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Containing Infectious
Disease
State of the World
Worldwatch Institute
Image: CDC
Infectious Disease
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•
A security threat
Outbreak dynamics
Current threats
Economic Impact
Managing future
outbreaks
© PAHO
Security Threats
Infectious diseases remain a
security challenge—the
dreaded Fourth Horseman of
the Apocalypse
–Diseases rank with wars and
famine as major security
threats
–Diseases are a leading cause
of death and disability
worldwide
Jean Colombo, The Horsemen of Death, Musee Conde, Chantilly
Security Threats
What are the global threats?
– the emergence of new
infectious diseases
– a resurgence of older
diseases
– a spread of resistance
to a growing number
of antibiotic drugs
© WHO
Historical Context
Infectious diseases have been called pestilences,
pests and plagues since ancient times
– Plague of Athens heralded
end of Greece' Golden Age
– 1300s Black Death in Europe
killed 40% of the population
– 1500s smallpox in Latin
America killed 10-15 million
– 1918 Influenza pandemic
during WWI took 20-40
million lives
A War Not Won
By the 1960s, with improved sanitation, medicine
and drugs, the U.S. Surgeon General stated, "the
war against infectious diseases has been won."
The war continues today:
– The campaign to eradicate
infectious disease is ongoing
– Pathogens are exhibiting
remarkable resilience and
flexibility
A War Not Won
Twenty well-known maladies
such as TB, malaria, cholera
and influenza have re-emerged
or spread
© WHO
At least 30 diseases not
previously known such as
Ebola, hepatitis C, hantavirus,
SARS and HIV have emerged
© WHO
Dynamics of Outbreaks
Which causes more deaths -- military combat
or diseases?
– All the wars of the 20th
century killed an average of
about 1.1 million combatants
and civilians a year
– Communicable diseases are
now killing 14 times as many
people annually
– A new influenza pandemic
could kill millions
© Digital Vision
Dynamics of Outbreaks
What factors can disturb the balance between
people and pathogens resulting in a large-scale
disease outbreak?
– changes in human
behavior or circumstances
– mutations in or movement
of pathogens
– changes in shared
environments
© Digital Vision
Historical Outbreaks
Changes in relationships between people and
microbes have facilitated disease outbreaks in
three recent historical periods
10,000 years ago
– domestication brought
people and animals
together
– settlements brought
people into close
contact with
accumulated wastes
© WHO
Historical Outbreaks
2,500 years ago
– the Roman Empire in the West and the Han
Dynasty in the East expanded trade and germs
were swapped in both directions
14th and 15th centuries
– transoceanic exploration and trade brought the
bubonic plague to Europe and smallpox, measles,
influenza and other diseases to indigenous
peoples in the western hemisphere
Contemporary Outbreaks
Today population growth, industrialization,
globalization, migration and urbanization have
created a fourth wave of outbreaks
20th and 21st centuries
– 1957 Asian flu and the
1968 Hong Kong flu
pandemics killed 4 million
worldwide
– 1981-2003 AIDS deaths
total more than 20 million
© Digital Vision
Globalization
What effect has the globalization of travel and
commerce had on the spread of diseases?
– In the 1300 the Black Death
took several years to spread
across Europe
– In 2002 in remote China,
SARS, a new respiratory
disease, jumped from
animals to people and within
6 months was reported in 29
countries around the world
© CDC
Population Growth
What can we expect as the world population
grows to over 7 billion people?
8
Billion people
7
6
5
4
3
2
1
0
1950
1960
1970
1980
1990
2000
2010
2020
Urbanization
• As populations become
more densely packed it is
easier for pathogens to
spread rapidly
• In 1965 36% of world's
population lived in cities,
today it is almost 50%
• By 2030 the U.N. predicts
2 billion people may live
in urban slums
© stock.xchng
Urbanization
Most growth will be in developing countries
Billions of people
10
8
Developing Nations—Urban
Developing Nations—Rural
More Developed Nations—Total
6
4
2
0
1970
2000
2030
Migration
What happens when people are displaced due to
population growth or ethnic violence in developing
countries?
New settlements push into forested
areas where microbes in wild animals
can spread to humans
© Yosef Hadar/World Bank
Crowed refugee camps around the
world become ideal incubators for
diseases
© UN
Rich or Poor
Does affluence or poverty make a difference?
– In poor nations, many people suffer from
infectious diseases of the underfed
– In affluent nations, an increasing number of
people are afflicted with chronic diseases of the
overfed
© UN/DPI
© stock.xchng
Poverty
Persistent Poverty
– An estimated 2.8 billion
people now live on less
than $2 per day with little
access to health care
– In Africa, infectious and
parasitic diseases account
for about 50% of all deaths,
while in Europe they
account for only 2%
© FAO
Technology
How has technology transformed the way in which
people and pathogens interact?
– Speed and pervasiveness of
international travel means
people and pathogens move
swiftly across borders
– Imports of agricultural
commodities increase the
risk of infectious microbes
on food
© USDA
Technology
– Urban sewage systems in
developing areas often
pollute water encouraging
waterborne diseases
– Industrial and auto pollution
contribute to global warming
allowing tropical pathogens
to expand their range
– Increased use and misuse
of antibiotics creates drug
resistant microbes
© Digital Vision
Current Status
Of an estimated 57 million people who died
worldwide in 2002, infectious diseases caused
14.9 million deaths
– 20 previously well-known diseases have
reemerged or spread geographically
– 30 diseases not previously known to be
infectious have been identified in the last
three decades
Global Deaths from Major
Communicable Diseases
Diseases
Worldwide
2000
(million)
2002
(million)
Share of all
Deaths in 2002
(percent)
Respiratory
infections
3.9
4.0
6.9
HIV/AIDS
2.9
2.8
4.9
Diarrhea
2.1
1.8
3.2
Tuberculosis
1.7
1.6
2.7
Malaria
1.1
1.3
2.2
HALE
HALE = the number of healthy years that a
newborn can expect to live based on current rates
of ill health and mortality
Big gap between the HALE of rich and poor
countries
– The HALE for Japan is 75 (75 healthy years and
6.9 years of disability due to infectious or chronic
diseases)
– In Sierra Leone the HALE is only 28.6 years
HALE
Highest
Lowest
Country
HALE
Country
HALE
Japan
75.0
Sierra Leone
28.6
Sweden
73.3
Lesotho
31.4
Switzerland
73.2
Angola
33.4
Italy
72.7
Zimbabwe
33.6
Australia
72.6
Swaziland
34.2
Spain
72.6
Malawi
34.9
Canada
72.0
Zambia
34.9
France
72.0
Burundi
35.1
Norway
72.0
Liberia
35.3
Germany
71.8
Afghanistan
35.5
Drugs and Developing Countries
Why are drugs not available in
developing countries?
• Between 1975-1997 only 13 out
of 1,233 drugs on the global
market were for tropical
diseases
• Each year, more than 2.3 million
people, primarily in poor
countries, die from 8 diseases
that could be prevented by
vaccinations
© WHO
Drugs and Developing Countries
• Pharmaceutical companies
are concerned about
intellectual property rights
and profits
• Poor countries lack money
and enough health care
workers to distribute
needed drugs
© WHO
HIV/AIDS
In the near future, what is the most
pressing global health issue?
© WHO
– Worldwide more than 20
million people have died from
HIV/AIDS
– Seven sub-Saharan African
countries have HALEs of less
than 35 years due to poverty
and the rampage of HIV/AIDS
– 34-46 million people are now
living with HIV/AIDS
HIV/AIDS
100
Millions
80
60
AIDS Deaths
40
20
HIV Infections
0
1980
Source: UNAIDS
1985
1990
1995
2000
2005
HIV/AIDS Future Impact
India, China, Nigeria, Ethiopia and Russia are
likely to see rapid growth of infections with 50-70
million infected by 2010
– India is expected to have
20-25 million cases and an
adult prevalence rate of 34%
– China is expected to have
10-15 million victims and
an adult prevalence rate
near 2%
© FAO
HIV/AIDS in the Military
HIV/AIDS is higher in many armed forces than in
civilian populations, particularly in developing
countries
– In Zimbabwe and Malawi
the infection rate among
armed forces is 70-75%
– Active duty military,
combatants and
peacekeeping forces are
contributing to the
spread of the disease
© UN
HIV/AIDS in the Military
How does AIDS in the military affect national
security in developing countries ?
–
–
–
–
–
–
Diminished efficiency of troops
Demoralization among troops
Effectiveness and discipline are threatened
Medical treatment is costly
Loss of leadership and professional standards
Destabilized governments
© UN
Influenza
What is influenza? It is a common virus that
continually undergoes small changes, evading
human immunity throughout the world
– Periodically the virus shifts to
new, more deadly forms that can
spread from person to person
– Deadly pandemics occurred in
1988, 1918, 1957 and 1968
– WHO estimates a new outbreak
could kill 650,000 and
hospitalize 2.3 million in
industrial countries alone
Courtesy of National Museum of Health and Medicine
Animal-Human Connection
People and animal interactions have a history
of disease transmissions
– West Nile virus passes from birds
to people via mosquitoes
– Lyme disease from mice to people
via deer ticks
– SARS virus jumped to people from
palm civets
– Avian flu in chickens transferred to
humans
© CDC
© ebi bioinformatics
Avian Flu in Asia
Avian Flu in Asia
• Recent avian influenza cases
occurred when the virus
jumped from poultry to humans
• In late 2004 the first case of
human-to-human infection was
documented
• Infected international travelers
could rapidly spread the
disease creating a pandemic
© FAO
Human Infections with Avian
Influenza Viruses, 1997-2004
1997
H5N1
Hong Kong
18 cases
6 deaths
1.4 million
chickens
slaughtered
1999
H9N2
Hong Kong
2 cases
2003
H5N1
Hong Kong
2 cases 1 death
H7N7
Netherlands
84 cases
30 million
chickens
slaughtered in
Europe
1 death
H9N2
Hong Kong
1 case
2004
H5N1
8 Asian countries
including Thailand
& Vietnam
34 cases
23 deaths
100 million fowl
culled
H7N3
Canada and US
2 cases
Late 2004 first
probable case of
human to human
transmission
Source: WHO
Genetic Mixing and Transmission
What is interspecies genetic mixing?
– Back-switches of human
viruses have emerged in pigs
– Both doubly mixed (pighuman) and triply mixed (pighuman-avian) viruses have
been isolated
– Mixing is suspected to have
occurred in the 1918 influenza
pandemic
© FAO
Bioterrorism
Are bioterrorism and biowarfare new concepts?
– 1346 historians suggest plague-ridden corpses were
catapulted over enemy walls in siege of Caffa (Ukraine)
– 1754-1763 during the Seven Years War, officers may
have given smallpox impregnated blankets to Indians
– 1984 Oregon religious cult
spiked restaurant salad bars
with Salmonellae
– 2001 terrorists mailed letters
filled with anthrax spores to
prominent U.S. citizens
© stock.xchng
Economic Consequences
Governments often attempt to keep disease
outbreaks under wraps because of the economic
consequences
– Nine countries in subSaharan Africa are losing
more than 10% of workingage population every five
years, largely due to HIV
– A 1994 outbreak of
pneumonic plague in India
resulted in $1.7 billion in
lost exports and tourism
African AIDS quilt
© FAO
Economic Consequences
In 2003 a SARS outbreak in East Asia had
major effects on travel and exports
– China's tourism industry lost an estimated $7.6
billion and 2.8 million jobs
– Overall loss to the travel economy was thought
to be $20.4 billion
– Economists shaved about 1.5 percentage
points off 2003 growth estimates for the
economies of Hong Kong, Singapore, and
Malaysia
Economic Consequences
In the world's poorest countries HIV prevalence
among the most productive working-age adults is
above 20% causing significant economic tolls
–
–
–
–
–
Retards industrial development
Reduces agricultural production
Devastates education
Weakens the military
Undermines political stability
© FAO
Economic Consequences
How has HIV/AIDS affected the GDP of
African countries?
– GDP declined by an
average of 1.1 % per
year between 1992 and
2002 in 33 countries
– By 2020 estimates of the
collective loss in
economic growth is 18%
or roughly $144 billion
© UN
Managing Future Outbreaks
Infectious diseases will continue to emerge
and re-emerge, leading to unpredictable
epidemics and difficult challenges to public
health and science
International security priorities need to include
revised expenditures to reflect the threat of
infectious diseases in our increasingly
interconnected world
Managing Future Outbreaks
1. Increase surveillance on a global scale to detect
new disease outbreaks quickly
2. Use anticipatory thinking and action to prepare for
and avoid rapidly moving future pandemics
3. Start campaigns to eradicate serious illness among
the world's poor
4. Develop better mechanisms to distribute
antiretroviral drugs and other pharmaceuticals to
poverty stricken disease victims
Managing Future Outbreaks
5. Create innovative ways to provide affordable drugs to
victims in poor countries
6. Encourage greater transparency by governments
where disease outbreaks are likely to occur
7. Redefine security priorities and funding to reflect the
serious challenges of new and resurgent disease in a
globalized world
8. Address economic liability issues arising from the
rapid development of vaccines for swiftly moving
diseases
Managing Future Disease
Outbreaks
9. Provide incentives for the
development of new vaccines and
medicines for endemic diseases in
developing countries
10. Fund and build effective public health
systems
© WHO
Worldwatch Institute
Further information and
references for the material in this
presentation are available in the
Worldwatch Institute’s publication
“State of the World 2005”
This presentation is based on
Chapter 3 “Containing Infectious
Disease” authored by:
Dennis Pirages
www.worldwatch.org