Transcript Global Threat of Epidemic Infectious Diseases

Why Have we Seen Such a Dramatic
Increase in Epidemic Infectious Diseases?
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Complacency, Lack of Political Will
Policy Changes
Changes in Public Health
Changing Life Styles/Behavior
Microbial Adaptation
Technology
Intent to Harm
Climate Change?
As Earth Warms Up, Tropical
Virus Moves to Italy“
nytimes.com/2007/12/23
Scientists Predict
Global Warming
Will Lead to
Spread of Disease
Climate change, globalization, and other
drivers have made Europe a “hot spot” for
emerging infectious diseases, which calls
for changes in monitoring systems
27 APRIL 2012 VOL 336 SCIENCE.
Chikungunya disease in NYC? Warming could
make it happen
Virus causes severe joint pain, is spread by two
mosquito species; NBC News
“Fueled by climate change,
dengue fever is on the rise again
throughout the developing world,
particularly in Latin America”.
Reference: Dengue fever: a deadly scourge.
The Economist, April 19, 2007.
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Number of Cases
Dengue/Dengue Hemorrhagic Fever, Average Annual Number of Cases Reported to
WHO, 1955-2003
There is no solid
scientific evidence
to date that global
warming has been
a major driving
force of the 20th
century reemergence of
vector-borne
infectious diseases!
Why Have we Seen Such a Dramatic
Increase in Epidemic Infectious Diseases?
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Major Drivers
Demographic Changes (Pop Growth)
 Environmental Change
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Uncontrolled Urbanization
Agricultural/Land Use Practices
Deforestation
Climate change
 Animal Husbandry
Modern Transportation (Globalization)
 Increased Movement of People, Animals,
Commodities
Lack of Public Health Infrastructure
Global population- 1950-2050
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Population (Millions)
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1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
More Developed Regions, Urban Population
More Developed Regions, Rural Population
Less Developed Regions, Urban Population
Less Developed Regions, Rural Population
Evaluation of urban and rural population between 1950 and 2050
Urban Growth in Asian(1) and American(2) Cities, 1950-2010
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Millons of People
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Mean population of Dhaka, Bangkok, Jakarta, Manila and Saigon.
Mean population of Rio de Janeiro, Sao Paulo, San Juan, Caracas
and Guayaquil.
The global air network
Million of Passenger (Mil)
Average annual number of global airline
passengers by decade, 1950-2010
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IATA 2010
Decade
Commercial Air Traffic Over a 24 Hour Period
Global distribution of dengue virus serotypes, 1970
DEN 1
DEN 2
DEN 1
DEN 2
DEN 3
DEN 4
Gubler, 1998
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DEN 2
Global distribution of dengue virus serotypes, 2013
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DEN 2
DEN 3
DEN 4
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DEN 2
DEN 3
DEN 4
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DEN 2
DEN 3
DEN 1
DEN 2
DEN 3
DEN 4
DEN 1
DEN 2
DEN 3
DEN 4
DEN 1
DEN 2
DEN 3
DEN 4
Adapted from Gubler, 1998
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DEN 2
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DEN 4
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Exotic Infectious Diseases That Have
Recently Been Introduced to the US
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West Nile Fever
Dengue Fever
Yellow Fever
Mayaro Fever
Chikungunya
Epidemic
Polyarthritis
• SARS
• Influenza
• Lassa Fever
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Monkeypox
CJD/BSE
HIV/AIDS
Cholera
E. coli O157
Malaria
Leishmaniasis
Chagas Disease
Cyclospora
Live Animal Importation into the USA - 2002
• 47,000 mammals
 28 species of rodents
• 379,000 birds
• 2 million reptiles
& Poisonous snakes
• 49 million amphibians
• 223 million fish
Data from U.S. Fish & Wildlife Service
Exotic Mosquito Species Recently
Introduced and Established in the US
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Aedes (Stegomyia) albopictus
Ochlerotatus (Aedes Finlaya) togoi
Ochlerotatus (Aedes Finlaya)
japonicus
Aedes bahamensis
Culex biscayensis
Demographic Changes
Global
climate
change
Technology/Globalization
Socio-cultural organization
Urbanization
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Agricultural, land use
and animal husbandry
changes/practices
Habitat
alteration
REGIONAL ENVIRONMENTAL CHANGE
Species’ Ecological-evolutionary Dynamics
Opportunistic habitat expansion/ecological release
Vector (domestication)
Wildlife/reservoir transport/encroachment
Domestic vector/reservoir species
Human encroachment
Host-Pathogen Dynamics
Emergence Processes of ‘Host-Parasite Biology’
Host switching (host novelty) • Breaching of pathogen persistence thresholds
Transmission amplification and genetic change (pathogen novelty)
Disease Emergence
ecosystem continuum
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Aedes aegypti
POTENTIAL GLOBAL SPREAD OF URBAN YELLOW FEVER
Global Threat of Epidemic Infectious Diseases
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Disease and Trade-interwoven History
 14th century, Europe discovers exotic goods from
Asia
Global Trade Flourishes
 18th, 19, 20th centuries
New Millennium
 Integrated global economic system with a
transnational flow of knowledge, capital, products,
people, animals, and pathogens
 Rapid spread of epidemic infectious disease from
point of origin
Global Threat of Epidemic Infectious Diseases
Lessons Learned
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Dawn of 21st century, we have come full circle
Expect the unexpected
New diseases will emerge
Old diseases will re-emerge
Modern transportation and globalization will
disseminate
Unlikely that a zoonotic disease can be eradicated
Global Threat of Epidemic Infectious Diseases
Lessons Learned
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Disease detection and identification systems must
be improved and maintained
International communication and cooperation are
critical
Rapid response plans must be developed and
implemented appropriately
More emphasis must be placed on prevention as
opposed to emergency response
Outbreaks should be contained as local public
health events if possible
Public and Press need reliable information to
prevent panic and overreaction
The Global Threat of Infectious Diseases
Global Trends, 2012-20025
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Most of global economic growth in Asian countries
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Increased trade
Increased movement of people, animals and
commodities from Asia to rest of world
Most of global population growth in cities of Asia
 Rural to urban circular migration
Globalization
Increased movement of pathogens
Global Threat of Epidemic Infectious Diseases
Challenge to Reverse the Trend
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Movement of Pathogens and Vectors via Modern
Transportation
International cooperation and data sharing
Lack of Effective Laboratory-based Surveillance
Lack of Public Health Infrastructure to Prevent & control
Vector-borne and Zoonotic Diseases
 Trained personnel
 Laboratory capacity
 Tools (vaccines, drugs, insecticides, vector control tools)
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 Understanding disease ecology
Political Will
 Economic support
 Regional prevention and control programs