Smallpox (Variola Virus) is a lethal infection caused by the variola virus which has at least two strains, variola major and variola minor. Cases of smallpox date back over 2000 years, and is the oldest-known human pathogen. Conquistadors brought the disease from Spain during the 1700s and it was transmitted to tha American Indians, which wiped out over 90% of the population over the next 100 years. It is believed that Ramses V, the Egyptian pharaoh who died in 1157 B.C., may have had pock marks on his mummified face. Naturally occuring smallpox was declared erdicated from the earth in 1980 by the World Health Organization (WHO), a branch of the U.N. The last reported case in the world occured in Somalia in 1977. Two laboratories in the world still hold the last-known stocks of variola virus: the CDC in Atlanta, and VECTOR in Novizbersk, Russia. Clandestine stocks could exsist in other parts of the world, but are as yet unknown. If they do exsist, smallpox could come into the hands of terrorists and be used as a biological weapon.
Vaccination of civilians in the U.S. was discontinued in the early 1980s, although some military forces vaccinated until 1989 may still retain some immunity. Children, who are no longer vaccinated, would be at great risk from exposure to smallpox. The Japanese government considered using smallpox as a biological weapon during World War II and the virus has been considered a threat to U.S. military forces for many years. Monkeypox and cowpox are closely related to variola and might be genetically manipulated to produce a smallpox-like virus.
Once exposure to the smallpox virus occurs, the incubation period is approximately 12 days. Those who may have contacted exposed persons are quarantined for a minimum of 16 to 17 days following the exposure. Symptoms of smallpox include malaise, fever, rigors, vomiting, headache, and backache, and about 15% of the patients develop delirium (hallucinations). In approximately 2 to 3 days, an enanthem develops concomitantly with a particular rash on the face, hands, and forearms. This is followed by eruptions on the lower extremities and the trunk of the body, which occur over a week's time. Lesions progress from discolored spots flush with the surface of the skin to raised spots on the skin, and finally to an inflamed swelling containing pus on the skin (skin blisters). Lesions are more abundant on the extremities and face, which is important in the diagnosis of the disease. Within 8 to 14 days, scabs form on the skin blisters. Once the scab falls off, a discolored depression is left behind. As long as the scabs are in place the patient is considered contagious and should be isolated.
