Such views were held in disdain, however, and Galen's miasma theory remained dominant among scientists and doctors.The nature of this doctrine prevented them from understanding how diseases actually progressed, with predictable consequences.
The germ theory was proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762.The earliest physical evidence of it is probably the pustular rash on the mummified body of Pharaoh Ramses V of Egypt. Variola major was the severe and most common form, with a more extensive rash and higher fever.Variola minor was a less common presentation, and a much less severe disease, with historical death rates of 1 percent or less.Hirschsprung's (HIRSH-sproongz) disease is a condition that affects the large intestine (colon) and causes problems with passing stool.The condition is present at birth (congenital) as a result of missing nerve cells in the muscles of the baby's colon.Patients with ordinary-type smallpox usually had bumps filled with a thick and opaque fluid, often with a depression or dimple in the center.
This is a major distinguishing characteristic of the disease.
Bayoud destroyed the world's most renowned varieties that are susceptible to the disease and particularly those which produce high quality and quantity fruit (Medjool, Deglet Nour, Bou Fegouss).
It also accelerated the phenomenon of desertifi cation (Figures 90a and b).
Blindness resulting from corneal ulceration and scarring, and limb deformities due to arthritis and osteomyelitis were less common complications, seen in about 2–5 percent of cases.
Smallpox is believed to have been acquired by humans originally as a zoonosis from a terrestrial African rodent between 16,000 and 68,000 years ago, well before the dawn of agriculture and civilization.
Infection with smallpox is focused in small blood vessels of the skin and in the mouth and throat before disseminating.