A person with the smallpox disease is only contagious through spread of the fluids from the rashes or pustules A small circumscribed elevation of the skin containing pus and having an inflamed base. that develop as a result of the disease. Direct contact with infected skin can transmit the virus. However, the first locations lesions An abnormal change in structure of an organ or part due to injury or disease; especially one that is circumscribed and well defined. appear are typically inside the mouth. Therefore, coughing, sneezing, speaking and even breathing can spread the virus through saliva droplets expelled from the mouth. As a result, the greatest risk comes from prolonged face-to-face contact (6 feet or less, most often after 1 or more hours), with an infected person. This is particularly troubling for emergency workers because the patient may present with nothing more than a fever and sores inside their mouth that the emergency worker may or may not detect.

Where smallpox originated is uncertain. However, it is thought to have originated in Africa and after that spread to India and China thousands of years ago. The first smallpox epidemic to be recorded was in 1350 BC in the time of the Egyptian-Hittite war. Smallpox got to Europe between the 5th and 7th centuries and by 18th century it was present in major European cities.

The first symptoms of smallpox usually appear 12 to 14 days after you're infected. During the incubation period of seven to 17 days, you look and feel healthy and can't infect others. Following the incubation period, a sudden onset of flu-like signs and symptoms occurs. These include:

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. There are four types of variola major smallpox: ordinary (the most frequent type, accounting for 90% or more of cases); modified (mild and occurring in previously vaccinated persons); flat; and hemorrhagic (both rare and very severe). Historically, variola major has an overall fatality rate of about 30%; however, flat and hemorrhagic smallpox usually are fatal. Variola minor is a less common presentation of smallpox, and a much less severe disease, with death rates historically of 1% or less.