Generality
Smallpox is a very contagious and lethal infectious disease, fortunately extinct for thirty years.
It is caused by the Variola major virus, a microorganism belonging to the Poxviridae family, viral agents that share great dimensions and the ability to determine vesicular rashes.
Contagion
The disease is transmitted by close contact with skin lesions or respiratory secretions of sick people, or through contaminated objects.
Symptoms
To learn more: Smallpox
After the infection, the incubation period varies from 7 to 17 days, generally from 10 to 14.
The first symptoms are flu-like: high fever, general malaise, exhaustion and osteo-articular pain, often accompanied by a fleeting erythematous rush spread to the whole body; after 2-4 days the fever is attenuated and an eruption takes place that affects the mucous membranes and the skin, with uniform progression in macules, papules and pustules (resumes fever and general conditions worsen), which then evolve into blackish crusts (the fever regresses and general conditions improve); each of these phases lasts from 2 to 3 days and the disease, in cases of benign prognosis, resolves within two weeks, often leaving disfiguring scarring.
The morbid picture can however present itself in a more or less severe form (hemorrhagic smallpox or black smallpox, confluent smallpox and attenuated smallpox); in general, mortality reaches 30%.
Vaccination
The general vaccination of the population led to the definitive eradication of the disease in the late 1970s, but the specter of smallpox continues to live in the possibility of bioterrorist attacks, forcing the nations to conserve large stocks of vaccines.
Regarding the latter, we recall how the smallpox vaccine was the first man-made product; this discovery dates back to 1798, when, after 22 years of studies, Edoardo Jenner discovered a way to prevent the disease based on graft of the cowpox virus on human skin.
