Swine Flu and You

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Swine Flu and You

• Don Skillman, M.D.
• Infectious Diseases / Internal Medicine
• St Peters Hospital

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Swine Flu

• Where does the name come from?
• Where is it spreading?
• How bad is it?
• Is there a treatment or vaccine?
• Whats the situation in Helena?

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Its scaring people all over the world.
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Swine Flu

• Theyve changed the name of it
• Swine-origin Influenza A (H1N1) Virus
• S-OIV

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Swine Flu

• A respiratory disease of pigs, caused by type A
  influenza viruses.
• They cause regular outbreaks in pigs.
• People do not normally get swine flu, but human
  infections can happen.
• Swine flu viruses can spread from
  person-to-person.
• In the past, this transmission was limited and
  not sustained beyond three people.

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Swine Flu in the USA

• 1976
• A swine flu outbreak in Fort Dix, New Jersey
• More than 200 cases.
• Serious illness in several people and one death.
• September 1988
• A previously healthy 32-year-old pregnant woman
  in Wisconsin got infected and died 8 days later.
• 2005 to January 2009
• 12 human cases of swine flu were detected.
• No deaths.

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Influenza ABCs

• There are three types of Influenza viruses,
  Influenza A, B, and C .
• Influenza C Causes mild disease in humans and is
  not associated with epidemics.
• Influenza B Causes disease in humans, but it is
  usually mild. It occurs during annual epidemics,
  but has not been associated with pandemics.
• Influenza A is associated with annual epidemics
  and with prior pandemics.
• Bird Flu and Swine Flu are influenza A
  viruses.

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Influenza Hs and Ns

• These are two surface proteins
• They affect viral spread.
• H Hemagglutinin it helps the virus get into
  cells.
• 16 different H proteins have been identified.
• N Neuraminidase it facilitates the release of
  new viral particles from the infected cells.
• 9 different N proteins have been identified.
• Circulating strains are identified by the H and N
  proteins present, for example H1N1 or H2N3.

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An example of an Influenza A virus and its
official name.
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Swine Flu (H1N1)

• Influenza A viruses
• 16 different HAs
• 9 distinct NAs

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Hemagglutinin has 4 major variable regions. They
are involved in what animal species the influenza
A virus can infect.
Humans Swine Horses Birds Mink Ferrets Marine
animals Whales
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How do virus types get mixed together?

• Large swine breeding farms.
• Large chicken ranches.
• Families with pigs or chickens/ducks/geese.
• Close relationships between animals and humans.

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Influenza A

• Only a few of the 16 HA and 9 NA types can
  usually infect Humans.
• Only affected by subtypes with H1, H2, H3 and N1,
  N2.
• And possibly N8
• In late 1997 a new strain of influenza A crossed
  from chickens into humans, H5N1.

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Antigenic Drift

• Changes in H and N proteins occur continuously.
• These small changes make you susceptible to the
  new virus thats circulating each year.
• Called Seasonal Influenza
• Thats why you need a new influenza vaccine each
  year, to protect you from the new circulating
  strain.

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Antigenic Shift

• This is a larger change in the H and N surface
  proteins.
• When Antigenic Shift occurs, there may be little
  or no protection from prior infections.
• For example, infection with H1N1 virus confers
  little resistance to infection with an H3N2
  virus.
• These larger changes, or shifts, may result in
  influenza pandemics, infecting much larger
  numbers of people than the annual epidemics.

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Pandemic Influenza

• 1918 - Spanish Flu, H1N1
• 1957 - Asian Flu, H2N2
• 1968 - Hong Kong Flu, H3N2
• 1977 Russian Flu
• An H1N1 influenza strain that had not been seen
  since 1957 re-emerged.
• Older people were less frequently affected by it.
• They had been exposed to H1N1 before.
• Younger people who had not been previously
  exposed to the H1N1 strain were more frequently
  infected.

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Influenza Pandemics

• Pandemic means that a virus is circulating
  widely.
• Its about geography, not death tolls.
• Calling it a pandemic it doesnt automatically
  mean that it will be like the flu pandemic of
  1918, which killed 20 to 50 million people
  worldwide.

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Influenza Pandemics

• Worldwide, the Asian flu pandemic of 1957 killed
  about 2 million.
• The Hong Kong flu of 1968 killed about 1 million.
• Ordinary flu kills about 250,000 to 500,000
  people each year.
• Within the United States, the 1968 flu pandemic
  killed about 34,000 people.
• This is about how many die from seasonal
  influenza every year in the USA.

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Pandemic Influenza Phases
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Pandemic Influenza Phases

• Phase 5
• Most countries will not be affected at this
  stage.
• Phase 5 is a strong signal that a pandemic is
  imminent.
• The time to finalize the organization,
  communication, and implementation of the planned
  mitigation measures is short.

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Swine Flu - Where is it Now?
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11 Oclock, Eastern Daylight Time 6 May 2009
Swine Flu Confirmed in 41 states 642 total
cases 2 deaths
12 other states had 1 or 2 cases. Montana has had
none.
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Global Cases of Swine Flu

• 6 May 2009 23 countries with 1,893 cases.
• Mexico has reported 942 cases, including 29
  deaths.
• Austria (1) Canada (165) Hong Kong (1) Colombia
  (1) Costa Rica (1) Denmark (1)
• El Salvador (2) France (5) Germany (9) Guatemala
  (1) Ireland (1) Israel (4)
• Italy (5) Netherlands (1) New Zealand (5)
  Portugal (1) South Korea (2) Spain (73)
• Sweden (1) Switzerland (1) United Kingdom (28)
• WHO is not recommending travel restrictions.

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Swine Flu - How Bad Is It?
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Swine Flu - How bad is it?

• Each year, ordinary influenza kills about
  36,000 Americans.
• Swine flu has killed 2.
• A Mexican man who came to Texas for treatment.
• A Texan woman, pregnant, with underlying chronic
  diseases.

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Uncomplicated Swine Flu

• Fever
• Headache
• Upper respiratory tract symptoms
• cough, sore throat, runny nose
• Sore muscles
• Fatigue
• Vomiting, or diarrhea.

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Mild Influenza Sounds a Lot like the Common Cold!
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Influenza vs. the Common Cold
Influenza
Common Cold
Onset Fever Sore Muscles Fatigue Sore
Throat Headache Sneezing Stuffy Nose Cough
Nasal Discharge
Abrupt Virtually always, 101oF often Common,
often severe Severe, near exhaustion Sometimes Pro
minent Sometimes Sometimes Dry, nonproductive,
may be severe Clear, modest amounts
Gradual Practically never Mild, or
nonexistent Mild Common Rare Usually Usually
Hacking, possibly productive Clear or
green/yellow, possibly lots
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Complicated Swine Flu

• With previous variants of swine flu viruses,
  clinical syndromes have ranged from mild
  respiratory illness, to lower respiratory tract
  illness, dehydration, or pneumonia.
• Deaths caused by previous variants of swine
  influenza viruses have occasionally occurred.

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Complicated Swine FluExpect complications to be
similar to seasonal influenza.

• Worsening of underlying chronic medical
  conditions
• Upper respiratory tract disease
• sinusitis, otitis media, croup
• Lower respiratory tract disease
• pneumonia, bronchiolitis, status asthmaticus
• Cardiac
• myocarditis, pericarditis

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Complicated Swine FluExpect complications to be
similar to seasonal influenza

• Musculoskeletal
• myositis, rhabdomyolysis
• Neurologic
• acute and post-infectious encephalopathy,
  encephalitis, febrile seizures, status
  epilepticus
• Toxic shock syndrome
• Secondary bacterial pneumonia with or without
  sepsis.

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Groups at higher risk for seasonal influenza
complications.

• Children less than 5 years old
• Persons aged 65 years or older
• Children and adolescents (less than 18 years) who
  are receiving long-term aspirin therapy and who
  might be at risk for experiencing Reyes syndrome
  after influenza virus infection
• Pregnant women
• Adults and children who have chronic pulmonary,
  cardiovascular, hepatic, hematological,
  neurologic, neuromuscular, or metabolic
  disorders
• Adults and children who have immunosuppression
  (including immunosuppression caused by
  medications or by HIV)
• Residents of nursing homes and other chronic-care
  facilities.

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Swine Flu Hopeful Signs

• It appears to lack the traits that made previous
  flu viruses so deadly.
• Cases in the USA dont appear to be more severe
  than ordinary flu.
• Most people older than 55 have already faced a
  similar kind of flu virus, so their immune
  systems may already be primed to resist severe
  disease.
• The outbreak in Mexico, which began earlier than
  in the United States, appears to be waning.

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Swine Flu Testing in Montana

• About 400 samples were sent in from around the
  state in the past week.
• 20 were positive for influenza A.
• None, so far, have been Swine Flu
• This tells us that seasonal influenza is still
  active in Montana.

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Swine Flu - Is there a treatment or vaccine?
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Swine Flu Who Needs Treatment?

• Everyone with suspected swine flu doesnt need to
  be seen by a health care provider.
• Patients with severe illness, and those at high
  risk for complications from influenza should
  contact their medical provider or seek medical
  care.

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Groups at higher risk for seasonal influenza
complications.

• Children less than 5 years old
• Persons aged 65 years or older
• Children and adolescents (less than 18 years) who
  are receiving long-term aspirin therapy and who
  might be at risk for experiencing Reyes syndrome
  after influenza virus infection
• Pregnant women
• Adults and children who have chronic pulmonary,
  cardiovascular, hepatic, hematological,
  neurologic, neuromuscular, or metabolic
  disorders
• Adults and children who have immunosuppression
  (including immunosuppression caused by
  medications or by HIV)
• Residents of nursing homes and other chronic-care
  facilities.

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Swine Flu Treatment?

• This swine flu virus is susceptible to
  oseltamivir and zanamivir.
• Tamiflu and Relenza

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Treatment of influenza does no good if started
more than 48 hours after onset of
symptoms.Dont waste the drug or the expense!!!

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Therapy

• More than a quarter-million prescriptions for
  Tamiflu pills were filled at retail U.S
  pharmacies in the week ending May 1st.
• That's 34 times higher than the week before as
  the regular influenza season wound down and
  more than double the peak of last winter's flu
  season.

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Infectious Period

• The duration of shedding with this virus is
  unknown.
• The estimated duration of viral shedding is based
  upon seasonal influenza virus.
• Infected persons are assumed to be shedding virus
  from one day prior to illness onset until
  resolution of symptoms.

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Infectious Period

• In general, persons should be considered
  potentially infectious from one day before to 7
  days following illness onset.
• Children, especially younger children, might be
  infectious for up to 10 days.

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Swine Flu - Vaccine

• Work is already under way.
• Making a completely new influenza vaccine can
  take five to six months.
• The seasonal vaccines will confer little or no
  protection against this swine flu virus.

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Vaccine Availability?

• A conservative estimate of global capacity for
  flu vaccine production is at least 1 to 2 billion
  doses per year.
• The current annual demand for seasonal influenza
  vaccine, globally, is for less than 500 million
  doses per year.

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Prevention / Avoidance of the Flu

• Cover your nose and mouth with a tissue when you
  cough or sneeze. Throw the tissue in the trash
  after you use it.
• Wash your hands often with soap and water,
  especially after you cough or sneeze.
  Alcohol-based hand cleaners are also effective.
• Avoid touching your eyes, nose or mouth.
• Try to avoid close contact with sick people.
• If you get sick with influenza, stay home from
  work or school and limit contact with others to
  keep from infecting them.

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Human Influenza Transmission

• Influenza viruses are spread from person to
  person through respiratory droplets.
• The virus infects through the nose and throat,
  and is expelled by coughing and sneezing.
• Droplets are believed to fall to the ground
  within 3 ft from an infected person. More distant
  spread is unlikely.

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If you are doing this STAY HOME !!
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Helena girls wearing flu masks, winter of
1918-19.
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Dont become too relaxed. Seasonal influenza is
still with us, and it will be back again. Stay
informed about changes in the swine flu
situation. Swine flu or not, wash your hands and
cover your cough! Fever, cough and being really
sick is a reason to stay home and call your
doctor.
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Lets go back in time..
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Back to El Paso, Texas, 1918

• A dominant railroad center.
• Population 75,000 people
• Ft. Bliss is a large military post.
• Commander John J. Pershing
• Soldiers returning from Europe, WWI

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Influenza - October 3, 1918

• The mayor of El Paso closed all schools,
  churches, theaters and other public places.
• Even funerals cannot be held in churches.
• An ordnance is passed making it mandatory to wear
  a face mask in public.
• Ft Bliss soldiers are ordered to not leave the
  base, and are subject to arrest if they do.

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Influenza - Oct 15, 1918

• Ft Bliss reports 1,309 cases of influenza.
• The Ft Bliss commander volunteers the services of
  his medical officers to help the city with the
  epidemic.
• 37 people in El Paso died of the flu on Oct 15th
• 22 sick people were found in one house.

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Influenza - Oct 16, 1918

• City officials convert all 28 rooms of a local
  school into an emergency hospital for influenza
  patients.
• Volunteers from all over the city donate food,
  blankets, and clothing.
• Others use their private vehicles as ambulances
• Oct 17th 102 people died from the flu in the
  previous week.
• Oct 23rd 142 people died from the flu in the
  previous week.

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Influenza El Paso, 1918

• No new businesses may be opened.
• Public gathering places of any kind may not
  permit more than 25 people (other than employees)
  to congregate on one floor.
• Nov 9th The prohibition on public gathering is
  lifted, and Ft Bliss lifts its quarantine.
• El Paso recorded 600 fatalities from the flu.

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Influenza - 1918

• The United States recorded 500,000 deaths.
• Europe noted 2 million deaths.
• In Asia 16 million died, with about 5 million
  just in India.
• From September 1918 till January 1919 influenza
  killed 20 40 million people worldwide
• A period of just 17 weeks.
• Young, healthy adults were especially afflicted.

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How many people is 40 million?
Thats every single person in

• Alaska
• Arkansas
• Delaware
• Washington DC
• Hawaii
• Idaho
• Iowa
• Kansas
• Kentucky

• Louisiana
• Maine
• Nebraska
• Nevada
• New Mexico
• North Dakota
• Oregon
• South Dakota
• Utah
• Vermont
• West Virginia
• Wyoming

They all died in a 17-week span. Seventeen weeks
ago it was Jan 7.
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1918 Pandemic Influenza

• Researchers have reconstructed its DNA.
• From preserved pathologic samples.
• From the bodies of victims who were buried in
  permafrost in the arctic.
• The 1918 virus was probably of avian origin.
• It bears many genetic similarities to the H5N1
  virus infecting humans in small numbers now.