Going slimy

Cold and flu viruses are, as usual at this time of year, wreaking havoc. In Latin, a virus was a slimy liquid or poison. We borrowed the word around 1600 to designate snake venom. A century later, it was thought that disease caused the body to produce poisonous substances, for which this word meaning “venom” was appropriate. But then in the 19th century Louis Pasteur realized that nasty submicroscopic organisms are not the result of disease, but its cause, and used the word “virus” in the way we have understood it ever since. Computers have been suffering from viruses since 1972.
"Viral marketing" has been with us since 1989, and postings on the Internet have been "going viral" since 2004. Somehow, I don't think this phrase would have caught on with such positive connotations if it were instead "go slimy" or "go venomous"! But speaking of which, it would be great if Wordlady went viral, so do click on those "share this on Facebook/Twitter" buttons!