Transmission
"A person ill with smallpox shed millions of infective viruses into his immediate environment from the rash on his skin and open sores in the throat. Each victim remained infectious from just before the rash appeared until the last scab dropped off about three weeks later, but was most highly contagious during the first several days of that period. Corpses of victims who died of the infection were also a dangerous source of virus. Sometimes clothing, shrouds, or blankets recently contaminated with pus or scabs served as a vehicle for the virus, whereby persons who were not in direct contact with a patient would become infected. Most victims, however, acquired the virus through droplet infection, while in face-to-face contact with a patient by inhaling contaminated air. Only very rarely was airborne smallpox virus known to have infected another person beyond the immediate vicinity of the victim. Not all persons who were exposed to smallpox became infected. The chances of being infected were about fifty-fifty for other susceptible members of the same household, for example."
- Donald R. Hopkins; Princes and Peasants: Smallpox in History
- Donald R. Hopkins; Princes and Peasants: Smallpox in History
"Variola's relationship to humankind is both parasitic and paradoxical. To thrive and multiply, the virus has to have a host. Variola consumes its human hosts as a fire consumes its fuel, leaving spent bodies, dead or immune, behind. To survive, the virus has to find a constant supply of new victims. In a large urban population, such individuals might become available through immigration or childbirth. But elsewhere, if Variola is to succeed, it has to travel. It has to find more hosts and then, inexorably, still more.
Variola has no animal vector. It is not transmitted by insects like malaria or by water like cholera. It passes only from one human being to another. As a result, Variola's story is necessarily a story of connections between people."
- Elizabeth A. Fenn; Pox Americana
Variola has no animal vector. It is not transmitted by insects like malaria or by water like cholera. It passes only from one human being to another. As a result, Variola's story is necessarily a story of connections between people."
- Elizabeth A. Fenn; Pox Americana
"The smallpox virus is unique among viruses in that it infects only humans- no other animals. It has survived for thousands of years by infecting one person after another in an unbroken chain of disease. Usually, transmission of the virus occurred only as a result of face-to-face contact. As soon as a patient started to develop a rash, lesions in his mouth and throat began to shed millions of microscopic virus particles into his saliva. These particles would be carried into the air when he spoke or coughed. Anyone close enough to inhale them became the next link in the chain of infection."
" For the smallpox virus to survive, it needs a population large enough to enable one susceptible person after another to be infected."
- D.A. Henderson, MD; Smallpox: The Death of a Disease
" For the smallpox virus to survive, it needs a population large enough to enable one susceptible person after another to be infected."
- D.A. Henderson, MD; Smallpox: The Death of a Disease