🔎Introduction :
Smallpox is a serious and often deadly viral infection. It's contagious — meaning it spreads from person to person — and can cause permanent scarring. Sometimes, it causes disfigurement.Smallpox has affected humans for thousands of years but was wiped out worldwide by 1980 thanks to smallpox vaccines. It's no longer found naturally in the world. The last case of naturally occurring smallpox was reported in 1977.
🔎History of Smallpox :
The origin of smallpox is unknown. The finding of smallpox-like rashes on Egyptian mummies suggests that smallpox has existed for at least 3,000 years. The earliest written description of a disease like smallpox appeared in China in the 4th century CE (Common Era).
A huge pandemic reached from Europe to the Middle East in 1614, and epidemics arose regularly in Europe throughout the 17th and 18th centuries. There were frequent outbreaks in the American colonies and in British India as well. Introduced to the Americas by European conquerors and settlers, smallpox decimated native populations from the Plains Indians of Canada and the United States to the Aztecs of Mexico and the Araucanians of Chile. The Australian Aboriginals also suffered large losses from the disease in the 19th century.
The history of smallpox is uncertain. Genetic analyses of viral DNA isolated from a mummified child who had been interred in a church in Lithuania suggest that variola virus had evolved by at least the 17th century. It is likely, however, that the virus was circulating in human populations much earlier, based on the recovery of variola virus DNA from teeth and bones of human remains dated to 600–1050 that were uncovered in the region of modern-day Denmark and Russia. Prior to that discovery, the disease had been thought by some scholars to have arisen among settled agricultural populations in Mesopotamia as early as the 5th millennium BCE and in the Nile River valley in the 3rd millennium BCE, though evidence for those events was lacking. Around 570, Bishop Marius of Avicentum (near Lausanne, Switzerland) introduced the Latin term variola (meaning “pox” or “pustule”). The English term pox was used to describe various eruptive diseases, including a pox disease that came to be known as smallpox. In the 16th century, variola became popularly known as the “small pox,” to distinguish it from syphilis (the “Great Pox”). By that time the “small pox” seems to have succeeded plague as the most-feared pestilence in Europe.
A huge pandemic reached from Europe to the Middle East in 1614, and epidemics arose regularly in Europe throughout the 17th and 18th centuries. There were frequent outbreaks in the American colonies and in British India as well. Introduced to the Americas by European conquerors and settlers, smallpox decimated native populations from the Plains Indians of Canada and the United States to the Aztecs of Mexico and the Araucanians of Chile. The Australian Aboriginals also suffered large losses from the disease in the 19th centuries.
By the beginning of the 20th century, smallpox was no longer endemic in several countries of continental Europe. Endemic smallpox was eradicated from the United Kingdom in 1934, the U.S.S.R. in 1936, Canada in 1946, the United States in 1949, Japan in 1951, and China in 1961. Still, in an age of global travel only an international effort could completely eradicate the disease. In 1967 WHO began to vaccinate entire populations around every reported outbreak of smallpox. The disease was no longer endemic in India by 1975 and in Ethiopia by 1976. The last endemic case of smallpox (actually an infection of variola minor) was recorded in Somalia in 1977. No cases were reported from 1977 to 1980, with the exception of two cases in England in 1978 whose source was in a laboratory, and in 1980 the disease was declared exterminated.
🔎EDWARD JENNER :
The smallpox vaccine, introduced by Edward Jenner in 1796, was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.
The basis for vaccination began in 1796 when the English doctor Edward Jenner noticed that milkmaids who had gotten cowpox were protected from smallpox. Jenner also knew about variolation and guessed that exposure to cowpox could be used to protect against smallpox.
🔎Symptoms :
The first symptoms of smallpox usually appear 12 to 14 days after you're exposed to the smallpox virus. However, the virus can be in your body from 7 to 19 days before you look or feel sick. This time is called the incubation period.
After the incubation period, sudden flu-like symptoms occur. These include:
🧿 Fever
🧿 Muscle aches
🧿 Headache
🧿 Severe fatigue
🧿 Severe back pain
🧿 Vomiting, sometimes
A few days later, flat, red spots appear on the body. They may start in the mouth and on the tongue and then spread to the skin. The face, arms and legs are often affected first, followed by the torso, hands and feet.
🔎Causes of Smallpox:
The variola virus causes it. There are two forms of the virus. The more dangerous form, variola major, led to smallpox disease that killed about 30% of people who were infected. Variola minor caused a less deadly type that killed about 1% of those who got it.
Two forms of smallpox were more deadly than the common strain: Hemorrhagic and malignant.
Hemorrhagic smallpox tended to affect adults, including pregnant women, not children. People had more serious symptoms, including fever, pain, and headaches, and they leaked blood from their blisters and mucous membranes. People usually died of blood poisoning within a week.
🔎Treatment for Smallpox :
Treatment of smallpox patients generally involves supportive care. Vaccination with replication-competent smallpox vaccines (i.e., ACAM2000 and APSV) can prevent or lessen the severity of disease if given within 2 to 3 days of the initial exposure. They may decrease symptoms if given within the first week of exposure.
There is no cure for the smallpox virus. As a result of worldwide, repeated vaccination programs, the variola virus (smallpox) has been completely eradicated.
🔎Is there vaccine for smallpox?
Smallpox vaccination provides full 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.
🔎prevention of Smallpox :
The smallpox vaccine is the only way to prevent smallpox. The vaccine is made from a virus called vaccinia, which is another pox-type virus related to smallpox. The vaccine helps the body develop immunity to smallpox. It was successfully used to eradicate smallpox from the human population.
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