What are virus?

  • (noun): A software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer.
    Example: "A true virus cannot spread to another computer without human assistance"
    Synonyms: computer virus
    See also — Additional definitions below


A virus is a small infectious agent that can replicate only inside the living cells of an organism. Viruses can infect all types of organisms, from animals and plants to bacteria and archaea.

Read more about Virus.

Some articles on virus:

Parvovirus B19
... The B19 virus, generally referred to as parvovirus B19 or sometimes erythrovirus B19, was the first (and until 2005 the only) known human virus in the family of parvoviruses, genus ... B19 virus causes a childhood rash called fifth disease or erythema infectiosum which is commonly called slapped cheek syndrome ... The virus was discovered by chance in 1975 by Australian virologist Yvonne Cossart ...
Other Neglected Tropical Diseases
... Taenia solium Scabies Sarcoptes scabiei Flavivirus Infections Yellow fever virus, West Nile virus, dengue virus, Tick-borne encephalitis virus Some tropical diseases are ...
Paget's Disease Of Bone - Causes - Viral
... Paget's disease may be caused by a slow virus infection (i.e ... Canine distemper virus Respiratory syncytial virus Contamination has been suggested to have played a role in producing past positive results ...
Chikungunya - Causes
... Chikungunya virus is indigenous to tropical Africa and Asia, where it is transmitted to humans by the bite of infected mosquitoes, usually of the genus Aedes ... Chikungunya virus belongs to alphavirus genus of the Togaviridae family ... The main virus reservoirs are monkeys, but other species can also be affected, including humans ...
Virus - Applications - Weapons
... Further concern was raised by the successful recreation of the infamous 1918 influenza virus in a laboratory ... The smallpox virus devastated numerous societies throughout history before its eradication ... There are officially only two centers in the world that keep stocks of smallpox virus – the Russian Vector laboratory, and the United States Centers for ...

More definitions of "virus":

  • (noun): (virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein.
  • (noun): A harmful or corrupting agency.
    Example: "Bigotry is a virus that must not be allowed to spread"; "the virus of jealousy is latent in everyone"

Famous quotes containing the word virus:

    Think of the earth as a living organism that is being attacked by billions of bacteria whose numbers double every forty years. Either the host dies, or the virus dies, or both die.
    Gore Vidal (b. 1925)

    [If a woman athlete who had contracted the AIDS virus admitted that she] had been with one hundred or two hundred men, they’d call her a slut, and the corporations would drop her like a lead balloon.
    Martina Navratilova (b. 1956)

    Freedom is the most contagious virus known to man.
    Hubert H. Humphrey (1911–1978)