Wed, 30 Apr 2003

Smallpox was contagious, still incurable

Donya Betancourt, Pediatrician,

Smallpox was once found throughout the world but thanks to global vaccination programs, smallpox outbreaks have been eradicated.

The Centers for Disease Control and Prevention (CDC) says the smallpox vaccination offers a high-level immunity for three to five years with decreasing immunity after five years.

The variola virus is what causes smallpox. This disease is serious, highly contagious and sometimes fatal. It spreads from one person to another by direct contact with lesions and by breathing infected droplets in the air.

The smallpox virus now exists only as a stored virus in several countries. The only way you could get smallpox today is if the virus were used as an agent of bioterrorism.

Smallpox outbreaks have occurred from time to time for thousands of years. The last naturally occurring case in the world was in Somalia in 1977. Since that time the eradication program has taken hold and the routine vaccination for smallpox has stopped, as it was no longer necessary for prevention.

The name smallpox is derived from the Latin word for "spotted" and refers to the raised bumps that appear on the face and body of an infected person.

Smallpox is not known to be transmitted by insects or animals. Humans are the only natural hosts of variola.

There are two clinical forms of smallpox.

Variola major is the severe and most common form of smallpox, with a more extensive rash and higher fever. Historically, variola major has an overall fatality rate of about 30 percent; however, flat and hemorrhagic smallpox are usually fatal. Variola minor is a less common presentation of smallpox, and a much less severe disease, with death rates historically of 1 percent or less.

After exposure to the smallpox virus there is an incubation period which has no symptoms, during this time people are not contagious. The first symptoms are high fever (38 C or 101 F up), malaise, head and body aches, and sometimes vomiting. The infected person will look very sick, then a rash emerges as red spots on the tongue and in the mouth. The sores break open, which spreads large amounts of the virus throughout the mouth and throat, at this time the infected person is most contagious.

Typically, a rash appears on the face to arms, legs, hands and feet within 24 hours. As the rash appears, fever will go down and the infected person will start to feel better, after that the rash will be raised bumps, then turn thick with an opaque fluid and a depression in the center which is the distinguishing characteristic of a smallpox rash. Fever will rise again at this time and remain high until a scab forms over the bumps. The pustules (sharply raised, usually round and firm to the touch as if there's a small round object under the skin.) begin to form a crust and then scab.

By the end of the second week after the rash appears, most of the sores will have scabbed over and the worst is over.

There's no cure for smallpox. Treatment with antibiotics is not effective. The only prevention is vaccination.

As I stated earlier there is currently no routine vaccine program for the smallpox virus and most medical professionals will agree that today the only way to be infected by smallpox is via bio terrorism however the CDC does have a vaccine available for special cases.