From this thread:
Clinical Features
The incubation period of smallpox is usually 12-14 days (range 7-17) during which there is no evidence of viral shedding. During this period, the person looks and feels healthy and cannot infect others. The incubation period is followed by the sudden onset of influenza-like symptoms including fever, malaise, headache, prostration, severe back pain and, less often, abdominal pain and vomiting. Two to three days later, the temperature falls and the patient feels somewhat better, at which time the characteristic rash appears, first on the face, hands and forearms and then after a few days progressing to the trunk. Lesions also develop in the mucous membranes of the nose and mouth, and ulcerate very soon after their formation, releasing large amounts of virus into the mouth and throat.
The centrifugal distribution of lesions, more prominent on the face and extremities than on the trunk, is a distinctive diagnostic feature of smallpox and gives the trained eye cause to suspect the disease. Lesions progress from macules to papules, to vesicles, to pustules. All lesions in a given area progress together through these stages. From 8 to 14 days after the onset of symptoms, the pustules form scabs which leave depressed, depigmented scars upon healing.
Smallpox was sometimes confused with chickenpox, a worldwide infection of children that is seldom lethal. Chickenpox can be distinguished from smallpox by its much more superficial lesions, their presence more on the trunk than on the face and extremities, and by the development of successive crops of lesions in the same area. Smallpox is a disease which can be easily diagnosed by trained health workers without the need for laboratory support. During the eradication campaign, WHO produced training materials designed to help health staff recognize smallpox, distinguish it from chickenpox, and avoid common diagnostic errors. These materials are now available electronically. (A WHO slide set on the diagnosis of smallpox can be found at http://www.who.int/emc/diseases/smallpox/slideset/index.htm).
Infectivity
Persons carrying the virus during the incubation period cannot infect others. The frequency of infection is highest after face-to-face contact with a patient once fever has begun and during the first week of rash, when the virus is released via the respiratory tract. Although patients remain infectious until the last scabs fall off, the large amounts of virus shed from the skin are not highly infectious. Exposure to patients in the late stages of the disease is much less likely to produce infection in susceptible contacts. As a precaution, WHO isolation policy during the eradication campaign required that patients remain in isolation, in hospital or at home, until the last scab had separated.
See 101. :-)
Yes, I have read this. It's just not accurate.
The description of the lesions first showing up on the head and extremities before moving to the trunk sounded a lot like the case of Chickenpox I had about nine years ago. I think I almost looked as bad as that picture someone else posted on this thread.
All I can say is that anyone stupid enough to cultivate smallpox as a weapon is definitely stupid enough to try to use it. If they do, I'd definitely support using a nuke to take out the lab or warehouse that produced and stored it, just to be sure it was good and dead. A little one ought to do.
Gamma