Smallpox
Recovery/Mortality Rate:
- Death is likely in one third of all smallpox cases, usually during the first or second week of illness.
- Of those who recover, 65 to 85 percent are marked with deep-pitted scars.
- Some who recover may be permanently blind.
Diagnosis
Physicians have not seen cases of smallpox for more than two decades, and making a diagnosis would require familiarity with the disease and its history. However, the Centers for Disease Control and Prevention has worked on educating first responders and emergency room personnel about the signs and symptoms of smallpox.
- Smallpox is most commonly identified by the distinctive rash it causes.
- The rash can sometimes be confused initially with chicken pox.
- The smallpox lesions are painful (as opposed to chicken pox lesions).
- The distribution of smallpox lesions on the body is different from those of chicken pox.
- Patients with smallpox are typically much sicker.
- Testing of the fluid from the lesions can confirm smallpox.
Treatment
There is little that physicians can do, other than giving supportive care, to treat the illness itself; containing a smallpox outbreak becomes the priority once a case is suspected or confirmed. The public health community becomes involved to track down and vaccinate those who may have been exposed to an infected patient and their close contacts (e.g., family). Strict home or hospital isolation of cases is very important; close contacts must be kept under close daily surveillance and isolated if they develop fever.
- Antibiotics are not effective.
- There is no way to fight the virus once patients become sick.
- Patients with smallpox are isolated.
- Patients with smallpox may require intravenous fluids and medication to control fever or pain.
- Secondary bacterial infections of the skin sometimes occur. These can be treated with antibiotics.
- Research is currently underway on the use of the antiviral drug cidofovir as a treatment for smallpox.
Vaccine
After the September 11 attacks, fears that terrorists would use the smallpox virus as a biological weapon led to renewed vaccine production. There is now enough vaccine available in the Strategic National Stockpile for every American in case of an attack.
- The vaccine contains a live virus (vaccinia) which is related to the smallpox virus but entirely different from it; the vaccinia virus is weaker so that people produce antibodies but usually develop only the single pustule at the site of vaccination and, sometimes, a low-grade fever.
- The vaccine provides a high level of immunity from infection for three to five years after vaccination and decreasing immunity thereafter. It is unclear how long the vaccine provides some protection against the disease. If a person is vaccinated again later, immunity lasts even longer.
- However, if a person actually has had smallpox and survives, he or she then has lifelong immunity.
- The vaccine prevents disease in 95 percent of those vaccinated.
- Given within three days after exposure to the smallpox virus, the vaccine will prevent or significantly modify smallpox in the majority of persons. Vaccination four to seven days after exposure most likely offers some protection from disease or may modify the severity of the disease.
- The smallpox vaccine is currently not administered to the general public because:
The likelihood of an attack is not known.
Vaccination can result in complications for several specific groups of people with skin conditions, such as eczema, as well as for people with HIV/AIDS and others with compromised immune systems
Pregnant women, infants under 1 year old, and those taking steroids could also suffer complications
Recent research indicates that people with certain heart conditions should not receive the vaccine (at least until further research is conducted). - The vaccine is effective after one dose, so it could easily be given to many people if a smallpox event or outbreak takes place.
- Vaccination of only those people who might have been exposed to the smallpox virus and their contacts (ring vaccination) was used successfully in the past to eradicate smallpox. However, mass vaccination might be necessary in the aftermath of a terrorist attack.
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