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Smallpox is a serious disease caused by the variola virus that was announced as eradicated, or wiped out, by the World Health Organization in 1980.
However, smallpox remains a serious threat due to the possibility that some of the remaining stock, if in the wrong hands, could be grown and adapted for bioterrorism purposes.
Smallpox has a fatality rate of 30 percent or more.
How smallpox is spread
Smallpox spreads directly from person to person, primarily from the mouth and throat droplets or aerosols from the infected person.
In addition, contaminated clothes or linens can also spread the virus.
Transmission is highest during the onset of rash through the 7th to 10th days of the rash.
As the scabs form, the infectivity of smallpox declines.
Because of changes in temperature and humidity, there is more occurrence of smallpox in the winter and early spring.
There are no known animal or insect reservoirs or carriers to transmit smallpox.
The symptoms of smallpox are
After the incubation period, 10-12 days on average, high fever, malaise, headache, and backache develop.
Abdominal pain and delirium or disorientation sometimes occur.
Small, colored, bumpy rash begins on the mouth, pharynx, face, and forearms, spreading to the trunk and legs.
Within 1-2 days, the rash becomes blisters, and then round and deeply set pimples with pus form in the skin.
Within 8-9 days, the pimples with pus become crusted.
Scabs separate, leaving pigment-free skin, and eventually pitted scars form.
How smallpox can be treated
Treatment of smallpox is limited to supportive therapy and antibiotics for secondary bacterial infections.
There are no antivirals, treatments to kill or suppress the virus that have proven to be effective.
The smallpox vaccine
There is a vaccination for smallpox. However, routine vaccination stopped in the United States in 1972, and production of the vaccine had ceased by 1980, due to the eradication of smallpox.
Those who received the vaccinations before 1972 do not have lifelong immunity because it declines within a 5-10 year period after the vaccination.
A limited supply of vaccine still exists in the United States under Center for Disease Control and Prevention authority.
Vaccines administered within 3 days of the first exposure have shown to offer some protection against getting infection and significant protection from mortality.
Precautions against smallpox
Patients should be isolated or confined in rooms with high air filtration.
Standard precautions (gloves, mask, and gown) should be worn.
All laundry and waste should be sterilized with steam under pressure before being laundered or destroyed.
Standard hospital disinfectants should be used for surface decontamination.