-Old world disease and an indiscriminate disease, can target anybody
-From domesticated animals, first found in mummified Pharaoh Ramses V who had pockmarks.
-100AD, Plague of Antonine, known in Greece and Rome, brought from soldiers in Mesopotamia
(italy), trade caravans assisted in the spread of smallpox
-16th century became a serious disease in England and Europe
-Biological warfare: French-Indian war, used smallpox against the Indian troops, on blankets and
-After 9 days of exposure, acute onset: fever, malaise, rigors, vomiting, headache, backache and
occasionally delirium, high intensity but short period of time.
-2-3 days later skin lesions appear; 8 to 14 days after symptoms appear, the pustules develop scabs
and heal, can lead to severe scarring
-Infectious: day prior to the appearance of the rash and until the time the scabs have separated
-Secondary infections, eyebrows or eyelashes falling, disfiguration, hand and feet.
-1/3 of infected people became blind
Death: may occur a few days or a week after the rash appears, complications from secondary
infections, destruction of sebaceous (oil) glands, leaves pockmarks, death highest among infants,
induce abortions in all trimesters of pregnancy
-Inhalation of infected droplet, direct contact or contaminated fomites, skin scabs (inanimate
objects, outside (blankets) – can live up to 2 days),
-not zoonotic only exists in humans, human are short-term carriers
-spreads more rapidly during winter in mild climates and during dry season in tropics
-Virus multiplies in the mucous membranes of the mouth and nose then moves to the lymph nodes
and then to internal organs, there it re-enters the bloodstream.
-In the mucous membrane – incubation period. Average incubation period is of 12-14 days.
-Potential for long-distance spread is controversial (does exist). Transmission on fomites is possible
for short-period of time.
-Transmission of 1978, transmission did not occur from direct contact from long distance, aerosol
via air vents
Virus: (one of the largest)
·Orthopoxvirus (genus), Poxviridae (family) – also includes cow pox, monkey pox (symptoms same