pandemic

1. PANDEMIC :
CAUSES
&
PREVENTION
submitted by
Sreelakshmi A
1st Year B.Ed
Physical science
GCTE Trivandrum

2. What is a Pandemic
According to the WHO , a pandemic is
defined as the “worldwide spread of a
new disease.
Pandemics are large-scale outbreaks of
infectious disease that can greatly
increase morbidity and mortality over a
wide geographic area and cause
significant economic, social, and
political disruption.

3. EPIDEMIC v/s PANDEMIC
EPIDEMIC
An epidemic disease is
one “affecting many
persons at the same
time, and spreading
from person to person
in a locality where the
disease is not
permanently
prevalent.
PANDEMIC
A pandemic disease is
an epidemic that has
spread over a large
area, that is, it’s
“prevalent
throughout an entire
country, continent, or
the whole world.”

4. A Timeline of Historical Pandemics
• Disease and illnesses have plagued humanity
since the earliest days.
• Widespread trade created new opportunities for
human and animal interactions that sped up
such epidemics.
• The more civilized humans built larger cities,
more exotic trade routes, and increased contact
with different populations of people, animals,
and ecosystems – the more likely pandemics
would occur.
• Here are some of the major pandemics that
have occurred over time:

5. Name Time period
Type / Pre-human
host
Death toll
Antonine Plague 165-180 Believed to be
either smallpox or
measles
5M
Japanese smallpox
epidemic
735-737 Variola major virus 1M
Plague of Justinian 541-542 Yersinia pestis
bacteria / Rats, fleas
30-50M
Black Death 1347-1351 Yersinia pestis
bacteria / Rats, fleas
200M
New World
Smallpox Outbreak
1520 – onwards Variola major virus 56M
Great Plague of
London
1665 Yersinia pestis
bacteria / Rats, fleas
100,000
Italian plague 1629-1631 Yersinia pestis
bacteria / Rats, fleas
1M
Cholera Pandemics
1-6
1817-1923 V. cholerae bacteria 1M+

6. Third Plague 1885 Yersinia pestis
bacteria / Rats, fleas
12M (China and
India)
Yellow Fever Late 1800s Virus / Mosquitoes 100,000-150,000
(U.S.)
Russian Flu 1889-1890 Believed to be H2N2
(avian origin)
1M
Spanish Flu 1918-1919 H1N1 virus / Pigs 40-50M
Asian Flu 1957-1958 H2N2 virus 1.1M
Hong Kong Flu 1968-1970 H3N2 virus 1M
HIV/AIDS 1981-present Virus / Chimpanzees 25-35M
Swine Flu 2009-2010 H1N1 virus / Pigs 200,000
SARS 2002-2003 Coronavirus / Bats,
Civets
770
Ebola 2014-2016 Ebolavirus / Wild
animals
11,000
MERS 2015-Present Coronavirus / Bats,
camels
850
COVID-19 2019-Present Coronavirus –
Unknown (possibly
pangolins)
147,600 (Johns
Hopkins University
estimate as of
8:38am PT, April 17)

7. Reason for pandemic
The variety of pandemic threats is
driven by the great diversity of
pathogens and their interaction with
humans.
Pathogens vary across multiple
dimensions, including the mechanism
and dynamics of disease transmission

8. REASONS FOR SPREAD
OF PANDEMIC
Likelihood of pandemics has increased over
the past century because of
1. Increased global travel and integration
2. Urbanization
3. Changes in land use
4. Greater exploitation of the natural
environment

9. Origin of Pandemics
• Most new pandemics have originated
through the “zoonotic” transmission of
pathogens from animals to humans.
• Through increased human-animal
interaction following domestication,
and potentially high-risk zoonoses
(including avian influenzas) continue to
emerge from livestock production
systems.

10. •some pathogens (including Ebola) have
emerged from wildlife reservoirs and entered
into human populations through the hunting
and consumption of wild species

11. Pandemic Risk Factors
Pandemic risks is driven by the combined
effects of spark risk and spread risk.

12. Spark risk
• A zoonotic spark could arise from the
introduction of a pathogen from either
domesticated animals or wildlife.
• Zoonoses from domesticated animals
are concentrated in areas with dense
livestock production systems such as
areas of China, India, Japan, the United
States, and Western Europe.

13. • Key drivers for spark risk from domesticated
animals include intensive and extensive farming
•Wildlife zoonosis risk is distributed far more
broadly, with foci in China, India, West and Central
Africa, and the Amazon Basin
• Risk drivers include behavioral factors such as
meat hunting and use of animal-based traditional
medicines, natural resource extraction , the
extension of roads into wildlife habitats, and
environmental factors

14. Spread risk
• The risk that a pathogen will spread
within a population is influenced by
pathogen-specific factors such as
genetic adaptation &mode of
transmission
• Human population-level factors such as
the density of the population and the
susceptibility to infection

15. • Patterns of movement driven by
travel, trade, and migration.
• Speed and effectiveness of public
health surveillance and response
measures

16. Social factors such as
•Dense concentrations of population,
especially in urban centers
• overcrowded informal settlements.
•Social Inequality
•Poverty

17. •Malnutrition
•Deficits weaken an individual’s
immune system
•Marginalized populations, including
refugees and people living in urban
slums and informal settlements, likely
face elevated risks of morbidity and
mortality during a pandemic.

18. Environmental Factors
• Lack of clean water
• Adequate sanitation amplify
transmission rates and
increase morbidity and
mortality

19. Consequences of Pandemic
• Health Impacts
• Economic impact
• Social impact
• Political impact
• Environmental impacts

20. PANDEMIC MITIGATION:
PREPAREDNESS AND RESPONSE

21. Pre-pandemic period
(before a pandemic starts)
• Stockpile building
• Continuity planning
• Public health workforce training
• Simulation exercises
• Risk transfer mechanism set-up
• Situational awareness

22. Spark period
(as a pandemic starts)
• Initial outbreak detection
• Pathogen characterization or laboratory
confirmation
• Risk communication and community
engagement
• Animal disease control
• Contact tracing, quarantine, and isolation
• Situational awareness

23. Spread period
(after a pandemic starts)
• Global pandemic declaration
• Risk communications
• Contact tracing, quarantine, and isolation
• Social distancing
• Stockpile deployment
• Vaccine or antiviral administration
• Care and treatment
• Situational awareness

24. Reducing Pandemic Spread
Once a pandemic has begun in earnest, public health
efforts often focus on minimizing its spread. Some
measures taken for this purpose are:
• Curtailing interactions between infected and
uninfected populations: for example, through patient
isolation, quarantine, social distancing practices, and
school closures
• Reducing infectiousness of symptomatic patients: for
example, through antiviral and antibiotic treatment
and infection control practices
• Reducing susceptibility of uninfected individuals: for
example, through vaccines.