how does smallpox work?

Question

what happens to the person that has it? is it just like chicken pox, but deadly?

Answer 1

"The disease is only moderately infectious, far less so than chickenpox. Unlike chickenpox, smallpox is not notably infectious in the prodromal period—viral shedding being delayed until the appearance of the rash. Smallpox transmission is a risk of prolonged social contact, direct contact with infected body fluids or contaminated objects. Infection in the natural disease will be via the lungs. The incubation period to obvious disease is around 12 days. In the initial growth phase the virus seems to move from cell to cell, but around the 12th day, lysis of many infected cells occurs and the virus will be found in the bloodstream in large numbers. The initial or prodromal symptoms are essentially similar to other viral diseases such as influenza and the common cold—fevers, muscle pain, stomach aches, etc. The digestive tract is commonly involved, leading to vomiting. Most cases will be prostrated.

Smallpox virus preferentially attacks skin cells and by days 12–15, smallpox infection becomes obvious. The attack on skin cells causes the characteristic pimples associated with the disease. The pimples tend to erupt first in the mouth, then the arms and the hands, and later the rest of the body. At that point the pimples, called macules, should still be fairly small. This is the stage at which the victim is most contagious.

By days 15–16 the condition worsens—at this point the disease can take two vastly different courses. The first form is of classical ordinary smallpox, in which the pimples grow into vesicles, and then fill up with pus (turning them into pustules). Ordinary smallpox generally takes one of two basic courses. In discrete ordinary smallpox, the pustules stand out on the skin separately—there is a greater chance of surviving this form. In confluent ordinary smallpox, the blisters merge together into sheets which begin to detach the outer layers of skin from the underlying flesh—this form is usually fatal. If the patient survives for the course of the disease, the pustules will deflate in time (the duration is variable), and will start to dry up, usually beginning on day 28. Eventually the pustules will completely dry and start to flake off. Once all of the pustules flake off, the patient is considered cured."