Smallpox virus

Smallpox is an infectious disease caused by two virus variants, Variola major and Variola minor. The disease was originally known as the "pox" and was a major cause of death worldwide, with an estimated 300–500 million deaths in the 20th century. In 1967, the World Health Organization (WHO) initiated an intensive global smallpox eradication campaign. By 1980, the WHO had certified the eradication of smallpox, making it the first disease to be eradicated by human effort.

History

The earliest evidence of smallpox is found on the teeth of a child buried in Egypt over 3,000 years ago. The disease was a significant factor in the invasions of Europe by the Huns and later by the Mongols. Smallpox was introduced to the Americas by European colonists, where it devastated the indigenous populations.

Transmission

Smallpox is transmitted from person to person via infective droplets during close contact with infected symptomatic people. Unlike most other DNA viruses, smallpox was able to spread in the absence of a living host, surviving on inanimate objects such as bedding or clothing.

Symptoms

The initial symptoms include high fever, fatigue, and severe back pain. This is followed by the development of a characteristic skin rash. The rash develops into raised bumps, which fill with a thick fluid and later crust over.

Treatment and Prevention

There is no specific treatment for smallpox. Prevention is achieved through the smallpox vaccine. The vaccine was developed by Edward Jenner in 1796, who discovered that milkmaids who had contracted cowpox did not catch smallpox.

Eradication

The global eradication of smallpox was certified by a commission of eminent scientists in December 1979 and subsequently endorsed by the World Health Assembly on 8 May 1980. The first two sentences of the resolution read "Having considered the development and results of the global program on smallpox eradication initiated by WHO in 1958 and intensified since 1967... Declares solemnly that the world and its peoples have won freedom from smallpox."