In , the four countries that either served as a WHO collaborating center or were actively working with variola virus were the United States, England, Russia, and South Africa.
By , England and South Africa had either destroyed their stocks or transferred them to other approved labs. Three-year-old Rahima Banu with her mother in Bangladesh. Rahima was the last known person to have had naturally acquired smallpox in the world. An 8-year-old girl named Bilkisunnessa reported the case to the local Smallpox Eradication Program team and received a Taka reward. Foster M. WHO poster commemorating the eradication of smallpox in October , which was officially endorsed by the 33rd World Health Assembly on May 8, Courtesy of WHO.
Skip directly to site content Skip directly to page options Skip directly to A-Z link. Section Navigation. Facebook Twitter LinkedIn Syndicate. History of Smallpox. Minus Related Pages. Origin of Smallpox The origin of smallpox is unknown. Spread of Smallpox Historians trace the global spread of smallpox to the growth of civilizations and exploration. Early Control Efforts Smallpox was a terrible disease. Edward Jenner — Photo courtesy of the National Library of Medicine.
Last Cases of Smallpox In late , three-year-old Rahima Banu from Bangladesh was the last person in the world to have naturally acquired variola major. Scabs form over the lesions leaving survivors with pitted scars. The process of eradicating smallpox was long and complicated, requiring the coordinated efforts of people around the globe. Not every disease can be eradicated; it just so happened that smallpox has many characteristics that lend ease to eradication. The incubation period, the time between initial infection and visible symptoms, is relatively short, which prevents the disease from spreading undetected.
The symptoms are also very distinctive, allowing for easy identification of smallpox patients. The World Health Organization put in place a "ring vaccination" method whereby vaccines weren't given only to infected people, but also to anyone who may have been exposed to an infected person.
In remote areas, World Health Organization workers tracked down infected persons by showing locals pictures of people with smallpox symptoms and asking if they had seen anyone with them. Luckily for humans, smallpox only infects us. The lack of of an animal reservoir really aided in eradicating the disease. A large number of diseases affecting humans can be caught and transmitted by other species. For example, Dengue Fever is spread by infected mosquitoes, while the Black Plague was spread by fleas on rats.
Even if all humans were somehow vaccinated against Dengue Fever, the virus would still not be eradicated since it would still survive in the mosquito population. Since smallpox only infects us, once the human population was vaccinated the virus was wiped out. Effective vaccination also helped in the eradication process. The smallpox vaccine can prevent infection up to four days after initial exposure. But it can also be passed on via the fluid from smallpox blisters.
Typically, someone would need to have been in close proximity to an infected person before catching it themselves. There are no effective treatments or cures for smallpox, but vaccination can be used effectively to prevent infection from developing.
The earliest attempts at immunization involved a process known as variolation. The recipient would usually make a full recovery and develop immunity to smallpox. But they may also have been shedding the virus and spread the disease to people who subsequently became seriously ill and died. Two people in particular are credited with developing what we now think of as the smallpox vaccine. The first was farmer Benjamin Jesty, who spotted a link between smallpox and cowpox.
More than two decades later there was Edward Jenner, a doctor from England who is usually credited with the discovery and whose rigorous, scientific approach helped the idea of vaccination take off more widely. He observed that agricultural workers who had contracted cowpox seemed to be immune to smallpox. In , Jenner set out to prove there was a connection between these two illnesses. He found a cowpox sufferer, extracted fluid from one of her blisters and — using the variolation technique — infected an eight-year old boy.
Mild reactions to the vaccine can include fever, fatigue and tiredness. But it carries a small risk of serious side-effects , including a condition called progressive vaccinia, where the vaccine triggers an uncontrolled replication of the virus at the vaccination site. We discuss estimates of this discrepancy in the data quality section of our entry. In the s and 60s the number of reported cases started to decline and by the end of the s there were no cases reported anymore.
The WHO search teams continued to search for more smallpox cases but, with the exception of two tragic cases in Birmingham in the United Kingdom due to a laboratory accident in , 2 found none. Therefore, in the World Health Organization declared smallpox the first — and so far only human — disease to be eradicated globally. Imagine what this means, a disease that was once common across the world and caused millions of deaths and disfigured the faces of even more simply does not exist anymore.
For more detailed information on the characteristics of smallpox, its global history, and the vaccine that ended the disease, visit our entry on Smallpox that we published simultaneously with this blog post.
0コメント