The diseases caused by poxviruses, particularly smallpox have long
been feared as agents of terrible illness. Even during the Egyptian
empire, smallpox was known and it is believed that the Pharoah Ramses V
died of the disease in 1157 B.C. In India, smallpox was already endemic
two thousand years agoand
quickly spread to China,Japan, and Northern Africa. It is believed that
slave traders introduced smallpox in sub-Saharan Africa. In the nations in
which smallpox was endemic, it became a part of
*Special thanks to the
American Museum of Natural History and Phyllis Galembo for the use of
the photograph.
Molluscum contagiosum is a human disease that has been largely regarded as
a trivial infection. However, since 1980 with the surgence of HIV
disease, many people have become immunocompromised, and thus are often
the victims of such opportunistic infections.
The incidence of human monkey pox was discovered in West and Central
Africa in the early 1970's. Smallpox had already been eradicated from
these regions, but the signs and symptoms were very similar.The human
disease of monkeypox has been cosidered a rare zoonosis, and though
vaccinia can prevent the development of disease, it is so rare vaccination
is believed unnecessary.
In 1957 and 1962, an epidemic of people of the flood plain of the Tana
River in Kenya occurred that brought attention to the acute illness that
produced skin lesions. This disease, now known as Tanapox is endemic to
the region and was the disease later reported in
monkeys in US centers in 1966 by which handlers were infected. Yabapox was
observed in tumors that ocurred in rhesus monkeys in Nigeria. Though it is
believed to infect human beings, none has been found in the field of
Africa.
700 A.D.
Smallpox endemic in India, spread to China, Japan, Europe, and north
Africa
1518
1520
1796
1800's
1957
1958
1962
1967
1970
1977
1979
1980's
Leslie Collier: Eradication of infectious diseases is often difficult
because nations vary not only in political, economic, and cultural
backgrounds, but in infrastructure. Many developing countries lack the
transportation systems that are necessary for the delivery of supplies to
rural regions of the nation. Therefore, Collier's development of the
freeze-dried vaccine was vital in distributing the smallpox vaccine to
even the most rural regions of the world. Thus, he made a tremendous
contribution leading to the final worldwide eradication of smallpox.
The mural decorations behind her suggest
the marks of smallpox when Obulawaye strikes.
The disease reached Europe in 710 A.D., and its spread to the rest
of the world is thought to have been facilitated by European voyages of
discovery and colonization.
In 1520, Hernando Cortez led the conquest that toppled the Aztec empire.
Cortez' success was due to the work of smallpox which may killed 3.5
million Aztecs died in only 2 years.
In the 10th century, smallpox scab material or pustule fluid
was inoculated into the skin in what was called "variolation." In
some cases, the procedure was effective in preventing severe disease.
Edward Jenner in 1796, innoculated individuals with a close relative of
the smallpox virus, the cowpox virus. He showed that those given the
innoculation were completely resistant to smallpox. The use of a smallpox
"vaccine" quickly spread, and later the live attenuated vaccina virus
vaccine predominated in use. Although the origin of this virus strain has
not been completely deciphered, the results of its use were phenomenal.
By the 1950's smallpox had been largely eradicated from the industrialized
countries in which it had been endemic. In 1967, the Smallpox Eradication
Unit was established by the World Health Assembly at the World Health
Organization center. Innovative means of storage as well as the effective
distribuation of vaccines led to mass vaccination worldwide, which was
strongly aided by surveillance, containment. Interestingly, the
bifurcated needle is also credited with aiding in the eradication process.
Slowly, the progress of eradication was becoming clear. In 1979, the World
Health Organiation declared the world free of endemic smallpox.
Currently, vaccination is only recommended for laboratory workers who work
directly with cultures or animals infected with vaccinia, its
recombinants, or other human infecting orthopoxviruses.
Cowpox
Human Monkeypox
Yabapox and Tanapox
Timeline
1157 B.C.
Pharoah Ramses V dies of smallpox
Smallpox introduced to the Caribbean by the African slave trade
Millions of Aztec people die in smallpox epidemic
Jenner shows persons inoculated with cowpox virus are resistant to
smallpox
Vaccinia virus used in vaccinations against variola
Most industrialized contries have eliminated endemic smallpox
Tanapox epidemic in Kenya
World Health Assembly accepts the global eradication concept
Monkeypox virus discovered in laboratory primates in Copenhagen
Tanapox epidemic in Kenya
Smallpox Eradication Unit established at WHO
Surveillance of monkeypox infections by WHO
Global eradication of smallpox achieved
World officially declared free of smallpox
Molluscum contagiosum associated with immunocompromised patients
Important Researchers