The English word "virus" comes from the Latin vīrus, which refers to poison and other noxious liquids. Vīrus comes from the same See more

Discovery
The first evidence of the existence of viruses came from experiments with filters that had pores small … See more

Examples of common human diseases caused by viruses include the common cold, influenza, chickenpox, and cold sores. … See more

Viruses are the most abundant biological entity in aquatic environments. There are about ten million of them in a teaspoon of seawater. Most of these viruses are bacteriophages infecting heterotrophic bacteria and cyanophages infecting cyanobacteria and … See more

Viruses are found wherever there is life and have probably existed since living cells first evolved. The origin of viruses is unclear because they do not form fossils, so See more

Classification seeks to describe the diversity of viruses by naming and grouping them on the basis of similarities. In 1962, André Lwoff, Robert Horne, and Paul Tournier were the first to develop a means of virus classification, based on the Linnaean See more

Viruses infect all cellular life and, although viruses occur universally, each cellular species has its own specific range that often infects only that species. Some viruses, called satellites, can replicate only within cells that have already been infected by another … See more