It’s hard to think of a good word for something that has the potential to ruin the lives of millions of people as it multiplies and spreads around the planet. Fortunately we already have a good word: it’s “virus”. 

“Virus” is good, because it has a shared meaning. There is no need to define our terms before we discuss it to death. In medicine, a “virus” is a parcel of genetic material that invades our cells, starts to multiply, and then either gives us a bit of a sniffle or kills us. On the one hand, it might be “justavirus”, the last resort of the hard-pressed GP: on the other, Ebola.

We had better hope that the scientific work to tackle Ebola does not succumb to that other planetary plague, known as computer malware (mal=bad). The most famous type is the “virus”. Conversely, useful prevention or fund-raising activities may benefit from another type of rapid transmission, as training videos and public health promotions “go viral”.

A “virus” has always been a nasty thing. According to the OED (a phrase I shall be employing on my Desert Island) it  comes from the same Indo-European root as the Sanskrit visa, meaning poison. Sadly, I know no Sanskrit, but that language can be traced back more than a millennium before Christ; no wonder we all know know what “virus” means. Closer to home, the Romans used virus to mean slime, poison or secretion, particularly if it had a medicinal or magical quality. It also meant semen, first animal, then human. Perhaps we won’t look too closely into that. 

In English, from c.1400, “virus” meant the discharge from a wound (which, as we know, is highly infections). Later it came to mean the venom of a snake, which is not infectious, but perhaps those describing its effects did not make the distinction. It’s still a murderous secretion. 

Jacobethan doctors were particularly concerned with venereal diseases, which had arrived mysteriously, killed or maimed remorselessly, and spread rapidly. They didn’t have much clue about why they did this, but they recognised the sequence of events. Here’s Joseph Browne’s 1712 A Compleat History of Druggs, a translation of a French treatise by Pierre Pomet:  “The venereal Virus consists in an Humour that is salt or acid, tartarous and gross, which fermenting by Degrees corrupts the Blood and other Humours, and causes all the ill Accidents that follow it.” 

In 1798, Edward Jenner, in Gloucestershire, talked of the “cow-pox virus”. He meant the secretion, rather than the parcel of genetic material it contained. But he was working in the right direction. Later scientists distinguished viruses from other pathogens. They got past filters designed to trap bacteria and were invisible by optical microscope. It took late 20th century science to work out what they were. 

The “virus” analogy, meaning anything ubiquitous and bad, was there from the late 18th century. The computer version first appeared in late 1970s science fiction. It means a piece of code that multiplies itself and spreads. Writers such as John Brunner and David Gerrold conjured them up and then, in the 1980s, people found out how to build them for real and make them destructive. But when things go “viral” on the internet, they need not be harmful. Watching someone being beheaded is bad; watching elephants flying, through the magic of computer graphics, is probably not.  

Richard Dawkins, the evolutionary biologist and agent provocateur, gave a lecture in November 1992 at Conway Hall, entitled “viruses of the mind”. Chief among them was religion. Religious beliefs were “mind-parasites” and said “gangs [of them] will come to constitute a package, which may be sufficiently stable to deserve a collective name such as Roman Catholicism”. This idea, not Catholicism but the idea that religions are viruses, soon displayed virus-like qualities, spreading, embedding itself, replicating itself, taking over the the host, spreading again. Perhaps Richard Dawkins will denounce himself.