1N1 cases within 7 days

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Fundamentals of Infection Control Hierarchy of
Infection Control
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Fundamentals of Infection ControlHierarchy of
Infection Control

• Administrative controls reduce risk of exposure
  via effective IC program
• Environmental controls prevent spread and reduce
  concentration of droplet nuclei
• Respiratory protection controls further reduce
  risk of exposure in special areas and
  circumstances

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Administrative Controls for H1N1 Flu

• Identify patients flu-like symptoms
• Defer elective treatment until patient is no
  longer infectious
• Refer for medical treatment and follow-up (TB)
• Advise patients to contact their HCP to report
  illness (by phone or other remote means) before
  seeking care

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Respiratory Hygiene/Cough Etiquette
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• Make available
• Surgical face masks,
• Facial tissue,
• Receptacles for tissues, and
• Hand sanitizer in all waiting areas.

• http//www.cdc.gov/flu/images/CoverCgh-hcp-view.gi
  f

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www.smartpractice.com
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Masks and Respiratory Protection (RP)

• Surgical mask
• Used to protect the wearer and patient against
  exposure to contaminated droplets in sprays and
  spatter FDA cleared
• N95 respirator
• NIOSH certified Used to protect the wearer
  against exposure to small particle aerosols (lt5
  microns)
• Surgical N95 respirator
• NIOSH certified and FDA cleared used to protect
  wearer from droplets and aerosols
• Filtering N95 respirators for use by public
• NOT for occupational use in health-care settings

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Emergency Dental Care for Patients With Confirmed
or Suspected H1N1 Flu

• Provide the patient with a surgical mask
• Place them in a room with the door closed
• Wear surgical mask, non-sterile gloves,
  protective eyewear, and gown when evaluating
  patient for dental treatment options
• If urgent dental treatment is required, wear an
  N95 respirator in place of surgical mask
• For non-aerosol generating procedures (e.g.,
  tooth extractions, ID) an Airborne Infection
  Isolation (AII, negative pressure) room is not
  necessary

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AII Airborne Infection Isolation (negative
pressure) room
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Cleaning/Disinfection of Environmental Surfaces

• Can survive 2-8 hours on environmental surfaces
• Is one of the least resistant microorganisms to
  chemical disinfectants
• Can be inactivated by hospital grade, low-level
  disinfectant

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Relative Resistance of Microorganisms to
Chemical Germicides
Bacterial Spores?Mycobacteria?Non-lipid or
small viruses?Fungi?Vegetative
bacteria?Lipid or medium-sized
viruses(influenza viruses)
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Summary

• H1N1 flu is a novel influenza virus against which
  there is no pre-existing immunity or vaccine.
• At this time, H1N1 flu does not appear to be more
  severe than seasonal flu.
• However, infection control precautions will
  remain conservative until more information is
  available. These precautions include standard,
  contact, droplet, and airborne.

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We All Know Who He Got It From