[SaneVax: Everything you always wanted to know about dormant viruses. What happens when you are exposed to a virus? Once they are in your body do they ever go away? How much risk is involved when you are exposed to different types of viruses? The graphic below answers all of these questions and more. It was originally published by www.bestmedicaldegrees.com, who kindly granted permission to republish it on this site for the purpose of educating medical consumers.]
Dormant viruses can lie within a human host until the proper conditions for their activity are provided. You might think of viruses’ as robots that need to take over a factory to make more of themselves. Without that, the viruses are dormant.
One million PLUS: number of years that viruses have existed since the beginning of life on Earth.
A virus is a very small infectious agent (20-300 nanometers in diameter) with a genome consisting of a single kind of nucleic acid (RNA or DNA) contained within a protein shell.
Size: 20 nanometers: length of the smallest virus. The largest is the size of the smallest bacteria.
Shape: viruses look like rods, filaments, crystals, helixes, polyhedrons and spheres, with added extensions. Almost all human viruses are close to being spherical.
FACT: The discovery of viruses is credited to the St. Petersburg Academy of Science in 1892 by Dmitri Iwanowsk (1864-1920), a Russian botanist. While studying a tobacco disease, he found that the agent causing the disease was small enough to pass through a ceramic filter that was small enough to trap all bacteria. This was beginning of Virology.
1930: the first time a virus is seen by the human eye — thanks to the introduction of the electron microscope.
Dead or Alive: viruses are not classifiably alive or dead. They seem to be in limbo between each state.
Persistent viruses can enter and exit host cells without killing them.
There are normally very few viruses found within a human being. Unlike bacteria, there are no known viruses whose presence is either essential or particularly beneficial to humans.
Thank you for a most informative, useful and pedagogically supreme graphic!