Pg. 80

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AVIAN FLU
Pg. 80 AVIAN BIRD FLU-DISCUSSION WHAT IS A
VIRUS? 1.) It is considered simply as genetic
material in a protective shell. 2.) This genetic
material may be RNA or DNA depending on the kind
of virus A) RNA (ribonucleic acid)cant locate
and fix mutations a) single strand b) has a
hydroxyl group which makes RNA more susceptible
to hydrolysisunstable B) DNA (deoxyribonucleic
acid)locates and fixes mutations a) double
strand b) no hydroxyl group (has
hydrogen) less susceptible to
hydrolysisstable 3.) The protective coating is
called a capsid
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AVIAN FLU
Pg. 80 AVIAN BIRD FLU-DISCUSSION WHAT IS A
VIRUS? 4.) Some viruses have an additional outer
protective layer called an envelope. This may be
made of sugars, lipids (fats), or proteins.
These materials are acquired from the host cell
where the virus was made. THEIF!!!! 5.) The
surface of the virus is covered
with receptor-binding proteins.
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AVIAN FLU
Pg. 80-81 HOW DO VIRUSES REPRODUCE animation 1.)
All viruses reproduce by taking over the
reproductive mechanism of the host cell. 2.)
Receptor-binding proteins (RPB hemmagglutinin)
are attached to the capsid or envelope. 3.) RPB
stick out of the virion and hook up to
specific receptors on the host cell. 4.) Only
certain RPBs can bind with certain host
cell receptors. 5.) The host cell believes
that the virion is something it needs or
wants.
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AVIAN FLU
Pg. 80-81 HOW DO VIRUSES REPRODUCE animation 6.)
The virus tricks the host cell and it is
then internalized/injects material. 7.)
After internalization the virus sheds its capsid
and/or envelope. 8.) The virus then takes over
the host cells reproduction mechanism. 9.) The
virus (parasite) then builds up large amounts
of offspring which are released into various
systems of the body. 10.) These offspring
repeat the process with other host cells.
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AVIAN FLU
Pg. 81 A LITTLE MORE DETAIL ON VIRUS
REPRODUCTION LETS START TO CONSIDER THE
H5N1 1.) On the outside of a virion there are a
number of nails or spikes sticking
out. 2.) About 80 of these is the viral
protein hemagglutinin a.) This is the same
protein that helps red blood cells stick
together. b.) hemagglutinin is the
receptor-binding protein. c.) This is what
sticks to the host cell. d.) And helps the
virus get into the host cell.
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AVIAN FLU
Pg. 81 A LITTLE MORE DETAIL ON VIRUS
REPRODUCTION LETS START TO CONSIDER THE H5N1 3.)
The other 20 is a viral protein called
neuraminidase. a.) this protein destroys a
molecule in the host cell called neuraminic
acid. b.) It is thought (possibly) that this
protein may help the virus enter the host
cell. c.) It does help the offspring virus
(virions) to get out of the host cell. ADD 4.)
What does the H and N mean in H5N1? a.)H5
stands for the fifth of several known types of
the protein hemagglutinin. b.) N1 stands for
the first of several known types of the
protein neuraminidase
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AVIAN FLU
Pg. 81-82 HOW DOES OUR BODY FIGHT VIRUSES 1.)
The virus produces an antigen (a specific viral
protein). 2.) Your bodys immune system
recognizes these antigens as a threat. 3.) They
produce an antibody that specifically goes
after and attaches to the antigen. 4.) The
antigen and antibody fit together like a
lock and key. This coupling renders the
antigen ineffective stopping further attacking
of host cells and virion production. The
antibody focuses on docking on the
hemaglutinin sites.
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AVIAN FLU
Pg. 81-82 HOW DOES OUR BODY FIGHT VIRUSES 5.)
Now that your body has antibodies for that
antigen you will not ever get that same strain
of flu. BUT 6.) You are still susceptible to
other strains because they result in different
antigens for which you have no antibodies. Yet.
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AVIAN FLU
Pg. 82 WHERE DO THESE NEW STRAINS COME
FROM? There are two basic methods for the
development of new flu virus strains. 1.)
Antigenic DRIFT a.) This is basically molecular
evolution. b.) Genetic material (DNA and RNA)
have small mutations or errors. RNA tends to
have more errors or mistakes. c.) This means
that RNA viruses evolve faster than DNA viruses
AND human DNA. d.) If these changes are
beneficial to the survival of the virus the
virus will persist and may later change into
another strain.
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AVIAN FLU
Pg. 82 1.) Antigenic DRIFT continued e.) The
antigen for this new strain is of a different
shape and does not fit the antibodies from
the old strain. You can now get sick from
it. f.) This mode of change is responsible for
many local and regional outbreaks of influenza
B. g.) Problem? There is no antiviral
medication for these new strains until they
happen
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AVIAN FLU
WHERE DO THESE NEW STRAINS COME FROM? There are
two basic methods for the development of new flu
virus strains. Pg. 82-83 2.) Antigenic
SHIFT a.) This is the one we are most worried
about. b.) Happens because of gene sharing that
occurs in influenza A types not B and C. c.)
Occurs when two type A influenza strains infect a
host cell simultaneously. d.) The offspring
virions can then have genetic material from
BOTH parent viruses.
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AVIAN FLU
Pg. 82-83 2.) Antigenic SHIFT e.) For example
1.) H3N5 and H2N4 infect a host cell. 2.) You
may get H3N5 and H2N4 offspring, but also 3.)
because of recombining you may get H3N4 and/or
H2N5 4.) This occurs very rapidly. HOW CHANGE
ANTIBODY ANTIGEN RELATIONSHIP?
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AVIAN FLU
Pg. 82-83 2.) Antigenic SHIFT f.) So even though
the bird flu cannot go from person to person
easily (yet) the idea is that with
each infection (and antigenic SHIFT) there is a
greater risk of the recombination occurring that
would allow it to be transmitted person to
person very easily. g.) The problem is that
there is no medication until it happens. Talk
about NOT being proactive. You cant.
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AVIAN FLU
Pg. 84 PANDEMIC vs. SEASONAL OUTBREAKS(EPIDEMICS)
PANDEMIC pandemic outbreaks are caused by
three possible conditions 1.) new
subtypes 2.) subtypes that have never
circulated among people 3.) subtypes that
have not circulated among people for a long
time. Usually spread to numerous
continents. SEASONAL OUTBREAKS Seasonal
outbreaks are caused by subtypes of influenza
viruses that already circulate among people
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AVIAN FLU
Pg.87 CONSIDER PAST PANDEMICS During the 20th
century, the emergence of several new influenza
A virus subtypes caused three pandemics, all of
which spread around the world within a year of
being detected.
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AVIAN FLU
Pg.87 1.) 1918-19, "Spanish flu," A
(H1N1) a.) caused the highest number of known
influenza deaths. b.) More than 500,000
people died in the United States c.) up to 50
million people may have died worldwide. d.)
Many people died within the first few
days after infection, and others died of
secondary complications. e.) Nearly half of
those who died were young, healthy adults.
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AVIAN FLU
Pg. 87 2.) 1957-58, "Asian flu," A (H2N2). a.)
caused about 70,000 deaths in the United
States. b.) First identified in China in
late February 1957, the Asian flu spread to
the United States by June 1957.
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AVIAN FLU
3.) 1968-69, " Hong Kong flu," A (H3N2). a.)
caused about 34,000 deaths in the United
States b.) This virus was first detected in
Hong Kong in early 1968 and spread to the
United States later that year.
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AVIAN FLU
Pg. 87 Both the 1957-58 and 1968-69 pandemics
were caused by viruses containing a combination
of genes from a human influenza virus and an
avian influenza virus. Remember Antigenic
SHIFT???? The 1918-19 pandemic virus appears
to have an avian origin. Possibly from Antigenic
DRIFT????
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AVIAN FLU
Pg. 88 STAGES OF A PANDEMIC INTERPANDEMIC
PERIOD Phase 1 No new influenza virus subtypes
have been detected in humans. May be present in
animals. Phase 2 No new influenza virus
subtypes have been detected in humans. However,
there is a circulating subtype that poses a
substantial risk of human disease.
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AVIAN FLU
Pg. 8 PANDEMIC ALERT PERIOD Phase 3 Human
infection(s) with a new subtype, but no
human-to-human spread, or at most rare
instances of spread to a close contact. Phase
4 Small cluster(s) with limited human-to-human
transmission but spread is highly localized,
suggesting that the virus is not well adapted to
humans. Phase 5 Larger cluster(s) but
human-to-human spread still localized, suggesting
that the virus is becoming increasingly better
adapted to humans but may not yet be fully
transmissible (substantial pandemic risk).
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AVIAN FLU
Pg. 88 PANDEMIC PERIOD Phase 6 Pandemic
increased and sustained transmission in general
population.
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AVIAN FLU
Pg. 89 PANDEMIC PREDICTIONS 1.) Many scientists
believe it is only a matter of time until the
next influenza pandemic occurs. 2.) The
severity of the next pandemic cannot be
exactly predicted, but a.) modeling studies
suggest that the impact of a pandemic on the
United States could be substantial.
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AVIAN FLU
Pg. 89 PANDEMIC PREDICTIONS (continued) b.)
without any control measures (vaccination or
drugs), it has been estimated that in the
United States a mediumlevel pandemic could
cause. 1.) 89,000 to 207,000 deaths. 2.)
314,000 and 734,000 hospitalizations. 3.) 18 to
42 million outpatient visits. 4.) and another
20 to 47 million people being sick. 5.) Between
15 and 35 of the U.S. population could be
affected by an influenza pandemic. 6.) The
economic impact could range between 71.3 and
166.5 BILLION.
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AVIAN FLU
Pg. 90 HOW IS A PANDEMIC DIFFERENT FROM
OTHER NATURAL DISASTERS INFLUENZA PANDEMICS ARE
DIFFERENT from many of the natural disaster
threats for which public health and health-care
systems are currently planning 1.) A
pandemic will last much longer than most
public health emergencies a.) May include
waves of influenza activity separated by
months (occurred with other 20th century
pandemics). b.) In the past a second wave of
influenza activity occurred 3 to 12 months
after the first wave.
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AVIAN FLU
Pg. 90 HOW IS A PANDEMIC DIFFERENT FROM
OTHER NATURAL DISASTERS (continued) 2.) The
numbers of health-care workers and
first responders available to work can be
expected to be reduced more profoundly than
other natural disasters. a.) They will be
at high risk of illness through exposure in
the community and in health-care
settings. b.) Some may have to miss work to
care for ill family members. 3.) Resources
in many locations could be limited, depending
on the severity and spread of an influenza
pandemic. Socioeconomic class issues?
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AVIAN FLU
Pg. 91 WHY SO MUCH CONCERN ABOUT H5N1? 1.) H5N1
mutates rapidly 2.) Has a documented propensity
to acquire genes from viruses infecting other
animal species. Hence, the bird flu affects
us. 3.) Its ability to cause severe disease in
humans has now been documented on two occasions.
4.) Laboratory studies have demonstrated that
isolates from this virus have a high
pathogenicity(nastiness) with potential to cause
severe disease in humans. 5.) Birds that
survive infection excrete virus for at least 10
days, orally and in feces. Facilitates
further spread. Transmission.
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AVIAN FLU
Pg. 94-95 INTERNATIONAL EFFORTS World Health
Oraganization (WHO) ANTIVIRAL DRUGS their role
during a pandemic 1.) Following a donation by
industry, BIG ASSUMPTION WHO will have a
dedicated stockpile of antiviral drugs
(oseltamivir), sufficient for 3
million treatment courses, by early 2006. 2.)
These drugs are strictly reserved for use in the
first areas affected by an emerging pandemic
virus. 3.) Mathematic modeling suggest these
drugs could be used in a prophylactic way in the
early onset of pandemic outbreak.
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AVIAN FLU
Pg. 94-95 INTERNATIONAL EFFORTS World Health
Oraganization (WHO) 4.) This would allow for two
things a.) reduce risk of mutation because
number of transmissions is decreased. b.) gain
time to augment vaccine supplies (development
and delivery) 5.) The drugs will be stored
centrally WHO has considerable experience in
the rapid dispatch of medical supplies during
emergencies.
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AVIAN FLU
Pg. 94-95 INTERNATIONAL EFFORTS World Health
Oraganization (WHO) 6.) This strategy has never
been tested. AND it depends on several
assumptions a.) The behavior of the pandemic
virus in the early stages, which cannot be
fully known. b.) Excellent surveillance to
detect clusters of cases closely related in
time and space. This needs to improve. c.)
Excellent logistic capacity in initially
affected areas. This needs to improve.
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AVIAN FLU
Pg. 94-95 INTERNATIONAL EFFORTS World Health
Oraganization (WHO) 7.) Countries must decide
who will get the drug. Who do you think? 8.)
Mass deployment not advisable as it may
contribute to resistance. We cant anyways. 9.)
At present manufacturing capacity, which
has recently quadrupled, it will take a decade
to produce enough oseltamivir to treat 20 of
the worlds population.
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AVIAN FLU
Pg. 95-96 NON-PHARMACEUTICAL INTERVENTIONS (reduci
ng transmission and spread) FACT at the start
of a pandemic the world will have inadequate
supplies of antiviral drugs. 1.) The
effectiveness of several measures will depend on
the characteristics of the pandemic
virus (attack rate, virulence, principal age
groups affected, modes of spread within and
between countries), and these cannot be known in
advance. 2.) Evaluation of these measures has
been based on limited experience/data during
past pandemics and on what is known about the
behavior of normal influenza viruses.
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AVIAN FLU
Pg. 95-96 NON-PHARMACEUTICAL INTERVENTIONS (reduci
ng transmission and spread) 3.) After a pandemic
is declared, WHO will monitor its evolution in
real time. Problems ???? 4.) Recommendations
about the most effective measures will therefore
become more precise as the epidemiological
potential of the virus unfolds. For all these
reasons, the recommendations below should be
taken as general guidance, and not as formal WHO
advice. Recommended measures are specific to
the phase of alert in the WHO six-phase scale.
BUT WILL CHANGE ON THE FLY
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AVIAN FLU
SO WHERE ARE WE AT??? CURRENT DISTRIBUTION OF
AVIAN FLU CASES CONFIRMED CASES RECORDED BY
WORLD HEALTH ORGANIZATION (WHO) WHAT DO YOU
THINK? DEFEND YOUR POSITION. AGREE DISAGREE STRONG
LY DISAGREE STRONGLY AGREE There is great cause
for concern that world populations will be
heavily impacted by an H5N1 pandemic
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AVIAN FLU

• QUIZ
• 1.) What best describes how WHO and other
  agencies will
• have to deal with developing problems regarding
• a pandemic?
• Figure it out ahead of time using models
• b) Have it figured prior to outbreak using info.
  from past
• pandemics
• c) Have no clue
• d) Deal with new problems on the fly

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AVIAN FLU

• QUIZ
• 2.) Regarding adequate drug supplies what best
  describes
• the BIG ASSUMPTION?
• Industry will donate adequate drug supplies
• b) People will respond poorly to drugs
• c) Drugs may cause allergic reactions
• d) Drug supplies will be insufficient
• 3.) What is the main concern with mass deployment
  of
• drugs and the reason drugs will be used in areas
  of
• initial outbreak??
• People will react poorly to drugs
• b) Drug supplies will be insufficient
• c) May cause resistance in influenza virus
• d) Difficulty in distribution

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AVIAN FLU

• QUIZ
• 4.) What is true concerning current drug
  production?
• There are adequate drug supplies
• b) At current capacity it will take about a year
  to supply
• world population
• c) At current capacity it will take about a year
  to supply
• 20 of world population
• d) At current capacity it will take about a
  decade to
• supply 20 of world population

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AVIAN FLU

• QUIZ
• 5.) Why do RNA virions mutate faster than DNA
  virions?
• RNA produces less mistakes
• b) RNA produces more mistakes
• c) There are more RNA virions
• d) There are less DNA virions
• 6.) What best describes antigenic shift?
• The mixing of the genetic material from two
• virions-fast mutation
• b) The slow mutation of genetic material within a
• single virion
• c) The fast mutation of genetic material within a
• single virion
• d) The mixing of the genetic material from two
• virions- slow mutation

39
AVIAN FLU

• QUIZ
• 7.) Why are we most concerned about the H5N1
  strain?
• Mutates slowly
• b) Acquires genes from viruses only in humans
• c) Surviving birds can excrete virus for 10 days
• d) We think it will hit isolated populations hard
• 8.) What is different about pandemics compared to
  other
• natural disasters?
• May last longer, come and go in waves
• b) Will hit isolated populations hard
• c) Will have large effects for short period of
  time
• d) Mitigation is a more straight forward

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AVIAN FLU
QUIZ 9.) What phase are we in currently for the
H5N1 strain? a) Phase 1 b) Phase 2 c) Phase 3 d)
Phase 4 e) Phase 5
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AVIAN FLU
10.) What best describes the current situation
with H5N1? a) Human infection(s) with a new
subtype, but no human-to-human spread, or at
most rare instances of spread to a close
contact b) Larger cluster(s) but human-to-human
spread still localized, suggesting that the
virus is becoming increasingly better adapted to
humans but may not yet be fully transmissible
(substantial pandemic risk). c) increased and
sustained transmission in general population.
d) No new influenza virus subtypes have been
detected in humans. However, there is a
circulating subtype that poses a substantial
risk of human disease.
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AVIAN FLU

• QUIZ
• 11.) What are the little spikes on a virion that
  allow it to
• hook up to receptors on the host cell?
• Hemaglutinin
• b) Neuraminidase
• c) Capsid
• d) Envelope

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AVIAN FLU
QUIZ 12.) On the figure below what does A, B, C,
D represent? Consider this a model for H5N1.
C
A
virion
D
B
antibody