Geoscience Reference
In-Depth Information
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Support for the efforts of governments of other countries and international
organizations to contain [virus] strains and control their evolution to diseases
that are transmitted easily from person to person.
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Building stockpiles of vaccines, improving antiviral drugs, and putting in
place new technologies that allow effective vaccines to be produced more
rapidly and in large quantities.
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Improving the capacity of the health system to care for many people in all
parts of the country who are sick simultaneously.
Plans at other levels (states, regions, localities, and individual organizations and
entities) have parallel goals appropriate for their own needs, but the last objective
typically is the driving goal for planners.
Pandemics at Hand—Pandemic Influenzas: Avian and Swine
A pandemic of great recent concern is
avian flu,
. This flu infects birds, such as
domestic poultry (e.g., chickens) and wild fowl (e.g., ducks). “Avian flu ... is caused
by influenza viruses that occur naturally among wild birds. Low pathogenic [avian
flu] is common in birds and causes few problems [to humans]. Highly pathogenic
H5N1 is deadly to domestic fowl, can be transmitted from birds to humans, and
is deadly to humans. There is virtually no human immunity, and human vaccine
availability is very limited
.
”
23
In fact, “viruses of the H5 subtype are not known
to have ever circulated among the human population, which means that there
would be little immunity to it.”
19
Therefore, it is this highly pathogenic version of
avian flu that is a risk to communities and has the potential for pandemic impact.
Similarly,
swine flu,
is caused by influenza viruses that occur in swine. However,
although the immunity and human vaccine availability is like that of avian flu, the
2009 and 2010 Swine Flu pandemic appeared to be a variant that was a mutation
(or “reassortment”) of avian flu, swine flu, and human flu.*
*
The resultant virus
appeared to be transmitted with some efficiency from human to human, leading
the WHO to raise the pandemic alert phase to 5 in April 2009. This phase carried
with it the fact that the virus was “characterized by human-to-human spread ...
into at least two countries in one WHO region. Although most countries [would]
not be affected at this stage, the declaration of Phase 5 [was] a strong signal that a
pandemic [was] imminent and that the time to finalize the organization, commu-
nication, and implementation of the planned mitigation measures [was] short.”
24
A
*
“According to virologists at the U.S. Centers for Disease Control and Prevention (CDC), the
influenza A subtype H1N1 isolated from ... patients in April [2009] was a genetic reassort-
ment of four different influenza virus strains, including human influenza gene segments, swine
influenza from North America and Eurasia, and avian gene segments from North America,
never before reported among swine or human isolates from anywhere in the world.” Food
and Agricultural Organization [FAO] (2009). “The human influenza due to a novel subtype
H1N1.” www.fao.org/ag/againfo/programmes/en/empres/AH1N1/Background.html.
