October 2012
Chapter 9: Smallpox, the Spotted Plague
Smallpox spread from village to village throughout the Yucatan
Smallpox had arrived in Peru by land in 1526, killing most of the Inca population
Smallpox was considered an old world disease and the new world had never been exposed to it, so they did not
have immunity to it
A Look Back
Smallpox was at one time one of the most devastating of all human diseases
No one really knows when smallpox began to infect humans
o People thought that it came from another infectious agent from one of the pox like diseases from
domesticated animals
The best evidence of smallpox was found in three Egyptian mummies
o Pharaoh Ramses, his face, neck, shoulders are covered with scars, pockmarks
Smallpox spread form west to china
o Trade caravans helped the spread of smallpox
It was also known in Greece and Rome but was not a major health problem until the Plague of Antonine
The major spread of smallpox spread in the 8 and 9 century during the Islamic expansion across North
America and into Spain and Portugal
The movements of caravans and people to and from Asia Minor helped reintroduce smallpox to Europe
The English used smallpox as a weapon of germ warfare
o Blankets were purposefully contaminated with scabby material from the smallpox pustules and
delivered to the Indians, causing the spread for the disease
o This lead to a lot of deaths, and ensured the Indian’s defeat
The Disease of Smallpox
Smallpox is caused by one of the largest viruses, and it can be seen with a light microscope
The virus has about 200 genes, 35 which are involved in virulence
Smallpox virus enters the body through droplet infection by inhalation
o It can also be acquired by direct contact or through contaminated objects
Cycle:
o There is no signs of illness in the first week of infection
o Virus moved on to the lymph nodes and to internal organs via bloodstream, multiplies again
o The first symptoms appear around the ninth day, headache, fever, chills, nausea, muscle ache
o Few days later, a rash appears , scars start to form (pockmarks)
o Around a day later, the scabs will fall off, people may die
There are two forms of the smallpox virus
o Variola Major: deadlier form, kill up to 25 % of the victims
o Variola Minor: milder form, kill up to 2 %
Smallpox can cause blindness, up to 1/3 of the population
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The 18 century in Europe was called the “age of powder and patches”
1 October 2012
Catching Smallpox
Smallpox is a contagious disease that is spread from person to person, and there are no animal reservoirs
There has to be enough susceptible persons born annually to keep the chain of infection indefinite
Smallpox spreads more rapidly during the winter in temperate climates and during the dry season in the tropics
Smallpox became a disease of childhood, since mostly children were susceptible to it because of immunity
within the older generation
Variolation
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