- Click to share on Facebook (Opens in a new window)
- Click to share on Twitter (Opens in a new window)
- Click here to share on LinkedIn (Opens in a new window)
- Click to email a friend (Opens in a new window)
(CNN) - Smallpox is a contagious and sometimes fatal infectious disease. The most severe and common form of the smallpox virus is known as variola major.
Types of variola major smallpox:
Ordinary: it is the most common, 85% of cases
Modified: it is mild and occurs in those who have been vaccinated
Flat: occurs more frequently in children and is usually fatal
Hemorrhagic: occurs more frequently in adults; It is serious and generally fatal
LOOK: A Russian laboratory that has samples of the deadly smallpox virus exploded and caught fire
How is it transmitted?
Smallpox is transmitted by prolonged face-to-face contact or by direct contact with infected body fluids or contaminated objects.
Insects and animals do not transmit smallpox.
The incubation period on average is between 10 and 14 days (but may vary from 7 to 19 days) after exposure. The subjects are not contagious at that time.
The symptoms
Initial symptoms include high fever, fatigue and headaches and backaches. A characteristic rash that is prominent on the face, arms and legs arrives two or three days later. The rash begins with flat red lesions that evolve at the same rate. The lesions fill with pus and begin to form scabs at the beginning of the second week. The scabs develop and then separate and fall off after about three or four weeks.
Most patients with smallpox recover, but death occurs in up to 30% of cases.
MIRA: What is comecarne bacteria?
Timeline
1950 - Worldwide, 15 million cases of smallpox are reported each year
1977 - The last natural case of smallpox in the world occurs in Somalia
1979 - Smallpox meets the eradication criteria by not having natural cases for two years
1980 - The World Health Organization announces the official eradication of smallpox
2008 - According to a study published in the American Journal of Medicine, "researchers found that lifetime protection is obtained from a single vaccine, even if that vaccine was produced 88 years ago."
2014 - Six vials containing the smallpox virus are in an unused storage room on the Bethesda, Maryland, campus of the Food and Drug Administration. Subsequent tests show that at least two of the vials, dating from 1954, contain the live virus. There are only two regulated deposits that have stocks of variola, the virus that causes smallpox: the Centers for Disease Control and Prevention in Atlanta and the Russian State Center for Virology and Biotechnology Research in Koltsovo.
2016 - The oldest known sample of the virus that causes smallpox is found within the DNA of a 17th-century infant mummy, in a crypt under a Lithuanian church, according to a study published in the journal Current Biology. The finding offered more details of how long ago smallpox affected humans: it was much less than had been estimated.
LOOK: Keys to understand what is the amoebra bristle
Smallpox vaccine
In people exposed to smallpox, the vaccine may decrease the severity or prevent the disease when administered within three to four days after exposure.
Vaccine pathogen exposure in the vaccine can cause serious complications in rare cases. The people most at risk are those with compromised immune systems and people with certain skin conditions that may be more sensitive to the virus in the vaccine.
Most Americans under 40 have not been vaccinated. The last case of smallpox in the United States was in 1949, and routine vaccination was stopped in 1972. Some doctors and military are still vaccinated.