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CLIMATE CHANGE AND
PANDEMIC INFLUENZA:
THRESHOLDS AND
ADAPTATION
Kirsty Duncan PhD FSAScot
Health Studies, University of Toronto at
Scarborough ©
H5N1 IN HUMANS:
SYMPTOMS
• fever
• abdominal pain, bleeding from the gums
and nose, chest pain, diarrhoea, vomiting
• pneumonia
• multi-organ dysfunction
H5N1 IN HUMANS:
TREATMENT
• some anti-viral drugs (e.g. Tamiflu)
-improve chance of survival
• older antivirals
• antibiotics
• the disease currently kills over 60% of its
victims [357 cases, 225 deaths (31/01/08)]
H5N1: THE CONCERN
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•
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•
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is affecting new animal hosts
is increasing its geographic range
is highly pathogenic
is mutating rapidly
several instances of limited human-to-human
transmission have occurred
• causes severe disease in humans
• has many genetic similarities to the 1918 virus
PANDEMICS
• global epidemic due to a newly-emerged
strain of flu
• few, if any, people have any immunity
• three pandemics in the last century
– 1918 (H1N1)
– 1957 (H2N2)
– 1968 (H3N2)
EPIDEMIOLOGY
• the principal vectors are:
– the migration of wild birds harboring the virus
• Bar-headed geese
• Brown-headed gulls
• Great black-headed gulls, etc.
– trade in domestic poultry
• crew
• egg flats
• trucks
WEATHER AND MIGRATION
• weather can directly and indirectly affect
breeding success and migration
–
–
–
–
–
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chilling or starving young
foraging conditions
temperature affects pre-migratory preparation
fronts signal when to migrate
high pressures signal when to feed
wind conditions affect flying
CLIMATE CHANGE AND
MIGRATION
• global temperature is expected to increase
1.1-6.4 C over the coming century
– this warming is likely to be without precedent
during the last 10,000 years
• if springs become warmer, birds will nest
earlier
– in North America, Tree Swallows breed 9 days
earlier than 30 y.a.
SUMMER AND FALL 2006
• sixth-warmest year on record since 1850
• Europe experienced its warmest fall in 500 years
– Central England experienced warmest, July, September,
and autumn temperatures
– Switzerland experienced November and earlyDecember temperatures 10C above normal
– anecdotally, in North America: New York City
experienced no snowfall in November and December
for the first time since 1877; in Maryland, buds
appeared in apple trees, and crocuses pushed up from
the ground in New Jersey; and frogs re-emerged from
winter hibernation
FUTURE
CAN A PANDEMIC BE
AVERTED?
• the answer is unknown
Adaptation
• the best way to prevent a pandemic would
be to eliminate the influenza virus from
birds
• antiviral medications to treat early cases
ADAPTATION
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global problem
global responsibility
national responsibility
organizational responsibility
– U.S. officials asked business, health, and religious
groups in June, 2007 to urge Americans to prepare for a
possible pandemic
• personal responsibility