Small pox

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1. Small POX

3. Smallpox Disease Overview
pox part of smallpox is derived from the Latin
word for “spotted” and refers to the raised
bumps that appear on the face and body of an
infected person.

4. Two clinical forms
1.Variola major
 is the severe and most common form of smallpox,
 more extensive rash and higher fever.
 four types of variola major smallpox
1. ordinary (the most frequent type, accounting for 90% or more of cases)
2.modified (mild and occurring in previously vaccinated persons);
3.flat,
4. hemorrhagic (both rare and very severe).
 variola major has an overall fatality rate of about 30%; however, flat and
hemorrhagic smallpox usually are fatal.
2.Variola minor is a less common presentation of smallpox, and a much less
severe disease, with death rates historically of 1% or less

5. Incubation period..
Incubation Period
(Duration: 7 to 17 days)
Not contagious
Initial Symptoms (Prodrome)
(Duration: 2 to 4 days)
Sometimes contagious*

6. Early Rash
(Duration: about 4 days)
Most contagious
Rash distribution:
Pustular Rash
(Duration: about 5 days)
Contagious

7. Pustules and Scabs
(Duration: about 5 days)
Contagious
Resolving Scabs
(Duration: about 6 days)
Contagious
Scabs resolved
Not contagious

8. Smallpox may be contagious during the
prodrome phase,
most infectious during the first 7 to 10 days
following rash onset.

9. Possible Ways of Getting Smallpox
Prolonged face-to-face contact with
someone who has smallpox
Direct contact with infected bodily fluids or
an object such as bedding or clothing that
has the virus on it.
Exposure to an aerosol release of smallpox
(the virus is put in the air).

10. Treatment
There is no proven treatment for smallpox

11. best ways to prevent smallpox is
through vaccination
If given before exposure to smallpox – complete
protection
within 3 days after exposure will prevent or greatly
lessen the severity of smallpox in most people.
4 to 7 days after exposure likely offers some
protection from disease or may decrease the severity
of disease.
Vaccination will not protect smallpox patients who
already have a rash

12. Eradication

13. one of the greatest triumphs in medicine
The global eradication of smallpox in 1977
the last naturally occurring case in the world
was in Somalia in 1977.

14. Smallpox Eradication Timeline
Written descriptions occurred as early as 400
AD.

15. In science credit goes to the man who
convinces the world, not the man to whom the
idea first occurs..
Francis Galton

17. 1796: The first smallpox
vaccine was developed by
Edward Jenner.

18. After WWI: Most of Europe smallpox-free.
After WWII: Transmission interrupted in
Europe and North America

19. 1940s
 the development of a freeze-dried vaccine
 was more stable in higher temperature and
humidity climates,
the smallpox vaccine was available for wider
use throughout the world

20. 1950:
The Pan American Sanitary Organization,
undertook a program to eradicate smallpox in
the Western Hemisphere.

21. 1958:
The first proposal for global eradication was
made to the World Health Assembly by the
USSR in 1958.
They proposed a worldwide vaccination
program to be completed in a 3-to-5 year
period.
 Some progress was made during the next 7
years, but the results overall were
disappointing.

22. 1966
The World Health Assembly decided to
intensify the eradication program by
providing a special budget of $2.4 million per
year specifically for this effort.

23. 1967: The Intensified Global
Eradication program began
 cases still occurred in 31 countries where the
disease was endemic.
A major reservoir was Africa.
A second major reservoir was in Asia, extending
from Bangladesh through India, Nepal, Pakistan, and
Afghanistan.
The third was the Indonesian archipelago,
The fourth was Brazil, which compromised half the
people of South America

24. Global Eradication Initiative
The initial eradication campaign was based on a
two-fold strategy.
1.Mass vaccination campaigns in each country, using
vaccine of ensured potency and stability, that would
reach at least 80% of the population.
2.The development of surveillance systems to find
cases and outbreaks so that more focused
containment measures could be implemented.

25. Mass Vaccination
In 1966, the Smallpox Eradication and
Measles Control Program was initiated in 18
West African countries to move toward
eradication in this disease-endemic area.
 Sierra Leone had the highest infection rates
in the world

26. Efforts..
Through the use of vaccination guns,
government resources, and, most importantly,
traditional health authorities, large numbers of
people were vaccinated.
The program administered over 100 million
vaccinations in a 5-year period.
 Surveys showed that 90% of the population
had been vaccinated.
 Smallpox rates fell as a result of these efforts.

27. Ring vaccination-Key strategy of
global eradication program
great impact on smallpox transmission even in areas
where overall vaccination coverage was low by
using a strategy called surveillance and containment,
or ring vaccination.
The principle behind this strategy was to identify
cases of smallpox,
vaccinate their household and other close contacts,

vaccinate the close contacts of the primary
household and close contacts to the case

28. If the primary contacts developed smallpox
despite vaccination, their close contacts
would already be protected and the chain of
transmission would have been broken.

29. Special surveillance teams…
were recruited and trained to search for smallpox cases and
vaccinate their contacts.
 They visited each health unit in an area of endemic smallpox
to ensure that each week the health officer submitted a report
indicating the number of cases seen.
When cases were reported, the teams worked with local
health staff to find additional cases and to contain the
outbreaks by vaccinating the contacts.
Although setbacks occurred, this surveillance and
containment strategy proved to be the strategy that finally
brought about the eradication of smallpox throughout the
world.

30. Final Eradication
By the end of 1975, smallpox persisted only in the
Horn of Africa
Conditions were very difficult in Ethiopia and
Somalia, where there were few roads.
 Civil war, famine, and refugees made the task even
more difficult.
With the interruption of smallpox transmission in
Asia, more resources were made available in Africa,
including more staff and transport

31. world’s last indigenous patient with
smallpox
intensive surveillance and containment and
vaccination program was initiated in the
spring and summer of 1977.
 As a result, the world’s last indigenous
patient with smallpox on earth was a hospital
cook in Merka, Somalia, on October 26, 1977
with variola minor.

32. Laboratory accident-1978
Searches for additional cases continued in
Africa for more than 2 years, during which
time thousands of rash illnesses were
investigated. None proved to be smallpox
Although 2 cases of smallpox occurred in
England in 1978 as a result of a laboratory
accident, smallpox was gone as a naturally
transmitted disease

33. Eradication Declared..
The World Health Organization officially
certified that smallpox had been eradicated on
December 9, 1979, 2 years after the last case
in Somalia.
 In 1980 the World Health Assembly
recommended that all countries cease routine
vaccination

34. Small pox virus today
kept in two approved labs in the U.S. and
Russia.

36. bronze grouping
symbolizes the coming together of peoples
from all nations
 to solve a major health scourge that plagued
the human family since the beginning of
recorded history.
Together, the peoples of the world achieved
this unprecedented success of eradicating
smallpox

37. Why Smallpox is a
Concern today??

38. smallpox virus, Today,
credible concern exists that the virus was
made into a weapon by some countries and
that terrorists may have obtained it.
CDC calls it a “Category A” agent. Category
A agents are believed to present the greatest
potential threat for harming public health

39. After 9/11
the U.S. govt improved its level of
preparedness against terrorism.
be prepared for an intentional release of the
smallpox virus
updating and releasing a smallpox response
plan.

40. bioterrorism
Category A
can be easily disseminated or transmitted from
person to person;
result in high mortality rates and have the potential
for major public health impact;
might cause public panic and social disruption; and
require special action for public health preparedness

41. Category A
Bacillus anthracis)
Botulism (Clostridium botulinum toxin)
Plague (Yersinia pestis)
Smallpox (variola major)
Tularemia (Francisella tularensis)
Viral hemorrhagic fevers (filoviruses [e.g.,
Ebola, Marburg] and arenaviruses [e.g.,
Lassa, Machupo])

42. Category B
Brucella species)
Epsilon toxin of Clostridium perfringens
Food safety threats (e.g., Salmonella species, Escherichia coli O157:H7,
Shigella)
Glanders (Burkholderia mallei)
Melioidosis (Burkholderia pseudomallei)
Psittacosis (Chlamydia psittaci)
Q fever (Coxiella burnetii)
Ricin toxin from Ricinus communis (castor beans)
Staphylococcal enterotoxin B
Typhus fever (Rickettsia prowazekii)
Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis,
eastern equine encephalitis, western equine encephalitis])
Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)

43. How Public Health Officials will
Respond to a Smallpox Outbreak
CDC has a detailed plan to protect Americans
against the use of smallpox as a biological
weapon.

44. If a smallpox outbreak happens
1.public health officials will use television,
radio, newspapers, the Internet and other
channels to inform members of the public
about what to do to protect themselves and
their families.

45. 2. Officials will tell people where to go for care
if they think they have smallpox.
3. Smallpox patients will be isolated and will
receive the best medical care possible.
Isolation prevents the virus from spreading to
others.

46. 4.Anyone who has had contact with a smallpox patient
will be offered smallpox vaccination as soon as
possible.
Then, the people who have had contact with those
individuals will also be vaccinated.
Following vaccination, these people will need to
watch for any signs of smallpox.
People who have been exposed to smallpox may be
asked to take their temperatures regularly and report
the results to their health department.

47. 5.The smallpox vaccine may also be offered to
those who have not been exposed, but would
like to be vaccinated.
At local clinics, the risks and benefits of the
vaccine will be explained and professionals
will be available to answer questions.

48. No one will be forced to be vaccinated, even if they
have been exposed to smallpox.
To prevent smallpox from spreading, anyone who
has been in contact with a person with smallpox but
who decides not to get the vaccine may need to be
isolated for at least 18 days. During this time, they
will be checked for symptoms of smallpox.
People placed in isolation will not be able to go to
work. Steps will be taken to care for their everyday
needs (e.g., food and other needs)

49. The Smallpox Vaccine
The vaccine is made from a virus called
vaccinia which is a “pox”-type virus related
to smallpox. The smallpox vaccine contains
the “live” vaccinia virus

50. Length of Protection
Smallpox vaccination provides high level
immunity for 3 to 5 years and decreasing
immunity thereafter.
 If a person is vaccinated again later,
immunity lasts even longer.
Historically, the vaccine has been effective in
preventing smallpox infection in 95% of those
vaccinated. In

51. Receiving the Vaccine
The vaccine is given using
a bifurcated (two-pronged)
needle that is dipped into
the vaccine solution. When
removed, the needle retains
a droplet of the vaccine.
The needle is used to prick
the skin a number of times
in a few seconds.
.

52. Anyone directly exposed to
smallpox…
regardless of health status, would be offered
the smallpox vaccine
because
the risks associated with smallpox disease are
far greater than those posed by the vaccine

53. Smallpox Vaccine Availability
Until recently, the U.S.
government provided
the vaccine only to a
few hundred scientists
and medical
professionals working
with smallpox and
similar viruses in a
research setting.

54. Vaccine availability..
the U.S. government has enough vaccine to
vaccinate every person in the United States in
the event of a smallpox emergency

55. Smallpox Vaccination May Have
Protected Against HIV Infection
Weinstein RS et al. Significantly reduced CCR5-tropic HIV-1
replication in vitro in cells from subjects previously immunized with
Vaccinia virus. BMC Immunology 2010, 11: 23.

56. Small pox vs HIV
As the HIV virus enters T cells, it makes use of a
cell-surface receptor called CCR5.
The smallpox virus also uses this receptor.
 when the smallpox virus grabs hold of this CCR5
receptor to penetrate the T cell, it alters it in some
way.
The HIV virus may then subsequently find it harder
to gain entry and therefore replicate in the cells

57. Weinstein’s study is based on a small number
of subjects,
 these results are intriguing enough to warrant
further investigation

58. scientists are focusing on understanding the
effects that the smallpox virus, Vaccinia, has
on the immune system and how those effects
may influence HIV infection rates and
progression to full-blown AIDS

59. …it stands as a reminder
of the power of
international health
cooperation to do great
and lasting good

Dr Margaret Chan